LayoutAnimationController
public
class
LayoutAnimationController
extends Object
java.lang.Object | |
↳ | android.view.animation.LayoutAnimationController |
A layout animation controller is used to animate the children of a layout or a view
group. Each child uses the same animation but for every one of
them, the animation starts at a different time. A layout animation controller
is used by ViewGroup
to compute the delay by which each
child's animation start must be offset. The delay is computed by using
characteristics of each child, like its index in the view group.
This standard implementation computes the delay by multiplying a fixed
amount of miliseconds by the index of the child in its parent view group.
Subclasses are supposed to override
getDelayForView(android.view.View)
to implement a different way
of computing the delay. For instance, a
GridLayoutAnimationController
will compute the
delay based on the column and row indices of the child in its parent view
group.
Information used to compute the animation delay of each child are stored
in an instance of
LayoutAnimationController.AnimationParameters
,
itself stored in the ViewGroup.LayoutParams
of the view.
Summary
Nested classes | ||
---|---|---|
class |
LayoutAnimationController.AnimationParameters
The set of parameters that has to be attached to each view contained in the view group animated by the layout animation controller. |
XML attributes | ||
---|---|---|
android:animation |
Animation to use on each child. | |
android:animationOrder |
The order in which the animations will be started. | |
android:delay |
Fraction of the animation duration used to delay the beginning of the animation of each child. | |
android:interpolator |
Interpolator used to interpolate the delay between the start of each animation. |
Constants | |
---|---|
int |
ORDER_NORMAL
Distributes the animation delays in the order in which view were added to their view group. |
int |
ORDER_RANDOM
Randomly distributes the animation delays. |
int |
ORDER_REVERSE
Distributes the animation delays in the reverse order in which view were added to their view group. |
Fields | |
---|---|
protected
Animation |
mAnimation
The animation applied on each child of the view group on which this layout animation controller is set. |
protected
Interpolator |
mInterpolator
The interpolator used to interpolate the delays. |
protected
Random |
mRandomizer
The randomizer used when the order is set to random. |
Public constructors | |
---|---|
LayoutAnimationController(Context context, AttributeSet attrs)
Creates a new layout animation controller from external resources. |
|
LayoutAnimationController(Animation animation)
Creates a new layout animation controller with a delay of 50% and the specified animation. |
|
LayoutAnimationController(Animation animation, float delay)
Creates a new layout animation controller with the specified delay and the specified animation. |
Public methods | |
---|---|
Animation
|
getAnimation()
Returns the animation applied to each child of the view group on which this controller is set. |
final
Animation
|
getAnimationForView(View view)
Returns the animation to be applied to the specified view. |
float
|
getDelay()
Returns the delay by which the children's animation are offset. |
Interpolator
|
getInterpolator()
Returns the interpolator used to interpolate the delays between the children. |
int
|
getOrder()
Returns the order used to compute the delay of each child's animation. |
boolean
|
isDone()
Indicates whether the layout animation is over or not. |
void
|
setAnimation(Animation animation)
Sets the animation to be run on each child of the view group on which this layout animation controller is . |
void
|
setAnimation(Context context, int resourceID)
Sets the animation to be run on each child of the view group on which this layout animation controller is . |
void
|
setDelay(float delay)
Sets the delay, as a fraction of the animation duration, by which the children's animations are offset. |
void
|
setInterpolator(Context context, int resourceID)
Sets the interpolator used to interpolate the delays between the children. |
void
|
setInterpolator(Interpolator interpolator)
Sets the interpolator used to interpolate the delays between the children. |
void
|
setOrder(int order)
Sets the order used to compute the delay of each child's animation. |
void
|
start()
Starts the animation. |
boolean
|
willOverlap()
Indicates whether two children's animations will overlap. |
Protected methods | |
---|---|
long
|
getDelayForView(View view)
Returns the amount of milliseconds by which the specified view's animation must be delayed or offset. |
int
|
getTransformedIndex(LayoutAnimationController.AnimationParameters params)
Transforms the index stored in
|
Inherited methods | |
---|---|
XML attributes
android:animation
Animation to use on each child.
May be a reference to another resource, in the form
"@[+][package:]type/name
" or a theme
attribute in the form
"?[package:]type/name
".
Related methods:
android:animationOrder
The order in which the animations will be started.
Must be one of the following constant values.
Constant | Value | Description |
---|---|---|
normal | 0 | Animations are started in the natural order. |
random | 2 | Animations are started randomly. |
reverse | 1 | Animations are started in the reverse order. |
Related methods:
android:delay
Fraction of the animation duration used to delay the beginning of the animation of each child.
May be a floating point value, such as "1.2
".
May be a fractional value, which is a floating point number appended with
either % or %p, such as "14.5%
".
The % suffix always means a percentage of the base size;
the optional %p suffix provides a size relative to some parent container.
android:interpolator
Interpolator used to interpolate the delay between the start of each animation.
May be a reference to another resource, in the form
"@[+][package:]type/name
" or a theme
attribute in the form
"?[package:]type/name
".
Related methods:
Constants
ORDER_NORMAL
public static final int ORDER_NORMAL
Distributes the animation delays in the order in which view were added to their view group.
Constant Value: 0 (0x00000000)
ORDER_RANDOM
public static final int ORDER_RANDOM
Randomly distributes the animation delays.
Constant Value: 2 (0x00000002)
ORDER_REVERSE
public static final int ORDER_REVERSE
Distributes the animation delays in the reverse order in which view were added to their view group.
