haiku/docs/user/interface/Menu.dox
John Scipione 47852bff02 IK documentation update
* Add \since directive to each method.
* Add documentation for BScrollBar and BScrollView classes.
* Title Case group titles.
* Some other minor documentation updates.
2014-06-13 17:44:22 -04:00

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/*
* Copyright 2013 Haiku, Inc. All rights reserved.
* Distributed under the terms of the MIT License.
*
* Authors:
* John Scipione, jscipione@gmail.com
*
* Corresponds to:
* headers/os/interface/Menu.h hrev46321
* src/kits/interface/Menu.cpp hrev46321
*/
/*!
\file Menu.h
\ingroup interface
\ingroup libbe
\brief BMenu class definition and support structures.
*/
/*!
\enum menu_layout
\ingroup interface
Constants to define the layout of the menu items in a menu.
\since BeOS R3
*/
/*!
\var menu_layout B_ITEMS_IN_ROW
Items are arranged in a row, one next to the other.
\since BeOS R3
*/
/*!
\var menu_layout B_ITEMS_IN_COLUMN
Items are arranged in a column, one on top of the other.
\since BeOS R3
*/
/*!
\var menu_layout B_ITEMS_IN_MATRIX
Items are arranged in a matrix, a free-form arrangement that you create.
\since BeOS R3
*/
/*!
\struct menu_info
\ingroup interface
\ingroup libbe
\brief Information about a menu such as font size and family, background
color, and flags.
\since BeOS R3
*/
/*!
\var menu_info::font_size
The font size to draw menu items with.
\since BeOS R3
*/
/*!
\var menu_info::f_family
The font family used to draw menu items.
\since BeOS R3
*/
/*!
\var menu_info::f_style
The font style used to draw menu items.
\since BeOS R3
*/
/*!
\var menu_info::background_color
The menu's background color.
\since BeOS R3
*/
/*!
\var menu_info::separator
The style of horizontal line to use to separates groups of items in a menu.
\since BeOS R3
*/
/*!
\var menu_info::click_to_open
Whether or not the menu opens on click. The default value is \c true.
\since BeOS R3
*/
/*!
\var menu_info::triggers_always_shown
Whether or not trigger underlines should always be shown. The default value
is \c false.
\since BeOS R3
*/
/*!
\fn status_t get_menu_info(menu_info* info)
\brief Fill out the menu_info struct into \a info.
\since BeOS R3
*/
/*!
\fn status_t set_menu_info(menu_info* info)
\brief Set the menu's menu_info struct to \a info adjusting how the menu
will look and work.
\since BeOS R3
*/
/*!
\typedef bool (*menu_tracking_hook)(BMenu* menu, void* state)
\brief Defines the function passed into BMenu::SetTrackingHook().
\since BeOS R3
*/
/*!
\class BMenu
\ingroup interface
\ingroup libbe
\brief Displays a list of menu items including additional menus
arranged hierarchically.
A newly created BMenu object doesn't contain any menu items, you need to call
AddItem() or AddList() to add some.
In addition to BMenuItem objects you can also add additional BMenu objects in
order to create a menu hierarchy. Unlike menus in other operating systems you
can always select both the submenu and menu items, although selecting the
submenu might not actually produce any action other than to close the menu.
The name of a submenu is used to draw its label.
\image html BMenu_example.png
BMenu is the basis of several other Interface Kit classes including BMenuBar
and BPopUpMenu. See BMenu::SetRadioMode() and BMenu::SetLabelFromMarked()
for additional details on how BMenu and BPopUpMenu are related.
Menus arrange their items in one of three possible layouts:
<table>
<tr>
<td>\c B_ITEMS_IN_COLUMN</td>
<td>
The menu items are stacked vertically in a column, one on top
of another, as in a typical pop-up menu.
</td>
</tr>
<tr>
<td>\c B_ITEMS_IN_ROW</td>
<td>
The menu items are laid out horizontally in a row, from end to
end, as in a typical menu bar.
