Build 1.0_r1(from source)

android.widget
Class Scroller

java.lang.Object
  extended by android.widget.Scroller

public class Scroller
extends Object

This class encapsulates scrolling. The duration of the scroll can be passed in the constructor and specifies the maximum time that the scrolling animation should take. Past this time, the scrolling is automatically moved to its final stage and computeScrollOffset() will always return false to indicate that scrolling is over.


Constructor Summary
Scroller(Context context)
          Create a Scroller with the default duration and interpolator.
Scroller(Context context, Interpolator interpolator)
          Create a Scroller with the specified interpolator.
 
Method Summary
 void abortAnimation()
           
 boolean computeScrollOffset()
          Call this when you want to know the new location.
 void extendDuration(int extend)
          Extend the scroll animation.
 void fling(int startX, int startY, int velocityX, int velocityY, int minX, int maxX, int minY, int maxY)
          Start scrolling based on a fling gesture.
 void forceFinished(boolean finished)
          Force the finished field to a particular value.
 int getCurrX()
          Returns the current X offset in the scroll.
 int getCurrY()
          Returns the current Y offset in the scroll.
 int getDuration()
          Returns how long the scroll event will take, in milliseconds.
 int getFinalX()
          Returns where the scroll will end.
 int getFinalY()
          Returns where the scroll will end.
 boolean isFinished()
          Returns whether the scroller has finished scrolling.
 void setFinalX(int newX)
           
 void setFinalY(int newY)
           
 void startScroll(int startX, int startY, int dx, int dy)
          Start scrolling by providing a starting point and the distance to travel.
 void startScroll(int startX, int startY, int dx, int dy, int duration)
          Start scrolling by providing a starting point and the distance to travel.
 int timePassed()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

Scroller

public Scroller(Context context)
Create a Scroller with the default duration and interpolator.


Scroller

public Scroller(Context context,
                Interpolator interpolator)
Create a Scroller with the specified interpolator. If the interpolator is null, the default (viscous) interpolator will be used.

Method Detail

isFinished

public final boolean isFinished()
Returns whether the scroller has finished scrolling.

Returns:
True if the scroller has finished scrolling, false otherwise.

forceFinished

public final void forceFinished(boolean finished)
Force the finished field to a particular value.

Parameters:
finished - The new finished value.

getDuration

public final int getDuration()
Returns how long the scroll event will take, in milliseconds.

Returns:
The duration of the scroll in milliseconds.

getCurrX

public final int getCurrX()
Returns the current X offset in the scroll.

Returns:
The new X offset as an absolute distance from the origin.

getCurrY

public final int getCurrY()
Returns the current Y offset in the scroll.

Returns:
The new Y offset as an absolute distance from the origin.

getFinalX

public final int getFinalX()
Returns where the scroll will end. Valid only for "fling" scrolls.

Returns:
The final X offset as an absolute distance from the origin.

getFinalY

public final int getFinalY()
Returns where the scroll will end. Valid only for "fling" scrolls.

Returns:
The final Y offset as an absolute distance from the origin.

computeScrollOffset

public boolean computeScrollOffset()
Call this when you want to know the new location. If it returns true, the animation is not yet finished. loc will be altered to provide the new location.


startScroll

public void startScroll(int startX,
                        int startY,
                        int dx,
                        int dy)
Start scrolling by providing a starting point and the distance to travel. The scroll will use the default value of 250 milliseconds for the duration.

Parameters:
startX - Starting horizontal scroll offset in pixels. Positive numbers will scroll the content to the left.
startY - Starting vertical scroll offset in pixels. Positive numbers will scroll the content up.
dx - Horizontal distance to travel. Positive numbers will scroll the content to the left.
dy - Vertical distance to travel. Positive numbers will scroll the content up.

startScroll

public void startScroll(int startX,
                        int startY,
                        int dx,
                        int dy,
                        int duration)
Start scrolling by providing a starting point and the distance to travel.

Parameters:
startX - Starting horizontal scroll offset in pixels. Positive numbers will scroll the content to the left.
startY - Starting vertical scroll offset in pixels. Positive numbers will scroll the content up.
dx - Horizontal distance to travel. Positive numbers will scroll the content to the left.
dy - Vertical distance to travel. Positive numbers will scroll the content up.
duration - Duration of the scroll in milliseconds.

fling

public void fling(int startX,
                  int startY,
                  int velocityX,
                  int velocityY,
                  int minX,
                  int maxX,
                  int minY,
                  int maxY)
Start scrolling based on a fling gesture. The distance travelled will depend on the initial velocity of the fling.

Parameters:
startX - Starting point of the scroll (X)
startY - Starting point of the scroll (Y)
velocityX - Initial velocity of the fling (X) measured in pixels per second.
velocityY - Initial velocity of the fling (Y) measured in pixels per second
minX - Minimum X value. The scroller will not scroll past this point.
maxX - Maximum X value. The scroller will not scroll past this point.
minY - Minimum Y value. The scroller will not scroll past this point.
maxY - Maximum Y value. The scroller will not scroll past this point.

abortAnimation

public void abortAnimation()

extendDuration

public void extendDuration(int extend)
Extend the scroll animation. This allows a running animation to scroll further and longer, when used with setFinalX() or setFinalY().

Parameters:
extend - Additional time to scroll in milliseconds.

timePassed

public int timePassed()

setFinalX

public void setFinalX(int newX)

setFinalY

public void setFinalY(int newY)

Build 1.0_r1(from source)

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