/**
* @ClassName: MatrixImageView
* @Description: 带放大、缩小、移动效果的ImageView
* @author LinJ
* @date 2015-1-7 上午11:15:07
*
*/
public class MatrixImageView extends ImageView{
private final static String TAG="MatrixImageView";
private GestureDetector mGestureDetector;
/** 模板Matrix，用以初始化 */
private Matrix mMatrix=new Matrix();
/** 图片长度*/
private float mImageWidth;
/** 图片高度 */
private float mImageHeight;
public MatrixImageView(Context context, AttributeSet attrs) {
super(context, attrs);
MatrixTouchListener mListener=new MatrixTouchListener();
setOnTouchListener(mListener);
mGestureDetector=new GestureDetector(getContext(), new GestureListener(mListener));
//背景设置为balck
setBackgroundColor(Color.BLACK);
//将缩放类型设置为FIT_CENTER，表示把图片按比例扩大/缩小到View的宽度，居中显示
setScaleType(ScaleType.FIT_CENTER);
}
@Override
public void setImageBitmap(Bitmap bm) {
// TODO Auto-generated method stub
super.setImageBitmap(bm);
//设置完图片后，获取该图片的坐标变换矩阵
mMatrix.set(getImageMatrix());
float[] values=new float[9];
mMatrix.getValues(values);
//图片宽度为屏幕宽度除缩放倍数
mImageWidth=getWidth()/values[Matrix.MSCALE_X];
mImageHeight=(getHeight()-values[Matrix.MTRANS_Y]*2)/values[Matrix.MSCALE_Y];
}
public class MatrixTouchListener implements OnTouchListener{
/** 拖拉照片模式 */
private static final int MODE_DRAG = 1;
/** 放大缩小照片模式 */
private static final int MODE_ZOOM = 2;
/** 不支持Matrix */
private static final int MODE_UNABLE=3;
/** 最大缩放级别*/
float mMaxScale=6;
/** 双击时的缩放级别*/
float mDobleClickScale=2;
private int mMode = 0;//
/** 缩放开始时的手指间距 */
private float mStartDis;
/** 当前Matrix*/
private Matrix mCurrentMatrix = new Matrix();
/** 用于记录开始时候的坐标位置 */
private PointF startPoint = new PointF();
@Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
switch (event.getActionMasked()) {
case MotionEvent.ACTION_DOWN:
//设置拖动模式
mMode=MODE_DRAG;
startPoint.set(event.getX(), event.getY());
isMatrixEnable();
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
reSetMatrix();
break;
case MotionEvent.ACTION_MOVE:
if (mMode == MODE_ZOOM) {
setZoomMatrix(event);
}else if (mMode==MODE_DRAG) {
setDragMatrix(event);
}
break;
case MotionEvent.ACTION_POINTER_DOWN:
if(mMode==MODE_UNABLE) return true;
mMode=MODE_ZOOM;
mStartDis = distance(event);
break;
default:
break;
}
return mGestureDetector.onTouchEvent(event);
}
public void setDragMatrix(MotionEvent event) {
if(isZoomChanged()){
float dx = event.getX() - startPoint.x; // 得到x轴的移动距离
float dy = event.getY() - startPoint.y; // 得到x轴的移动距离
//避免和双击冲突,大于10f才算是拖动
if(Math.sqrt(dx*dx+dy*dy)>10f){
startPoint.set(event.getX(), event.getY());
//在当前基础上移动
mCurrentMatrix.set(getImageMatrix());
float[] values=new float[9];
mCurrentMatrix.getValues(values);
dx=checkDxBound(values,dx);
dy=checkDyBound(values,dy);
mCurrentMatrix.postTranslate(dx, dy);
setImageMatrix(mCurrentMatrix);
}
}
}
/**
* 判断缩放级别是否是改变过
* @return true表示非初始值,false表示初始值
*/
private boolean isZoomChanged() {
float[] values=new float[9];
getImageMatrix().getValues(values);
//获取当前X轴缩放级别
float scale=values[Matrix.MSCALE_X];
//获取模板的X轴缩放级别，两者做比较
mMatrix.getValues(values);
return scale!=values[Matrix.MSCALE_X];
}
/**
* 和当前矩阵对比，检验dy，使图像移动后不会超出ImageView边界
* @param values
* @param dy
* @return
*/
private float checkDyBound(float[] values, float dy) {
float height=getHeight();
if(mImageHeight*values[Matrix.MSCALE_Y]<height)
return 0;
if(values[Matrix.MTRANS_Y]+dy>0)
dy=-values[Matrix.MTRANS_Y];
else if(values[Matrix.MTRANS_Y]+dy<-(mImageHeight*values[Matrix.MSCALE_Y]-height))
dy=-(mImageHeight*values[Matrix.MSCALE_Y]-height)-values[Matrix.MTRANS_Y];
return dy;
}
/**