</td>
</tr>
<tr>
<td>\c B_ITEMS_IN_MATRIX</td>
<td>
The menu items are arranged in a free-form arrangement that you
create, such as a matrix.
</td>
</tr>
</table>
Either \c B_ITEMS_IN_COLUMN or \c B_ITEMS_IN_ROW can be passed into the
default constructor, but, you should use the constructor that allows you to
set the height and width of the menu in order to utilize the
\c B_ITEMS_IN_MATRIX layout.
Several methods will only work in some layouts as noted in the method
description below.
\since BeOS R3
*/
/*!
\fn BMenu::BMenu(const char* name, menu_layout layout)
\brief Creates a new menu object with the specified \a name and \a layout.
Don't pass \c B_ITEMS_IN_MATRIX into \a layout with this method, use
BMenu::BMenu(const char* name, float width, float height) instead.
\param name The menu's \a name, serves as a label for submenus.
\param layout The menu layout, possibilities include:
- \c B_ITEMS_IN_ROW items are displayed in a single row,
- \c B_ITEMS_IN_COLUMN items are displayed in a single column.
\since BeOS R3
*/
/*!
\fn BMenu::BMenu(const char* name, float width, float height)
\brief Creates a new menu object with a \c B_ITEMS_IN_MATRIX layout and the
specified \a name, \a width, and \a height.
\param name The menu's \a name, serves as a label for submenus.
\param width The menu \a width.
\param height The menu \a height.
\since BeOS R3
*/
/*!
\fn BMenu::BMenu(BMessage* archive)
\brief Archive constructor.
\param archive The message data to construct the menu from.
\since BeOS R3
*/
/*!
\fn BMenu::~BMenu()
\brief Destructor.
Also frees the memory used by any attached menu items and submenus.
\since BeOS R3
*/
/*!
\name Archiving
*/
//! @{
/*!
\fn BArchivable* BMenu::Instantiate(BMessage* archive)
\brief Creates a new BMenu object from an \a archive message.
\returns A newly created BMenu object or \c NULL if the message doesn't
contain an archived BMenu.
\since BeOS R3
*/
/*!
\fn status_t BMenu::Archive(BMessage* data, bool deep) const
\brief Archives the the BMenu object into the \a data message.
\param data A pointer to the BMessage to archive the object into.
\param deep Whether or not to archive attached menu items as well.
\return A status code, \c B_OK if everything went well or an error code
otherwise.
\retval B_OK The object was archived successfully.
\retval B_NO_MEMORY Ran out of memory while archiving the object.
\since BeOS R3
*/
//! @}
/*!
\name Hook Methods
*/
//! @{
/*!
\fn void BMenu::AttachedToWindow()
\brief Lays out the menu items and resizes the menu to fit.
\since BeOS R3
*/
/*!
\fn void BMenu::Draw(BRect updateRect)
\brief Draws the menu.
\param updateRect The area to draw in.
\since BeOS R3
*/
/*!
\fn void BMenu::MessageReceived(BMessage* message)
\brief Handles a \a message received by the associated looper.
Responds to mouse wheel events scrolling the menu if it is too
long to fit in the window. Hold \c B_SHIFT_KEY to cause the menu
to scroll faster.
\param message The \a message received by the associated looper.
\since BeOS R3
*/
/*!
\fn void BMenu::KeyDown(const char* bytes, int32 numBytes)
\brief Hook method that is called when a keyboard key is pressed.
Handles keyboard navigation and triggers.
\param bytes The bytes of the key combination pressed.
\param numBytes The number of bytes in \a bytes.
\since BeOS R3
*/
//! @}
/*!
\fn bool BMenu::AddItem(BMenuItem* item)
\brief Adds a menu \a item to the end of the list.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
or \c B_ITEMS_IN_ROW layout, it is an error to use this method for
a menu in \c B_ITEMS_IN_MATRIX layout.
\param item The menu \a item to add.
\return Whether or not the \a item was added to the menu.
\since BeOS R3
*/
/*!
