Commit Graph

217 Commits

Author SHA1 Message Date
Emmanuele Bassi
b6bd8be6cb Merge branch 'internal-flag' into ebassi-next
* internal-flag:
  conform: Add test unit for the destruction of Containers
  actor: Add internal child flag
  Clean up whitespace, indentation and comments
2009-12-20 17:33:51 +00:00
Emmanuele Bassi
d2ea7cd6a8 Clean up whitespace, indentation and comments 2009-12-11 20:17:58 +00:00
Colin Walters
1374b5aac9 Add clutter_get_current_event
When getting signals from higher level toolkits, occasionally
one wants access to the underlying event; say for a Button
widget's "clicked" signal, to get the keyboard state.

Rather than having all of the highlevel widgets emit
ClutterEvent just for the more unusual use cases,
add a global function to access the event state.

http://bugzilla.openedhand.com/show_bug.cgi?id=1888

Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
2009-12-10 22:20:36 +00:00
Emmanuele Bassi
28cb2cdab5 Remove clutter_set_default_text_direction()
Setting the default text direction programmatically is wrong: it is a
value dependent on the locale or by the environment.
2009-12-07 19:00:55 +00:00
Emmanuele Bassi
3b9575baf8 Queue a relayout when the default text direction changes
We need a relayout cycle if the default direction for the text changes
while the main loop is running.
2009-12-07 18:41:15 +00:00
Emmanuele Bassi
17e3b526d5 docs: Document Clutter's threading model
Be explicit on how to deal with threads and Clutter.
2009-12-02 14:15:43 +00:00
Emmanuele Bassi
02398c0cf1 Remove unused variable 'lang'
Fix a compiler warning.
2009-12-01 18:16:48 +00:00
Emmanuele Bassi
586750751a Merge branch 'text-direction'
* text-direction:
  docs: Add text-direction accessors
  Set the default language on the Pango context
  actor: Set text direction on parenting
  tests: Display the index inside text-box-layout
  box-layout: Honour :text-direction
  text: Dirty layout cache on text direction changes
  actor: Add :text-direction property
  Use the newly added ClutterTextDirection enumeration
  Add ClutterTextDirection enumeration
2009-12-01 14:55:19 +00:00
Neil Roberts
c3e640e6e3 Use the correct colour when clearing the stage for picking
The colour test for the stage in _clutter_do_pick checks for white to
determine whether the stage was picked but since 47db7af4d we were
setting the colur to black. This usually worked because the id of the
default stage ends up being 0 which equates to black. However if a
second stage is created then it will always end up picking the first
stage.
2009-11-30 19:09:05 +00:00
Emmanuele Bassi
3cb974ee8b Set the default language on the Pango context
When creating the Pango context we should also set the language
to be the default Pango language.
2009-11-30 16:15:19 +00:00
Robert Bragg
47db7af4d3 picking: avoid redundant picking geometry for the stage.
The stage's pick id can be written to the framebuffer when we call
cogl_clear so there's no need for the stage to also chain up in it's pick
function resulting in clutter-actor.c also emitting a rectangle for the
stage.
2009-11-27 00:43:57 +00:00
Emmanuele Bassi
53a9d0c637 Use the newly added ClutterTextDirection enumeration
Instead of using PangoDirection directly we should use the
ClutterTextDirection enumeration.

We also need a pair of accessor functions for setting and
getting the default text direction.
2009-11-10 11:06:20 +00:00
Robert Bragg
abae6013e1 Remove all internal use of deprecated cogl_clip_* API
cogl_clip_push, and cogl_clip_push_window_rect which are now deprecated were
used in various places internally so this just switches to using the
replacement functions.
2009-11-05 21:10:18 +00:00
Robert Bragg
b2ebb7db48 [main] Use cogl_read_pixels not glReadPixels in clutter-main.c
The debugging function read_pixels_to_file() and _clutter_do_pick were both
directly calling glReadPixels, but we don't wan't Clutter making direct
OpenGL calls and Cogl provides a suitable alternative.  It also means
read_pixels_to_file() doesn't need to manually flip the data read due to
differences in Clutter/Cogl coordinate systems.
2009-11-04 03:34:03 +00:00
Robert Bragg
f7d64e5abd [draw-buffers] First pass at overhauling Cogl's framebuffer management
Cogl's support for offscreen rendering was originally written just to support
the clutter_texture_new_from_actor API and due to lack of documentation and
several confusing - non orthogonal - side effects of using the API it wasn't
really possible to use directly.

