MyGallery.java

package coolbuy360.control;

import android.content.Context;
import android.graphics.Matrix;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.Log;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.widget.Gallery;

/**
 * android.widget.Gallery���Ӻ������������Ҫ��
 * @author chenlw
 *
 */
public class MyGallery extends Gallery {
	/**
	 * GestureDetector��
	 * ��onTouch()�����У����ǵ���GestureDetector��onTouchEvent()������
	 * ����׽����MotionEvent����GestureDetector  
     * �������Ƿ��к��ʵ�callback�����������û�������  
	 */
	private GestureDetector gestureScanner; 
	private MyImageView imageView;

	public MyGallery(Context context) {
		super(context);

	}

	public MyGallery(Context context, AttributeSet attrs, int defStyle) {
		super(context, attrs, defStyle);
	}

	public MyGallery(Context context, AttributeSet attrs) {
		super(context, attrs);

		gestureScanner = new GestureDetector(new MySimpleGesture());
		this.setOnTouchListener(new OnTouchListener() {

			float baseValue;
			float originalScale;

			//��дonTouch����ʵ������
			@Override
			public boolean onTouch(View v, MotionEvent event) {
				View view = MyGallery.this.getSelectedView();
				if (view instanceof MyImageView) {
					imageView = (MyImageView) view;

					if (event.getAction() == MotionEvent.ACTION_DOWN) {
						baseValue = 0;
						originalScale = imageView.getScale();
					}
					if (event.getAction() == MotionEvent.ACTION_MOVE) {
						//�����϶�
						if (event.getPointerCount() == 2) {
							float x = event.getX(0) - event.getX(1);
							float y = event.getY(0) - event.getY(1);
							float value = (float) Math.sqrt(x * x + y * y);// ��������ľ���
							// System.out.println("value:" + value);
							if (baseValue == 0) {
								baseValue = value;
							} else {
								float scale = value / baseValue;// ��ǰ�����ľ��������ָ����ʱ�����ľ��������Ҫ���ŵı�����
								// scale the image
								imageView.zoomTo(originalScale * scale, x + event.getX(1), y + event.getY(1));

							}
						}
					}
				}
				return false;
			}

		});
	}
	@Override
	public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
		View view = MyGallery.this.getSelectedView();
		if (view instanceof MyImageView) {
			imageView = (MyImageView) view;

			float v[] = new float[9];
			Matrix m = imageView.getImageMatrix();
			m.getValues(v);
			// ͼƬʵʱ��������������
			float left, right;
			// ͼƬ��ʵʱ����
			float width, height;
			width = imageView.getScale() * imageView.getImageWidth();
			height = imageView.getScale() * imageView.getImageHeight();
			// �����߼�Ϊ�ƶ�ͼƬ�ͻ���gallery�������߼������û����������˽�ķdz������������´���
			if ((int) width <= MyShowImgDialog.screenW && (int) height <= MyShowImgDialog.screenH)// ���ͼƬ��ǰ��С<��Ļ��С��ֱ�Ӵ������¼�
			{
				super.onScroll(e1, e2, distanceX, distanceY);
			} else {
				left = v[Matrix.MTRANS_X];
				right = left + width;
				Rect r = new Rect();
				imageView.getGlobalVisibleRect(r);

//				if (distanceX > 0)// ���󻬶�
//				{
//					if (r.left > 0) {// �жϵ�ǰImageView�Ƿ���ʾ��ȫ
//						super.onScroll(e1, e2, distanceX, distanceY);
//					} else if (right < MianActivity.screenWidth) {
//						super.onScroll(e1, e2, distanceX, distanceY);
//					} else {
//						imageView.postTranslate(-distanceX, -distanceY);
//					}
//				} else if (distanceX < 0)// ���һ���
//				{
//					if (r.right < MianActivity.screenWidth) {
//						super.onScroll(e1, e2, distanceX, distanceY);
//					} else if (left > 0) {
//						super.onScroll(e1, e2, distanceX, distanceY);
//					} else {
//						imageView.postTranslate(-distanceX, -distanceY);
//					}
//				}
				
				if (distanceX > 0)// ���󻬶�
				{
				if (r.left > 0) {// �жϵ�ǰImageView�Ƿ���ʾ��ȫ
				super.onScroll(e1, e2, distanceX, distanceY);
				} else if (right <= MyShowImgDialog.screenW) {
				super.onScroll(e1, e2, distanceX, distanceY);
				} else {
				imageView.postTranslate(-distanceX, -distanceY);
				}
				} else if (distanceX < 0)// ���һ���
				{
				if (r.right == 0) {
				super.onScroll(e1, e2, distanceX, distanceY);
				} else {
				imageView.postTranslate(-distanceX, -distanceY);
				}
				}
			}

		} else {
			super.onScroll(e1, e2, distanceX, distanceY);
		}
		return false;
	}
	@Override
	public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
		return false;// ��������ȫ����fling
		}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		gestureScanner.onTouchEvent(event);
		switch (event.getAction()) {
		case MotionEvent.ACTION_UP:
			// �ж����±߽��Ƿ�Խ��
			View view = MyGallery.this.getSelectedView();
			if (view instanceof MyImageView) {
				imageView = (MyImageView) view;
				float width = imageView.getScale() * imageView.getImageWidth();
				float height = imageView.getScale() * imageView.getImageHeight();
				if ((int) width <= MyShowImgDialog.screenW && (int) height <= MyShowImgDialog.screenH)// ���ͼƬ��ǰ��С<��Ļ��С���жϱ߽�
				{
					break;
				}
				float v[] = new float[9];
				Matrix m = imageView.getImageMatrix();
				m.getValues(v);
				float top = v[Matrix.MTRANS_Y];
				float bottom = top + height;
				if (top > 0) {
					imageView.postTranslateDur(-top, 200f);
				}
				Log.i("lyc", "bottom:" + bottom);
				if (bottom < MyShowImgDialog.screenH) {
					imageView.postTranslateDur(MyShowImgDialog.screenH - bottom, 200f);
				}
			}
			break;
		}
		return super.onTouchEvent(event);
	}

	private class MySimpleGesture extends SimpleOnGestureListener {
		// �����µĵڶ���Touch downʱ����
		public boolean onDoubleTap(MotionEvent e) {
			View view = MyGallery.this.getSelectedView();
			if (view instanceof MyImageView) {
				imageView = (MyImageView) view;
				if (imageView.getScale() > imageView.getScaleRate()) {
					imageView.zoomTo(imageView.getScaleRate(), MyShowImgDialog.screenW / 2, MyShowImgDialog.screenH / 2, 200f);
					// imageView.layoutToCenter();
				} else {
					imageView.zoomTo(1.0f, MyShowImgDialog.screenW / 2, MyShowImgDialog.screenH / 2, 200f);
				}
			} else {
			}
			// return super.onDoubleTap(e);
			return true;
		}
	}
}