\fn bool BMenu::AddItem(BMenuItem* item, int32 index)
\brief Adds a menu \a item at the specified \a index.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
or \c B_ITEMS_IN_ROW layout, it is an error to use this method for
a menu in \c B_ITEMS_IN_MATRIX layout.
\param item The menu \a item to add.
\param index The \a index where to add the \a item to the menu.
\return Whether or not the \a item was added to the menu.
\since BeOS R3
*/
/*!
\fn bool BMenu::AddItem(BMenuItem* item, BRect frame)
\brief Adds a menu \a item in the specified \a frame rectangle within the menu.
\warning This method should only be used for a menu in \c B_ITEMS_IN_MATRIX
layout, it is an error to use this method for a menu in
\c B_ITEMS_IN_COLUMN or \c B_ITEMS_IN_ROW layout.
\param item The menu \a item to add.
\param frame The \a frame rectangle where to add the \a item to the menu.
\return Whether or not the \a item was added to the menu.
\since BeOS R3
*/
/*!
\fn bool BMenu::AddItem(BMenu* submenu)
\brief Add a \a submenu to the end of the list.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
or \c B_ITEMS_IN_ROW layout, it is an error to use this method for
a menu in \c B_ITEMS_IN_MATRIX layout.
\param submenu The submenu to add.
\return Whether or not the \a submenu was added to the menu.
\since BeOS R3
*/
/*!
\fn bool BMenu::AddItem(BMenu* submenu, int32 index)
\brief Add a \a submenu at the specified \a index.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
or \c B_ITEMS_IN_ROW layout, it is an error to use this method for
a menu in \c B_ITEMS_IN_MATRIX layout.
\param submenu The \a submenu to add.
\param index The \a index where to add the \a submenu to the menu.
\return Whether or not the \a submenu was added to the menu.
\since BeOS R3
*/
/*!
\fn bool BMenu::AddItem(BMenu* submenu, BRect frame)
\brief Adds a \a submenu in the specified \a frame rectangle within the
menu.
\warning This method should only be used for a menu in \c B_ITEMS_IN_MATRIX
layout, it is an error to use this method for a menu in
\c B_ITEMS_IN_COLUMN or \c B_ITEMS_IN_ROW layout.
\param submenu The submenu to add.
\param frame The \a frame rectangle where to add the submenu to the menu.
\return Whether or not the \a submenu was added to the menu.
\since BeOS R3
*/
/*!
\fn bool BMenu::AddList(BList* list, int32 index)
\brief Add a \a list of menu items at the specified \a index.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
or \c B_ITEMS_IN_ROW layout, it is an error to use this method for
a menu in \c B_ITEMS_IN_MATRIX layout.
\param list The \a list of menu items to add.
\param index The \a index where to add the \a list to the menu.
\return Whether or not the \a list of menu items was added to the menu.
\since BeOS R3
*/
/*!
\fn bool BMenu::AddSeparatorItem()
\brief Adds a separator item to the end of the menu.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
layout, it is an error to use this method for a menu in
\c B_ITEMS_IN_ROW or \c B_ITEMS_IN_MATRIX layout.
\return Whether or not the separator item was added to the menu.
\since BeOS R3
*/
/*!
\fn bool BMenu::RemoveItem(BMenuItem* item)
\brief Remove and delete the specified \a item from the menu.
\return Whether or not the \a item was removed from the menu.
\since BeOS R3
*/
/*!
\fn BMenuItem* BMenu::RemoveItem(int32 index)
\brief Remove the item at the specified \a index from the menu.
The menu item object is not deleted.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
or \c B_ITEMS_IN_ROW layout, it is an error to use this method for
a menu in \c B_ITEMS_IN_MATRIX layout.
\param index The \a index of where to remove the menu item.
\return The menu item object or \c NULL if not found.
\since BeOS R3
*/
/*!
\fn bool BMenu::RemoveItems(int32 index, int32 count, bool deleteItems)
\brief Remove \a count number of items from the menu starting at the specified
\a index and delete them if \a deleteItems is \c true.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
or \c B_ITEMS_IN_ROW layout, it is an error to use this method for
a menu in \c B_ITEMS_IN_MATRIX layout.
