haiku/docs/interface_guidelines/index.xml

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<book>

<bookinfo>
<date>9-1-2006</date>
<title>Haiku Human Interface Guidelines</title>
<subtitle>Better Known as "How <emphasis>NOT</emphasis> to Write Software</subtitle>
<authorgroup>
	<author>DarkWyrm</author>
</authorgroup>
</bookinfo>

<chapter id="chapter1">
<title>How to Design Software Good</title>

<para>Haiku is an operating system which is known for its speed and being easy
	for anyone to use. This is partly because good programmers try to design
	their apps for more than just themselves. We are going to examine how you
	can also make your program more appealing. The reason is easy: easier to use
	means more people using your program. Writing good software can be hard, but
	it is worth the time and effort.</para>

<sect1> <title>Who's Gonna Use It?</title>

<para>You probably already know what kind of program you are going to write.  If
	not, put this book away and do some thinking first. Without a clear idea of
	what you want, it's hard to do something about it. Once you know what
	general kind of program you would like to create, you also need to figure
	out who the program is meant for. This can be something as general as
	'desktop users' to something as specific as 'Haiku Web Developers'. When you
	know who the main users of your program will be, you can make certain
	assumptions about what your users know. You can't necessarily expect a
	musician to understand how to effectively use a 3D modelling program as
	advanced as, say, 3D Studio Max, but you can expect them to have skills
	which lend themselves to using a program for writing music.</para>

<para>Depending on how concerned you are about details, you may even want to
	create a user profile -- a fictional idea of an example user. This can
	consist of just one or two sentences or can be several paragraphs. A short
	user profile contains the person's first name, occupation, level of
	expertise, and what kinds of things they want to be able to do with their
	computer. One thing to be sure of is to make the user profile believable --
	like a person you might know. In fact, when you design your app, it may be
	helpful if you know someone who fits into the target audience. You don't
	want to design your app for that person specifically, but, rather, someone
	just like them.</para> </sect1>

<sect1> <title>What will the User be Doing?</title>

<para>Most people will use your software to get work done, unless, of course,
	you're writing the next hit game, and despite experiences you may have had
	which might make you wonder, users are fairly intelligent. The saying that
	no one reads manuals is mostly true: people generally have better things to
	do than read software manuals except when either in trouble or as bathroom
	reading. Try to keep in mind how busy most people are and how valuable their
	time is to them when you are designing your program.</para>

<para>In order to make doing work with your program easier, you need to
	prioritize what kinds of work they will do in order of how often the work is
	done. Come up with a list of tasks the user will be doing and put them into
	one of 3 categories: Common, Uncommon, and Rare. Common tasks,
	unsurprisingly, are those things which the user does all the time. In a word
	processor, this would include typing in text, changing font sizes and
	styles, and adjusting margins. Uncommon tasks are those which the user does
	just from time to time. Depending on the user, this might be something like
	printing labels, adding color to a table, or counting the words in the
	document. Rare tasks are those which are done every once in a great while.
	Often times, these tasks are ones which the user would quite likely not miss
	if it were not possible to do it with your program. This would also be the
	kinds of things that only 20 percent of your users or less would end up
	using. If you do decide to include features to handle Rare tasks, think
	carefully about each task's importance in the grand scheme of things before
	deciding with any finality.</para>

<para>To paraphrase Einstein, you must make your software as simple as possible
	but no simpler. Complexity must be kept to a minimum. One major way this can
	be done is by avoiding features which are used only in remote instances --
	the tasks in the Rare group. Design your application to meet the needs of 80
	percent of your target audience. Features add complexity and complexity adds
	difficulty.</para> </sect1>

<sect1>
<title>How will Your Users Do Their Work?</title>

<para>Once you know who your users are and what they will be doing, you will
	need to figure out how it will be done in a general sense. This does not
	include what your program will actually look like, however. In a personal
	finance application, one of the user's primary tasks will be entering in
	transactions. The user will need to type in the data for each transaction or
	download them from their bank over the Internet. You need to know this kind
	of information for each task the user will have to perform, common or
	otherwise.</para>

<para>The actual implementation is determined last, which is why it has not been
	discussed until now. This is where the general usage of the application is
	determined. For example, the user will have a form to enter transactions
	into an account. The form should have text fields for each of the different
	kinds of data, such as the payee, the amount, and the check number.
	Somewhere nearby, the user will be able to see a list of all the
	transactions in the current account.  Because this is where the actual
	building of the look of the program takes place, it is crucial at this point
	in development to know and understand what makes software truly easy to use,
	so this is what we will examine next. Note that what technologies will be
	used to actually create the program have not even been mentioned yet. For
	your audience, technology is merely the means to an end -- a tool -- and not
	the goal itself.</para>
</sect1>

<sect1>
<title>Summary</title>

<para>Careful planning is the key to writing excellent software, regardless of
	what stage of development a project may be in. In order to be easy, good
	software only has what is really needed. It also helps the user do their work
	wherever possible. Only by thoroughly understanding what the work is, how it
	is to be done, and who is doing it can a program provide the best experience
	possible.</para>
</sect1>

</chapter>


<chapter id="chapter2">
<title>Qualities of Good Software</title>

<para>When it comes to software, the proof is in the usage. If a piece of
	software requires significant time to learn, users will only invest the
	time in learning it if (a) they have no other choice but to use that particular
	software and (b) the importance of the need filled by the software is much
	greater than the importance of the user's time. In short, users will learn
	only what they must in order to do their job and even then only when forced to
	do so.</para>


<sect1>
<title>Good Software Focuses on a User's Actual Needs</title>

<para>In Chapter 1, it was mentioned that your program should meet the needs of
	80 percent of your target audience. It is impossible to meet the needs of
	all users in the same software and still retain some semblance of being easy
	to use. Sometimes users don't even know that they need or don't need a
	feature and it is up to the designer and developer to figure out what is
	needed. Most often, it is better to have a small collection of more
	specialized tools than one which does everything.</para>
</sect1>

<sect1>
<title>Good Software Uses Everyday Language</title>

<para>Jobs in the Information Technology industry are almost always professional
	positions. One aspect which makes IT a profession is that it has its own
	body of knowledge and terminology to go with it. Most people have only a
	rudimentary 'computerese' vocabulary. The thing that they look at when they
	use a computer is called a monitor or just 'the screen'; the little arrow on
	the screen is called the cursor, and the thing they type with is called a
	keyboard. Few users know (or care) what a 'file format' is and fewer still
	do know what an 'invalid sector' on a floppy disk might be.</para>

<para>Good programs use language appropriate for the audience. The problem is
	that quite a lot of software intended for the general desktop user reads
	like Yiddish for Joe User. In such cases, regular, everyday language should
	be used as much as is possible. For file management software, 'volumes' are
	really disks -- even though the term isn't quite accurate, a normal person
	thinks a disk is a storage container and that volume is what you have up too
	high at really good parties. Images are 'pictures'. A person doesn't 'kill'
	a application that has 'hung' -- they 'force a frozen program to quit'.
	Details like this may seem minor, but many small improvements in a program's
	usability can have a profound effect overall. Of course, if your target
	audience is IT professionals, these kinds of terms are perfectly acceptable.
	Be sure that you match the everyday language of your audience and when in
	doubt, err toward using less technical language.</para>
</sect1>

<sect1>
<title>Good Software Does Not Expose Its Implementation</title>

<para>Good software works a certain way because it is the best way to be done or
	close to it, not because the code was written in a certain way or because it
	was dictated by an underlying API. An example of this would be if a music
	composition program has an easily-reached maximum song size because the code
	monkey who wrote it used a 16-bit variable instead of a 32-bit one. While
	there are sometimes limitations that cannot be overcome, the actual code
	written and the architecture used when it was written should have as little
	effect as possible on what the user sees and works with when using your
	software.</para>
</sect1>

<sect1>
<title>Good Software Uses Graphical Controls Properly</title>

<para>GUI controls were meant to be used in certain ways, and when a program
	does not use them in that particular way, it is confusing to the user and
	possibly hazardous to the user's data. Check boxes, for example, are
	commonly used in lists where a value can be turned on or off. Some programs,
	however, uses them for choosing one option in a list even though radio
	buttons are meant for this task. Text boxes should not be used for labelling
	other controls. This might seem to be common sense for most, but, rest
	assured, there are many programs which do not do something as simple as
	this. In short, use standard controls the way they were intended.</para>
</sect1>

<sect1>
<title>Good Software has a Natural Layout to its Controls</title>

<para>Some tasks have a natural, logical workflow, and good programs are
	designed in a way that capitalizes on this workflow. When entering an
	address in the United States, the natural order is Name, Street and Number,
	City, State, and Zip Code. Following any other order would both frustrate
	the user and also lead to more mistakes in entering data. This also applies
	to the Tab navigation order of controls in a window. Generally speaking,
	this order should either be left-to-right, top-to-bottom or in a
	counter-clockwise circle, depending on how the controls themselves are
	placed and the expectations associated with the work to be done.</para>
</sect1>

<sect1>
<title>Good Software Gives Plenty of Feedback</title>

<para>Imagine for a moment that you have just started converting a movie file to
	another format. You hit the button marked 'Go' and wait. Then you wait some
	more. You go to the restroom, brew a new pot of coffee, get the mail from
	the box, confirm that mullets are still out-of-style, and come back to wait
	some more. You're sure you clicked the button, but nothing seems to be
	happening. Did something go wrong? Only after some snooping around with a
	file manager do you find out that everything is OK. You didn't know what was
	happening because the program didn't tell you what it was doing.</para>

<para>Good software keep the lines of communication open. Good feedback just
	means making sure that the user knows what your program is doing at any
	given time, especially if the program is busy doing something which makes
	them wait. CD and DVD burning programs tell the user how much is left before
	they are finished making a CD or DVD. File management programs tell how many
	files are left to copy or move. Web browsers animate a little icon while
	they download a web page. Users have a natural tendency to think that if
	nothing seems to be happening, then the program is probably frozen. Making
	sure that the user knows your program is hard at work puts their mind at
	ease.</para>