This commit does a number of things:
- It removes {gl,gles}/cogl-fbo.{c,h} and adds shared cogl-draw-buffer.{c,h}
  files instead which should be easier to maintain.
- internally CoglFbo objects are now called CoglDrawBuffers. A
  CoglDrawBuffer is an abstract base class that is inherited from to
  implement CoglOnscreen and CoglOffscreen draw buffers.  CoglOffscreen draw
  buffers will initially be used to support the
  cogl_offscreen_new_to_texture API, and CoglOnscreen draw buffers will
  start to be used internally to represent windows as we aim to migrate some
  of Clutter's backend code to Cogl.
- It makes draw buffer objects the owners of the following state:
  - viewport
  - projection matrix stack
  - modelview matrix stack
  - clip state
(This means when you switch between draw buffers you will automatically be
 switching to their associated viewport, matrix and clip state)

Aside from hopefully making cogl_offscreen_new_to_texture be more useful
short term by having simpler and well defined semantics for
cogl_set_draw_buffer, as mentioned above this is the first step for a couple
of other things:
- Its a step toward moving ownership for windows down from Clutter backends
  into Cogl, by (internally at least) introducing the CoglOnscreen draw
  buffer.  Note: the plan is that cogl_set_draw_buffer will accept on or
  offscreen draw buffer handles, and the "target" argument will become
  redundant since we will instead query the type of the given draw buffer
  handle.
- Because we have a common type for on and offscreen framebuffers we can
  provide a unified API for framebuffer management. Things like:
  - blitting between buffers
  - managing ancillary buffers (e.g. attaching depth and stencil buffers)
  - size requisition
  - clearing
2009-11-03 17:23:03 +00:00
Emmanuele Bassi
f551cbfb61 Add run-time version checks
Just like CLUTTER_CHECK_VERSION does version checking at compile
time, we need a way to verify the version of the library that we
are linking against. This is mostly needed for language bindings
and for run-time loadable modules -- when we'll get those.
2009-10-30 11:02:35 +00:00
Robert Bragg
dd8e4dcd62 [debug] Guard the use of gdk_pixbuf for pick debugging by #ifdef USE_GDKPIXBUF
gdk is an optional clutter dependency, so the pick buffer debugging option
needs some guards so we don't break, for example, the OSX builds.  This also
adds a comment for the bit fiddling done on the pick colors used to ensure
the pick colors are more distinguished while debugging.  (we swap the
nibbles of each color component so that pick buffers don't just look black.)
2009-10-05 17:35:46 +01:00
Robert Bragg
dae569b468 [debug] Adds a dump-pick-buffers CLUTTER_DEBUG option
Now if you export CLUTTER_DEBUG=dump-pick-buffers clutter will write out a
png, e.g.  pick-buffer-00000.png, each time _clutter_to_pick() is called.
It's a rather crude way to debug the picking (realtime visualization in a
second stage would probably be nicer) but it we've used this approach
successfully numerous times when debugging Clutter picking issues so it
makes sense to have a debug option for it.
2009-09-24 21:41:49 +01:00
Ole André Vadla Ravnås
ab5a10768c Initialize pixel data before glReadPixels(). 2009-07-28 12:13:43 +01:00
Colin Walters
f1044a279c Use the (allow-none) annotation for clutter_init*
We accept NULL for some parameters in the initialization functions.

Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
2009-07-02 13:15:42 +01:00
Emmanuele Bassi
250b775926 [x11] Fix the race between resize and glViewport calls
The race we were experiencing in the X11 backends is apparently
back after the fix in commit 00a3c698.

This time, just delaying the setting of the SYNC_MATRICES flag
is not enough, so we can resume the use of a STAGE_IN_RESIZE
private flag.

This should also fix bug:

  http://bugzilla.openedhand.com/show_bug.cgi?id=1668
2009-07-01 15:30:21 +01:00
Robert Bragg
6d9498da7c Adds a cogl_flush() to give developers breaking into raw GL a fighting chance
This function should only need to be called in exceptional circumstances
since Cogl can normally determine internally when a flush is necessary.

As an optimization Cogl drawing functions may batch up primitives
internally, so if you are trying to use raw GL outside of Cogl you stand a
better chance of being successful if you ask Cogl to flush any batched
geometry before making your state changes.

cogl_flush() ensures that the underlying driver is issued all the commands
necessary to draw the batched primitives.  It provides no guarantees about
when the driver will complete the rendering.