\param index The \a index of where to start removing menu items.
\param count The number of items to remove.
\param deleteItems Whether or not to delete the items after removing them.
\return Whether or not the items were removed from the menu.
\since BeOS R3
*/
/*!
\fn bool BMenu::RemoveItem(BMenu* submenu)
\brief Remove and delete a \a submenu from the menu.
\param submenu The submenu to remove.
\return Whether or not the \a submenu was removed from the menu.
\since BeOS R3
*/
/*!
\fn int32 BMenu::CountItems() const
\brief Returns the number of items added to the menu.
\return The number of items added to the menu.
\since BeOS R3
*/
/*!
\fn BMenuItem* BMenu::ItemAt(int32 index) const
\brief Returns a pointer to the menu item at the specified \a index.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
or \c B_ITEMS_IN_ROW layout, it is an error to use this method for
a menu in \c B_ITEMS_IN_MATRIX layout.
\return A pointer to a menu item or \c NULL if not found.
\since BeOS R3
*/
/*!
\fn BMenu* BMenu::SubmenuAt(int32 index) const
\brief Returns a pointer to a submenu at the specified \a index.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
or \c B_ITEMS_IN_ROW layout, it is an error to use this method for a
menu in \c B_ITEMS_IN_MATRIX layout.
\return A pointer to a submenu or \c NULL if not found.
\since BeOS R3
*/
/*!
\fn int32 BMenu::IndexOf(BMenuItem* item) const
\brief Returns the index of the specified menu \a item.
The index starts at the left for a menu in \c B_ITEMS_IN_COLUMN layout going
right or start at the top for a menu in \c B_ITEMS_IN_ROW layout going down.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
or \c B_ITEMS_IN_ROW layout, it is an error to use this method for
a menu in \c B_ITEMS_IN_MATRIX layout.
\return The index of the menu \a item or \c B_ERROR of not found.
\since BeOS R3
*/
/*!
\fn int32 BMenu::IndexOf(BMenu* submenu) const
\brief Returns the index of the specified \a submenu.
The index starts at the left for a menu in \c B_ITEMS_IN_COLUMN layout going
right or at the top for a menu in \c B_ITEMS_IN_ROW layout going down.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
or \c B_ITEMS_IN_ROW layout, it is an error to use this method for
a menu in \c B_ITEMS_IN_MATRIX layout.
\return The index of the \a submenu or \c B_ERROR of not found.
\since BeOS R3
*/
/*!
\fn BMenuItem* BMenu::FindItem(const char* label) const
\brief Returns a pointer to the menu item with the specified \a label.
\param label The \a label of the menu item to find.
\return A pointer to a menu item or \c NULL if not found.
\since BeOS R3
*/
/*!
\fn BMenuItem* BMenu::FindItem(uint32 command) const
\brief Returns a pointer to the menu item with the specified \a command for
its associated message.
\param command The \a command of the associated message of the menu item to
find.
\return A pointer to a menu item or \c NULL if not found.
\since BeOS R3
*/
/*!
\fn status_t BMenu::SetTargetForItems(BHandler* handler)
\brief Set the target to \a handler for each item in the menu.
This is a convenient way to set the target for all the items in a menu.
\param handler The BHandler object to set the target of the menu item to.
This method doesn't descend into submenus recursively and only acts on items
that have already been added to the menu.
\return \c B_OK on success or an error code on error.
\since BeOS R3
*/
/*!
\fn status_t BMenu::SetTargetForItems(BMessenger messenger)
\brief Set the target to \a messenger for each item in the menu.
This is a convenient way to set the target for all the items in a menu.
This method doesn't descend into submenus recursively and only acts on items
that have already been added to the menu.
\param messenger The BMessenger object to set the target of the menu item
to.
\return \c B_OK on success or an error code on error.
\since BeOS R3
*/
/*!
\fn void BMenu::SetEnabled(bool enable)
\brief Enables or disables the menu.