</sect1>

<sect1>
<title>Good Software Makes Errors Hard</title>

<para>It has been said that nothing can be made foolproof because fools are so
	ingenious. Even so, make it tough for the user to make a mistake. If, for
	example, the user needs to enter in some text and certain characters are not
	allowed, then disable those characters for the text box it needs to be
	entered in instead of nagging the user with a message box. If resizing a
	window horizontally should not be done for some reason, don't let the user
	do it. Does your program require a selection from a list before the user
	clicks OK? Tell the user that -- nicely, of course -- and then disable the
	OK button until a selection is made. An even better solution would be to
	select a good default choice for the user and give them the option to change
	it. Build constraints into your application which prevent errors. This would
	be why 3.5" floppy disks have a notch in one side -- it can be inserted into
	a drive only one way. Constraints are also good for lazy developers because
	then their software crashes less and they don't need to write as much
	error-handling code.</para>
</sect1>

<sect1>
<title>Good Applications Handle Errors Gracefully</title>

<para>Even if you make it hard for a user to make a mistake, expect your program
	to have to deal with errors. It is possible for a program to handle errors
	in a way that doesn't leave the user wondering what happened. When code is
	written, errors of all sorts need to be anticipated and handled, such as
	lack of memory, lack of disk space, permissions errors, corrupted files, and
	loss of network connectivity. As Murphy's Law states, if something can go
	wrong in a given situation, it probably will. Hope for the best but prepare
	for the worst: without bordering on the completely ridiculous, handle every
	error that is likely to occur. Doing so greatly improves the perception of
	your software by the outside world. Crashes are unacceptable in all cases.
	Period. Error messages, for example, need to describe at the user's level of
	expertise what happened and suggest what the user can do to remedy the
	situation. In the worst case, the program needs to provide an easy way for
	the user to send technical information about the problem back to you via
	e-mail or some other means. In all cases, the user's data is to be
	preserved.</para>

<para>One way that you can see how well your program handles errors is to
	deliberately try to break it in every way possible. Feed the entire text of
	your Aunt May's quiche recipe into a text box all at once. Try to open files
	it has no business being given. Take a valid document, back it up, open it
	in DiskProbe, enter as much junk data into it as you like, and then try to
	open it. Break your Internet connection while it's in the middle of an
	update. Try to use files with really wonky filenames. Be creative and
	ridiculous and, most of all, have fun breaking things!</para>
</sect1>

<sect1>
<title>Good Software is Forgiving</title>

<para>Computers are excellent tools for people because they are good at many
	things that people are not. From a perspective which focuses on technology,
	humans are imprecise, illogical, disorganized, and make mistakes frequently.
	They are, however, excellent at forming habits and matching patterns, two
	things computers have a difficult time doing. Make commands undoable
	whenever possible and when it is not possible, be sure to inform the user
	that such is the case. Capitalize on a computer's strengths to make up for a
	person's inherent weaknesses.</para>
</sect1>

<sect1>
<title>Summary</title>

<para>Good software takes real work to produce. It is not for the stereotypical
	'lazy programmer' unless they know where it is acceptable to be lazy. In
	creating something of value to customers, good software creates a positive
	image for a company and loyal customers who will do your own advertising for
	you. The best advertising is done by your customers to their friends,
	family, and coworkers.</para>
</sect1>

</chapter>

<chapter id="chapter3">
<title>Conventions of Haiku</title>

<para>Just as a person generally doesn't go barging into a stranger's home and
	start redecorating and otherwise making himself at home merely because the
	owner does not own a shotgun, your program needs to have good manners in
	getting along with both the operating system and the other programs the user
	has installed on the system. Some of these are merely good coding practices
	meant to make your job easier and others are for ensuring that your program
	can be more easily maintained. None of them are difficult or much work, so
	there. Now you have no choice but to follow them. :D</para>


<sect1>
<title>Program Settings: Format and Location</title>

<para>While there are lots of ways to store program settings, the easiest and
	recommended method is placing them in a BMessage and flattening it to a
	BFile. By using BMessages as your container, you don't have to concern
	yourself with writing and debugging other code. The exact location used to
	store them depends on the number of files you will need. If your software
	needs only one file and will only ever need one, then it is just simplest to
	place it in the user's config/settings folder. However, should you need more
	than one file, please put them in their own folder to minimize the clutter.
	The folder should either follow the format
	home/config/settings/your_app_name_here or
	home/config/settings/your_company_name_here/your_app_name_here.</para>
</sect1>

<sect1>
<title>Maintain Responsiveness</title>

<para>Probably the best-known quality about BeOS and Haiku as operating systems
	is speed. This largely comes from the extensive use of multithreading in
	applications. Being responsive does not necessarily mean that your program
	should never be busy. It should just respond to input and redraw requests
	even when it's doing something. A common experience encountered by Linux and
	Windows users is the "blanking out" of a window or an entire program because
	it is busy doing something else. This comes from two things: the program has
	one thread of execution devoted to all its windows and that thread is busy
	doing some sort of time-consuming work. Instead of falling into this trap,
	which is unprofessional for you and confusing for the user, spawn another
	thread to do the actual processing and allow the message-handling thread to
	continue to do its job. This makes sure the user knows that your application
	is still running properly and has not frozen.</para>
</sect1>

<sect1>
<title>Avoid Hardcoded File Paths</title>

<para>Whenever your program needs to specify a particular location on the
	system, use the find_directory() function to generate it. If and when the
	day comes that Haiku supports multiple users, your application will make a
	smooth transition to the new architecture. This will also allow for backward
	compatibility with older versions of BeOS, such as the change in locations
	for B_COMMON_FONTS_DIRECTORY being in a different place for Haiku than on
	R5. find_directory() is supported in both C and C++ environments.</para>
</sect1>

<sect1>
<title>Make Your App's Look Fit in with Others</title>

<para>Certain function calls have been provided in the API to aid in making sure
	that your software shares the same general look as other applications and
	allow the user to make customizations to the system at the same time. Unless
	there is a very good reason for it, get colors for your program with
	ui_color() and the constants which go with it. Determine the size of your
	controls dynamically - use the ResizeToPreferred and GetPreferredSize for
	system controls and calculate the size of your own controls based on font
	sizes obtained from the system instead of hardcoded values. If you're
	writing code specifically for Haiku and don't care about compatibility with
	other BeOS flavors, use the new layout API. All of this will allow better
	ease-of-use for the user who prefers tiny fonts to increase use of desktop
	real estate and also for older users who need larger font sizes to
	accommodate weaker visual acuity. Graphics are an important part of a
	program's look, but don't reimplement the look of the buttons and other
	standard controls just to make your application stand out from the rest. By
	keeping visual consistency with the rest of the operating system, you avoid
	confusing the user with buttons that do not look like you can click on them,
	strange-acting menus, and so forth.</para>
</sect1>

<sect1>
<title>Live Updates</title>

<para>One way to make sure that your application communicates effectively with
	the user is to provide "live" updates to information in it. This mostly
	relates to files in the system. A good example is an address book program
	which automatically removes and adds entries when new People files are added
	to the People folder. The information doesn't even have to be data that is
	outside your program. It could just be as simple as updating an entry in a
	list of items as the user types makes changes to it in a form in a different
	part of the GUI. Responsiveness like this in a program helps the user feel
	more in control of the work they are doing and prevents possible loss of
	data.</para>
</sect1>

<sect1>
<title>Translators</title>

<para>Haiku comes with bits of technology that allows lazy programmers to be
	lazy and still have their programs be good ones. One of them is the
	Translation Kit. Merely including the library and making use of even
	something as simple as the BTranslationUtils class will help to ensure that
	at least this portion of your code is free of bugs. In general, you will
	probably find yourself making use of image translators most in order to load
	image resources that your program will use. Just remember that translators
	are system add-ons and that unless your program has installed a translator
	for a particular file format, depend only on the formats installed by
	default in the system. As an aside, some formats are undocumented or require
	licensing, which makes it difficult for users to access their own data. Use
	open and documented formats as much as possible.</para>

</sect1>

<sect1>
<title>Squeezing the Most Out of BFS: Queries and Attributes</title>

<para>The filesystem that Be created was nothing short of amazing in the 1990s.
	Even with the gradual evolution of other operating systems having progressed
	since then, it is still one of the most powerful around. Attributes are a
	powerful tool which allow you to store data about a file without being part
	of the file. This kind of power is easily put to use with audio files, such
	as FLAC, Ogg Vorbis, and the ubiquitous MP3. By attaching attributes to
	audio files, you can search for them with a query. Queries also leverage the
	filesystem's power. As long as the attribute you are querying for is indexed
	in the filesystem, there is no place a file with that attribute can hide. To
	top it all off, they are also a fast way of search for files meeting a
	certain criteria.</para>

<para>Although both attributes and queries are very powerful, use good sense. It
	takes quite a while to read a large number of attributes from a file, so you
	may wish to cache them if you are writing a program which will need to read
	more than just a few of them. Queries can only make use of attributes which
	are indexed, and their speed goes down as more and more attributes are
	indexed.</para>
</sect1>

<sect1>
<title>The System Tray: It's Not Just for Dinner Anymore</title>

<para>Because it can very easily become cluttered, install icons in the
	Deskbar's shelf only when it provides information that is updated often or
	if it provides functionality which will be frequently accessed by the user.
	Examples of these kinds of situations would be monitoring memory and
	processor load, checking mail, or quick access to features provided by a
	personal information management program. If it is unlikely that the user
	will need to access the information or functionality less than once per
	session, don't use the Deskbar -- accessing your program through the Be menu
	or an icon on the desktop should be sufficient.</para>
</sect1>

<sect1>
<title>Tracker and its Uses</title>

<para>Tracker can be quite a useful tool for your program which requires little
	effort to provide some courtesies to the user which would otherwise be a lot
	of work. The Open and Save windows have already been done for you. Please
	use them. If just a certain type of entry is needed, such as a
	folder or specific type of file, make a filter that shows only those types
	of entries. By removing unneeded items from the file navigation window, you
	are reducing the number of choices the users must pick from and also
	preventing them from opening the wrong kinds of files. Keep in mind that
	there may be files that may not have had their MIME type identified, so do
	not exclude them either. You can also make Tracker show a window for a
	particular folder in order to show the user where a particular file has been
	stored and give them access to it directly.</para>
</sect1>

