60542da091
"Set" the wallpaper during startup only sometimes Since commit 4f5e0e7, i3 would take a screenshot and set that as the background pixmap of the root window during startup. This is the easy part of setting a proper X11 wallpaper. The code in question was added because something either set the background pixmap of the root window to NONE or the X11 server was started with "-background none". This is apparently done by default by e.g. gdm to avoid some flickering while the X11 server starts up. This commit makes this code conditional: Only when no wallpaper is detected is a screenshot taken. Since I could not find any way to query the background of a window, a more direct approach is taken to detect this situation: First, we find some part of the root window that is not currently covered. Then we open a white window there, close it again and grab a screenshot. If a wallpaper is set, the X11 server will draw this wallpaper after the window is closed and something else will be visible in the screenshot. However, the wallpaper could have a white pixel at the tested position. Thus, this procedure is repeated with a black window. Only when this procedure produces two different pixel values is a screenshot taken and set as the wallpaper. Fixes: https://github.com/i3/i3/issues/4371 Fixes: https://github.com/i3/i3/issues/2869 Signed-off-by: Uli Schlachter <psychon@znc.in>
Introduction ============ libi3 is an *INTERNAL* library which contains functions that i3 and related tools (i3-msg, i3-input, i3-nagbar, i3-config-wizard, i3bar) use. It is NOT to be used by other programs. Structure ========= Every function gets its own .c file, which in turn gets compiled into an .o object file. Afterwards, all .o files are archived into one static library (libi3.a). This library will be linked into all i3 binaries. The linker is able to eliminate unused .o files when linking, so only the functions which you actually use will be included in the corresponding binary.