When the threshold-trigger-edge property was introduced in
GestureAction, it was late in the cycle and I elected to keep it
private, given the fact that nobody was subclassing GestureAction
outside of Clutter itself.
These days, people are experimenting more with the GestureAction API, so
they will need access to the various knobs that control the class
default behaviour.
https://bugzilla.gnome.org/show_bug.cgi?id=710227
PanAction is a GestureAction-subclass that implements the panning
concept for scrollable actors, with the ability to emit interpolated
signals to emulate the kinetic inertia of the panning. PanAction provides:
• pan signal, notifying users of the panning gesture status;
• pan-stopped signal, emitted at the end of the interpolated phase
of the panning gesture, if enabled;
• pan-axis property, to allow constraining the dragging to a specific
axis;
• interpolated property, to enable or disable the inertial behaviour;
• deceleration property, to customize the rate at which the momentum
of the panning will be slowed down;
• acceleration-factor property, applied to the inertial momentum when
starting the interpolated sequence.
An interactive test is also provided.
https://bugzilla.gnome.org/show_bug.cgi?id=681648
Another progress function from the CSS3 Transitions specification, using
a parametrices cubic bezier curve between (0, 0) and (1, 1) with two
control points.
(sadly, no ASCII art can approximate a cubic bezier, so no graph)
The cubic-bezier() progress function comes with a bunch of preset easing
modes: ease, ease-in, ease-out, and ease-in-out, that we can map to
enumeration values.
The CSS3 Transitions specification from the W3C defines the possibility
of using a parametrized step() timing function, with the following
prototype:
steps(n_steps, [ start | end ])
where @n_steps represents the number of steps used to divide an interval
between 0 and 1; the 'start' and 'end' tokens describe whether the value
change should happen at the start of the transition, or at the end.
For instance, the "steps(3, start)" timing function has the following
profile:
1 | x
| |
| x---|
| ' |
| x---' |
| ' |
0 |---' |
Whereas the "steps(3, end)" timing function has the following profile:
1 | x---|
| ' |
| x---' |
| ' |
x---' |
| |
0 | |
Since ClutterTimeline uses an enumeration for controlling the progress
mode, we need additional API to define the parameters of the steps()
progress; for this reason, we need a CLUTTER_STEPS enumeration value,
and a method for setting the number of steps and the value transition
policy.
The CSS3 Transitions spec helpfully also defines a step-start and a
step-end shorthands, which expand to step(1, start) and step(1, end)
respectively; we can provide a CLUTTER_STEP_START and CLUTTER_STEP_END
enumeration values for those.
ClutterContent implementations may allow repeating their contents when
painting; we should provide the repeat policy on the actor, like we do
for scaling filters and content gravity.
ClutterGridLayout is port of GtkGrid to a Clutter layout manager. All
the logic is taken from gtkgrid.c, so all the credits should go to
Matthias Clasen for writing this nice piece of code.
ClutterGridLayout supports adding children with it's own methods
GridLayout.attach() and GridLayout.attach_next_to() as well as
Actor.add_child() and friends. The latter adds children in a similar
fashion to ClutterBoxLayout
https://bugzilla.gnome.org/show_bug.cgi?id=677372
Some events may contain precise scrolling information coming from
devices like trackpads and touchscreens. ClutterEvent should allow
setting and getting this information.
Yes, it's not really the proper GL name for a linear-on-every-axis of a
texture plus linear-between-mipmap-levels minification filter, but it
has three redeeming qualities as a name:
- LINEAR_MIPMAP_LINEAR sucks, as it introduces GL concepts like
mipmaps in the API naming, while we're trying to avoid that;
- people using GL already know what 'trilinear' means in this context
without going all Khronos on their asses;
- we're using 2D textures anyway, so 'linear on two axes and linear
between mipmap levels' can be effectively approximated to
'trilinear'.
I mean, if even the OpenGL official wiki says:
Unfortunately, what most people think of as "trilinear" is not linear
filtering of a 3D texture, but what in OpenGL terms is GL_LINEAR mag
filter and GL_LINEAR_MIPMAP_LINEAR in the min filter in a 2D texture.
That is, it is bilinear filtering of each appropriate mipmap level,
and doing a third linear filter between the adjacent mipmap levels.
Hence the term "trilinear".
-- http://www.opengl.org/wiki/Texture
then the horse has already been flogged to death, and I don't intend to
be accused of necrophilia and sadism by flogging it some more.
Prior art: every single GL tutorial in the history of ever;
CoreAnimation's scaling filter enumerations.
If people want to start using 1D or 3D textures they they are probably
going to be using Cogl API directly, and that has the GL naming scheme
for minification and magnification filters anyway.
ClutterContent is an interface for creating delegate objects that handle
what an actor is going to paint.
Since they are a newly added type, they only hook into the new PaintNode
based API.
The position and size of the content is controlled in part by the
content's own preferred size, and by the ClutterContentGravity
enumeration.
It is sometimes useful to be able to have better control on when a
repaint function is called. Currently, all repaint functions are called
prior to the stages update phase of the frame processing.
We can introduce flags to represent the point in the frame update
process in which we wish Clutter called the repaint function.
As a bonus, we can also add a flag that causes adding a repaint function
to spin the master clock.
Now that we reinstated Group to its "former glory", we need to ensure
that applications using the deprecated containers with the new DOM API
in ClutterActor can actually work - or, at least, not break horribly.
This actually means making sure that ClutterStage and ClutterGroup can
cope with the DOM, while retaining their old implementations, as well as
their bizarre idiosyncrasies and their utter, utter brokenness.
Just like ClutterBindConstraint has two shorthand enumerations for binding
position and size and avoid using multiple instances, ClutterAlignConstraint
should have a way to align an actor with the same alignment factor on both
axis at the same time; this is especially useful for centering actors.