This provides no guarantees about the GL state upon returning and to avoid
confusing Cogl you should aim to restore any changes you make before
resuming use of Cogl.

If you are making state changes with the intention of affecting Cogl drawing
primitives you are 100% on your own since you stand a good chance of
conflicting with Cogl internals.  For example clutter-gst which currently
uses direct GL calls to bind ARBfp programs will very likely break when Cogl
starts to use ARBfb programs internally for the material API, but for now it
can use cogl_flush() to at least ensure that the ARBfp program isn't applied
to additional primitives.

This does not provide a robust generalized solution supporting safe use of
raw GL, its use is very much discouraged.
2009-06-30 17:13:38 +01:00
Robert Bragg
845ff67301 [cogl] Improving Cogl journal to minimize driver overheads + GPU state changes
Previously the journal was always flushed at the end of
_cogl_rectangles_with_multitexture_coords, (i.e.  the end of any
cogl_rectangle* calls) but now we have broadened the potential for batching
geometry.  In ideal circumstances we will only flush once per scene.

In summary the journal works like this:

When you use any of the cogl_rectangle* APIs then nothing is emitted to the
GPU at this point, we just log one or more quads into the journal.  A
journal entry consists of the quad coordinates, an associated material
reference, and a modelview matrix.  Ideally the journal only gets flushed
once at the end of a scene, but in fact there are things to consider that
may cause unwanted flushing, including:

- modifying materials mid-scene
    This is because each quad in the journal has an associated material
    reference (i.e. not copy), so if you try and modify a material that is
    already referenced in the journal we force a flush first)

    NOTE: For now this means you should avoid using cogl_set_source_color()
	      since that currently uses a single shared material. Later we
	  should change it to use a pool of materials that is recycled
	  when the journal is flushed.

- modifying any state that isn't currently logged, such as depth, fog and
  backface culling enables.

The first thing that happens when flushing, is to upload all the vertex data
associated with the journal into a single VBO.

We then go through a process of splitting up the journal into batches that
have compatible state so they can be emitted to the GPU together.  This is
currently broken up into 3 levels so we can stagger the state changes:

1) we break the journal up according to changes in the number of material layers
   associated with logged quads. The number of layers in a material determines
   the stride of the associated vertices, so we have to update our vertex
   array offsets at this level. (i.e. calling gl{Vertex,Color},Pointer etc)
2) we further split batches up according to material compatability. (e.g.
   materials with different textures) We flush material state at this level.
3) Finally we split batches up according to modelview changes. At this level
   we update the modelview matrix and actually emit the actual draw command.

This commit is largely about putting the initial design in-place; this will be
followed by other changes that take advantage of the extended batching.
2009-06-30 17:13:34 +01:00
Robert Bragg
26d5afd203 [debug] Adds a "nop-picking" clutter debug option to NOP _clutter_do_pick()
I've found this is something I do quite often when debugging rendering
problems since its a simple way to wipe out lots of geometry and removes a
lot of unpredictable noise when logging geometry passing through the Cogl
journal.
2009-06-29 23:49:06 +01:00
Emmanuele Bassi
b5f4befeaa Allow checking initialization without side-effects
The _clutter_context_get_default() function will automatically
create the main Clutter context; if we just want to check whether
Clutter has been initialized this will complicate matters, by
requiring a call to g_type_init() inside the client code.

Instead, we should simply provide an internal API that checks
whether the main Clutter context exists and if it has been
initialized, without any side effect.
2009-06-19 14:09:42 +01:00
Emmanuele Bassi
184df2a5fa [input] Rework input device API
The input device API is split halfway thorugh the backends in a very
weird way. The data structures are private, as they should, but most
of the information should be available in the main API since it's
generic enough.

The device type enumeration, for instance, should be common across
every backend; the accessors for device type and id should live in the
core API. The internal API should always use ClutterInputDevice and
not the private X11 implementation when dealing with public structures
like ClutterEvent.