*和当前矩阵对比，检验dx，使图像移动后不会超出ImageView边界
* @param values
* @param dx
* @return
*/
private float checkDxBound(float[] values,float dx) {
float width=getWidth();
if(mImageWidth*values[Matrix.MSCALE_X]<width)
return 0;
if(values[Matrix.MTRANS_X]+dx>0)
dx=-values[Matrix.MTRANS_X];
else if(values[Matrix.MTRANS_X]+dx<-(mImageWidth*values[Matrix.MSCALE_X]-width))
dx=-(mImageWidth*values[Matrix.MSCALE_X]-width)-values[Matrix.MTRANS_X];
return dx;
}
/**
* 设置缩放Matrix
* @param event
*/
private void setZoomMatrix(MotionEvent event) {
//只有同时触屏两个点的时候才执行
if(event.getPointerCount()<2) return;
float endDis = distance(event);// 结束距离
if (endDis > 10f) { // 两个手指并拢在一起的时候像素大于10
float scale = endDis / mStartDis;// 得到缩放倍数
mStartDis=endDis;//重置距离
mCurrentMatrix.set(getImageMatrix());//初始化Matrix
float[] values=new float[9];
mCurrentMatrix.getValues(values);
scale = checkMaxScale(scale, values);
setImageMatrix(mCurrentMatrix);
}
}
/**
* 检验scale，使图像缩放后不会超出最大倍数
* @param scale
* @param values
* @return
*/
private float checkMaxScale(float scale, float[] values) {
if(scale*values[Matrix.MSCALE_X]>mMaxScale)
scale=mMaxScale/values[Matrix.MSCALE_X];
mCurrentMatrix.postScale(scale, scale,getWidth()/2,getHeight()/2);
return scale;
}
/**
* 重置Matrix
*/
private void reSetMatrix() {
if(checkRest()){
mCurrentMatrix.set(mMatrix);
setImageMatrix(mCurrentMatrix);
}
}
/**
* 判断是否需要重置
* @return 当前缩放级别小于模板缩放级别时，重置
*/
private boolean checkRest() {
// TODO Auto-generated method stub
float[] values=new float[9];
getImageMatrix().getValues(values);
//获取当前X轴缩放级别
float scale=values[Matrix.MSCALE_X];
//获取模板的X轴缩放级别，两者做比较
mMatrix.getValues(values);
return scale<values[Matrix.MSCALE_X];
}
/**
* 判断是否支持Matrix
*/
private void isMatrixEnable() {
//当加载出错时，不可缩放
if(getScaleType()!=ScaleType.CENTER){
setScaleType(ScaleType.MATRIX);
}else {
mMode=MODE_UNABLE;//设置为不支持手势
}
}
/**
* 计算两个手指间的距离
* @param event
* @return
*/
private float distance(MotionEvent event) {
float dx = event.getX(1) - event.getX(0);
float dy = event.getY(1) - event.getY(0);
/** 使用勾股定理返回两点之间的距离 */
return (float) Math.sqrt(dx * dx + dy * dy);
}
/**
* 双击时触发
*/
public void onDoubleClick(){
float scale=isZoomChanged()?1:mDobleClickScale;
mCurrentMatrix.set(mMatrix);//初始化Matrix
mCurrentMatrix.postScale(scale, scale,getWidth()/2,getHeight()/2);
setImageMatrix(mCurrentMatrix);
}
}
private class GestureListener extends SimpleOnGestureListener{
private final MatrixTouchListener listener;
public GestureListener(MatrixTouchListener listener) {
this.listener=listener;
}
@Override
public boolean onDown(MotionEvent e) {
//捕获Down事件
return true;
}
@Override
public boolean onDoubleTap(MotionEvent e) {
//触发双击事件
listener.onDoubleClick();
return true;
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
// TODO Auto-generated method stub
return super.onSingleTapUp(e);
}
@Override
public void onLongPress(MotionEvent e) {
// TODO Auto-generated method stub
super.onLongPress(e);
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
return super.onScroll(e1, e2, distanceX, distanceY);
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
// TODO Auto-generated method stub
return super.onFling(e1, e2, velocityX, velocityY);
}
@Override
public void onShowPress(MotionEvent e) {
// TODO Auto-generated method stub
super.onShowPress(e);
}
@Override
public boolean onDoubleTapEvent(MotionEvent e) {
// TODO Auto-generated method stub
return super.onDoubleTapEvent(e);
}
@Override
public boolean onSingleTapConfirmed(MotionEvent e) {
// TODO Auto-generated method stub
return super.onSingleTapConfirmed(e);
}
}
}
