Quit while the simulation was running. I used to just do
wxFrame::Close(TRUE) in the wxwindows thread, but the simulation
thread would keep on running even after the window had disappeared.
If the simulation thread sent any messages to the gui, it could
segfault. Now, when you click on Quit it asks the simulator to
quit, but does not close the gui. When the simulator thread finally
quits, THEN it calls wxFrame::Close(TRUE) from the sim_thread (with
appropriate gui mutex). Such tricks are only needed when the
simulation is running. I hope this will fix bug #616142: "wx: crash
from events after gui shutdown".
- move MyFrame::closing flag out into a global variable wxBochsClosing
so that it will be valid even when the MyFrame is deleted. See
comments on in wxmain.h.
- when wxBochsClosing is set, don't create any new windows. If any
errors appear, just print them to stderr because the gui is just
about to be closed.
- fix comment in SimThread::Entry to talk about longjmp instead of
kill_bochs_request
- (minor) move contents of DefaultCallback2 into DefaultCallback. It
doesn't refer to the wxApp at all. This is a bit safer in case it
gets called when the wxApp is in the process of being deleted.
- modified: gui/wxmain.cc gui/wxmain.h
bx_list_c can now be displayed as either a wxStaticBox with the
child parameters inside, or as a wxNotebook with each child
parameter in a separate tab. (The children can also be lists of
course.) The default display is the wxStaticBox type, but if you
set the option bit bx_list_c::USE_TAB_WINDOW in the list,
ParamDialog will use the wxNotebook display instead.
- to get the param trees working, I created a new struct
AddParamContext, which is passed to AddParam(). This struct is
critical when AddParam calls itself recursively to display lists
within lists.
- use the wxNotebook display feature for the ATA0,1,2,3 controller
dialog box. Now instead of being hundreds of pixels tall, it is
reasonable height with three different tabs. This fixed bug
#619074: "wx: ATA interface editor too tall" and was the whole
reason I started messing with this at all.
plus some minor cleanups
- when I added the enum constant bx_list_c::USE_TAB_WINDOW, I also
removed the BX_ prefix from all the other enum constants that are
used in parameter options in siminterface.cc. Since these constants
are enums within a class, there is no possibility of namespace
conflicts so the prefix is not needed.
- added wxADJUST_MINSIZE to all wxChoice controls, since that tells
wxWindows to adjust its size to the length of the longest string.
- instead of calling SetSize or SetSizeHints on every textcontrol with
a hardcoded width, I am using just two wxSize specifications for
everything: either normalTextSize or longTextSize.
- edit names of a few menus and params. For example now instead of
the tab saying "Master ATA device on channel 0" it will say
"First HD/CD on channel 0".
Modified Files:
main.cc gui/control.cc gui/gui.cc gui/siminterface.cc gui/siminterface.h
gui/wxdialog.cc gui/wxdialog.h gui/wxmain.cc
on the wxWindows interface. There are many more changes here than
absolutely required to fix the memory leaks. Instead, I've tried to
clean things up so that it does the right thing, and is easier to
read and maintain.
- For events that the text mode interface is going to ignore anyway, I #ifdefed
the event creation code instead of calling new and then delete.
- now all synchronous events in siminterface.cc are created as local variables
on the stack. Some of them were allocated with new before, and yes some of
them leaked.
- now I ignore the result of sim_to_ci_event (&event). It was always
returning a pointer to the input event anyway. This makes the event
sending code simpler.
- wxmain.cc:
- in the BxEvent handling functions, now all cases "break" down to common
code at the end which deletes async events. This is easier to read than
having each case handle the delete individually.
- in OnLogMsg, do not delete the event here because it is now handled
in the common code of OnSim2CIEvent instead.
- thanks to Christophe for pointing out the location of the worst
memory leak.
- make bx_init_main return -1 if any parse errors occur.
- wxWindows: if bx_init_main returns -1, don't even show the application
window. You'll get an error dialog and then it exits. So far this
only happens if you run with -q and the parse fails.
- non-wxWindows: if bx_init_main returns -1, just exit. So far this
only happens if you run with -q and the parse fails.
- with these changes, handling of bochsrc parse errors seems to work
as you would expect. And it certainly doesn't go into an infinite
recursive loop, as it used to!