By adding accessors for the device type and id, and by moving the
device type enumeration into the core API we can cut down the amount
of symbols private and/or visible only to the X11 backends; this way
when other backends start implementing multi-pointer support we can
share the same API across the code.
2009-06-19 13:12:05 +01:00
Emmanuele Bassi
c6fba47a52 Hide clutter_context_get_default()
The clutter_context_get_default() function is private, but shared
across Clutter. For this reason, it should be prefixed by '_' so
that the symbol is hidden from the shared object.
2009-06-18 14:20:28 +01:00
Emmanuele Bassi
8c676ebd87 Remove an unusued member from MainContext
The MainContext structure has a field for the master clock, but
clutter_master_clock_get_default() will return the same instance
from everywhere.
2009-06-17 15:43:53 +01:00
Emmanuele Bassi
e1cac4fece Fix clutter_redraw() to match the redraw cycle
The clutter_redraw() function is used by embedding toolkits to
force a redraw on a stage. Since everything is performed by
toggling a flag inside the Stage itself and then letting the
master clock advance, we need a ClutterStage method to ensure
that we start the master clock and redraw.
2009-06-09 16:29:29 +01:00
Owen W. Taylor
dcd8d28314 Limit the frame rate when not syncing to VBLANK
clutter-master-clock.c clutter-master-clock.h: When the
  SYNC_TO_VBLANK feature is not available, wait for 1/frame_rate
  seconds since the start of the last frame before drawing the next
  frame. Add _clutter_master_clock_start_running() to abstract
  the usage of g_main_context_wakeup()

clutter-stage.c: Add _clutter_master_clock_start_running()

clutter-main.c: Update docs for clutter_set_default_frame_rate()
  clutter_get_default_frame_rate() to no longer talk about timeline
  frame rates.

test-text-perf.c test-text.c: Set a frame rate of 1000fps so that
  frame-rate limiting doesn't affect the result.

http://bugzilla.openedhand.com/show_bug.cgi?id=1637

Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
2009-06-09 15:03:56 +01:00
Owen W. Taylor
6e69692e22 Compress events as part of the frame cycle
Instead of trying to guess about which motion events are
extraneous, queue up all events until we process a frame.
This allows us to look ahead and reliably compress consecutive
sequence of motion events.

clutter-main.c: Feed received events to the stage for queueing.
  Remove old compression code. Remove clutter_get_motion_events_frequency()
  clutter_set_motion_events_frequency()
clutter-stage.c: Keep a queue of pending events.
clutter-master-clock.c: Add processng of queued events to the
  clock source dispatch function.

http://bugzilla.openedhand.com/show_bug.cgi?id=1637

Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
2009-06-09 15:03:56 +01:00
Owen W. Taylor
3ab303b662 Only advance the master clock before drawing a frame
Remove code to advance the master clock after drawing a frame; if
there are any running timelines the master clock will do another
frame by itself, and the clock will be advanced before running
that frame.

With this change, there is no point in queueing an extra frame
redraw after completing a timeline, since we are always advancing
the timeline *before* redrawing, so remove that code as well.
(This does mean that calling clutter_timeline_stop() won't implicitly
cause the stage to be redrawn; this doesn't seem like something
an app should rely on in any case.)

http://bugzilla.openedhand.com/show_bug.cgi?id=1637

Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>
2009-06-09 15:03:55 +01:00
Emmanuele Bassi
6fe22ac850 [repaint] Run the repaint functions in clutter_redraw()
The clutter_redraw() function is used by libraries embedding
Clutter inside another toolkit, instead of queueing a redraw
on the embedded stage. This means that clutter_redraw() should
perform the same sequence of actions done by the redraw idle
callback.
2009-06-05 17:57:05 +01:00
Emmanuele Bassi
0187bb3965 [actor] Use flags to control allocations
Instead of passing a boolean value, the ::allocate virtual function
should use a bitmask and flags. This gives us room for expansion
without breaking API/ABI, and allows to encode more information to
the allocation process instead of just changes of absolute origin.
2009-06-04 16:30:31 +01:00
Emmanuele Bassi
7252c14197 [cogl] Make cogl_setup_viewport() a private function
The setup_viewport() function should only be used by Clutter and
not by application code.