</chapter>

<chapter id="chapter4">
<title>Getting Input from the User</title>

<para>While it might seem a simple case to get input from the user, it is often
	not the case if you wish to account for many external factors, such as
	accessibility, speed, and user expertise.</para>


<sect1>
<title>Mouse Vocabulary, AKA "What's This Button Do?"</title>

<para>The mouse, while the favorite rodent of most users, is not a very
	intuitive device: mouse skills must be learned. Most of the time, mouse
	skills are not an issue because the user is clicking on buttons, menus, and
	so forth, but sometimes a program must deal directly with mouse clicks and
	moves. Mouse operations fall into one of three categories.</para>

<variablelist>
<varlistentry><term>Skills you can expect the user to have:</term>
<para>
<itemizedlist>
	<listitem>Single-click</listitem>
	<listitem>Double-click on primary mouse button</listitem>
	<listitem>Single click with secondary mouse button</listitem>
	<listitem>Drag with primary mouse button</listitem>
</itemizedlist>
</para>
</varlistentry>

<varlistentry><term>Skills the user might have:</term>
<para>
<itemizedlist>
	<listitem>Drag with secondary mouse button</listitem>
	<listitem>Single-click with tertiary mouse button</listitem>
	<listitem>Single-click on primary mouse button with modifier key</listitem>
	<listitem>Triple-click with primary mouse button</listitem>
	<listitem>Scroll with scroll wheel</listitem>
	<listitem>Scroll with scroll wheel and modifier key</listitem>
	<listitem>Drag with the tertiary mouse button</listitem>
</itemizedlist>
</para>
</varlistentry>
<varlistentry><term>Don't Use These:</term>
<para>
<itemizedlist>
	<listitem>Click-and-a-half: Mouse down + mouse up + drag with a second mouse down</listitem>
	<listitem>Multiple click with non-primary mouse button</listitem>
	<listitem>More than 3 consecutive clicks (quadruple clicking or more)</listitem>
	<listitem>Drag with tertiary mouse button</listitem>
	<listitem>Drag with modifier keys</listitem>
	<listitem>Secondary/Tertiary click with modifier keys</listitem>
</itemizedlist>
</para>
</varlistentry>
</variablelist>

<para>In the event that your program must deal with directly handling mouse
	input, there are certain rules of thumb for how each of the expected skills
	is to be used. Single clicks are used for the most common actions in
	operating a control. This would be selecting items in a list, pushing a
	button, choosing a menu item, and placing the blinking text cursor in a
	BTextView. Double clicks are used for secondary functions, such as invoking
	an item in a BListView or selecting a word in a BTextView. Secondary mouse
	clicks (most commonly called "right-clicking") are generally used for a
	context-sensitive menu or, in the case of graphics programs, drawing with
	the secondary color. Mouse dragging is used for selecting text or moving
	things around. Mouse dragging with B_TERTIARY_BUTTON is generally used for
	panning. The scroll wheel by itself should be used just for scrolling, but
	your program may have a use for the scroll wheel when used with a modifier
	key, as below:</para>

<variablelist>
<title>Scroll Wheel +</title>

<varlistentry><term>B_COMMAND_KEY: </term><listitem>Zoom in/out</listitem></varlistentry>
<varlistentry><term>B_OPTION_KEY: </term><listitem>Scroll by one full page</listitem></varlistentry>
<varlistentry><term>B_CONTROL_KEY: </term><listitem>Increase/decrease font size</listitem></varlistentry>
</variablelist>

</sect1>

<sect1>
<title>Keyboard Accelerators: The Sports Cars of GUIs</title>

<para>More advanced users often like using keyboard shortcuts for common tasks
	because they reduce the considerable amount time spent switching between the
	keyboard and the mouse.</para>

<variablelist>
<title>Standard System Accelerators:</title>

<varlistentry><term>B_COMMAND_KEY + N: </term><listitem>New document</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + O: </term><listitem>Open document</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + S: </term><listitem>Save document</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + Shift + S: </term><listitem>Save as… (show Save dialog window)</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + P: </term><listitem>Print</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + W: </term><listitem>Close active window</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + Q: </term><listitem>Quit</listitem></varlistentry>

<varlistentry><term>B_COMMAND_KEY + C: </term><listitem>Copy</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + X: </term><listitem>Cut</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + V: </term><listitem>Paste</listitem></varlistentry>

<varlistentry><term>B_COMMAND_KEY + F: </term><listitem>Show find window</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + G: </term><listitem>Find again</listitem></varlistentry>

<varlistentry><term>B_COMMAND_KEY + B_OPTION_KEY + F: </term><listitem>Show Replace window</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + L: </term><listitem>Replace and Find</listitem></varlistentry>

<varlistentry><term>B_COMMAND_KEY + ,: </term><listitem>Settings window</listitem></varlistentry>

<varlistentry><term>B_COMMAND_KEY + B: </term><listitem>(Word processor) Bold font</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + U: </term><listitem>(Word processor) Underline font</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + I: </term><listitem>(Word processor) Italicized font</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + A: </term><listitem>Select all</listitem></varlistentry>

<varlistentry><term>B_COMMAND_KEY + Z: </term><listitem>Undo</listitem></varlistentry>
<varlistentry><term>B_COMMAND_KEY + B_SHIFT_KEY + Z: </term><listitem>Redo</listitem></varlistentry>

<varlistentry><term>Tab / Shift + Tab: </term><listitem>Keyboard navigation</listitem></varlistentry>

<varlistentry><term>B_CONTROL_KEY + Tab: </term><listitem>Switch programs</listitem></varlistentry>
</variablelist>

<para>When choosing keyboard accelerators for your program, use them only for
	commonly-used tasks. Do not use one of the system combinations for a task
	different from the list above. Doing so will only confuse and frustrate
	users. Choose key combinations which are easily associated with the
	functions that go with them. For example, Tracker uses Alt + Up to go to the
	parent folder of the current window. The Command key should be the main
	shortcut key. The Option key is generally used to modify an existing
	shortcut with a closely related function. Command + F shows the Find window.
	Command + Option + F shows the Replace window.</para>

</sect1>
<sect1>
<title>Design to Prevent Fitts</title>

<para>According to Mr. Fitts, when using a mouse or other pointing device, the
	amount of time it takes to point to something is proportional to how far
	away that something is and how big it is. While it might seem obvious, this
	is often overlooked when a program is designed. The easiest places for a
	user to click are the four corners of the screen and the pixel directly
	under the cursor. The reason for this is because the mouse does not need to be
	moved to click on the pixel under it. The user also does not have to think much
	when moving the cursor to a corner because as soon as it reaches an edge, it
	can go no farther in that direction regardless of how much the mouse is
	moved. The Deskbar is in one corner of the screen for this reason.</para>

<para>When you design the graphical interface for your program, make controls
	easy to click on. Toolbars that have a text label as part of each button are
	inherently easier to click because the labels add to the size of the
	buttons. A number of existing image editing programs use the secondary mouse
	button for a pop-up menu to access common features because the mouse doesn't
	have to move in order to bring the menu up. Researchers have even
	experimented with circular menus -- called pie menus -- which capitalize on
	Fitts' Law in order to make a menu as fast as possible. Your program need
	not go to such measures, but do keep in mind that teeny controls slow users
	down.</para>

</sect1>
</chapter>

<chapter id="chapter5">
<title>Dynamic Data Exchange: Pass Data Between Applications</title>


<sect1>
<title>Drag and Drop</title>

<para>Not to be confused with falling reptiles, the ability of a user to click
	on an object, drag it to some target, and drop it to make the target do
	something with it is both familiar and empowering, just as are other direct
	manipulation methods. Nonetheless, the drag-and-drop paradigm should be used
	only where it makes sense to do so -- rearranging items in a list, file
	management, opening a file dragged to your app from Tracker, etc.</para>

<para>If you plan on supporting dragging within your program or to other
	programs -- even just a little bit -- you should support drops to the most
	probable targets in your program. This shouldn't normally be all that
	difficult because drops to your program will come from either Tracker (in
	the form of an entry_ref) or from within your own program. Drops from other
	programs are not required, but if they are especially convenient, they can
	be a nice bullet point in a marketing blurb for your program.</para>

<para>When implementing dragging, be sure that your program provides feedback
	about what is being dragged. This is often best done by using an image which
	closely represents what is being dragged. If this is not possible, a
	rectangle which is the size of the dragged item's selection should be used
	in place of the picture.</para>

<para>A feature which is very helpful to a user is drop feedback. Any time the
	user is dragging something and the cursor passes over your program's window,
	it can react in a way to show the user that your program will accept the
	dragged object. Drop feedback can take a variety of forms:

<itemizedlist>
<listitem>A list control draws a line in between two items to show where
	the dragged item would be placed if the user released the button.</listitem>

<listitem>BTextView controls show a line where dragged text would be placed if
	dropped.</listitem>

<listitem>If the user drags an entry over a folder, Tracker shades it
	slightly.</listitem>

<listitem>A color well could highlight its border</listitem>
</itemizedlist>

There are other possible ways, but these should be enough for you to get the
idea. As mentioned before, feedback is a Good Thing (TM). It allows the user to
better understand how to use your program to get something done.</para>
</sect1>

<sect1>
<title>The Clipboard</title>

<para>Another way of getting data from one program into another is via the
	system clipboard. Unlike other forms of data exchange, using the clipboard
	requires very little effort or code because you have to do is plunk data
	into a particular BMessage. Some of the standard controls already do it for
	you. The BTextView class already implements copying, cutting, and pasting by
	way of keyboard accelerators. In cases like these, all that you will want to
	do is add some menu items for less advanced users.</para>

<variablelist>
	<title>Standardized Clipboard/Drag Data Formats</title>
<varlistentry><term>Plain Text</term>
	<listitem>
	<para>It is easiest to describe the basics with this code snippet.

	clipboard->AddData("text/plain", B_MIME_TYPE, your_text_string_here);
	</para>
	</listitem>
</varlistentry>

<varlistentry><term>Styled Text</term>
	<listitem>
	<para>
	Use the same format as for plain text but add a text run array field to the
	message also. You probably won't need to worry about this unless you're
	writing a word processor or something similar.

	clipboard->AddData("application/x-vnd.Be-text_run_array", B_MIME_TYPE, run_array, run_array_size);
	</para>
	</listitem>
</varlistentry>

<varlistentry><term>Generic File References</term>
	<listitem>
	<para>If the amount of data you wish to pass to another program is too large
		to place on the clipboard without straining the system, dump the data to
		a temporary file and place an entry_ref which points to it on the
		clipboard instead. Audio and video files commonly suffer from this
		problem. To do this, call AddRef() with the field name "refs" and add an
		entry_ref pointing to the file you wish to pass this may. Multiple
		entry_ref objects can be sent just by doing it more than once. If your
		program is going to handle these kinds of drops file references, it
		should look for multiple entries in the 'refs' field unless it would be
		inappropriate to do so.</para>
	</listitem>
</varlistentry>

<varlistentry><term>Image Data</term>
	<listitem>
	<para>If your program uses a different kind of data than what has already
		been standardized, there are some guidelines you can follow so that
		other programs can use it. First, make sure that the data that is put on
		the clipboard is in as generalized a form as possible.

