com.alexvasilkov.gestures.animation

Class ViewPositionAnimator

java.lang.Object

com.alexvasilkov.gestures.animation.ViewPositionAnimator

public class ViewPositionAnimator
extends java.lang.Object

Helper class to animate views from one position on screen to another.

Animation can be performed from any view (e.g. ImageView) to any gestures controlled view implementing GestureView (e.g. GestureImageView).

Note, that initial and final views should have same aspect ratio for correct animation. In case of ImageView initial and final images should have same aspect, but actual views can have different aspects (e.g. animating from square thumb view with scale type ImageView.ScaleType.CENTER_CROP to rectangular full image view).

To use this class first create an instance and then call enter(View, boolean).
Alternatively you can manually pass initial view position using enter(ViewPosition, boolean) method.
To exit back to initial view call exit(boolean) method.
You can listen for position changes using addPositionUpdateListener(PositionUpdateListener).
If initial view was changed you should call update(View) method to update to new view. You can also manually update initial view position using update(ViewPosition) method.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	ViewPositionAnimator.PositionUpdateListener

Constructor Summary

Constructors

Constructor and Description
ViewPositionAnimator(GestureView to)

Method Summary

Modifier and Type	Method and Description
void	addPositionUpdateListener(ViewPositionAnimator.PositionUpdateListener listener) Adds position state changes listener that will be notified during animations.
void	enter(boolean withAnimation) Starts 'enter' animation from no specific position (position will be calculated based on gravity set in Settings).
void	enter(android.view.View from, boolean withAnimation) Starts 'enter' animation from from view to to.
void	enter(ViewPosition fromPos, boolean withAnimation) Starts 'enter' animation from from position to to view.
void	exit(boolean withAnimation) Starts 'exit' animation from to view back to from.
float	getPosition()
float	getToPosition()
boolean	isAnimating()
boolean	isLeaving()
void	removePositionUpdateListener(ViewPositionAnimator.PositionUpdateListener listener) Removes position state changes listener as added by addPositionUpdateListener(PositionUpdateListener).
void	setState(float pos, boolean leaving, boolean animate) Stops current animation and sets position state to particular values.
void	setToState(State state, float position) Specifies target ('to') state and it's position which will be used to interpolate current state for intermediate positions (i.e.
void	stopAnimation() Stops current animation, if any.
void	update(android.view.View from) Updates initial view in case it was changed.
void	update(ViewPosition from) Updates position of initial view in case it was changed.
void	updateToNone() Updates position of initial view to no specific position, in case 'to' view is not available anymore.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ViewPositionAnimator

public ViewPositionAnimator(@NonNull
                            GestureView to)

Method Detail

enter

public void enter(boolean withAnimation)

Starts 'enter' animation from no specific position (position will be calculated based on gravity set in Settings).

Note, that in most cases you should use enter(View, boolean) or enter(ViewPosition, boolean) methods instead.

Parameters:

withAnimation - Whether to animate entering or immediately jump to entered state

enter

public void enter(@NonNull
                  android.view.View from,
                  boolean withAnimation)

Starts 'enter' animation from from view to to.

Note, if from view was changed (i.e. during list adapter refresh) you should update to new view using update(View) method.

Parameters:

from - 'From' view

withAnimation - Whether to animate entering or immediately jump to entered state

enter

public void enter(@NonNull
                  ViewPosition fromPos,
                  boolean withAnimation)

Starts 'enter' animation from from position to to view.

Note, if from view position was changed (i.e. during list adapter refresh) you should update to new view using update(ViewPosition) method.

Parameters:

fromPos - 'From' view position

withAnimation - Whether to animate entering or immediately jump to entered state

update

public void update(@NonNull
                   android.view.View from)

Updates initial view in case it was changed. You should not call this method if view stays the same since animator should automatically detect view position changes.

Parameters:

from - New 'from' view

update

public void update(@NonNull
                   ViewPosition from)

Updates position of initial view in case it was changed.

Parameters:

from - New 'from' view position

updateToNone

public void updateToNone()

Updates position of initial view to no specific position, in case 'to' view is not available anymore.

exit

public void exit(boolean withAnimation)

Starts 'exit' animation from to view back to from.

Parameters:

withAnimation - Whether to animate exiting or immediately jump to initial state

addPositionUpdateListener

public void addPositionUpdateListener(@NonNull
                                      ViewPositionAnimator.PositionUpdateListener listener)

Adds position state changes listener that will be notified during animations.

Parameters:

listener - Position listener

removePositionUpdateListener

public void removePositionUpdateListener(@NonNull
                                         ViewPositionAnimator.PositionUpdateListener listener)

Removes position state changes listener as added by addPositionUpdateListener(PositionUpdateListener).

Note, this method may be called inside listener's callback without throwing IndexOutOfBoundsException.

Parameters:

listener - Position listener to be removed

getToPosition

public float getToPosition()

Returns:

Target (to) position as set by setToState(State, float). Maybe useful to determine real animation position during exit gesture.

I.e. getPosition() / getToPosition() (changes from 0 to ∞) represents interpolated position used to calculate intermediate state and bounds.

getPosition

public float getPosition()

Returns:

Current position within range [0, 1], where 0 is for initial (from) position and 1 is for final (to) position.

Note, that final position can be changed by setToState(State, float), so if you need to have real value of final position (instead of 1) then you need to use getToPosition() method.

isLeaving

public boolean isLeaving()

Returns:

Whether animator is in leaving state. Means that animation direction is from final (to) position back to initial (from) position.

setToState

public void setToState(@NonNull
                       State state,
                       @FloatRange(from=0.0,to=1.0)
                       float position)

Specifies target ('to') state and it's position which will be used to interpolate current state for intermediate positions (i.e. during animation or exit gesture).
This allows you to set up correct state without changing current position (getPosition()).

Only use this method if you understand what you do.

Parameters:

state - Target ('to') state

position - Target ('to') position

See Also:

getToPosition()

setState

public void setState(@FloatRange(from=0.0,to=1.0)
                     float pos,
                     boolean leaving,
                     boolean animate)

Stops current animation and sets position state to particular values.

Note, that once animator reaches state = 0f and isLeaving = true it will cleanup all internal stuff. So you will need to call enter(View, boolean) or enter(ViewPosition, boolean) again in order to continue using animator.

Parameters:

pos - Current position

leaving - Whether we we are in exiting direction (true) or in entering (false)

animate - Whether we should start animating from given position and in given direction

isAnimating

public boolean isAnimating()

Returns:

Whether view position animation is in progress or not.

stopAnimation

public void stopAnimation()

Stops current animation, if any.