Select button press/release events on drawins

Some words about X11 event handling: Every X11 client can select input on any
window. For this, inside the X11 server each window has for each client a
bitmask for the kind of events that this client is interested in. When a mouse
button is pressed inside of a window, a corresponding event is generated for
that window and sent to all X11 clients which asked for
XCB_EVENT_MASK_BUTTON_PRESS. When no client is interested in this event, the
event is propagated to the parent window and the same procedure is done again
here. This continues up until the root window is reached.

Some words about the event masks that awesome uses: For clients, we ask for
button press events on the frame window that we reparent the client window into
so that we get any kind of press on the titlebar (and also events inside of the
client window if the client itself doesn't care for click events?). We are also
interested in button presses / releases on the root window. However, before this
commit, we didn't actually ask for button events on drawins (e.g. the wibox).
This worked fine, because no one asked for these events and the event propagated
to the root window where it was then sent to awesome.

However, newer Qt versions do something weird and the above broke. I don't
actually know what is going on. I know about the above propagation rules, but
looking at protocol traces of what Qt does, awesome should still get the button
events. During startup, Qt asks for button events on its own windows. After a
hotplug event, it asks the same again, but now also includes the root window.
So... how can Qt asking for button events on the root window cause awesome not
to get them? I have no idea.

(And yes, I guess that Qt asking for mouse events on the root window is a bug,
but I have no idea how exactly this happens nor about any other side effects of
it).

This commit makes us ask for button events on our drawins so that the server
will send them to us. This is the right thing to do anyway and it was reported
to have some positive effects.

Ref: https://github.com/awesomeWM/awesome/issues/415
Signed-off-by: Uli Schlachter <psychon@znc.in>
This commit is contained in:
Uli Schlachter 2015-12-13 17:54:37 +01:00
parent 15a242d195
commit a86d1137ee
1 changed files with 2 additions and 1 deletions

View File

@ -348,7 +348,8 @@ drawin_allocator(lua_State *L)
XCB_EVENT_MASK_SUBSTRUCTURE_REDIRECT
| XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY | XCB_EVENT_MASK_ENTER_WINDOW
| XCB_EVENT_MASK_LEAVE_WINDOW | XCB_EVENT_MASK_STRUCTURE_NOTIFY
| XCB_EVENT_MASK_POINTER_MOTION | XCB_EVENT_MASK_EXPOSURE
| XCB_EVENT_MASK_POINTER_MOTION | XCB_EVENT_MASK_BUTTON_PRESS
| XCB_EVENT_MASK_BUTTON_RELEASE | XCB_EVENT_MASK_EXPOSURE
| XCB_EVENT_MASK_PROPERTY_CHANGE,
globalconf.default_cmap,
xcursor_new(globalconf.cursor_ctx, xcursor_font_fromstr(w->cursor))