Android APIs
public static class

ScaleGestureDetector.SimpleOnScaleGestureListener

extends Object
implements ScaleGestureDetector.OnScaleGestureListener
java.lang.Object
   ↳ android.view.ScaleGestureDetector.SimpleOnScaleGestureListener

Class Overview

A convenience class to extend when you only want to listen for a subset of scaling-related events. This implements all methods in ScaleGestureDetector.OnScaleGestureListener but does nothing. onScale(ScaleGestureDetector) returns false so that a subclass can retrieve the accumulated scale factor in an overridden onScaleEnd. onScaleBegin(ScaleGestureDetector) returns true.

Summary

Public Constructors
ScaleGestureDetector.SimpleOnScaleGestureListener()
Public Methods
boolean onScale(ScaleGestureDetector detector)
Responds to scaling events for a gesture in progress.
boolean onScaleBegin(ScaleGestureDetector detector)
Responds to the beginning of a scaling gesture.
void onScaleEnd(ScaleGestureDetector detector)
Responds to the end of a scale gesture.
[Expand]
Inherited Methods
From class java.lang.Object
From interface android.view.ScaleGestureDetector.OnScaleGestureListener

Public Constructors

public ScaleGestureDetector.SimpleOnScaleGestureListener ()

Added in API level 8

Public Methods

public boolean onScale (ScaleGestureDetector detector)

Added in API level 8

Responds to scaling events for a gesture in progress. Reported by pointer motion.

Parameters
detector The detector reporting the event - use this to retrieve extended info about event state.
Returns
  • Whether or not the detector should consider this event as handled. If an event was not handled, the detector will continue to accumulate movement until an event is handled. This can be useful if an application, for example, only wants to update scaling factors if the change is greater than 0.01.

public boolean onScaleBegin (ScaleGestureDetector detector)

Added in API level 8

Responds to the beginning of a scaling gesture. Reported by new pointers going down.

Parameters
detector The detector reporting the event - use this to retrieve extended info about event state.
Returns
  • Whether or not the detector should continue recognizing this gesture. For example, if a gesture is beginning with a focal point outside of a region where it makes sense, onScaleBegin() may return false to ignore the rest of the gesture.

public void onScaleEnd (ScaleGestureDetector detector)

Added in API level 8

Responds to the end of a scale gesture. Reported by existing pointers going up. Once a scale has ended, getFocusX() and getFocusY() will return focal point of the pointers remaining on the screen.

Parameters
detector The detector reporting the event - use this to retrieve extended info about event state.