与Android Surfacech捏缩放效果

Question

我想缩放SurfaceView，这样我们可以视频播放器和相机too.I搜索了很多，但没有找到任何适当的指导原则。有问题的问题已被问到与此有关，但没有适当的解决方案我发现。实际上对于捏缩放我们使用矩阵，但问题是SurfaceView不支持Matrix.so任何可以告诉我如何做到这一点。我通过this PinchZoom。

你正确的指导方针将是巨大的appreciated.Thanks

Answer 1

可以正确设置MarginLayoutParams。详情请参阅以下源代码

/** 
* sonle.evizi 
*/ 
package com.philips.cl.insight; 

import android.graphics.PointF; 
import android.util.Log; 
import android.view.MotionEvent; 
import android.view.View; 
import android.view.View.OnTouchListener; 
import android.view.ViewGroup.MarginLayoutParams; 
import android.widget.FrameLayout; 

public class PanAndZoomListener1 implements OnTouchListener { 

    private enum Anchor { 
     NONE, LEFT, TOP, RIGHT, BOTTOM, LEFT_TOP, TOP_RIGHT, RIGHT_BOTTOM, LEFT_BOTTOM 
    } 

    private static final float SPACE_ZOOM = 10f; 
    private static final float SPACE_DRAG = 5f; 
    private static final float ZOOM_MAX = 8f; 
    private static final String TAG = "PanAndZoomListener"; 
    // We can be in one of these 3 states 
    static final int CLICK = 0; 
    static final int DRAG = 1; 
    static final int ZOOM = 2; 
    static final int NONE = 3; 
    int mode = NONE; 

    // Remember some things for zooming 
    PointF start = new PointF(); 
    PointF midPoint = new PointF(); 
    float oldDist = 1f; 
    MarginLayoutParams oldParams; 

    LiveStreamingActivity liveStreamingActivity; 
    View parentView; 
    View child; 

    public PanAndZoomListener1(FrameLayout containter, View surfaceView, 
     LiveStreamingActivity liveStreamingActivity) { 
     this.liveStreamingActivity = liveStreamingActivity; 
     this.parentView = containter; 
     this.child = surfaceView; 
    } 

    public boolean onTouch(View view, MotionEvent event) { 
     // Handle touch events here... 
     switch (event.getActionMasked()) { 
     case MotionEvent.ACTION_DOWN: 
      initDragInfo(view, event); 
      Log.i(TAG, "======ACTION_DOWN - CLICK ======" + event.getActionIndex()); 
      mode = CLICK; 
      break; 

     case MotionEvent.ACTION_POINTER_DOWN: 
      Log.i(TAG, "======ACTION_POINTER_1_DOWN======"); 
      oldDist = spacing(event.getX(0), event.getY(0), event.getX(1), event.getY(1)); 
      Log.i(TAG, "========oldDist:" + oldDist + "========="); 
      if (oldDist < SPACE_ZOOM) { 
       mode = NONE; 
      } else { 
       mode = ZOOM; 
       initZoomInfo(view, event); 
      } 
      break; 

     case MotionEvent.ACTION_POINTER_UP: 
      mode = NONE; 
      break; 

     case MotionEvent.ACTION_UP: 
      Log.i(TAG, "ACTION_UP"); 

      if (mode == CLICK) { 
       Log.i(TAG, "mode= onTouchDitect"); 
       liveStreamingActivity.onTouchDitect(); 
      } 
      mode = NONE; 
      break; 

     case MotionEvent.ACTION_MOVE: 
      if (mode == CLICK) { 
       if (spacing(start.x, start.y, event.getRawX(), event.getRawY()) >= SPACE_DRAG) { 
        mode = DRAG; 
       } else { 
        Log.i(TAG, "======ACTION_MOVE - CLICK======"); 
        break; 
       } 
      } 

      if (mode == DRAG) { 
       Log.i(TAG, "======ACTION_MOVE - DRAG======"); 
       doPan(event.getRawX() - start.x, event.getRawY() - start.y); 
       break; 
      } 

      if (mode == ZOOM) { 
       Log.i(TAG, "======ACTION_MOVE - ZOOM======"); 

       float newDist = spacing(event.getX(0), event.getY(0), event.getX(1), event.getY(1)); 
       if (newDist >= SPACE_ZOOM) { 
        doZoom(newDist); 
       } 
      } 
      break; 
     } 
     return true; // indicate event was handled 
    } 

    private void initDragInfo(View view, MotionEvent event) { 
     start.set(event.getRawX(), event.getRawY()); 
     // Initialize start motion info 
     oldParams = new MarginLayoutParams((MarginLayoutParams) child.getLayoutParams()); 
     oldParams.width = child.getWidth(); 
     oldParams.height = child.getHeight(); 
    } 

    // Caculate the space between two points 
    private float spacing(float x0, float y0, float x1, float y1) { 
     float x = x0 - x1; 
     float y = y0 - y1; 
     return (float) Math.sqrt(x * x + y * y); 
    } 

    // Calculate the mid point of the first two fingers 
    private void initZoomInfo(View view, MotionEvent event) { 
     midPoint.set((event.getX(0) + event.getX(1))/2, (event.getY(0) + event.getY(1))/2); 

     // Initialize start motion info 
     oldParams = new MarginLayoutParams((MarginLayoutParams) child.getLayoutParams()); 
     oldParams.width = child.getWidth(); 
     oldParams.height = child.getHeight(); 
    } 

    public void doZoom(float newDist) { 
     Anchor anchor = Anchor.NONE; 
     /* 
     Log.i(TAG, "=======MID POINT: " + midPoint.x + "; " + midPoint.y + "============"); 
     Log.i(TAG, "=======CHILD VIEW WIDTH: " + child.getWidth() + "============"); 
     */ 

