Commit Graph

6 Commits

Author SHA1 Message Date
Lionel Landwerlin
968022b83f test: interactive: port cairo clock to ClutterCanvas
https://bugzilla.gnome.org/show_bug.cgi?id=759074
2015-12-06 23:58:22 +00:00
Emmanuele Bassi
5b17b4e41b interactive/*: Update the API usage
Drop some deprecated methods.
2012-02-13 17:30:22 +00:00
Emmanuele Bassi
ac8e174eca tests/interactive: Add some descriptions 2011-09-28 15:18:21 +01:00
Emmanuele Bassi
110dff5823 test/cairo-clock: Remove a double source color set
Do not call cairo_set_source_rgba() right after calling
clutter_cairo_set_source_color().
2011-07-27 11:48:07 +01:00
Emmanuele Bassi
7f8838d7cc cairo-texture: Add the :auto-resize property
Keeping the backing Cairo surface of a CairoTexture canvas in sync with
the actor's allocation is tedious and prone to mistakes. We can
definitely do better by simply exposing a property that does the surface
resize and invalidation automagically on ::allocate.
2011-07-26 14:55:19 +01:00
Emmanuele Bassi
2f445682b1 cairo-texture: Use signal-based drawing
The current "create context/draw/destroy context" pattern presents
various problems. The first issue is that it defers memory management to
the caller of the create() or create_region() methods, which makes
bookkeeping of the cairo_t* harder for language bindings and third party
libraries. The second issue is that, while it's easier for
draw-and-forget texturs, this API is needlessly complicated for contents
that have to change programmatically - and it introduces constraints
like calling the drawing code explicitly after a surface resize (e.g.
inside an allocate() implementation).

By using a signal-based approach we can make the CairoTexture actor
behave like other actors, and like other libraries using Cairo as their
2D drawing API.

The semantics of the newly-introduced ::draw signal are the same as the
one used by GTK+:

  - the signal is emitted on invalidation;
  - the cairo_t* context is owned by the actor;
  - it is safe to have multiple callbacks attached to the same
    signal, to allow composition;
  - the cairo_t* is already clipped to the invalidated area, so
    that Cairo can discard geometry immediately before we upload
    the texture data.

There are possible future improvements, like coalescing multiple
invalidations inside regions, and performing clipped draws during
the paint cycle; we could even perform clipped redraws if we know the
extent of the invalidated area.
2011-07-26 12:40:52 +01:00