- a little more testing and I can close
bug 614175: infinite panic loop if bochsrc buggy
- modified: main.cc gui/siminterface.h gui/wxmain.cc
and into wxmain.cc, like other actions.
- set a default siminterface callback for the whole application, which is used
whenever the simulator is not running. This is important when the wx code
calls simulator or param code and triggers a BX_PANIC or something.
The default callback is responsible for displaying error messages which
appear while reading the bochsrc, for example.
- move the implementation of BX_SYNC_EVT_LOG_ASK and BX_ASYNC_EVT_LOG_MSG
into a separate function OnLogMsg(). In the future, OnLogMsg() may be called
from the application default callback on errors.
- modified: gui/wx.cc gui/wxmain.cc gui/wxmain.h
- Features :
. number of active channels defined at boot-time config
. new options in bochsrc
. up to 8 devices support (disks or cdroms)
. up to 4 cdrom devices can be changed at runtime config
. wxwindows config interface
parameter values associated with the dialog and updated the wxWindows
controls. At the time I didn't realize that I was overriding
wxWindow::Refresh() which repaints the window. Later, I renamed the method
to CopyParamToGui() to make it more clear, but many of the callers in
wxmain.cc continued to call Refresh(), which now reverted to the parent class
wxWindow::Refresh(). Since there was no compile error I didn't notice for a
while, but it caused the ParamDialogs to repaint themselves constantly but
never actually change their values. This is now fixed by changing those
method calls to CopyParamToGui().
I'm not sure why this wasn't needed before, but after switching to
wxWindows 2.3.3 it seems to be important.
- in a wxLogDebug() call I was trying to pass a struct instead of a string.
Fixed that.
- MyPanel::blankCursor
- MyFrame::panel
- AdvancedLogOptions::action (2d array of wxChoice *'s)
- ParamDialog::idHash, ParamDialog::paramHash, and ParamStructs
- file dialog in BrowseTextCtrl
- fix illegal use of a wxObject. I had been clearing the ParamStruct
with memset(), but I forgot that ParamStruct was a subclass of wxObject
so I was trashing the wxObject fields too! Instead I created a
ParamStruct constructor that clears the pointers to NULL.
- comment out debug output from AdvancedLogOptionsDialog::SetAction
- modified files: gui/wx.cc gui/wxdialog.cc gui/wxdialog.h
gui/wxmain.cc gui/wxmain.h
- LogOptionsDialog: show the "no change" option. When options other than
"no change" are selected, set both the default log action and the
specific log action for all devices.
- AdvancedLogOptionsDialog: store the wxChoice*'s in a 2d array since I
have to refer to them later.
- since both the log options and advanced log options dialogs needed to
create many wxChoices using similar rules, I moved the creation code
into a utility function makeLogOptionChoiceBox.
- I finally discovered the wxADJUST_MINSIZE option to wxSizer::Add(),
which solves some layout problems that I was having with wxChoices.
With this setting, the wxChoice will automatically grow to the size of
the largest string that can be selected.
- improve sizing of the scrollWin according to the desired size of the panel
that contains all the wxChoices.
- add sketches for proposed dialog that combines both LogOptionsDialog and
AdvancedLogOptionsDialog using tabs
- All mouse events in the VGA window go to MyPanel::OnMouse. Middle mouse
button and F12 both toggle mouse capture. OnMouse queues an event
for the simulation thread to process. The simulation thread calls
bx_devices.keyboard->mouse_motion() when it sees the event on the queue.
- add IFDBG_VGA around some display debug code. All wx mouse debug code
is controlled by IFDBG_MOUSE.
- modified: gui/wx.cc gui/wxmain.cc gui/wxmain.h
wxWindows without debugger, I needed to add some more cases of #if
BX_DEBUGGER to make it work. All the problems I found were things like
referencing a debug structure which was never initialized (NULL). It is
possible to handle such problems by always compiling in the debug dialogs but
only instantiating them if debug support is compiled in, but I have chosen
(for now) to put #if BX_DEBUGGER around things like this.
printed to stderr in the text debugger. Also allows the user to
type (text) debugger commands directly, which also appear in the log.
- all text output in the debugger now passes through dbg_printf()
(used to be fprintf to stderr) so that in wxWindows I can redirect
it all to the wxWindows debug log screen. Added debug_fputs to
siminterface which actually sends the text to the GUI by creating
a BX_ASYNC_EVT_DBG_MSG event.
