Scroller

public class Scroller
extends Object

This class encapsulates scrolling. You can use scrollers (Scroller or OverScroller) to collect the data you need to produce a scrolling animation—for example, in response to a fling gesture. Scrollers track scroll offsets for you over time, but they don't automatically apply those positions to your view. It's your responsibility to get and apply new coordinates at a rate that will make the scrolling animation look smooth.

Here is a simple example:

 private Scroller mScroller = new Scroller(context);
 ...
 public void zoomIn() {
     // Revert any animation currently in progress
     mScroller.forceFinished(true);
     // Start scrolling by providing a starting point and
     // the distance to travel
     mScroller.startScroll(0, 0, 100, 0);
     // Invalidate to request a redraw
     invalidate();
 }

To track the changing positions of the x/y coordinates, use computeScrollOffset(). The method returns a boolean to indicate whether the scroller is finished. If it isn't, it means that a fling or programmatic pan operation is still in progress. You can use this method to find the current offsets of the x and y coordinates, for example:

if (mScroller.computeScrollOffset()) {
     // Get current x and y positions
     int currX = mScroller.getCurrX();
     int currY = mScroller.getCurrY();
    ...
 }

Summary

Public constructors

public Scroller (Context context)

public Scroller (Context context, 
                Interpolator interpolator)

public Scroller (Context context, 
                Interpolator interpolator, 
                boolean flywheel)

Public methods

public void abortAnimation ()

public boolean computeScrollOffset ()

public void extendDuration (int extend)

public void fling (int startX, 
                int startY, 
                int velocityX, 
                int velocityY, 
                int minX, 
                int maxX, 
                int minY, 
                int maxY)

public final void forceFinished (boolean finished)

public float getCurrVelocity ()

public final int getCurrX ()

public final int getCurrY ()

public final int getDuration ()

public final int getFinalX ()

public final int getFinalY ()

public final int getStartX ()

public final int getStartY ()

public final boolean isFinished ()

public void setFinalX (int newX)

public void setFinalY (int newY)

public final void setFriction (float friction)

public void startScroll (int startX, 
                int startY, 
                int dx, 
                int dy, 
                int duration)

public void startScroll (int startX, 
                int startY, 
                int dx, 
                int dy)

public int timePassed ()