DEV [component] ProgressAnimationField

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Đây là một samples dùng để hiển thị ảnh động từ một ảnh bitmap nhiều frame...

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Mã:

import net.rim.device.api.system.*;
import net.rim.device.api.ui.*;
 
 
public class ProgressAnimationField extends Field implements Runnable
{
    private Bitmap _bitmap;
    private int _numFrames;
    private int _frameWidth;
    private int _frameHeight;
 
    private int _currentFrame;
    private int _timerID = -1;
 
    private Application _application;
    private boolean _visible;
   
    public ProgressAnimationField( Bitmap bitmap, int numFrames, long style )
    {
        super( style | Field.NON_FOCUSABLE );
        _bitmap = bitmap;
        _numFrames = numFrames;
        _frameWidth = _bitmap.getWidth() / _numFrames;
        _frameHeight = _bitmap.getHeight();
 
        _application = Application.getApplication();
    }
 
    public void run()
    {
        if( _visible ) {
            invalidate();
        }
    }
 
    protected void layout( int width, int height )
    {
        setExtent( _frameWidth, _frameHeight );
    }
 
    protected void paint( Graphics g )
    {
        g.drawBitmap( 0, 0, _frameWidth, _frameHeight, _bitmap, _frameWidth * _currentFrame, 0 );
        _currentFrame++;
        if( _currentFrame >= _numFrames ) {
            _currentFrame = 0;
        }
    }
 
    protected void onDisplay()
    {
        super.onDisplay();
        _visible = true;
        if( _timerID == -1 ) {
            _timerID = _application.invokeLater( this, 200, true );
        }
    }
 
    protected void onUndisplay()
    {
        super.onUndisplay();
        _visible = false;
        if( _timerID != -1 ) {
            _application.cancelInvokeLater( _timerID );
            _timerID = -1;
        }
    }
}