Move the double-buffering implementation and the x_win_call move into
x.c so we only need to call x_display_surface for each draw.
This isolates all uses of the cairo context and root surface outside of
x.c which will help to add support for other display servers.
Move the main window reference from xctx to draw.c and at the same time
make each X11 function that modifies the window require the pointer as a
parameter. This makes it easier to implement features that require
multiple windows.
Rather than calculating the width of the subsurface we are drawing on
everywhere simply add a return pointer to render_background.
This commit also fixes a bug where the text and icon where drawn more to
the right than usual (according to frame_width) which was caused because
we added the frame_width to the draw position while we are drawing in a
subsurface that already accounts for it.
Cleans up the clutter in draw and since only a single icon function is
called externally from icon.c it'll make things easier if we ever decide
to switch icon libraries.
Remove prefixes used to distinguish between X and draw functions in x.c,
this is obviously no longer necessary. Additionally, add appropriate
layout_ and color_ prefixes to the relevant functions.
Rename both functions to make clear, what the difference between the
previous functions _from_file and _from_path is. Also remove the
superfluous `== NULL` checks as these don't match dunst's current style.
The `dimension_t` struct was used in many different places and even held
on the geometry info at some point which is counter-intuitive as it's
best to have each struct serve a single purpose.
Change the value of geometry in settings from an unparsed string to a
struct containing the properly parsed geometry info. Since we depend on
X11 for geometry parsing this (unfortunately) introduces an X11
dependency on the settings module, this can only be resolved if we
implement our own parsing.
Copy-paste all the drawing functions from x.c to draw.c. In the spirit
of making changes easily traceable the minimal amount of changes
required to make the functions work was made. Further improvement (like
removing the cairo-xlib dependency) will be done in later commits.
Setup the initial template for draw.c to be between X11 calls and the
rest of the codebase. This prepares the file to move all the drawing
related function here in the next commit.
