6

ピンチズームとドラッグを使用するアプリを構築しています。問題は、今のところ、画像を境界の外にドラッグできることです。ドラッグを使用して、同時に画像が画面にとどまるようにする方法を知りたかったのです。

これが私のコードです:

public boolean onTouch(View v, MotionEvent event) {
      ImageView view = (ImageView)v;
      //handle touch events here.
      switch (event.getAction() & MotionEvent.ACTION_MASK) {
       case MotionEvent.ACTION_DOWN:
          savedMatrix.set(matrix);
          start.set(event.getX(), event.getY());
          Log.d(TAG, "mode=DRAG" );
          mode = DRAG;
          break;
       case MotionEvent.ACTION_POINTER_DOWN:
           oldDist = spacing(event);
           Log.d(TAG, "oldDist=" + oldDist);
           if (oldDist > 10f) {
              savedMatrix.set(matrix);
              midPoint(mid, event);
              mode = ZOOM;
              Log.d(TAG, "mode=ZOOM" );
           }
           break;
       case MotionEvent.ACTION_UP:
       case MotionEvent.ACTION_POINTER_UP:
          mode = NONE;
          Log.d(TAG, "mode=NONE" );
          break;
       case MotionEvent.ACTION_MOVE:
          if (mode == DRAG) {
             matrix.set(savedMatrix);
             matrix.postTranslate(event.getX() - start.x,
             event.getY() - start.y);
          }
          else if (mode == ZOOM) {
              Float newDist = spacing(event);
              Log.d(TAG, "newDist=" + newDist);
              if (newDist > 10f) {
                 matrix.set(savedMatrix);
                 Float scale = newDist / oldDist;

                 Matrix temp = new Matrix();
                 temp.set(matrix);
                 temp.postScale(scale, scale, mid.x, mid.y);
                 float[] f = new float[9];
                 temp.getValues(f);
                 Float xScale = f[0];
                 if(xScale >= 1 && xScale <= 10){
                     matrix.postScale(scale, scale, mid.x, mid.y);
                     savedMatrixZoom.set(matrix);
                 }else{
                     matrix.set(savedMatrixZoom);

              }

              }
          break;
          }       
     } //perform the transformation.

     view.setImageMatrix(matrix);
     return true; // indicate event was handled  
}
4

2 に答える 2

2

マトリックスを更新する前に、画面の寸法を取得し、MotionEvent 座標がこれらの範囲内にあることを確認してください。

何かのようなもの..

DisplayMetrics displaymetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
int screenHight = displaymetrics.heightPixels;
int screenWidth = displaymetrics.widthPixels;

   ...
   case MotionEvent.ACTION_MOVE:

      if (mode == DRAG) {

         int newX = event.getX() - start.x;
         int newY = event.getY() - start.y;
         if ( (newX <= 0 || newX >= screenWidth) ||
              (newY <= 0 || newY >= screenHeight) )
             break;

         matrix.set(savedMatrix);
         matrix.postTranslate(newX, newY);
      }
   ...
于 2012-02-02T13:04:01.810 に答える
1 
public boolean onTouch(View v, MotionEvent event) {
        int action = event.getAction();

        DisplayMetrics displaymetrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
        int sH = displaymetrics.heightPixels;
        int sW = displaymetrics.widthPixels;
        float dx, dy, newX, newY;

        switch (action) {
            case MotionEvent.ACTION_DOWN:
                dx = event.getRawX() - v.getX();
                dy = event.getRawY() - v.getY();
                break;

            case MotionEvent.ACTION_MOVE:
                newX = event.getRawX() - dx;
                newY = event.getRawY() - dy;

                if ((newX <= 0 || newX >= sW-v.getWidth()) || (newY <= 0 || newY >= sH-v.getHeight()))
                    break;

                v.setX(newX);
                v.setY(newY);
                break;   

            default:
                break;
        }

        return true;
    }
于 2016-01-26T06:12:16.710 に答える