- changed prefix and msg fields of BxLogMsgEvent to const char *,
and also in args of logmsg method of siminterface.
- don't trap SIGINT in wxWindows. There are other ways to stop execution.
Also, signal handling with multiple threads is very strange and different
on different platforms.
- minor changes to fix gcc -Wall warnings in dbg_main.cc
- add a new boolean parameter BXP_DEBUG_RUNNING that tells if the debugger is
running freely or not. This is used by the wxWindows GUI to enable or
disable certain choices.
- CpuRegistersDialog has continue,stop,step buttons. When the sim is running
freely, I disable continue and step, and enable stop. When the sim stops
to wait for the user, I disable stop and enable continue and step. The
change of enables used to be triggered by actually pressing the button,
but then if you started/stopped the simulation in some other way (typing
in debug log window) the enables were never changed. Now the enables are
controlled by the value of BXP_DEBUG_RUNNING, which is set by the debug code
itself, and the buttons are enabled at the right time.
- ParamDialog::Refresh() is now virtual so that child classes can redefine
its refresh behavior.
- in safeWxStrcpy, force the last element of the array to be a 0, since
I noticed that strncpy is not guaranteed to terminate the string!
- modified: debug/dbg_main.cc debug/debug.h gui/siminterface.cc
gui/siminterface.h gui/wxdialog.cc gui/wxdialog.h gui/wxmain.cc
gui/wxmain.h
Bochs debugger. The Bochs debugger calls SIM->debug_get_next_command() which
does not return until a debugger command is found. The siminterface sends an
synchronous event to the wxWindows thread with a blank to be filled in with a
debugger command. wxWindows fills in the blank and sends the synchronous
event back, and the Bochs debugger interprets it as if it was typed on
the command line. For the long term I haven't decided whether to stick with
sending text strings vs. some other method.
- so far the wxWindows debugger consists of one big dialog box that shows
all the standard registers, and a working Continue, Stop, and Step button.
- modify ParamDialog so that it is more useful as a base class, by moving
some things to protected members&fields, separating out functionality
that is most likely to be replaced into virtual functions, and making it
generally more flexible. The new CpuRegistersDialog is based on
ParamDialog.
- in wxdialog.cc, continue the convention of using wxID_HELP, wxID_OK,
wxID_CANCEL, etc. for the id's of buttons, instead of wxHELP, wxOK, etc.
which are intended to be ORred together in a bit field.
- cpu/init.cc: put ifdefs around DEFPARAMs for flags in configurations
where they don't exist. Add an eflags shadow parameter that represents all
of the bits of eflags at once. There are also boolean shadow params for
each bit.
- modified files: cpu/init.cc debug/dbg_main.cc debug/debug.h
gui/siminterface.cc gui/siminterface.h gui/wxdialog.cc gui/wxdialog.h
gui/wxmain.cc gui/wxmain.h
wxWindows thread. However, when the wxWindows thread calls
Bochs code, for example SIM->some_action() that triggers a
BX_PANIC(), then the Sim2CI event is created in the wxWindows
thread. This used to cause thread deadlock, but now it is
recognized and handled safely.
- modified files: config.h.in cpu/init.cc debug/dbg_main.cc gui/control.cc
gui/siminterface.cc gui/siminterface.h gui/wxdialog.cc gui/wxdialog.h
gui/wxmain.cc gui/wxmain.h iodev/keyboard.cc
----------------------------------------------------------------------
Patch name: patch.wx-show-cpu2
Author: Bryce Denney
Date: Fri Sep 6 12:13:28 EDT 2002
Description:
Second try at implementing the "Debug:Show Cpu" and "Debug:Show
Keyboard" dialog with values that change as the simulation proceeds.
(Nobody gets to see the first try.) This is the first step toward
making something resembling a wxWindows debugger.
First, variables which are going to be visible in the CI must be
registered as parameters. For some variables, it might be acceptable
to change them from Bit32u into bx_param_num_c and access them only
with set/get methods, but for most variables it would be a horrible
pain and wreck performance.
To deal with this, I introduced the concept of a shadow parameter. A
normal parameter has its value stored inside the struct, but a shadow
parameter has only a pointer to the value. Shadow params allow you to
treat any variable as if it was a parameter, without having to change
its type and access it using get/set methods. Of course, a shadow
param's value is controlled by someone else, so it can change at any
time.