It can be emulated by changing the Stage size and perspective and
requeueing a redraw after calling clutter_stage_ensure_viewport().
2009-05-28 14:14:50 +01:00
Emmanuele Bassi
87465355d3 Add repaint functions
Sometimes it is necessary for third party code to have a
function called during the redraw process, so that you can
update the scenegraph before it is painted.
2009-05-23 19:33:04 +01:00
Emmanuele Bassi
f8f54989be Merge commit 'origin/master' into 1.0-integration
Conflicts:
	clutter/clutter-texture.c
	clutter/cogl/gl/cogl-fbo.c
2009-05-20 16:49:22 +01:00
Robert Bragg
d1fa83039d [picking] Use cogl_clip_push_window_rect to greatly reduce the cost of picking.
cogl_clip_push_window_rect is implemented using GPU scissoring which allows
the GPU to cull anything that falls outside a given rectangle.  Since in the
case of picking we only ever care about a single pixel we can get the GPU to
ignore all geometry that doesn't intersect that pixel and only rasterize for
one pixel.
2009-05-12 15:44:34 +01:00
Neil Roberts
e9b863eba2 Don't clear the stencil buffer before painting and picking
The stencil buffer is always cleared the first time a clip is used
that needs it and the stencil test is disabled otherwise so there is
no need to clear before a paint.
2009-05-12 15:36:16 +01:00
Robert Bragg
08a73a215f Don't call glFinish in _clutter_do_pick
Calling glReadPixels is bad enough in forcing us to synchronize the CPU with
the GPU, but glFinish has even stronger synchonization semantics than
glReadPixels which may negate some driver optimizations possible in
glReadPixels.
2009-05-12 14:53:43 +01:00
Emmanuele Bassi
86bc31bd55 [clock] Rework the master clock
The master clock is currently advanced using a frame source driven
by the default frame rate. This breaks the sync to vblank because
the vblanking rate could be different than 60 Hz -- or it might be
completely disabled (e.g. with CLUTTER_VBLANK=none).

We should be using the main loop to check if we have timelines
playing, and if so queue a redraw on the stages we own.

We should also prepare the subsequent frame at the end of the redraw
process, so if there are new redraw we will have the scene already
in place.

This makes Clutter redraw at the maximum frame rate, which is
limited by the vblanking frequency.
2009-05-07 19:25:24 +01:00
Emmanuele Bassi
d6d208da7d Remove Units from the public API
With the recent change to internal floating point values, ClutterUnit
has become a redundant type, defined to be a float. All integer entry
points are being internally converted to floating point values to be
passed to the GL pipeline with the least amount of conversion.

ClutterUnit is thus exposed as just a "pixel with fractionary bits",
and not -- as users might think -- as generic, resolution and device
independent units. not that it was the case, but a definitive amount
of people was convinced it did provide this "feature", and was flummoxed
about the mere existence of this type.

So, having ClutterUnit exposed in the public API doubles the entry
points and has the following disadvantages:

  - we have to maintain twice the amount of entry points in ClutterActor
  - we still do an integer-to-float implicit conversion
  - we introduce a weird impedance between pixels and "pixels with
    fractionary bits"
  - language bindings will have to choose what to bind, and resort
    to manually overriding the API
    + *except* for language bindings based on GObject-Introspection, as
      they cannot do manual overrides, thus will replicate the entire
      set of entry points

For these reason, we should coalesces every Actor entry point for
pixels and for ClutterUnit into a single entry point taking a float,
like:

  void clutter_actor_set_x (ClutterActor *self,
                            gfloat        x);
  void clutter_actor_get_size (ClutterActor *self,
                               gfloat       *width,
                               gfloat       *height);
  gfloat clutter_actor_get_height (ClutterActor *self);

etc.

The issues I have identified are:

  - we'll have a two cases of compiler warnings:
    - printf() format of the return values from %d to %f
    - clutter_actor_get_size() taking floats instead of unsigned ints
  - we'll have a problem with varargs when passing an integer instead
    of a floating point value, except on 64bit platforms where the
    size of a float is the same as the size of an int

To be clear: the *intent* of the API should not change -- we still use
pixels everywhere -- but:

  - we remove ambiguity in the API with regard to pixels and units
  - we remove entry points we get to maintain for the whole 1.0
    version of the API
  - we make things simpler to bind for both manual language bindings
    and automatic (gobject-introspection based) ones
  - we have the simplest API possible while still exposing the
    capabilities of the underlying GL implementation
2009-05-06 16:44:47 +01:00
Robert Bragg
741c4bb5e9 [cogl] Adds a bitfield argument to cogl_clear for specifying which buffers to clear
Redundant clearing of depth and stencil buffers every render can be very
expensive, so cogl now gives control over which auxiliary buffers are
cleared.

Note: For now clutter continues to clear the color, depth and stencil buffer
each paint.
2009-05-02 04:12:12 +01:00
Emmanuele Bassi
678f99677f Use a single master "clock" to drive timelines
Currently, all timelines install a timeout inside the TimeoutPool
they share. Every time the main loop spins, all the timeouts are
updated. This, in turn, will usually lead to redraws being queued
on the stages.