	<segmentedlist>
	<segtitle>Field Type</segtitle><segtitle>Name</segtitle><segtitle>Description</segtitle>
	<seglistitem><seg>B_STRING_TYPE</seg><seg>class</seg><seg>"BBitmap"</seg></seglistitem>
	<seglistitem><seg>B_RECT_TYPE</seg><seg>_frame</seg><seg>A BRect containing the bounds of the bitmap data in pixels</seg></seglistitem>
	<seglistitem><seg>B_INT32_TYPE</seg><seg>_cspace</seg><seg>The color_space constant for the image data, such as B_RGBA32</seg></seglistitem>
	<seglistitem><seg>B_INT32_TYPE</seg><seg>_bmflags</seg><seg>The Flags() argument from BBitmap</seg></seglistitem>
	<seglistitem><seg>B_INT32_TYPE</seg><seg>_rowbytes</seg><seg>The number of bytes per row, including padding</seg></seglistitem>
	<seglistitem><seg>B_RAW_TYPE</seg><seg>_data</seg><seg>The raw image data</seg></seglistitem>
	<seglistitem><seg>B_POINT_TYPE</seg><seg>be:location</seg><seg>The location from which the image data was copied. May be ignored.</seg>	</seglistitem>
	</segmentedlist>

	</para>
	</listitem>
</varlistentry>
</variablelist>
</sect1>

<sect1>
<title>Replicants</title>

<para>Replicants take their cue from Dolly the sheep in allowing a BView to be
	cloned and allow you to do Really Neat Things(TM). As cool as replicant
	technology is, it is only an emerging technology in other operating systems
	and is unfamiliar to most users in general. As such, it is best left as an
	extra feature and not the primary mode of operation for a program. Here are
	some guidelines for using them, however.

<orderedlist>
<listitem>It is appropriate for a program to be a replicant if it is a lightweight
	program which provides information or a feature which the user will want to
	be able to access frequently.</listitem>

<listitem>Allow for the size of the dragger handle when computing layout.</listitem>

<listitem>Be sure it is big enough to not get lost when placed on a busy desktop
	background. At the same time, do not take over the user's desktop unless they
	want this to happen. 32 pixels square is a good minimum size, for
	example.</listitem>

<listitem>Provide a reliable way for the user to control your replicant. Do not
	rely on the menu provided by the dragger handle because the handle itself
	may have been hidden. Instead, provide another means which is immediately
	obvious or, at the very least, show a pop-up menu if the user clicks on it
	(with either button) and there are no other clickable controls.</listitem>

<listitem>Place a frame around the replicant's border so that it stands out from
	its surroundings.</listitem>

<listitem>Do not make it too visually distracting. This mainly amounts to
	avoiding lots of bright colors for the controls and limiting the amount of
	animation and movement.</listitem>
</orderedlist>

</para>
</sect1>
</chapter>

<chapter id="chapter6">
<title>Use of Text in the GUI</title>

<para>Almost without exception, if you are writing a program, you will need to
	pay at least a little attention to how it uses text. There are, believe it
	or not, right ways and wrong ways, and while most of the guidelines for text
	might seem trivial, paying attention to what seem like niggling little
	details is what sets a good program apart from the rest.</para>

<para>Above all else mentioned in this chapter, use language appropriate for
	your audience -- most of the time, this means avoiding technical terms --
	and be both clear and concise.</para>

<sect1>
<title>Error Messages, or, "I'm sorry Dave, I'm afraid I can't do that"</title>

<para>Perhaps the place where you should use text the most is in error messages.
	They should appear as seldom as possible because you anticipated and handled
	as many error conditions as possible and then tried to blow it up real good,
	right? ;) When your program can't handle a particular error, the error
	message given to the user should do the following:

<orderedlist>
<listitem>Explain what happened in everyday words.</listitem>

<listitem>Provide enough information to know what happened without providing
	details which could confuse the user. For example, if a mail client sends a
	request to a server for e-mail and the server fails to respond, a way to
	explain this might be something like "MyMailApp could not check your e-mail.
	The mail server did not respond when contacted."</listitem>

<listitem>Offer suggestions to help the user fix the problem, if possible. Using
	the above example, one possible suggestion might be "Try checking your
	Internet connection with your web browser. If your web browser works, the
	mail server might not be working correctly and you may want to try again
	later."</listitem>
</orderedlist>
</para>
</sect1>

<sect1>
<title>…Ellipses…</title>

<para>An ellipsis is a series of 3 dots (…) used to tell the user that a
	control, often a menu item or button, will require further input. For example, a
	menu item named "New…" will display a window which has the title "New".
	However, if creating a new document does not require showing a window, then
	an ellipsis should not be used. Please be sure to use the B_UTF8_ELLIPSIS
	character instead of 3 periods. Most Haiku keymaps
	allow you to type in an ellipsis with the Option + period keyboard
	shortcut.</para> </sect1>

<sect1>
<title>Abbreviations, Acronyms, and Contractions, oh my!</title>

<para>Sometimes space is at a premium. Abbreviations, acronyms, and contractions
	can come in very handy in these instances, but they can also be confusing.
	Whenever possible, avoid using them. Many times the reason there is not
	enough space is it isn't being used as efficiently as possible. When you use
	an abbreviation, please be sure that it is absolutely necessary, that it is
	both common and clear, and that it is appropriate for your program's target
	audience. For example, using the octothorpe (# symbol) as an abbreviation
	for the word 'number' in the English language fits these criteria in
	most cases. These same guidelines also apply to acronyms. For example, the
	acronym CMYK (Cyan, Magenta, Yellow, Black) is acceptable in a color picker
	for an image processing application designed for graphics professionals, but
	not in one meant for children. Menus and button labels should never be
	abbreviated or contain an acronym.</para>

<para>Special care must be used with contractions. They can be a pitfall for
	users who are not using a program in their native language. Because they
	require a more advanced command of a language, avoid using them in a place
	where their role is crucial in conveying the meaning of a message. For
	example, a checkbox for a message dialog with a checkbox marked "Don't show
	this message again" which is unchecked by default should be reworded "Always
	show this message" and have the checkbox checked by default.</para>

</sect1>

<sect1>
<title>Capitalization and Spelling</title>

<para>Nothing is more unprofessional than spelling and capitalization errors. If
	spelling is not your strong suit, consult a spell checker, dictionary, or at
	least a friend. This is particularly important if you are working with a
	language which is not your native one. Use sentence capitalization in all
	places, that is, follow the normal grammar rules of the language. For
	English, this means only to capitalize specific names like "Tracker" or
	"Deskbar".</para>

</sect1>
<sect1>
<title>Use of Fonts</title>

<para>Good use of fonts can way make your program more visually appealing, but
	when not used well, can make it ugly, hard to read, or worse. Stick to the
	plain, bold, and fixed system fonts to maintain some general visual
	consistency across the operating system. It is perfectly acceptable to use
	different font sizes, but do it only when you need a heading or something
	similar and try to limit the number of different sizes to just a few. A
	window which has lots of different font styles and sizes is harder to read
	and looks unprofessional. Control labels should always be in the system
	plain font and size specified by the system.</para>

<para>When calculating the layout for the controls, be sure that you do not
	depend on the system font being set to a particular font size. Most
	BControl-derived controls implement the methods GetPreferredSize and
	ResizeToPreferred to take font size into account. A basic idea of the line
	height for a font can be calculated by calling BFont::GetHeight() and adding
	together the values of the font_height structure.</para>

<para>Lastly, do not depend on the user having a particular font installed on
	the system unless you are willing to ensure that the user has it installed
	on the system. Font handling for your program is your responsibility, not
	the user's. If you do follow this route, be sure to check to see if you have
	redistribution rights for the font's license for the font in
	question.</para>
</sect1>

<sect1>
<title>Special Case: The Command Line</title>

<para>When designing a program to work in a command-line environment there are
	some special considerations which must be addressed. Interaction with other
	programs, use in shell scripts, and a generally consistent interface for
	command-line programs are just some of the things you will need to keep in
	mind. The major design decisions you should make are how your program will
	get its data, what options will be available, and what feedback the user
	will be given.</para>

<para>Spend some time thinking about how your program should interact with the
	shell and with other programs. Most of the time, this will boil down to
	whether your program is file-oriented or stream-oriented. Stream-oriented
	programs like grep and less work pretty much like filters, getting data from
	stdin and dumping data to stdout. File-oriented programs like zip and bzip2
	are given a list of files which the program then operates on. Your program
	can certainly do both, but choose a primary method because it will influence
	design decisions later on. Seriously consider handling wildcards instead of
	relying on the shell to do it for you if your program is file-oriented. This
	does mean more work for you as a developer, but it also reduces typing and,
	thus, typing errors for the user. Of course, if it doesn't make sense to
	support wildcards, then don't do it.</para>

<para>Choose options which are going to be accessible by command-line switches
	carefully. Make each one available only if it fills a reasonably common
	task. From the perspective of the user, adding an option is adding a
	feature, which will, in turn, increase the complexity of your program.
	Provide GNU-style (double dash + long name) switches for all options. The
	most commonly-used options should also have a short (single-dash + single
	letter) counterpart. The switches --help and -h are reserved for showing
	help information. Only standard UNIX applications (ls, tar, df, etc.) are
	not required to follow the standard for -h in order to avoid breaking
	backward compatibility. All new command-line programs need to follow this.
	Also, if your program requires one or more parameters, do the user a favor
	and show the help message if there are no extra parameters instead of
	telling the user to retype the command with the help switch.</para>