Constant Value: 1 (0x00000001)
Fields
mAnimation
protected Animation mAnimation
The animation applied on each child of the view group on which this layout animation controller is set.
mInterpolator
protected Interpolator mInterpolator
The interpolator used to interpolate the delays.
mRandomizer
protected Random mRandomizer
The randomizer used when the order is set to random. Subclasses should use this object to avoid creating their own.
Public constructors
LayoutAnimationController
public LayoutAnimationController (Context context, AttributeSet attrs)
Creates a new layout animation controller from external resources.
Parameters | |
---|---|
context |
Context : the Context the view group is running in, through which
it can access the resources |
attrs |
AttributeSet : the attributes of the XML tag that is inflating the
layout animation controller |
LayoutAnimationController
public LayoutAnimationController (Animation animation)
Creates a new layout animation controller with a delay of 50% and the specified animation.
Parameters | |
---|---|
animation |
Animation : the animation to use on each child of the view group |
LayoutAnimationController
public LayoutAnimationController (Animation animation, float delay)
Creates a new layout animation controller with the specified delay and the specified animation.
Parameters | |
---|---|
animation |
Animation : the animation to use on each child of the view group |
delay |
float : the delay by which each child's animation must be offset |
Public methods
getAnimation
public Animation getAnimation ()
Returns the animation applied to each child of the view group on which this controller is set.
Returns | |
---|---|
Animation |
an Animation instance |
getAnimationForView
public final Animation getAnimationForView (View view)
Returns the animation to be applied to the specified view. The returned
animation is delayed by an offset computed according to the information
provided by
LayoutAnimationController.AnimationParameters
.
This method is called by view groups to obtain the animation to set on
a specific child.
Parameters | |
---|---|
view |
View : the view to animate |
Returns | |
---|---|
Animation |
an animation delayed by the number of milliseconds returned by
getDelayForView(android.view.View) |
getDelay
public float getDelay ()
Returns the delay by which the children's animation are offset. The delay is expressed as a fraction of the animation duration.
Returns | |
---|---|
float |
a fraction of the animation duration |
See also:
getInterpolator
public Interpolator getInterpolator ()
Returns the interpolator used to interpolate the delays between the children.
Returns | |
---|---|
Interpolator |
an Interpolator |
getOrder
public int getOrder ()
Returns the order used to compute the delay of each child's animation.
Related XML Attributes:
Returns | |
---|---|
int |
one of ORDER_NORMAL , ORDER_REVERSE or
ORDER_RANDOM |
isDone
public boolean isDone ()
Indicates whether the layout animation is over or not. A layout animation is considered done when the animation with the longest delay is done.
Returns | |
---|---|
boolean |
true if all of the children's animations are over, false otherwise |
setAnimation
public void setAnimation (Animation animation)
Sets the animation to be run on each child of the view group on which this layout animation controller is .
Related XML Attributes:
Parameters | |
---|---|
animation |
Animation : the animation to run on each child of the view group |
setAnimation
public void setAnimation (Context context, int resourceID)
Sets the animation to be run on each child of the view group on which this layout animation controller is .
Related XML Attributes:
Parameters | |
---|---|
context |
Context : the context from which the animation must be inflated |
resourceID |
int : the resource identifier of the animation |
See also:
setDelay
public void setDelay (float delay)
Sets the delay, as a fraction of the animation duration, by which the children's animations are offset. The general formula is:
child animation delay = child index * delay * animation duration
Parameters | |
---|---|
delay |
float : a fraction of the animation duration |
See also:
setInterpolator
public void setInterpolator (Context context, int resourceID)
Sets the interpolator used to interpolate the delays between the children.
Related XML Attributes:
Parameters | |
---|---|
context |
Context : the context from which the interpolator must be inflated |
resourceID |
int : the resource identifier of the interpolator |
setInterpolator
public void setInterpolator (Interpolator interpolator)
Sets the interpolator used to interpolate the delays between the children.
Related XML Attributes:
Parameters | |
---|---|
interpolator |
Interpolator : the interpolator |
setOrder
public void setOrder (int order)
Sets the order used to compute the delay of each child's animation.
Related XML Attributes:
Parameters | |
---|---|
order |
int : one of ORDER_NORMAL , ORDER_REVERSE or
ORDER_RANDOM |
willOverlap
public boolean willOverlap ()
Indicates whether two children's animations will overlap. Animations overlap when the delay is lower than 100% (or 1.0).
Returns | |
---|---|
boolean |
true if animations will overlap, false otherwise |
Protected methods
getDelayForView
protected long getDelayForView (View view)
Returns the amount of milliseconds by which the specified view's
animation must be delayed or offset. Subclasses should override this
method to return a suitable value.
This implementation returns child animation delay
milliseconds where:
child animation delay = child index * delay
LayoutAnimationController.AnimationParameters
found in the view's ViewGroup.LayoutParams
.
Parameters | |
---|---|
view |
View : the view for which to obtain the animation's delay |
Returns | |
---|---|
long |
a delay in milliseconds |
getTransformedIndex
protected int getTransformedIndex (LayoutAnimationController.AnimationParameters params)
Transforms the index stored in
LayoutAnimationController.AnimationParameters
by the order returned by getOrder()
. Subclasses should override
this method to provide additional support for other types of ordering.
This method should be invoked by
getDelayForView(android.view.View)
prior to any computation.
Parameters | |
---|---|
params |
LayoutAnimationController.AnimationParameters : the animation parameters containing the index |
Returns | |
---|---|
int |
a transformed index |
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Last updated 2024-04-04 UTC.