ClutterKeyframeTransition: Clutter Reference Manual

## ClutterKeyframeTransition ClutterKeyframeTransition — Keyframe property transition |

## Functions

ClutterTransition * | clutter_keyframe_transition_new ()
void | clutter_keyframe_transition_set ()
void | clutter_keyframe_transition_set_key_frames ()
void | clutter_keyframe_transition_set_modes ()
void | clutter_keyframe_transition_set_values ()
guint | clutter_keyframe_transition_get_n_key_frames ()
void | clutter_keyframe_transition_set_key_frame ()
void | clutter_keyframe_transition_get_key_frame ()
void | clutter_keyframe_transition_clear ()

## Types and Values

| ClutterKeyframeTransition
struct | ClutterKeyframeTransitionClass

## Object Hierarchy

        GObject
        ╰── ClutterTimeline
            ╰── ClutterTransition
                ╰── ClutterPropertyTransition
                    ╰── ClutterKeyframeTransition

## Implemented Interfaces

ClutterKeyframeTransition implements ClutterScriptable.

## Description

ClutterKeyframeTransition allows animating a property by defining "key frames": values at a normalized position on the transition duration.

The ClutterKeyframeTransition interpolates the value of the property to which it's bound across these key values.

Setting up a ClutterKeyframeTransition means providing the times, values, and easing modes between these key frames, for instance:

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    ClutterTransition *keyframe;

    keyframe = clutter_keyframe_transition_new ("opacity");
    clutter_transition_set_from (keyframe, G_TYPE_UINT, 255);
    clutter_transition_set_to (keyframe, G_TYPE_UINT, 0);
    clutter_keyframe_transition_set (CLUTTER_KEYFRAME_TRANSITION (keyframe),
                                     G_TYPE_UINT,
                                     1, /* number of key frames */
                                     0.5, 128, CLUTTER_EASE_IN_OUT_CUBIC);

The example above sets up a keyframe transition for the “opacity” property of a ClutterActor; the transition starts and sets the value of the property to fully transparent; between the start of the transition and its mid point, it will animate the property to half opacity, using an easy in/easy out progress. Once the transition reaches the mid point, it will linearly fade the actor out until it reaches the end of the transition.

The ClutterKeyframeTransition will add an implicit key frame between the last and the 1.0 value, to interpolate to the final value of the transition's interval.

ClutterKeyframeTransition is available since Clutter 1.12.

## Functions

### clutter_keyframe_transition_new ()

    ClutterTransition *
    clutter_keyframe_transition_new (const char *property_name);

Creates a new ClutterKeyframeTransition for `property_name` .

#### Parameters

property_name | the property to animate |

#### Returns

the newly allocated ClutterKeyframeTransition instance. Use `g_object_unref()` when done to free its resources.

[transfer full]

Since: 1.12

### clutter_keyframe_transition_set ()

    void
    clutter_keyframe_transition_set (ClutterKeyframeTransition *transition,
                                     GType gtype,
                                     guint n_key_frames,
                                     ...);

Sets the key frames of the `transition` .

This variadic arguments function is a convenience for C developers; language bindings should use `clutter_keyframe_transition_set_key_frames()`, `clutter_keyframe_transition_set_modes()`, and `clutter_keyframe_transition_set_values()` instead.

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#### Parameters

transition | a ClutterKeyframeTransition |
gtype | the type of the values to use for the key frames |
n_key_frames | the number of key frames between the initial and final values |
... | a list of tuples, containing the key frame index, the value at the key frame, and the animation mode |

Since: 1.12

### clutter_keyframe_transition_set_key_frames ()

    void
    clutter_keyframe_transition_set_key_frames
                                   (ClutterKeyframeTransition *transition,
                                    guint n_key_frames,
                                    const double *key_frames);

Sets the keys for each key frame inside `transition` .

If `transition` does not hold any key frame, `n_key_frames` key frames will be created; if `transition` already has key frames, `key_frames` must have at least as many elements as the number of key frames.

