Added in API level 34

Summary: Constants | Ctors | Methods | Inherited Methods

BackEvent

Kotlin |Java

public final class BackEvent
extends Object

java.lang.Object
↳	android.window.BackEvent

Object used to report back gesture progress. Holds information about the touch event, swipe direction and the animation progress that predictive back animations should seek to.

Summary

Constants
`int`	`EDGE_LEFT` Indicates that the edge swipe starts from the left edge of the screen
`int`	`EDGE_RIGHT` Indicates that the edge swipe starts from the right edge of the screen

Public constructors
`BackEvent(float touchX, float touchY, float progress, int swipeEdge)` Creates a new `BackMotionEvent` instance.

Public methods
`float`	`getProgress()` Returns a value between 0 and 1 on how far along the back gesture is.
`int`	`getSwipeEdge()` Returns the screen edge that the swipe starts from.
`float`	`getTouchX()` Returns the absolute X location of the touch point, or NaN if the event is from a button press.
`float`	`getTouchY()` Returns the absolute Y location of the touch point, or NaN if the event is from a button press.
`String`	`toString()` Returns a string representation of the object.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Constants

EDGE_LEFT

Added in API level 34

public static final int EDGE_LEFT

Indicates that the edge swipe starts from the left edge of the screen

Constant Value: 0 (0x00000000)

EDGE_RIGHT

Added in API level 34

public static final int EDGE_RIGHT

Indicates that the edge swipe starts from the right edge of the screen

Constant Value: 1 (0x00000001)

Public constructors

BackEvent

Added in API level 34

public BackEvent (float touchX, 
                float touchY, 
                float progress, 
                int swipeEdge)

Creates a new BackMotionEvent instance.

Parameters
`touchX`	`float`: Absolute X location of the touch point of this event.
`touchY`	`float`: Absolute Y location of the touch point of this event.
`progress`	`float`: Value between 0 and 1 on how far along the back gesture is.
`swipeEdge`	`int`: Indicates which edge the swipe starts from. Value is `EDGE_LEFT`, or `EDGE_RIGHT`

Public methods

getProgress

Added in API level 34

public float getProgress ()

Returns a value between 0 and 1 on how far along the back gesture is. This value is driven by the horizontal location of the touch point, and should be used as the fraction to seek the predictive back animation with. Specifically,

The progress is 0 when the touch is at the starting edge of the screen (left or right), and animation should seek to its start state.
The progress is approximately 1 when the touch is at the opposite side of the screen, and animation should seek to its end state. Exact end value may vary depending on screen size.

After the gesture finishes in cancel state, this method keeps getting invoked until the progress value animates back to 0. In-between locations are linearly interpolated based on horizontal distance from the starting edge and smooth clamped to 1 when the distance exceeds a system-wide threshold.

Returns
`float`	Value is between 0 and 1 inclusive

getSwipeEdge

Added in API level 34

public int getSwipeEdge ()

Returns the screen edge that the swipe starts from.

Returns
`int`	Value is `EDGE_LEFT`, or `EDGE_RIGHT`

getTouchX

Added in API level 34

public float getTouchX ()

Returns the absolute X location of the touch point, or NaN if the event is from a button press.

Returns
`float`

getTouchY

Added in API level 34

public float getTouchY ()

Returns the absolute Y location of the touch point, or NaN if the event is from a button press.

Returns
`float`

toString

Added in API level 34

public String toString ()

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.

The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:

 getClass().getName() + '@' + Integer.toHexString(hashCode())

Returns
`String`	a string representation of the object.