2012-08-30 59 views
0

我已經在這裏搜索了很多,但還沒有找到解決方案。所以事情是,我有一個圖像3000 * 3000像素,我把它設置爲比例矩陣。現在我只顯示圖像的左側角落。現在我不希望人們在這個階段放大,只能縮小到最大'x'(仍然需要看多少)。
這是必須放大的imageview「kaart」。Android捏縮放,ZoomOut和縮放,在極限

問題:如何讓人們只在開始縮小,不要讓他們通過x和以後,不要讓他們在更放大比原來的尺寸

我沒試過嗎?負值,但沒有奏效

這裏是我的代碼:

// 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); 
} 
}  

希望有人能幫助我。我真的會讚賞它。

編輯

我加入了2個功能,我發現某處。

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); 
} 

我有開關情況後立即調用這些函數,只是之前被設置在我看來,imagematrix。 (我已經將此添加到上面的代碼中)

也許這不是最好的解決方案,但它的工作原理。

+0

你的問題是什麼? – Phonon

+0

問題:如何讓人們在開始時只縮小,不讓它們通過x?事後,不要讓他們放大超過原來的尺寸 – pieter

回答

0

如果我理解了你的代碼,你會繼續保存矩陣,以此來記住縮放和滾動的狀態(可以單獨使用一個矩陣完成,但也許你正在執行其他操作)。

這樣,每個動作效果都是相對於最後一個狀態而言的,並且很難爲放大設置絕對限制(並且也要滾動):要獲取它們的絕對值,您必須調用matrix.getValues( )並從它返回的數組中選擇值。

嘗試改爲保存當前的x-scroll,y-scroll和zoom,並在每個動作中檢查它們的更新值(現在是否爲絕對值)是否在您的極限內;如果真的更新它們,則重置矩陣並設置新的滾動/縮放值。

(另外,考慮使用手勢檢測器和ScaleGestureDetector)

+0

讓我們知道這個答案是否有幫助。 – bigstones