To demonstrate and test the registration of shadow parameters, I
added code in cpu/init.cc to register a few CPU registers and
code in iodev/keyboard.cc to register a few keyboard state values.
Now these parameters are visible in the Debug:Show CPU and
Debug:Show Keyboard dialog boxes.
The Debug:Show* dialog boxes are created by the ParamDialog class,
which already understands how to display each type of parameter,
including the new shadow parameters (because they are just a subclass
of a normal parameter class). I have added a ParamDialog::Refresh()
method, which rereads the value from every parameter that it is
displaying and changes the displayed value. At the moment, in the
Debug:Show CPU dialog, changing the values has no effect. However
this is trivial to add when it's time (just call CommitChanges!). It
wouldn't really make sense to change the values unless you have paused
the simulation, for example when single stepping with the debugger.
The Refresh() method must be called periodically or else the dialog
will show the initial values forever. At the moment, Refresh() is
called when the simulator sends an async event called
BX_ASYNC_EVT_REFRESH, created by a call to SIM->refresh_ci ().
Details:
- implement shadow parameter class for Bit32s, called bx_shadow_num_c.
implement shadow parameter class for Boolean, called bx_shadow_bool_c.
more to follow (I need one for every type!)
- now the simulator thread can request that the config interface refresh
its display. For now, the refresh event causes the CI to check every
parameter it is watching and change the display value. Later, it may
be worth the trouble to keep track of which parameters have actually
changed. Code in the simulator thread calls SIM->refresh_ci(), which
creates an async event called BX_ASYNC_EVT_REFRESH and sends it to
the config interface. When it arrives in the wxWindows gui thread,
it calls RefreshDialogs(), which calls the Refresh() method on any
dialogs that might need it.
- in the debugger, SIM->refresh_ci() is called before every prompt
is printed. Otherwise, the refresh would wait until the next
SIM->periodic(), which might be thousands of cycles. This way,
when you're single stepping, the dialogs update with every step.
- To improve performance, the CI has a flag (MyFrame::WantRefresh())
which tells whether it has any need for refresh events. If no
dialogs are showing that need refresh events, then no event is sent
between threads.
- add a few defaults to the param classes that affect the settings of
newly created parameters. When declaring a lot of params with
similar settings it's more compact to set the default for new params
rather than to change each one separately. default_text_format is
the printf format string for displaying numbers. default_base is
the default base for displaying numbers (0, 16, 2, etc.)
- I added to ParamDialog to make it able to display modeless dialog
boxes such as "Debug:Show CPU". The new Refresh() method queries
all the parameters for their current value and changes the value in
the wxWindows control. The ParamDialog class still needs a little
work; for example, if it's modal it should have Cancel/Ok buttons,
but if it's going to be modeless it should maybe have Apply (commit
any changes) and Close.
X windows, wxWindows. Each platform has its own way of returning
a variable length string, and its own rules about how you're supposed
to dispose of the string. Now all platforms do the same thing: they
allocate a Bit8u buffer with C++ "new" and copy the clipboard data in,
then release the clipboard data in the platform-specific correct way.
The Bit8u buffer is sent to the keyboard code, which frees it with
delete [] when finished.
- modified: gui/wxmain.cc gui/wxmain.h
delivered to both the GUI and simulator thread, so they both call
bx_signal_handler. This can lead to deadlock as multiple threads enter
BX_PANIC and try to show a dialog box at once. To solve the problem, I made
a function isSimThread() which can be called from anywhere. If the
bx_signal_handler is called from any thread OTHER THAN the simulation thread,
it returns without doing anything. As a result, only one thread is allowed
to enter the signal handler code, and now control-C works correctly.
Bochs to immediately read the bochsrc and start simulating immediately (as
opposed to going into the configuration interface first). Now -q does
the right thing in the wxWindows interface. It behaves as if you selected
Read Configuration and then Simulate:Start.
- modified: main.cc gui/siminterface.cc gui/siminterface.h gui/wxmain.cc
correct name for floppy and cdrom devices:on windows, A:, B:, etc;
on Linux /dev/fd0 and /dev/cdrom.
