How to disable the automatic middle-click mouse events in X (Xlib)? - linux

I am currently implementing a program in X11 using C. I got the program to handle right- and left-click events, however middle-clicking poses a problem. It seems my window manager (Gnome on Ubuntu 9.10) thinks it's better if, instead of having a single middle-click, I should have a series of other clicks instead. I assume it's got something to do with the middle-click being used for copying-pasting. I really don't want this, though, as I'm making a full-screen application with OpenGL, and such things aren't appropriate. Is there any way to have the middle mouse button just working like any other button?
My current code goes something like this:
switch(currentXEvent.type) {
case ButtonPress:
switch(currentXEvent.xbutton.button) {
case 1:
leftMouseButton(currentXEvent.xbutton.x, currentXEvent.xbutton.y);
break;
case 2:
middleMouseButton(currentXEvent.xbutton.x, currentXEvent.xbutton.y);
break;
}
}
My difficulty is that it behaves like leftMouseButton() has been pressed. Any ideas?

To do this, you have to grab controls from the server. Then the window manager is left out of the processing chain. The most comfortable way is to use libSDL. It creates the appropriate context for a fullscreen OpenGL application and is easier to handle than Xlib+GLX.

Related

How to prevent an X Window from receiving user input?

I would like to create some windows on a linux desktop for simple layout purposes. I need to avoid user input going to these windows (and I suppose avoiding the windows from gaining focus should suffice for that to happen).
I think that I can do this with the xprop command, by setting the WM_HINTS property, but I haven't found specific documentation on how to do it.
By the way, for an mplayer window, I can do this by using the option -input nodefault-bindings:conf=/dev/null. I simply need a general solution which I can enforce at a low level on any application's window.
Thanks!
A window indicates whether it wants to receive keyboard input by setting the KeyPress and KeyRelease bits in its event mask. If you do not want your window to receive keyboard input, simply do not set those event in CreateWindow()'s event mask. See http://www.x.org/releases/X11R7.7/doc/xproto/x11protocol.html#requests:ChangeWindowAttributes for more information.
Additionally, you should also set the input focus hints for your window to "NoFocus", as described in section 4.1.7 of ICCCM: http://tronche.com/gui/x/icccm/sec-4.html#s-4.1.7
If you want to fiddle with other applications' windows, you should be able to change their attributes and hints, although this may result in undesirable behavior and/or side effects.

PyQt: Simulate real mouse click on "desktop"?

If there's any way to simulate a real mouse click (press + release) at the absolute position of current desktop with PyQt, without other extenal library like PyUserInput?
I search around and just found this and this. But If I don't misunderstand, they seem to send their click event to Qt application it self, instead of the desktop?
Use PyQt's QTest, together with unittest or such. See also for example http://www.voom.net/pyqt-qtest-example.
If this is not for unit testing, look at sendEvent and postEvent (See http://doc.qt.digia.com/qq/qq11-events.html#syntheticevents). There are some limitations to Qt's mechanism for generating "artificial" events but based on what you describe, it is likely to work. If you have tried those and it doesn't work, please post the code you tried.

Tcl/Tk widgets and FocusOut not working as expected on linux

Do anyone know why FocusOut event is not working on linux?
I have 1 enabled textbox and 3 disabled combobox.
I bind the textbox with FocusOut event where it will call a proc that enables or disables the 3 combobox.
It works perfectly on Windows. However, it doesn't seem to trigger the FocusOut event when this action is done on Linux. One weird thing is that if I click on buttons, FocusOut event seems to be triggered.
Could it be because my combobox are disabled?
But why does it work on Windows?
I really hope someone can help me please.
Thanks in advance.
I have observed in the past that some window managers steal the focus temporarily from Tk on each button click before setting it back; I suspect that this has to do with the way that key event handling works, but I am unable to check at the moment (due to being on OSX, where things are different). Because of the complexities involved, I'd suggest that if you bind to <FocusOut>, you should also check whether you get a <FocusIn> event shortly after; a little extra delay (e.g., 0.1s) before doing the update of the buttons' disabled status will not hurt.
Or you could hang the code to do the disabling off the entry widget validation engine, perhaps like this:
.e configure -validation focusout -validatecommand doButtonEnableDisable
The validation interface is the same for both the old style entry and the new style ttk::entry widgets. It's also supported by spinboxes. Just be aware that you need to return a boolean true from doButtonEnableDisable or you'll reject the change to the entry, and you should take care to ensure that your code does not produce an error or it will disable itself; the docs list the things to watch out for.

How to create a mapped but not visible window with XLib?

I'm working on a I/O verification tool based on Linux in a game project. It is written in C++, and,since using the same I/O module as our game, it's based on OIS 1.2. Thus, though all I need is to print users' inputs on the console, I still need to create a window for OIS.
So here comes my question: How can I create a mapped window while it is still invisible and processes keyboard events?
I can't unmapped the window in that it won't process any keyboard event anymore. I also can't find function for show/hide a window.(maybe I search through a wrong diretion...)
My little tool works fine now except there is a stupid top-level empty window which needs to be focused for processing keyboard events...
Any advise is welcomed.
Thanks!!!
After reading this post: Linux/X11 input library without creating a window,
I realized my problem was that I misunderstood the philosophy of X11. All I need to do is simply pass the root window handle to OIS, and set the x11_grabkeyboard flag as true. The only drawback is maybe I can hardly debug my program with gdb since the keyboard is grabbed...
Though my situation is solved, there is one thing left.
Every article I read said an InputOnly window won't be visible and is capable for handling input events, while my InputOnly window is absolutely visible after mapped...
Maybe it's my Linux, or again, a misunderstanding...

How do I make a window move to the top of other windows in Gnome when that window already has the focus?

I have an application that sends the focus to other windows but those windows then don't automatically display themselves in the foreground, i.e. on top of all the other windows. Where can I configure the preferences of my window manager so that this is the default behaviour?
In particular I'm using the Ctrl-0 and Ctrl-Shft-0 shortcuts in the MATLAB IDE to move between the command window and the editor window and although the focus seems to be transferred the new window doesn't automatically redraw itself in the foreground.
Not sure of a key binding off hand that does it, but if you alt-click on a window (which allows you to drag a window) it should come to the front.
As codeDr suggests, MATLAB is also kind of bad about repainting its windows. If you draw to a figure while code is executing, the figure does not update unless you execute drawnow or have some similar pause in the execution to allow the GUI to repaint. Since we're talking about MATLAB, the figure command will also cause the indicated figure to come to the front (in fact, it's harder to get it to not come to the front). So you could do figure(gcf) to bring the current figure to the front, or save the figure number with h = figure; and then later do figure(h). Incidentally, if you want to switch current figures without switching focus, set(0, 'CurrentFigure', h) should set h to the current figure.
Your window manager (probably Metacity?) implements focus-stealing prevention so that rogue apps don't pop up windows that would disturb your typing. Matlab needs to raise its window, and give it the input focus with the correct timestamp. If this is being done from a KeyPress event handler, the timestamp for setting the input focus would be the timestamp from the KeyPress event (i.e. the timestamp of the user-generated event that caused a window to be raised/focused).
To politely give the input focus to a window, google for _NET_ACTIVE_WINDOW.
Usually when the window doesn't repaint, it means that the application's main application loop isn't running to refresh the window. Could it be that Matlab is doing some computation or disk activity when you are switching between windows?

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