The size of the surface used to draw the indicator depends on
the extents of the text being drawn on and under the indicator.
This commit refactors the `render_frame` function so that the surface
size is computed before drawing; before, `render_frame` drew onto a
buffer, estimated the size the buffer should have had, and recursively
called itself to try again with the estimated size, if necessary. This
was done because Cairo's methods to estimate font and text size
require that a cairo_t context object and an associated cairo_surface
already have been set up. Since the surface size depends on the text
size, the natural way to use Cairo would have a circular dependency.
In order to compute sizes _before_ the buffer is created, this commit
adds a 1x1 surface and a matching `test_cairo` context which is set to
the same font and drawing parameters as the buffer that will be
created. Font/text extent measurements should give the same results as
for the final buffer.
This commit adds a new command line option called --font-size to
specify a fixed font size in the indicator. The default value for
font-size is 0, which means that the text will autoscale. Any other
positive value will result in a fixed text size.
Displays the current keyboard layout below the unlock indicator if more
than one xkb layout is configured or the show-keyboard-layout option is
given. The text is displayed with a background box.
Adds commandline options for text color, background color and border
color of the box as well.
Keeps track of unsuccessful authentication attempts via an int counter
in the state struct. Displays on the unlock indicator, but will be
replaced by the Caps Lock text if enabled.
This implements customization for the indicator as proposed in sway#2788 with comments from sway#3367 in mind.
The default behaviour does not change exept for the caps lock text color.
Since these changes seem to be lost in the split I've remade them.