- It's perfectly ok to type device names into the blank on those dialog
boxes, but the label "Disk Image File:" sort of implies that it has to
be a file. To try to avoid confusion change the label to simply
"Disk Image:".
values. All wxWindows dialogs return wxID_OK or wxID_CANCEL. The
wxOK and wxCANCEL symbols are ONLY used in input arguments that determine
whether to display the ok and cancel buttons. Now I'm doing the same.
Return values are wxID_OK if they pressed the ok button, and wxID_CANCEL
if they pressed cancel.
SetToolBitmapSize() to set the icon size to 16x16; when I changed the icon
size I forgot to change SetToolBitmapSize() and somehow it looked ok on
wxGTK.
- change mouse tooltip to "(Mouse Not Implemented Yet!)" for now
- implement the Edit Keyboard dialog using ParamDialog instead of the
handcoded thing.
- make Serial/Parallel dialog look a little better
- change order of "other" dialog to get ips and vga_update_interval on top
a method to add the parameters (bx_param_c) that you want to edit,
and display it. It knows how to display and edit boolean, int,
enum, and string, so it can do a reasonable job on any parameter.
The end result is not as nice as a box that you lay out by hand, but
it's decent. The most obvious thing that's missing from
ParamDialog-generated dialogs is that I haven't found a way to
make an "Enable" button that enables/disables a bunch of other
parameters. I'll keep thinking about that.
- using ParamDialog, I made dialogs for Sound, Cmos, Serial/Parallel,
32bitOSloader, and an ugly catch-all category called other.
Now I believe you can edit every single option using wxWindows.
- remove the format string from GetTextCtrlInt() because the strtoul
conversion is better than the sscanf with a format string (it supports
both base 10 and 16 with 0xFF notation).
- modified files: gui/wxdialog.cc gui/wxdialog.h gui/wxmain.cc gui/wxmain.h
and also the optional rom settings. I think it all works except that
the Browse buttons aren't hooked up yet.
- modified Files: gui/wxdialog.cc gui/wxdialog.h gui/wxmain.cc gui/wxmain.h
die, or ask the user for each type of event. It has a button that
will lead to the "advanced" dialog, which doesn't exist yet.
- in gui/wxdialog.h, sketch a few more dialogs to be done soon
- modified: gui/wxdialog.cc gui/wxdialog.h gui/wxmain.cc gui/wxmain.h
- for all modal dialogs that return a boolean result, return either
wxOK or wxCANCEL instead of 0,-1.
- you can view the NetConfigDialog box if you choose the Edit:Network menu
item, but it's not connected to the actual parameter values yet.
into normal C strings. After asking about it on wx-users, I understand
it better now.
Example of unsafe code:
char *filename = dlg.GetFilename().c_str ();
printf ("file name is %s\n", filename);
The problem is that dlg.GetFilename() returns a temporary wxString
that goes out of scope at the end of that line of code. The "filename"
string is unstable if you write it this way.
Example of safe code:
char filename[1024];
wxString fn (dlg.GetFilename ());
strncpy (filename, fn.c_str (), sizeof(filename));
printf ("file name is %s\n", name);
Now we have a stable copy of the wxString in "fn" which is usable
as long as fn is in scope.
- also now we use wxStrings (almost) all the time in the interface to the
wxdialogs. Any conversion from char* to wxString and back is done in
wxmain.cc now.
- HDConfigDialog now uses an EnableChanged() method to set the enabled bit
on components controlled by the enable checkbox.
- now sets the present bit on hard disks and cdrom
- enforces the rule that you can't have DISKD and CDROMD (just in time for
Christophe to add another interface)
- now the megabytes field is a wxStaticText, which makes it clear that
it cannot be edited.
- add "enter size/compute geometry" button for HD image
- make a few more strings into #defines in wxdialog.h
- disable most of the Edit menu during simulation, reenable it when
simulation stops
choose the filename and capacity of a floppy image. This dialog
can recognize a list of names as physical disk drives, and it has a
Browse button so that you can click on a new image intead of having
to type it. If you press ok, then the Bochs parameters are updated.
- eventually we should make a function that makes a list of the
physical devices that should be mentioned here. For Windows it should
say "Physical drive A:" for "a:", while on Linux it should say
"Physical drive fd0" for "/dev/fd0" or something. Even if bochs
doesn't find the correct physical disk drives, you can still type
whatever file name you want.
gui/wxdialog.h and gui/wxdialog.cc. The first dialog box is
called LogMsgAskDialog. It displays panic messages and asks if you
want to continue, quit, etc.