<para>When an option requires a particular value, there is also a standard for
	how the user is to provide the information. GNU-style command options should
	follow the format --option=value with the option to enclose the value in
	quotes. Multiple values for a switch should be comma-separated. Short-style
	command options should place a space between each value that follows it like
	this: -t value1 value2 value3 ... As mentioned above, wildcards should be
	handled by the program except when it does not make sense. If your program
	does something which modifies data, make sure that your program requires
	some sort of parameter -- a switch, a file, or whatever -- so that data is
	not lost if the user invokes your program without knowing what it does. You
	can assume that the user is sharper than a bowling ball, but do not expect
	the user to have expert knowledge of the operating system or, for that
	matter, your program. Programs which merely report information -- ls and df
	come to mind -- are not required to do this as long as the information
	displayed gives the user an idea of what the program does.</para>

<para>Be sure to give enough feedback when your program does its thing. Like
	graphical programs, long tasks should inform the user of progress. This may
	be something as complex as a full-fledged progress meter drawn with text, a
	simple series of periods, a listing each file operated on, or something
	else. *All* programs should provide some sort of feedback; the only time a
	program may print nothing is if there is a "quiet" option which the user has
	specified. The feedback your program gives doesn't even have to be
	excessive; you can just give general details. A "verbose" option should
	provide more detail than the program does by default. As explained earlier
	in this chapter, error messages should be no more technical than absolutely
	necessary and should be helpful whenever possible. If your program requires
	a parameter of some sort and isn't given any, show either the same message
	as for the help option or an abbreviated version which is still reasonably
	informative along with something to point the user to the help option for
	more detailed information.</para>

</sect1>
</chapter>

<chapter id="chapter7">
<title>Branding - Program Icons, About Windows, Graphics, and Other Visuals at the OK Corral</title>

<para>With all this discussion, you may be beginning to think that having a
	well-designed program means that it is going to be boring to look at. You
	can definitely have it more interesting to look at than drying paint. There
	is plenty of freedom for creativity along with some suggestions to help get
	you started.</para>

<sect1>
<title>Program Icons</title>

<para>Your program's icon is one easy way to set it apart from the rest of the
	pack. BeOS-style icons follow one of two perspectives - flat and isometric.
	Flat icons look like a head-on view. Isometric icons "look down" on the icon
	from a point above and to the right of the object with angled lines being
	about 30 degrees from horizontal. A good icon can give your program a
	favorable and professional impression to people who otherwise doesn't know a
	thing about you or your program. Take some time to create or find a
	good-looking icon. Whatever you do, don't just slap together a
	shabby-looking icon. It would be better not provide an icon at all and rely
	on the system to show the default application icon than to have one which
	reflects poorly on your program's reputation. For more details on icon
	creation, consult the Haiku Icon Guidelines.  </para>

<variablelist>
<title>Design Tips</title>
<varlistentry>
<orderedlist>
<listitem>Remember that this will be small -- don't use too much detail.</listitem>
<listitem>Use color combinations pleasing to the eye.</listitem>
<listitem>Tie it into the general color scheme of your program if it has one.</listitem>
</orderedlist>
</varlistentry>
</variablelist>

</sect1>
<sect1>
<title>About Windows… Doorways to Creative Expression</title>

<para>Give yourself some credit in your program: make an About window. They
	don't need to be especially fancy, but they can be if you are so inclined.
	It should contain the title of your program, the version, you and any other
	authors or the name of your company, and copyright information. If nothing
	else, write a few lines of code to show a BAboutWindow with this information
	and you'll have enough. If there is a lot of information to show, using a
	marquee effect to automatically scroll the information or at least a
	read-only text view with a scroll bar. Do not include information about the
	computer itself, such as the amount of RAM or processor speed; it doesn't
	belong here. While you certainly may show something short about the
	licensing of your program like "Distributed under the terms of the GNU
	Public License," the full text of the license belongs elsewhere. The window
	should not have a tab and should either have a button marked 'Close' or
	simply disappear when clicked. It should also respond to the Command + W
	keyboard shortcut.</para>

</sect1>
<sect1>
<title>Graphics and Other Stuff</title>

<para>Graphics need not be limited to just the About window and the program
	icon. You can also use background images in BViews, toolbars, buttons, and
	other places. There are few hard-and-fast rules here, but there are some
	tips you might find useful:

<orderedlist>
<listitem>Follow the Dos and Don'ts for toolbars mentioned in Chapter 12</listitem>
<listitem>Background images should not be too busy and should not reduce overall readability.</listitem>
<listitem>If your program uses only a few small pictures, you may want to
	package them in a resource file to prevent them from somehow coming up
	missing in the installation on a user's machine. Crazy things happen on
	people's computers.</listitem>
</orderedlist>

</para>
</sect1>
</chapter>

<chapter id="chapter8">
<title>Cursors</title>

<sect1>
<title>Predefined Cursors and their Uses</title>

<para>There are predefined cursor icons in Haiku for a variety of uses,
	including text selection, hyperlinks, resizing, and the default hand used
	for anything else.</para>
</sect1>

<sect1>
<title>Making Your Own Cursors</title>

<para>You can very easily make your own cursors for your own purposes, but do it
	only if a different cursor will dramatically improve how well the user can
	work with your program. At the moment, cursors can only be 16 pixels square.
	Be sure that the hot spot -- the actual
	location passed to applications when a mouse button is pressed -- is very
	obvious. Good hot spots are the tip of the hand cursor, the point of an
	arrow, or the center of a crosshairs. Use the full dimensions available to
	increase the cursor's visibility at high screen resolutions.</para>

<para><emphasis>NOTE:</emphasis> There is not nor will there ever be a busy
	cursor in BeOS-based operating systems. This is a deliberate design
	decision. If you have a need for a busy cursor, you need to make your
	program more responsive. Often you can use multiple threads to eliminate the
	need for a busy cursor.</para>
</sect1>

<sect1>
<title>Animating Cursors</title>

<para>While Haiku does not provide explicit support for them, you can animate
	cursors to provide a little more graphical appeal. As with any kind of
	movement in the display, use animation sparingly so that it is not
	distracting.</para>
</sect1>
</chapter>

<chapter id="chapter9">
<title>Menus, Menu Bars, and Menu Fields</title>

<para>Menus are everywhere, but common as they may be, far too many programs
	could use them better. Attention to small details in a program's menus is
	one common difference between good programs and great ones. A developer can
	pack a lot of features into a small space and still not force the user to
	remember it all. Menus afford exploration of the interface in steps. This
	chapter will focus primarily on issues related to menus in general. Pop-up
	menus and menu fields are discussed in Chapter 12.</para>

<sect1>
<title>Naming and Organization</title>

<para>Choosing good names for menus and menu items is generally not difficult. A
	menu should have a name which is short and accurately describes the kinds of
	items it contains. For instance, a File menu should not have Copy and Paste
	items in it. The name for a menu item should both concisely and accurately
	describe the function it performs. Items are capitalized as described in
	Chapter 6 and an ellipsis is used with any item which requires further
	action. If a menu item opens a window, the names of both the item and the
	window should be the same.</para>

<para>Two ways to organize menus are the Noun-Verb method and the Verb-Noun
	method. Noun-Verb names menus after the kind of object that it operates on
	and items in the menu are actions which can be performed on the object. For
	example, the File menu contains items such as Open, Print, Save, and Close.
	Verb-Noun names menus with an action and the items are objects which the
	action can be performed on. Two example menus could be View and Go. Some
	"standardized" menus, such as the Edit menu, do not follow either
	method.</para>

<para>Items should be organized and grouped by function and/or attribute. Use a
	separator item between each item group. An example of this would be an Edit
	menu which looks like this:

<literallayout>
	_________
	| Edit  |
	|-------|
	| Undo  |
	| Redo  |
	|-------|
	| Cut   |
	| Copy  |
	| Paste |
	|_______|
</literallayout>
</para>

<para>Undo and Redo perform related, though opposite, functions. Cut, Copy, and
	Paste are all clipboard functions, so the belong in a group separate from
	Undo and Redo. A font menu would group font styles together. When organizing
	the menus in a menu bar, try to have a logical progression from one menu to
	another. A financial program might have these menus: Program, File, Account,
	Transaction, and Help.</para>

<para>Submenus are another possibility for grouping menu items, particularly for
	attributes. They should be avoided when other options exist because they
	slow the user down and also add complexity to the interface.
	Users may also have trouble navigating to submenus because of the fine
	motor skills required. If your submenu has 6 or more items in it, consider
	placing them in their own top-level menu.</para>
</sect1>

<sect1>
<title>Marking and Toggling Items</title>

<para>Menus can also contain items which indicate the state of a feature, such
as the visibility of a tool window. The preferred method is to place a checkmark
beside the item indicating the positive state. This is less confusing than to
dynamically change menu item labels and has the advantage that it can be used
for choosing from more than two states at the expense of screen space. When
there are more than two states, all possible states need to be listed in order
to prevent confusion.</para>

<literallayout>
<emphasis>Examples of Good Toogling/Multiple State Item Usage</emphasis>

|Help|
-----------------------
Open manual…
-----------------------
* Show tooltips
-----------------------
Go to the MyApp website
-----------------------

|Font|
-----------------------
Choose font and size…
-----------------------
* Normal
  Bold
  Italics
  Bold italics
  Strikeout
  Underline
-----------------------
</literallayout>

</sect1>
<sect1>
<title>Common Menus and their Contents</title>

<para>Below are descriptions for menus that are common to many programs. Because
	they are so common, there are some guidelines to their use so that there is
	some consistency from program to program. With the exception of the Program
	menu, each of these menus should be used only if they make sense for your
	program.</para>

<variablelist>
<title>Program: Items related to operating on the program itself.</title>

<varlistentry><term>About &lt;app name here&gt;…  </term><listitem><para>Shows
	the About window. This is not a commonly-accessed item, so do not provide a
	keyboard shortcut for it.</para></listitem></varlistentry>