     MarginLayoutParams childParams = (MarginLayoutParams) child.getLayoutParams(); 

     // Log.i(TAG, "=======CHILD VIEW LEFT MARGIN: " + childParams.leftMargin + "============"); 

     float scale = newDist/oldDist; 

     int oriWidth = parentView.getWidth(); 
     int oriHeight = parentView.getHeight(); 
     float tempWidth = oldParams.width * scale; 
     float tempHeight = tempWidth * oriHeight/oriWidth; 

     if (tempWidth < oriWidth || tempWidth > oriWidth * ZOOM_MAX) { 
      return; 
     } 

     childParams.width = (int) tempWidth; 
     childParams.height = (int) tempHeight; 

     float x1 = midPoint.x + oldParams.leftMargin; 
     float x2 = oriWidth - x1; 
     float y1 = midPoint.y + oldParams.topMargin; 
     float y2 = oriHeight - y1; 

     if (midPoint.x * scale <= x1) { 
      anchor = Anchor.LEFT; 
     } else if ((oldParams.width - midPoint.x) * scale <= x2) { 
      anchor = Anchor.RIGHT; 
     } 

     if (midPoint.y * scale <= y1) { 
      if (anchor == Anchor.LEFT) { 
       anchor = Anchor.LEFT_TOP; 
      } else if (anchor == Anchor.RIGHT) { 
       anchor = Anchor.TOP_RIGHT; 
      } else { 
       anchor = Anchor.TOP; 
      } 
     } else if ((oldParams.height - midPoint.y) * scale <= y2) { 
      if (anchor == Anchor.LEFT) { 
       anchor = Anchor.LEFT_BOTTOM; 
      } else if (anchor == Anchor.RIGHT) { 
       anchor = Anchor.RIGHT_BOTTOM; 
      } else { 
       anchor = Anchor.BOTTOM; 
      } 
     } 

     switch (anchor) { 
     case BOTTOM: 
      childParams.leftMargin = (int) (x1 - midPoint.x * scale); 
      childParams.topMargin = (int) (oriHeight - tempHeight); 
      break; 
     case LEFT: 
      childParams.leftMargin = 0; 
      childParams.topMargin = (int) (y1 - midPoint.y * scale); 
      break; 
     case LEFT_BOTTOM: 
      childParams.leftMargin = 0; 
      childParams.topMargin = (int) (oriHeight - tempHeight); 
      break; 
     case LEFT_TOP: 
      childParams.leftMargin = 0; 
      childParams.topMargin = 0; 
      break; 
     case NONE: 
      childParams.leftMargin = (int) (x1 - midPoint.x * scale); 
      childParams.topMargin = (int) (y1 - midPoint.y * scale); 
      break; 
     case RIGHT: 
      childParams.leftMargin = (int) (oriWidth - tempWidth); 
      childParams.topMargin = (int) (y1 - midPoint.y * scale); 
      break; 
     case RIGHT_BOTTOM: 
      childParams.leftMargin = (int) (oriWidth - tempWidth); 
      childParams.topMargin = (int) (oriHeight - tempHeight); 
      break; 
     case TOP: 
      childParams.leftMargin = (int) (x1 - midPoint.x * scale); 
      childParams.topMargin = 0; 
      break; 
     case TOP_RIGHT: 
      childParams.topMargin = 0; 
      childParams.leftMargin = (int) (oriWidth - tempWidth); 
      break; 
     default: 
      break; 
     } 

     child.setLayoutParams(childParams); 
    } 

    public void doPan(float panX, float panY) { 
     Anchor anchor = Anchor.NONE; 
     MarginLayoutParams childParams = (MarginLayoutParams) child.getLayoutParams(); 

     if (oldParams.width <= parentView.getWidth()) { 
      return; 
     } 

     if (oldParams.leftMargin + panX >= 0) { 
      anchor = Anchor.LEFT; 
     } else if (oldParams.leftMargin + panX + oldParams.width <= parentView.getWidth()) { 
      anchor = Anchor.RIGHT; 
     } 

     if (oldParams.topMargin + panY >= 0) { 
      if (anchor == Anchor.LEFT) { 
       anchor = Anchor.LEFT_TOP; 
      } else if (anchor == Anchor.RIGHT) { 
       anchor = Anchor.TOP_RIGHT; 
      } else { 
       anchor = Anchor.TOP; 
      } 
     } else if (oldParams.topMargin + panY + oldParams.height <= parentView.getHeight()) { 
      if (anchor == Anchor.LEFT) { 
       anchor = Anchor.LEFT_BOTTOM; 
      } else if (anchor == Anchor.RIGHT) { 
       anchor = Anchor.RIGHT_BOTTOM; 
      } else { 
       anchor = Anchor.BOTTOM; 
      } 
     } 

     switch (anchor) { 
     case BOTTOM: 
     case TOP: 
      childParams.leftMargin = (int) (oldParams.leftMargin + panX); 
      break; 
     case LEFT: 
     case RIGHT: 
      childParams.topMargin = (int) (oldParams.topMargin + panY); 
      break; 
     case NONE: 
      childParams.topMargin = (int) (oldParams.topMargin + panY); 
      childParams.leftMargin = (int) (oldParams.leftMargin + panX); 
      break; 
     case LEFT_BOTTOM: 
     case LEFT_TOP: 
     case RIGHT_BOTTOM: 
     case TOP_RIGHT: 
      break; 
     default: 
      break; 
     } 
     child.setLayoutParams(childParams); 
    } 
}