This behaviour leads to the potential starvation of timelines and
to excessive redraws.

One lesson learned from the games developers is that the scenegraph
should be prepared in its entirety before the GL paint sequence is
initiated. This means making sure that every ::new-frame signal
handler is called before clutter_redraw() is invoked.

In order to do so a TimeoutPool is not enough: we need a master
clock. The clock will be responsible for advancing all the active
timelines created inside a scene, but only when the stage is
being redrawn.

The sequence is:

  + queue_redraw() is invoked on an actor and bubbles up
    to the stage

  + if no redraw() has already been scheduled, install an
    idle handler with a known priority

  + inside the idle handler:

    - advance the master clock, which will in turn advance
      every playing timeline by the amount of milliseconds
      elapsed since the last redraw; this will make every
      playing timeline emit the ::new-frame signal

    - queue a relayout

    - call the redraw() method of the backend

This way we trade multiple timeouts with a single frame source
that only runs if a timeline is playing and queues redraws on
the various stages.
2009-04-24 15:28:15 +01:00
Emmanuele Bassi
709bb69970 Add debug annotations for the layout process
If we need to check that the layout sequence is correct in
terms of order of execution and with respect to caching, then
having a CLUTTER_DEBUG_LAYOUT debug flag would make things
easier.
2009-04-15 17:25:50 +01:00
Neil Roberts
a93a93d007 Count timeline frames using the FPS instead of an integer interval
Bug 1495 - Timelines run 4% short

Previously the timelines were timed by calculating the interval
between each frame stored as an integer number of milliseconds so some
precision is lost. For example, requesting 60 frames per second gets
converted to 16 ms per frame which is actually 62.5 frames per
second. This makes the timeline shorter by 4%.

This patch merges the common code for timing from the timeout pools
and frame sources into an internal clutter-timeout-interval file. This
stores the interval directly as the FPS and counts the number of
frames that have been reached instead of the elapsed time.
2009-03-16 15:40:18 +00:00
Emmanuele Bassi
52811b240f [stage] Coalesce fog and perspective API
The fog and perspective API is currently split in two parts:

  - the floating point version, using values

  - the fixed point version, using structures

The relative properties are using the structure types, since they
are meant to set multiple values at the same time. Instead of
using bare values, the whole API should be coalesced into two
simple calls using structures to match the GObject properties.

Thus:

  clutter_stage_set_fog (ClutterStage*, const ClutterFog*)
  clutter_stage_get_fog (ClutterStage*, ClutterFog*)

  clutter_stage_set_perspective (ClutterStage*, const ClutterPerspective*)
  clutter_stage_get_perspective (ClutterStage*, ClutterPerspective*)

Which supercedes the fixed point and floating point variants.

More importantly, both ClutterFog and ClutterPerspective should
using floating point values, since that's what get passed to
COGL anyway.

ClutterFog should also drop the "density" member, since ClutterStage
only allows linear fog; non-linear fog distribution can be achieved
using a signal handler and calling cogl_set_fog() directly; this keeps
the API compact yet extensible.

Finally, there is no ClutterStage:fog so it should be added.
2009-03-10 12:38:03 +00:00
Emmanuele Bassi
4e98fc5e79 [docs] Note that grabs are evil
Grabs are an entirely evil way to override the whole event delivery
machinery that Clutter has in place.

A pointer grab can be effectively replaced by a much more reliable
::captured-event signal handler, for instance.

Sometimes, grabs are a necessary evil -- and that is why Clutter
exposes them in the API; that should not fool anyone into thinking
that they should be used unless strictly necessary.
2009-03-10 12:38:03 +00:00
Øyvind Kolås
9df3fb993c Add a warning for recursive emit_event
When event delivery is invoked by synthetic events through
clutter_do_event from inside an event handler clutter was silently
ignoring it, this warning will hopefully help resolving some issues.
2009-02-27 17:59:16 +00:00
Emmanuele Bassi
b39223d8cb [backend] Constify font options
The font options accessors in ClutterBackend only deal with const
cairo_font_options_t values, since:

  - set_font_options() will copy the font options
  - get_font_options() will return a pointer to the internal
    font options

Not using const in these cases makes the API confusing and might lead
to erroneous calls to cairo_font_options_destroy().
2009-02-26 15:32:48 +00:00