<varlistentry><term>Settings…</term><listitem><para>Show the
	window which is used to customize settings for your program. This can be a
	submenu if your program only has a couple of settings.</para></listitem>
</varlistentry>

<varlistentry><term>Quit (Command + Q) </term><listitem><para>This should be the
	bottom item in the menu and a separator should go above it. Clicking on this
	item should close all windows and quit the program.</para></listitem></varlistentry>
</variablelist>

<variablelist>
<title>File: This contains items related to documents handled by your program.</title>

<varlistentry><term>
New (Command + N) </term><listitem><para>Create a new document. This item should
	have an ellipsis if it shows a window asking for further information (for
	example, canvas size for a drawing program), but not if it
	doesn't.</para></listitem></varlistentry>

<varlistentry><term>
Open… (Command + O) </term><listitem><para>Open a document from disk.</para></listitem></varlistentry>

<varlistentry><term>
Open recent </term><listitem><para>This is a submenu in the File menu to allow
	fast access to recent documents. It should not open a window of any kind
	except if your program uses a one-window-per-document architecture. The
	number of recent items should be limited to no more than 5
	items.</para>
</listitem></varlistentry>

<varlistentry><term>
Close (Command + W) </term><listitem><para>The function of this item depends on
	the program architecture. In a program which has one document per window,
	this closes the window. If there is only one open window, this quits the
	program. Although it is not recommended, if a program allows for multiple
	documents to be shown in the same window, this item closes one
	document.</para>
</listitem></varlistentry>

<varlistentry><term>
Save (Command + S) </term><listitem><para>Save the current document. This should
	not show a window unless it is a new document that has not yet been saved.
	It does not normally show a window, so no ellipsis is
	necessary.</para>
</listitem></varlistentry>

<varlistentry><term>
Save as… (Command + Shift + S) </term><listitem><para>This performs the same
	basic kind of task as Save, but it always shows a
	window.</para>
</listitem></varlistentry>

<varlistentry><term>
Save all </term><listitem><para>This item executes a Save command for all
	documents in the program. The procedure for handling new documents which
	have not yet been saved is as follows: <para>
	<orderedlist>
	<listitem>Remember the current document window</listitem>
	<listitem>For each document needing a name, bring it to the front, open a
		Save window, save the document, and proceed to the next document needing
		a name.</listitem>
	<listitem>When all documents have been processed, bring the window which was
		originally the active one back to the front.</listitem>
	</orderedlist>
	Note that the same procedure is to be applied when closing the program.
	</para>
</para></listitem></varlistentry>

<varlistentry><term>
Revert </term><listitem><para>Undoes all changes made to the document since the
	last save.</para>
</listitem></varlistentry>

<varlistentry><term>
Import from… </term><listitem><para>Import data from another file format into a
	new document. Like Open…, this always shows a
	window.</para></listitem></varlistentry>

<varlistentry><term>
Export to… </term><listitem><para>Convert the data in the current document to
	another format. Like Save as…, this always shows a
	window. This should be reserved for lossy conversions. If your program
	can save its data in multiple formats without any information loss,
	these should be available in the Save and Save as… menu items instead.</para>
</listitem></varlistentry>

<varlistentry><term>
Page setup… </term><listitem><para>Shows the page settings window for printer
	setup.</para>
</listitem></varlistentry>

<varlistentry><term>
Print… (Command + P) </term><listitem><para>This always shows the print window
	before printing the current document. This is not intended to be the same as
	when a toolbar button is pressed.</para>
</listitem></varlistentry>
</variablelist>


<variablelist>
<title>Edit: Items in this menu are used for different editing tasks</title>

<varlistentry><term>
Undo (Command + Z) </term><listitem><para>Undoes the most recently performed
	edit. When possible, this item should be dynamic and also include the name
	of the task that it would undo, such as 'Undo Cut' or 'Undo Typing.' User
	operations which do not change document data, such as changing zoom levels
	or the like, should not be included in Undo
	operations.</para></listitem></varlistentry>

<varlistentry><term>
Redo (Command + Shift + Z) </term><listitem><para>Undoes the most recent Undo
	operation. Like Undo, this menu item should also be dynamic when
	possible.</para></listitem></varlistentry>

<varlistentry><term>
Cut (Command + X) </term><listitem><para>Copies the currently-selected data in
	the current document to the clipboard and removes it from the
	document.</para></listitem></varlistentry>

<varlistentry><term>
Copy (Command + C) </term><listitem><para>Copies the currently-selected data in
	the current document to the clipboard.</para></listitem></varlistentry>

<varlistentry><term>
Paste (Command + V) </term><listitem><para>Inserts the data on the clipboard
	into the current document. If there is an existing selection in the current
	document, the paste operation replaces the selected data with the pasted
	data. Like undo and redo, this menu item should be dynamic according to
	the clipboard content ('Paste Text' or 'Paste Image')</para>
</listitem></varlistentry>

<varlistentry><term>
Select all (Command + A) </term><listitem><para>Selects all data in the current
	document.</para></listitem></varlistentry> </variablelist>


<variablelist>
<title>Search: Tasks in this menu include finding and replacing data and other
	navigation commands.</title>

<varlistentry><term>
Find… (Command + F) </term><listitem><para>This always shows a Find window for
	the program. The Find window should then allow the user to choose whatever
	options he desires for the find and disappear when the actual find is
	executed.</para></listitem></varlistentry>

<varlistentry><term>
Find again (Command + G) </term><listitem><para>This repeats the most recent
	Find. If no find has been performed in the program yet, it should show the
	Find window. Because this command does not normally show a window, no
	ellipsis is needed.</para></listitem></varlistentry> </variablelist>


<variablelist>
<title>Help: Different ways that the user can learn more about your program and
	get help when needed.</title>

<varlistentry><term>
Open manual… </term><listitem><para>Shows the manual for the program in a new
	window. The manual should never be shown in a BAlert, prefer opening an
	HTML or read-only text file (using the preferred application set by the
	user), or showing a non-editable text view from which the text can
	be copied.</para></listitem></varlistentry>

<varlistentry><term>
Go to (MyApp or MyCompany)'s website </term><listitem><para>Opens the default
	web browser at the website for the program or the program's company,
	respectively.</para></listitem></varlistentry> </variablelist>

</sect1>
</chapter>

<chapter id="chapter10">
<title>Windows</title>

<sect1>
<title>You Need the Basics</title>

<para>Windows are such common controls that every developer should know the
	basics of how to use them properly. Some operating systems suffer from the
	overuse and abuse of windows, such as bizarre error messages, incessant
	confirmations, wrong window types for tasks, and many other mistakes. Learn
	the proper ways of working with windows and you will have overcome a major
	usability hurdle.</para>
</sect1>

<sect1>
<title>Styles and Purpose</title>

<para>Haiku allows you to specify the look and feel when creating a window.
	Setting these properly will help the user immediately know what kind of
	window they are dealing with, and it also restricts the operations
	they are allowed to perform on it.</para>

<segmentedlist>
<segtitle>Look</segtitle><segtitle>Purpose</segtitle>
<seglistitem><seg>Document</seg><seg>Windows containing a user document, such as an editor or viewer</seg></seglistitem>
<seglistitem><seg>Titled</seg><seg>General purpose</seg></seglistitem>
<seglistitem><seg>Floating</seg><seg>Tool and utility windows</seg></seglistitem>
<seglistitem><seg>Modal</seg><seg>Modal window</seg></seglistitem>
<seglistitem><seg>Bordered</seg><seg>Alert-type dialog windows</seg></seglistitem>
<seglistitem><seg>Borderless</seg><seg>Splash screens</seg></seglistitem>
</segmentedlist>

<segmentedlist>
<segtitle>Feel</segtitle><segtitle>Purpose</segtitle>
<seglistitem><seg>Normal</seg><seg>General purpose</seg></seglistitem>
<seglistitem><seg>Modal:Subset</seg><seg>Only when you need to block all windows in a subset</seg></seglistitem>
<seglistitem><seg>Modal:App</seg><seg>When a user decision is required to continue with the rest of the program</seg></seglistitem>
<seglistitem><seg>Modal:All</seg><seg>When the user needs to make a
		system-critical decision, such as system shutdown confirmation. Use this
		feel only when you absolutely have to.</seg></seglistitem>
<seglistitem><seg>Floating:Subset</seg><seg>When a subset window needs to take
		priority in its subset.</seg></seglistitem>
<seglistitem><seg>Floating:App</seg><seg>Tool and utility windows</seg></seglistitem>
<seglistitem><seg>Floating:All</seg><seg>System monitors and other windows which
		the user will always want to have visible. Like Modal:All, use this only
		when absolutely necessary.</seg></seglistitem> </segmentedlist>

<segmentedlist>
<segtitle>Type</segtitle><segtitle>Look + Feel</segtitle>
<seglistitem><seg>Titled</seg><seg>Titled + Normal</seg></seglistitem>
<seglistitem><seg>Document</seg><seg>Document + Normal</seg></seglistitem>
<seglistitem><seg>Modal</seg><seg>Modal + Modal:App</seg></seglistitem>
<seglistitem><seg>Floating</seg><seg>Floating + Floating:App</seg></seglistitem>
<seglistitem><seg>Bordered</seg><seg>Bordered + Normal</seg></seglistitem>
</segmentedlist>

<para>Probably 90% of the time you will end up using Titled and Document windows
	with an occasional floating window. Borderless windows are used frequently
	for splash windows that are displayed as a program is loading. Bordered
	windows, which, by the way, do not have a window tab, aren't used much
	except in BAlerts. Modal windows shouldn't be used more than is absolutely
	necessary for reasons explained under the Modality section in this
	chapter.</para> </sect1>

<sect1>
<title>Naming, Placement, Size, and Other Decisions</title>

<para>Merely knowing what kind of window look and feel to use in a given
	situation is not enough: you also have to be aware of resizing, zooming,
	moving, closing, and minimizing because they affect your program in
	different ways. Once you know what kind of window you need, you should also
	figure out what its initial size and location are going to be. You also
	should not restrict the other actions a user can perform on a window unless
	you have a good reason that does not include "I don't want to write code to
	handle this."</para>

