2012-08-30 60 views
0

我已经在这里搜索了很多,但还没有找到解决方案。所以事情是,我有一个图像3000 * 3000像素,我把它设置为比例矩阵。现在我只显示图像的左侧角落。现在我不希望人们在这个阶段放大,只能缩小到最大'x'(仍然需要看多少)。
这是必须放大的imageview“kaart”。Android捏缩放,ZoomOut和缩放,在极限

问题:如何让人们只在开始缩小,不要让他们通过x和以后,不要让他们在更放大比原来的尺寸

我没试过吗?负值,但没有奏效

这里是我的代码:

// These matrices will be used to move and zoom image 
Matrix matrix = new Matrix(); 
Matrix savedMatrix = new Matrix(); 

// max and min zoom 
//private static final float MIN_ZOOM = 1.0f; 
//private static final float MAX_ZOOM = 5.0f; 
//scale = Math.max(MIN_ZOOM, Math.min(scale, MAX_ZOOM)); 

// We can be in one of these 3 states 
static final int NONE = 0; 
static final int DRAG = 1; 
static final int ZOOM = 2; 

int mode = NONE; 

// Remember some things for zooming 
PointF start = new PointF(); 
PointF mid = new PointF(); 
float oldDist = 1f; 
String savedItemClicked; 

ImageView view; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.kaart); 
    view = (ImageView) findViewById(R.id.kaart); 
    view.setOnTouchListener(this); 
} 



public boolean onTouch(View v, MotionEvent event) { 
    // TODO Auto-generated method stub 

    ImageView view = (ImageView) v; 
    dumpEvent(event); 


    // 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.postScale(scale, scale, mid.x, mid.y); 

      } 
     } 
     break; 
    } 
    limitZoom(matrix); 
    limitDrag(matrix); 
    view.setImageMatrix(matrix); 
    return true; 
} 

@SuppressWarnings("deprecation") 
private void dumpEvent(MotionEvent event) { 
    String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE", 
      "POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" }; 
    StringBuilder sb = new StringBuilder(); 
    int action = event.getAction(); 
    int actionCode = action & MotionEvent.ACTION_MASK; 
    sb.append("event ACTION_").append(names[actionCode]); 
    if (actionCode == MotionEvent.ACTION_POINTER_DOWN 
      || actionCode == MotionEvent.ACTION_POINTER_UP) { 
     sb.append("(pid ").append(
       action >> MotionEvent.ACTION_POINTER_ID_SHIFT); 
     sb.append(")"); 
    } 
    sb.append("["); 
    for (int i = 0; i < event.getPointerCount(); i++) { 
     sb.append("#").append(i); 
     sb.append("(pid ").append(event.getPointerId(i)); 
     sb.append(")=").append((int) event.getX(i)); 
     sb.append(",").append((int) event.getY(i)); 
     if (i + 1 < event.getPointerCount()) 
      sb.append(";"); 
    } 
    sb.append("]"); 
    // Log.d(TAG, sb.toString()); 
} 

/** Determine the space between the first two fingers */ 
private float spacing(MotionEvent event) { 
    float x = event.getX(0) - event.getX(1); 
    float y = event.getY(0) - event.getY(1); 
    return FloatMath.sqrt(x * x + y * y); 
} 

/** Calculate the mid point of the first two fingers */ 
private void midPoint(PointF point, MotionEvent event) { 
    float x = event.getX(0) + event.getX(1); 
    float y = event.getY(0) + event.getY(1); 
    point.set(x/2, y/2); 
} 
}  

希望有人能帮助我。我真的会赞赏它。

编辑

我加入了2个功能,我发现某处。

private void limitZoom(Matrix m) { 

    float[] values = new float[9]; 
    m.getValues(values); 
    float scaleX = values[Matrix.MSCALE_X]; 
    float scaleY = values[Matrix.MSCALE_Y]; 
    if(scaleX > MAX_ZOOM) { 
     scaleX = MAX_ZOOM; 
    } else if(scaleX < MIN_ZOOM) { 
     scaleX = MIN_ZOOM; 
    } 

    if(scaleY > MAX_ZOOM) { 
     scaleY = MAX_ZOOM; 
    } else if(scaleY < MIN_ZOOM) { 
     scaleY = MIN_ZOOM; 
    } 

    values[Matrix.MSCALE_X] = scaleX; 
    values[Matrix.MSCALE_Y] = scaleY; 
    m.setValues(values); 
} 

private void limitDrag(Matrix m) { 
    float[] values = new float[9]; 
    m.getValues(values); 
    float transX = values[Matrix.MTRANS_X]; 
    float transY = values[Matrix.MTRANS_Y]; 
    float scaleX = values[Matrix.MSCALE_X]; 
    float scaleY = values[Matrix.MSCALE_Y]; 

    ImageView iv = (ImageView)findViewById(R.id.kaart); 
    Rect bounds = iv.getDrawable().getBounds(); 
    int viewWidth = getResources().getDisplayMetrics().widthPixels; 
    int viewHeight = getResources().getDisplayMetrics().heightPixels; 

    int width = bounds.right - bounds.left; 
    int height = bounds.bottom - bounds.top; 

    float minX = (-width + 20) * scaleX; 
    float minY = (-height + 20) * scaleY; 

    if(transX > (viewWidth - 20)) { 
     transX = viewWidth - 20; 
    } else if(transX < minX) { 
     transX = minX; 
    } 

    if(transY > (viewHeight - 80)) { 
     transY = viewHeight - 80; 
    } else if(transY < minY) { 
     transY = minY; 
    } 

    values[Matrix.MTRANS_X] = transX; 
    values[Matrix.MTRANS_Y] = transY; 
    m.setValues(values); 
} 

我有开关情况后立即调用这些函数,只是之前被设置在我看来,imagematrix。 (我已经将此添加到上面的代码中)

也许这不是最好的解决方案,但它的工作原理。

+0

你的问题是什么? – Phonon

+0

问题:如何让人们在开始时只缩小,不让它们通过x?事后,不要让他们放大超过原来的尺寸 – pieter

回答

0

如果我理解了你的代码,你会继续保存矩阵,以此来记住缩放和滚动的状态(可以单独使用一个矩阵完成,但也许你正在执行其他操作)。

这样,每个动作效果都是相对于最后一个状态而言的,并且很难为放大设置绝对限制(并且也要滚动):要获取它们的绝对值,您必须调用matrix.getValues( )并从它返回的数组中选择值。

尝试改为保存当前的x-scroll,y-scroll和zoom,并在每个动作中检查它们的更新值(现在是否为绝对值)是否在您的极限内;如果真的更新它们,则重置矩阵并设置新的滚动/缩放值。

(另外,考虑使用手势检测器和ScaleGestureDetector)

+0

让我们知道这个答案是否有帮助。 – bigstones