#### Parameters

transition | a ClutterKeyframeTransition |
n_key_frames | the number of values |
key_frames | an array of keys between 0.0 and 1.0, one for each key frame. | [array length=n_key_frames]

Since: 1.12

### clutter_keyframe_transition_set_modes ()

    void
    clutter_keyframe_transition_set_modes (ClutterKeyframeTransition *transition,
                                           guint n_modes,
                                           const ClutterAnimationMode *modes);

Sets the easing modes for each key frame inside `transition` .

If `transition` does not hold any key frame, `n_modes` key frames will be created; if `transition` already has key frames, `modes` must have at least as many elements as the number of key frames.

#### Parameters

transition | a ClutterKeyframeTransition |
n_modes | the number of easing modes |
modes | an array of easing modes, one for each key frame. | [array length=n_modes]

Since: 1.12

### clutter_keyframe_transition_set_values ()

    void
    clutter_keyframe_transition_set_values
                                   (ClutterKeyframeTransition *transition,
                                    guint n_values,
                                    const GValue *values);

Sets the values for each key frame inside `transition` .

If `transition` does not hold any key frame, `n_values` key frames will be created; if `transition` already has key frames, `values` must have at least as many elements as the number of key frames.

#### Parameters

transition | a ClutterKeyframeTransition |
n_values | the number of values |
values | an array of values, one for each key frame. | [array length=n_values]

Since: 1.12

### clutter_keyframe_transition_get_n_key_frames ()

    guint
    clutter_keyframe_transition_get_n_key_frames
                                   (ClutterKeyframeTransition *transition);

Retrieves the number of key frames inside `transition` .

#### Parameters

transition | a ClutterKeyframeTransition |

#### Returns

the number of key frames

Since: 1.12

### clutter_keyframe_transition_set_key_frame ()

    void
    clutter_keyframe_transition_set_key_frame
                                   (ClutterKeyframeTransition *transition,
                                    guint index_,
                                    double key,
                                    ClutterAnimationMode mode,
                                    const GValue *value);

Sets the details of the key frame at `index_` inside `transition` .

The `transition` must already have a key frame at `index_` , and `index_` must be smaller than the number of key frames inside `transition` .

#### Parameters

transition | a ClutterKeyframeTransition |
index_ | the index of the key frame |
key | the key of the key frame |
mode | the easing mode of the key frame |
value | a GValue containing the value of the key frame |

Since: 1.12

### clutter_keyframe_transition_get_key_frame ()

    void
    clutter_keyframe_transition_get_key_frame
                                   (ClutterKeyframeTransition *transition,
                                    guint index_,
                                    double *key,
                                    ClutterAnimationMode *mode,
                                    GValue *value);

Retrieves the details of the key frame at `index_` inside `transition` .

The `transition` must already have key frames set, and `index_` must be smaller than the number of key frames.

#### Parameters

transition | a ClutterKeyframeTransition |
index_ | the index of the key frame |
key | return location for the key, or `NULL`. | [out][allow-none]
mode | return location for the easing mode, or `NULL`. | [out][allow-none]
value | a GValue initialized with the type of the values. | [out caller-allocates]

Since: 1.12

### clutter_keyframe_transition_clear ()

    void
    clutter_keyframe_transition_clear (ClutterKeyframeTransition *transition);

Removes all key frames from `transition` .

#### Parameters

transition | a ClutterKeyframeTransition |

Since: 1.12

## Types and Values

### ClutterKeyframeTransition

    typedef struct _ClutterKeyframeTransition ClutterKeyframeTransition;

The `ClutterKeyframeTransition` structure contains only private data and should be accessed using the provided API.

Since: 1.12

### struct ClutterKeyframeTransitionClass

    struct ClutterKeyframeTransitionClass {
    };

The `ClutterKeyframeTransitionClass` structure contains only private data.

Since: 1.12