<para>Care should be given to what name is used for a window. The main window of
	your program should include your program's name. Windows which were opened
	from a menu item should have the same name as that of the menu item without
	the ellipsis. Document windows should include the document's name. The first
	new document in the application should use the name "Untitled" with
	subsequent new documents appending a number. A titled window should never
	have an empty title bar.</para>

<para>The size of a window depends on a number of factors. An application window
	should have an initial size which is the minimum needed to see all controls
	in it without overcrowding. Controls should never overlap. This initial size
	should also be the minimum size for the window which is passed to
	SetSizeLimits. The initial size for a document window should be large enough
	to see the entire document or at least a significant portion of the document
	if it is larger than the screen. Do not arbitrarily restrict resizing unless
	it does not make sense to allow resizing in a particular direction. If a
	window allows resizing, its size should generally be saved when closed or
	the program quits and restored to that size when shown again.</para>

<para>Zooming is similar to resizing, but there are differences in which should
	permit zooming and how it should be done. Utility windows, for example, are
	not intended to be the main focus of the program, so they should not allow
	zooming even though they should allow resizing except where inappropriate.
	Document windows should expand to fill the most sensible space to allow
	viewing or editing. Often times this is the entire screen, but some for
	some programs, this doesn't make sense. An image viewer, for example, should
	set its size to fit exactly the image currently being shown at its current
	zoom level.</para>

<para>The placement of a window on the screen also varies depending on its
	usage. Program windows should initially either show themselves in the center
	of the screen or just a little above it (use BWindow::CenterOnScreen).
	The same goes for the initial
	placement of a document window. Additional document windows should duplicate
	the most recent document window's frame offset by the window tab height in both
	directions. As with size, a program should generally remember the screen
	placement of the windows and movement should not be restricted unless there
	is a good reason for it.</para>

<para>A window need not always be visible. Duh. Considering that it can be
	hidden or closed altogether may be a bit confusing. Generally, a document
	should allow minimizing to make it possible for the user to get the document
	"out of the way" for a moment without having to close it entirely. Utility
	windows and program windows which are not the main window should normally
	not permit minimizing and just allow closing. The main window should allow
	minimizing. Note that when a program is not the focus, utility windows with
	the Floating:Subset and Floating:App behaviors will be hidden. Windows
	should normally be allowed to close unless there is a very good reason for
	it.</para>

<para>A number of times in this document it has been mentioned that you should
	not prevent something unless there is sufficient reason to do so.
	Particularly on other platforms, developers have been known to just disallow
	resizing because they didn't want to bother themselves with writing handler
	code. There are other instances where, for example, a window could not be
	closed because the code had a design flaw which would cause a crash if the
	window were closed. Remember: the more work you do in making your program
	helpful means the less work the user has to do, which means that your
	program is easier to use.</para>

</sect1>
<sect1>
<title>B_ACCEPTS_FIRST_CLICK</title>

<para>In MacOS X, the feature this flag enables is called click-through. It
	means that clicking on the window passes the click through to the control
	the mouse was under at the time even when the window does not have the
	focus. As a rule, this behavior should not be used, but there are times when
	it is quite useful, such as for system monitor programs, the Deskbar, and so
	forth. Typically, this flag is used for "helper" applications and utility
	windows. Note that the user can override this from the Mouse preferences
	if they wish so, forcing all windows to accept the first click.</para>
</sect1>

<sect1>
<title>Modality</title>

<para>By default, windows in BeOS operating systems are modeless, meaning that
	you can click on other windows besides the one with the focus. Occasionally,
	there is a need to force the user to make a decision before moving on. This
	is an appropriate time to use a modal window. The need is far less often
	than what many would believe, however. Most of the time the only reason to
	use a modal window would be if not doing so would make potential for the
	user to lose data and there is nothing that can be done to the code
	architecture to prevent it. This follows the "no restrictions for no good
	reason" way of thinking mentioned above -- modal windows place restrictions
	on what windows he can or can't click on. </para>
</sect1>

</chapter>

<chapter id="chapter11">
<title>Special Purpose Windows</title>

<sect1>
<title>Alert Windows</title>

<para>Alert windows are the single easiest way to make usability mistakes. Most
	often, they are used to show error messages. The problem is that they are
	used *far* more often than they should be and the error messages that are
	used in them are too technical for a regular user to understand or are just
	plain useless. They are also used to ask the user a question. More often
	than not, the question that is asked could have just as easily been answered
	by the developer, had he thought ahead a bit. Do just about whatever it
	takes to gracefully handle errors without bothering the user. Only when all
	other options have been exhausted should you show an error message. For help
	on writing good error messages, see Chapter 6.</para>

<para>Before you ask the user a question, be sure that it is one which you
	honestly can't answer yourself or can't do without possibly disturbing the
	way the user works. For example, it is good courtesy to ask the user if he
	would like your program to be the default handler for a particular kind of
	file when your program is installed. It is *never* acceptable to ask the
	user "Are you sure you want to quit?" If your program is asked to quit,
	handle unsaved documents and quit. "Are you sure…" questions should be
	asked only if the action involves the undoable destruction of data, such as
	deleting a file instead of moving it to the Trash. Avoiding these kinds of
	situations entirely is a better solution. If the confirmation is asked too
	often, the user will develop the habit of confirming it without a second
	thought and your asking the question will be rendered moot.</para>

<para>When you do use an alert window, please follow these guidelines:

<orderedlist>
<listitem><para>On a notification, such as an error message, use "OK" for the label of the button</para></listitem>

<listitem><para>When asking a question, make the least destructive of the most common choices the default.</para></listitem>

<listitem><para>Avoid Yes / No button labels. It is much better to use the name
		of the action in the label, such as Save Changes / Discard Changes. Only
		in *very* rare cases are Yes / No labels the best
		choice.</para></listitem>
</orderedlist>
</para>
</sect1>
<sect1>
<title>Find Windows</title>

<para>Windows used to search for data in a document are not very different from
	others, but how they are used can help, hinder, or annoy the user when
	searching. It only needs to be shown when the user needs to set the search
	terms. Once they are set, the window should itself disappear and the search
	should be performed. A find window which stays visible clutters the screen
	and often obscures part of the current document, even the result of the
	search. It also places the program in a separate mode, which should
	generally be avoided. The search itself should default to case-insensitive
	searches with an option to allow case sensitivity. Search by regular
	expression is an option that should normally be limited to programs which
	have programmers as the intended audience.</para>

</sect1>
<sect1>
<title>Settings Window Design</title>

<para>Windows to allow the user to change various program settings are another
	place where developers commonly commit a usability faux pas or two. The most
	common mistakes are poorly-chosen defaults, inappropriate language for the
	target audience, and too many choices. Here are some guidelines for making a
	good one:

<itemizedlist>
<listitem><para>Choose defaults which fit the most number of people.</para></listitem>

<listitem><para>When possible, have changes take place immediately instead of
		requiring the user to click OK. If you do this, provide buttons to
		revert changes and also to set the default values.</para></listitem>

<listitem><para>Provide settings for significant features. This would include
		things like default file format for CD ripper, European vs American date
		format (although the system-wide setting should be used instead),
		or the default account in a mail client. Unncessary settings
		include "Use Ins key for paste" and "Confirm Program Quit".</para></listitem>

<listitem><para>Use language appropriate for the target audience as mentioned in
		Chapter 2. For example, the web browser option "Move system caret with
		focus/selection changes" requires some technical knowledge. A better way
		to label such an option would be "Allow text to be selected with the
		keyboard." Both refer to the same option. The difference is how many
		people can understand what it does.</para></listitem> </itemizedlist>

</para>
</sect1>
<sect1>
<title>Open and Save Panels</title>

<para>BFilePanel is used for both opening and saving files, but there is more to
	using them well than merely showing a list of files. Remember the location
	the user was viewing, and if it is inaccessible for some reason, show the
	Home folder. When possible, make use of file filters to eliminate files your
	program does not handle. By filtering out "bad" files, you eliminate errors
	and at the same time reduce the amount of time the user needs to find the
	file he wants by reducing the number of options. Offering a possible file
	name when saving a new document is another way to help the user. The title
	of the panel needs to match the task, whether it is Import, Export as,
	Save as, Save, Open, or something else.</para>
</sect1>
</chapter>


<chapter id="chapter12">
<title>Controls</title>

<para>BeOS operating systems, while perhaps not as fully-featured as others,
	possess controls which are the bread and butter of working with GUI
	programs. Their basic usage is obvious to most, but for the sake of those
	not sure and for those who want their programs to be the very best, they are
	covered in detail from the basics to advanced details.</para>


<variablelist>
<varlistentry><term>Buttons</term>
<listitem>
<para>
	Buttons are all around us in the computer world and in the real one, too. A
	button is used to invoke a command or, much less often, show a window.
	<table frame="all">
<title>Do's and Don'ts of Buttons</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Use GetPreferredSize and ResizeToPreferred to reduce your work</listitem>
<listitem>Avoid using one button for opposite functions without appropriate feedback</listitem>
<listitem>Leave sufficient padding around them</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Make them too small or ridiculously large -- like 100 pixels square
	for the word 'OK' when the font size is 10 point.</listitem>
<listitem>Leave them blank</listitem>
<listitem>Show a menu with one</listitem>
<listitem>Use them for labels</listitem>
<listitem>Change the label font</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>

<varlistentry><term>Checkboxes</term>
<listitem>
<para>
	Checkboxes are like a light switch with a label attached to it. Aside from
	turning an option on or off, they can also be used for quickly choosing
	multiple selections in a list of choices.

<table frame="all">
<title>Do's and Don'ts of Checkboxes</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Label checkboxes so that the user understands ahead of time what clicking on it will do.</listitem>
<listitem>Use care in calculating bounding boxes</listitem>
<listitem>Carefully choose label text</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Use them for choosing one item from a list. Use a group of radio buttons instead.</listitem>
<listitem>Use a checkbox in place of a button</listitem>
<listitem>Use a list of checkboxes as a progress indicator</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>


<varlistentry><term>Radio Buttons</term>
<listitem>
<para>
	Radio buttons are used to choose an exclusive choice from a list of choices.
	They can also be used to turn an option on or off if you have plenty of
	space.

