In begin_expose(), we call cairo_scaled_font_text_to_glyphs()
with (x,y) = (0,0), in order to calculate the glyph extents (needed
for width calculation).
Then, in expose(), we called it again, but with correct (x,y) offsets.
Simplify this, by caching the glyphs from begin_expose(). Then, in
expose(), simply adjust the glyph offsets before calling
cairo_show_text_glyphs().
When limiting a string (due to it exceeding it's max length), make
sure not to cut it in the middle of an utf-8 multibyte, as this
results in an invalid utf-8 string.
In particular, use cairo_scaled_font_text_to_glyphs() to calculate the
extents, since the cairo_scaled_font_text_extents() will leave the
scaled font in an error state, which is impossible to recuperate from.
Because it's the right thing to do. It worked without it, since the
f00bar main binary is linked with -rdynamic (to give plugins access to
core functions).
Since this struct only contained function pointers, make all particles
export those functions directly.
The plugin manager now defines a particle interface struct, and fills
it it by dlsym:ing the functions that used to be in particle_info.
This allows us to a) move away from cairo's "toy" API, and b) let the
user specify font options in a single font "name" string:
Serif:size=10:weight=bold:slant=italic
This also allows us to simplify the font code significantly (except
for the fontconfig parts...); the font no longer sets itself in a
cairo surface - font users do that; the font simply returns a
cairo_scaled_font_t.
Furthermore, font_clone() has now been simplified to basically just
refcount the scaled font. I.e. there's no need to run the full
constructor and lookup and instantiate the cairo scaled font again.
Now that we have a wrapper exposable, we need to implement
on_mouse(). In it, we need to check if we have our own on-click
handler, or else, check if mouse is inside the sub-exposable, or in
the left- or right margin.
Now that we have a wrapper exposable, we need to implement
on_mouse(). In it, we need to check if we have our own on-click
handler, or else, check if mouse is inside the sub-exposable, or in
the left- or right margin.
This is done by wrapping the selected particle/exposable in a
ramp-specific exposable. This way, we can add the margins before
delegating begin_expose() and expose() to the selected exposable.
This is done by wrapping the selected particle/exposable in a
ramp-specific exposable. This way, we can add the margins before
delegating begin_expose() and expose() to the selected exposable.
Since we're typically interrested in *where* (on the progress-bar) the
user clicked, we need a way to pass the clicked position to the
handler.
Normally, the on-click handler is expanded when a particle
instantiates its exposable. At this point, we (obviously) don't have
the click position.
This is solved by expanding the handler a second time, when the bar is
clicked.
Thus, the user can use the "{where}" tag in the click handler. "where"
will be expanded to a percentage value (0-100).
