For normal cairo-widgets ardour should not use image surfaces on macOS,
because that bypasses retina scaling. In theory explicit upsampling could
be performed (compere to openGL/cairo), but for the case at hand that is
overkill and inconvenient.
Performance critical widgets that render periodically can enable openGL
backing. Casual widgets (buttons with text, knobs, sliders etc) can be
rendered directly without any significant performance penalty.
ArdourButton draws a custom insensitive background, using
the color "gtk_background". This can conflict with gtk's
insensitive background color when using round-corners.
For MacOS/X this is equivalent, rendering happens using a
CGBitmapContext + image-surface. Windows and Linux needs profiling
for respective equivalent surfaces.
This is an intermediate commit, before replacing image surfaces with
cairo pattern groups.
The eventual goal is to reduce flickering and/or use
CPU + bitblt for specific widgets instead of cairo
graphics-cards accel.
This also removes excessive calls to getenv() for every rendering
operation.
This fixes an -Woverloaded-virtual ambiguity introduced in b5e613d45
void render (cairo_t*, cairo_rectagle*)
void render (Cairo::RefPtr<Cairo::Context> const&, cairo_rectangle_t*)
ArdourCanvas prefers cairomm and CairoWidget itself uses Cairo::Context,
this improves overall API consistency.
This functor/closure is responsible for stealing focus from any existing text entry (or whatever else may have focus)
when clicking on a CairoWidget or derived class.
The old implementation just gave focus back to the editor canvas. The new version walks up the widget packing
heirarchy to find a focusable parent (from the CairoWidget for which it is invoked). If no focusable parent
is found, it cancels keyboard focus in the toplevel window containing the CairoWidget
If a CairoWidget does not a GtkRC-defined style, then changing its name does not trigger on_style_changed(). Since we want to use CairoWidget::set_name()
to trigger changes in the rendering of a widget, this is ... bad. Adding on_name_changed() provides a workaround for that.