<table frame="all">
<title>Do's and Don'ts of Radio Buttons</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Label radio buttons so that the user understands ahead of time what clicking on one will do.</listitem>
<listitem>Use care in calculating bounding boxes</listitem>
<listitem>Set a default value</listitem>
<listitem>Carefully choose label text</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Use them individually or use them the same way as checkboxes</listitem>
<listitem>Use more than 5 or 6 in a group. Consider a list view instead.</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>


<varlistentry><term>Control Groups</term>
<listitem>
<para>
	Control groups, namely, the BBox class, are often abused because they are
	not well-understood. Control groups are for visually associating different
	controls which work together for a common function. Unfortunately, they are
	most often used just for fluff.

<table frame="all">
<title>Do's and Don'ts of Control Groups</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Label control group</listitem>
<listitem>Use control groups when there are lots of controls in window</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Use a control group to label a single control</listitem>
<listitem>Nest control groups</listitem>
<listitem>Use a control group around all controls in a window</listitem>
<listitem>Mix control group border styles</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>


<varlistentry><term>Sliders</term>
<listitem>
<para>
	Sliders are a good way to allow a user to choose a value that must be within
	a certain range, especially if the effect isn't exactly concrete or the
	value has no meaning to the user. Good uses for sliders include setting
	volume, mouse acceleration, and movie playback position.

<table frame="all">
<title>Do's and Don'ts of Sliders</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Label the ends of the slider</listitem>
<listitem>Show tick marks for each value if your slider has distinct increments</listitem>
<listitem>Place the largest value at the right or top</listitem>
<listitem>Use the appropriate orientation</listitem>
<listitem>Label each slider position when the increment size changes, such as logarithmically</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Use a slider for a progress indicator or scrollbar</listitem>
<listitem>Label each slider position for sliders with fixed increment sizes</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>


<varlistentry><term>Labels</term>
<listitem>
<para>
	Labels help the user know what a particular control is for. Most of the
	controls in the BeOS API include and handle their own labels. This section
	deals with both the labels included with controls and ones created on their
	own.

<table frame="all">
<title>Do's and Don'ts of Labels</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Label controls</listitem>
<listitem>Use a separate label when layout makes it hard to use a control's built-in label.</listitem>
<listitem>Use proximity to associate labels with their controls</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Use a label for large amounts of static text. Consider a read-only text view.</listitem>
<listitem>Use a separate label object for controls which have label functions built-in</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>


<varlistentry><term>Text Controls</term>
<listitem>
<para>
	Text controls are one-line editable text boxes. They are useful for entering
	text into forms.

<table frame="all">
<title>Do's and Don'ts of Text Controls</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Disable characters you don't want in the field</listitem>
<listitem>Try hard to validate text entered</listitem>
<listitem>Make them large enough to accommodate the length of common entries</listitem>
<listitem>Allow clipboard operations when possible</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Use a text control for a label</listitem>
<listitem>Make them too small</listitem>
<listitem>Use them for static text</listitem>
<listitem>Arbitrarily limit the number of characters without a very good reason</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>


<varlistentry><term>Text Views</term>
<listitem>
<para>
	Text views are multiline text controls. They also provide undo, styled text,
	and a number of other useful text functions.

<table frame="all">
<title>Do's and Don'ts of Text Views</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Disable editing if you use one to display static text</listitem>
<listitem>Allow both undo and selection of text unless there is a good reason not to</listitem>
<listitem>Allow clipboard operations when possible</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Use one for single-line input</listitem>
<listitem>Forget to pad the text rectangle inside the text view</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>


<varlistentry><term>Lists</term>
<listitem>
<para>
	Lists are used to display lots of individual items, possibly in a hierarchy.
	They can also allow multiple or single selections.

<table frame="all">
<title>Do's and Don'ts of List Views</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Provide a way to select all items in multiple-selection lists.</listitem>
<listitem>Sort your list</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Use just enough space to display just a couple of items</listitem>
<listitem>Try to use it to select from hundreds of items. Use a search instead.</listitem>
<listitem>Use list items to toggle options like a list of checkboxes</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>


<varlistentry><term>Tabs</term>
<listitem>
<para>
	Tabs can be quite handy for displaying multiple views in a small space.
	Unfortunately, they seem to suffer from being too easy to abuse.

<table frame="all">
<title>Do's and Don'ts of Tabs</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Use tabs to manage and organize otherwise complex dialog windows</listitem>
<listitem>Use a list instead of tabs to manage large numbers of views</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Use tabs to select a particular mode</listitem>
<listitem>Nest tab views</listitem>
<listitem>Use so many tabs that a scrolling is needed to see them all</listitem>
<listitem>Place confirm / cancel buttons inside tabs</listitem>
<listitem>Overlay toolbars by using tabs</listitem>
<listitem>Use vertical text with vertical tabs</listitem>
<listitem>Use tabs on more than one side at once</listitem>
<listitem>Use one tab all by itself</listitem>
<listitem>Use unlabelled icons for tab titles</listitem>
<listitem>Use a scrollbar to scroll a form inside a tab</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>


<varlistentry><term>Scrollbars</term>
<listitem>
<para>
	Scrollbars, unlike tabs, tend to not be abused. Use them to display more
	items than can fit on the screen, but don't overuse them.

<table frame="all">
<title>Do's and Don'ts of Scrollbars</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Adjust range and step size when their target view is resized</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Scroll forms</listitem>
<listitem>Try to customize their look</listitem>
<listitem>Use them like a slider control</listitem>
<listitem>Nest BScrollViews</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>


<varlistentry><term>Menu Fields</term>
<listitem>
<para>
	Menu fields are buttons which display a label and pop up a menu when clicked.

<table frame="all">
<title>Do's and Don'ts of Menu Fields</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Use them in place of radio buttons when space is limited</listitem>
<listitem>Remember to follow the menu construction guidelines mentioned in Chapter 9</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Use them instead of a menu bar for the main program menu</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>


<varlistentry><term>Pop-up Menus</term>
<listitem>
<para>
	Pop-up menus differ from regular menus in that they can be invoked from
	anywhere on the screen.

<table frame="all">
<title>Do's and Don'ts of Popup Menus</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Make pop-up menus sticky</listitem>
<listitem>Use pop-up menus for context menus</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Show a pop-up menu by clicking on a button or do other similar
	nonsensical control daisy-chaining.</listitem>
<listitem>Use a pop-up menu as a tooltip</listitem>
<listitem>Use the primary mouse button to show a context menu</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>


<varlistentry><term>Progress Meters</term>
<listitem>
<para>
	BStatusBars are used to show progress in BeOS operating systems.

<table frame="all">
<title>Do's and Don'ts of Progress Meters</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Choose a color carefully if you don't use the default</listitem>
<listitem>Use them whenever an operation has the potential to take a while</listitem>
<listitem>Properly label the progress bar</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Use a slider or scrollbar for a progress bar.</listitem>
<listitem>Use a progress bar as a control separator</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>


<varlistentry><term>Toolbars</term>
<listitem>
<para>
	Toolbars are little more than a collection of graphical
	buttons. They are used for providing fast access to commonly-used functions.

<table frame="all">
<title>Do's and Don'ts of Toolbars</title>
<tgroup cols="2" align="left" colsep="1" rowsep="1">
<colspec colname="c1" />
<colspec colname="c2" />
<thead><row><entry>Do</entry><entry>Don't</entry></row></thead>
<tbody><row>
<entry>
<itemizedlist>
<listitem>Use them to speed up access to common functions</listitem>
<listitem>Use icons from the standard set if possible</listitem>
<listitem>Make the function of each button obvious from the icons used</listitem>
<listitem>Follow the specific icon guidelines for toolbar icons</listitem>
</itemizedlist>
</entry>
<entry>
<itemizedlist>
<listitem>Add a toolbar just for looks</listitem>
<listitem>Scroll toolbars</listitem>
<listitem>Use put too many buttons in a toolbar or have too many toolbars on the screen</listitem>
</itemizedlist>
</entry>
</row></tbody>
</tgroup>
</table>
</para>
</listitem>
</varlistentry>

</variablelist>
</chapter>

<appendix>
<title>How to Make a Good Error</title>

<para>By nature of not being perfect, developers make mistakes and no program is
	without its bugs. As mentioned earlier, conditions which could cause errors
	should be anticipated and handled as much as reasonably possible. In those
	instances where there is nothing left to be done except show an error
	message, be helpful, polite, and as non-technical as possible.</para>

<sect1>
<title>Examples of Good Error Messages</title>

<para>Uh-oh... MyMP3Ripper couldn't create the playlist
	/boot/home/playlists/foo. This may have happened for a number of different
	reasons, but most often happens when making playlists on a non-BeOS drive,
	such as one shared with Windows. Certain characters, such as question marks
	and slashes cause problems on these disks. You may want to check the names
	of the artist, album, and songs for such characters and put a good
	substitute in its place or remove the character entirely.</para>

<para>MyApp can't copy your file to the disk because there isn't enough space
	for it. If you would like to copy it, move or delete files on the
	destination disk and try again.</para>

<para>MyApp didn't recognize the data in the file '/boot/home/foo'. It might not
	be a MyApp file or perhaps the file is corrupted.</para>

<para>(From a website):: O No! If you are reading this message, it means we have
	made a mistake. Don't worry, you can be sure that as you are reading this
	people are freaking out around here - testing circuits, rebooting systems,
	and even typing resumés (just kidding). Please try back in 5 minutes, as we
	still have plenty of great stuff.</para>

</sect1>
<sect1>
<title>Real World Examples of Bad Error Messages</title>


<para>Wrong Button! This button doesn't work. Solution: Try another.</para>

<para>The project file "e:\ws\foo" may have been modified on disk by the
	preceding Source Control operation. However, you also have made changes to
	this project which have not been saved. If you reload the project you will
	lose your current changes, but if you don't, you risk overwriting the new
	changes on disk, which is usually much worse. Do you want to reload it now?
	[Yes] [No]</para>

<para>Mail Engine: No Error</para>

<para>Spell Check Cancelled</para>

<para>Unexpected Error. Please investigate.</para>

<para>System Error 0x80004005 (02147467259). Unspecified error.</para>

<para>Question or information that needs the user's immediate attention.</para>

</sect1>
</appendix>
</book>