I use setjmp() to save the context just before calling
bx_continue_after_config_interface(). Then, in
bx_real_sim_c:quit_sim, I use longjmp() to jump back to that context.
This happens in main.cc and in gui/wxmain.cc (wxWindows only).
I haven't tested with the debugger yet. Possibly with debugger
the quit longjmp() should jump back to the debugger prompt loop
instead of actually quitting the program.
- clean up BX_ASYNC_EVT_LOG_MSG implementation by creating a different,
synchronous event called BX_SYNC_EVT_LOG_ASK. The async event
could be used to simply tell the CI that an event has occurred,
for example if the user wanted to view the events on screen
(not implemented). The sync event is used when you want the user
to respond before the simulation can continue, such as a for the
"panic=ask" behavior.
- in wxmain.cc, move the updates to the Start,Stop,Pause,Resume menu
items into a separate method simStatusChanged(). This makes the code that
does important stuff more readable.
- remove wxMutexGuiEnter()/Leave() from MyFrame::OnSim2CuiEvent().
This method is an event handler called in the gui thread, so it
already has the gui lock. This call caused thread lock on my linux
box.
the terminology a bit. In particular, the term "gui" has started
to mean different things in different contexts, so I've defined
some more specific names for the parts of the user interface, and
updated comments and some variable names to reflect it. See
siminterface.h for a more complete description of all of these.
VGAW: VGA display window and toolbar buttons, the traditional Bochs
display which is ported to X, win32, MacOS X, etc. Implemented
in gui/gui.* and platform dependent gui/*.cc files.
CI: configuration interface that lets the user change settings such
as floppy disk image, ne2k settings, log options. The CI consists
of two parts: configuration user interface (CUI) which does the
actual rendering to the screen and handles key/mouse/menu events,
and the siminterface object.
CUI: configuration user interface. This handles the user interactions
that allow the user to configure Bochs. To actually change any
values it talks to the siminterface object. One implementation of
the CUI is the text-mode menus in gui/control.cc. Another
implementation is (will be) the wxWindows menus and dialogs in
gui/wxmain.cc.
siminterface: the glue between the CUI and the simulation code,
accessible throughout the code by the global variable
bx_simulator_interface_c *SIM;
Among other things, siminterface methods allow the simulator to ask the
CUI to display things or ask for user input, and allows the CUI
to query and modify variables in the simulation code.
GUI: Literally, "graphical user interface". Until the configuration menus
and wxWindows came along, everyone understood that "gui" referred to the
VGA display window and the toolbar buttons because that's all there
was. Now that we have the wxWindows code, which implements both the VGAW
and the CUI, while all other platforms implement only the VGAW, it's not
so clear. So, I'm trying to use VGAW, CI, and CUI consistently since
they are more specific.
control panel: This has been used as another name for the configuration
interface. "control panel" is also somewhat unspecific and it sounds
like it would be graphical with buttons and sliders, but our text-mode
thing is not graphical at all. I've replaced "control panel" with
"configuration interface" wherever I could find it. In configure script,
the --disable-control-panel option is still supported, but it politely
suggests that you use --disable-config-interface instead.
- clean up comments in siminterface,wx* code
- add comments and examples for bx_param_* and BxEvents
- remove some obsolete stuff: notify_*_args,
bx_simulator_interface_c::[sg]et_enabled() methods
- in siminterface.cc, move a few bx_real_sim_c methods to where they belong,
with the rest of the methods. No changes to the actual methods.
- remove some DOS ^M's which crept in and confused my editor.
- loading default bochsrc for the wx gui no longer necessary
- the wx gui version of bochs now accepts the same command line arguments as
the other guis
the guest OS. The shortcut can be defined in the bochsrc or in the config
interface. It is possible to change it at runtime.
These shortcuts are currently recognized:
ctrlaltdel, ctrlaltesc, ctrlaltf1, alttab
Here is the list of changes:
* userbutton.h and userbutton.xpm added in gui/bitmaps
* config options for the userbutton shortcut added
* initialize the new button in the gui.cc
* the new userbutton handler generates keypresses and relaeses depending on
the shortcut keyword
* the gui stops adding buttons to the headerbar if not enough space is left.
This can happen when the screen width is 320 pixels (done for X11 only).
* TODO: build a dialog box for the wxWindows gui