\param enable \c true to enable, \c false to disable.
\since BeOS R3
*/
/*!
\fn void BMenu::SetRadioMode(bool on)
\brief Turns radio mode on or off.
Turning radio mode off also turns off label-from-marked mode.
Radio mode means that only one menu item can be set as marked at a time.
Marking a menu item automatically unmarks all other menu items and draws
a check mark on the left side of the marked menu item. You don't have to
call BMenuItem::SetMarked() yourself for a menu in radio mode, this is done
for you automatically.
Radio mode does not work recursively, only the current menu is considered.
If you want to make a menu work in radio mode recursively you'll have to
turn radio mode off and iterate through each menu marking and unmarking
the items yourself.
\param on \c true to turn radio mode on, \c false to turn it off.
\since BeOS R3
*/
/*!
\fn void BMenu::SetTriggersEnabled(bool enable)
\brief Enables or disables triggers.
\param enable \c true to enable triggers, \c false to disable triggers.
\since BeOS R3
*/
/*!
\fn void BMenu::SetMaxContentWidth(float width)
\brief Sets the maximum width of the menu items' content area.
This is the maximum width that a menu item can draw in. Note that menu
items have built-in margins on the left and right sides that are not
included as part of the maximum content width.
\param width The maximum width for the menu item contents to draw in.
\since BeOS R3
*/
/*!
\fn void BMenu::SetLabelFromMarked(bool on)
\brief Sets whether or not the label of the menu is set according to the
marked item.
Turning label-from-marked mode on also turns radio mode on.
\param on \c true to turn label-from-marked mode on, \c false to turn it
off.
\since BeOS R3
*/
/*!
\fn bool BMenu::IsLabelFromMarked()
\brief Returns whether or not the menu is in label-from-marked mode.
\return \c true if menu is in label-from-marked mode, \c false if not.
\since BeOS R3
*/
/*!
\fn bool BMenu::IsEnabled() const
\brief Returns whether or not the menu is enabled.
\return \c true if menu is enabled, \c false if it is disabled.
\since BeOS R3
*/
/*!
\fn bool BMenu::IsRadioMode() const
\brief Returns whether or not the menu is in radio mode.
\return \c true if menu is in radio mode, \c false if not.
\since BeOS R3
*/
/*!
\fn bool BMenu::AreTriggersEnabled() const
\brief Returns whether or not triggers are enabled.
\return \c true if triggers are enabled, \c false if triggers are disabled.
\since BeOS R3
*/
/*!
\fn bool BMenu::IsRedrawAfterSticky() const
\brief Returns whether or not the menu is in redraw-after-sticky mode.
\return \c true if menu is in redraw-after-sticky mode, \c false if not.
\since Haiku R1
*/
/*!
\fn float BMenu::MaxContentWidth() const
\brief Return the maximum width of the menu items' content area.
\return The maximum width of the menu items' content area as a float.
\sa SetMaxContentWidth()
\since BeOS R3
*/
/*!
\fn BMenuItem* BMenu::FindMarked()
\brief Return a pointer to the first marked menu item.
The index starts at the left for a menu in \c B_ITEMS_IN_COLUMN layout going
right or at the top for a menu in \c B_ITEMS_IN_ROW layout going down.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
or \c B_ITEMS_IN_ROW layout, it is an error to use this method for
a menu in \c B_ITEMS_IN_MATRIX layout.
\return A pointer to the first marked menu item or \c NULL if not found.
\since BeOS R3
*/
/*!
\fn int32 BMenu::FindMarkedIndex()
\brief Return the index of the first marked menu item.
The index starts at the left for a menu in \c B_ITEMS_IN_COLUMN layout going
right or at the top for a menu in \c B_ITEMS_IN_ROW layout going down.
\warning This method should only be used for a menu in \c B_ITEMS_IN_COLUMN
or \c B_ITEMS_IN_ROW layout, it is an error to use this method for
a menu in \c B_ITEMS_IN_MATRIX layout.
\return The index of the first marked menu item or -1 if not found.
\since Haiku R1
*/
/*!
\fn BMenu* BMenu::Supermenu() const
\brief Returns the pointer to the menu that this menu it attached to.
\return A pointer to a BMenu object or \c NULL if not found.
\since BeOS R3
*/
/*!
\fn BMenuItem* BMenu::Superitem() const
\brief Returns the pointer to the menu item that this menu it attached to.
\return A pointer to a BMenuItem object or \c NULL if not found.
\since BeOS R3
*/
/*!
\fn BMenu::BMenu(BRect frame, const char* name, uint32 resizingMode,
uint32 flags, menu_layout layout, bool resizeToFit)
\brief Implemented by derived classes to create a new menu object.
This method is intended to be used by derived classes that don't simply wish
to utilize different sorts of menu items or arrange them in a different way,
but wish to invent a different kind of menu altogether.
If the \a layout is set to \c B_ITEMS_IN_MATRIX the \a resizeToFit flag should
be set to \c false.
\param frame The \a frame rectangle to create the menu in.
\param name The menu's \a name, serves as a label for submenus.
\param resizingMode The resizing mode flags, see BView for more details.
\param flags The view \a flags, see BView for more details.
\param layout The menu layout, possibilities include:
- \c B_ITEMS_IN_ROW items are displayed in a single row,
- \c B_ITEMS_IN_COLUMN items are displayed in a single column,
- \c B_ITEMS_IN_MATRIX items are displayed in a custom matrix.
\param resizeToFit Whether or not the menu should automatically resize
itself to fit its contents, this will not work in
\c B_ITEMS_IN_MATRIX layout.
\since BeOS R3
*/
/*!
\fn void BMenu::SetItemMargins(float left, float top, float right,
float bottom)
\brief Set the menu item margins.
\param left The left margin to set.
\param top The top margin to set.
\param right The right margin to set.
\param bottom The bottom margin to set.
\since BeOS R3
*/
/*!
\fn void BMenu::GetItemMargins(float* _left, float* _top, float* _right,
float* _bottom) const
\brief Fill out the margins into the passed in float pointers.
\param _left The left margin to fill out, can be \c NULL.
\param _top The top margin to fill out, can be \c NULL.
\param _right The right margin to fill out, can be \c NULL.
\param _bottom The bottom margin to fill out, can be \c NULL.
\since BeOS R3
*/
/*!
\fn menu_layout BMenu::Layout() const
\brief Returns the current menu_layout constant.
\since BeOS R3
*/
/*!
\fn BMenuItem* BMenu::Track(bool sticky, BRect* clickToOpenRect)
\brief Initiates tracking the cursor within the menu.
This method passes tracking control to submenus hierarchically depending on
where the user moves their mouse.
You only need to call this method yourself if you are implementing a menu
that needs to track the cursor under nonstandard circumstances.
\param sticky If \c true Track() leaves the menu open even after the mouse
button is no longer held down.
\param clickToOpenRect If \a sticky is \c true, leave the menu open even if
the user releases the mouse button while the cursor is inside
\a clickToOpenRect.
\return A BMenuItem object if the user ends tracking by invoking an item or
\c NULL if the user didn't invoke an item.
\since BeOS R3
*/
/*!
\fn bool BMenu::AddDynamicItem(add_state state)
\brief Implemented by subclasses to Add a dynamic item to the menu.
\param state Possibilities include:
- \c B_INITIAL_ADD,
- \c B_PROCESSING,
- \c B_ABORT
\return \c true if the dynamic item was added, \c false otherwise.
\since Haiku R1
*/
/*!
\fn void BMenu::DrawBackground(BRect updateRect)
\brief Draw the menu background within the bounds of \a updateRect.
\param updateRect The area to draw the background in.
\since Haiku R1
*/
/*!
\fn void BMenu::SetTrackingHook(menu_tracking_hook func, void* state)
\brief Sets a hook function that is called when tracking begins.
\param func The hook function to call.
\param state A variable passed to the hook function.
\since Haiku R1
*/