BlackBerry - Développer une application comme Cropit

Question

Je veux développer une application de type cropit, je veux juste savoir comment augmenter ou diminuer la taille du rectangle sur l'image (événements multitouch), qui définissent la partie de l'image à rogner.

Merci beaucoup

Answer 1

Utilisez onTouchEvent, recherchez DOWN et déplacer des événements pour dessiner correctement la sélection.

Pour faire un simulateur multitouch: Alt + T, puis utilisez le bouton gauche de la souris pour le doigt 1 et le bouton droit de la souris pour le doigt 2.

Exemple de code

:

class Scr extends MainScreen { 

    XYPoint mLeftUp = null; 
    XYPoint mRightBottom = null; 
    XYPoint mCoursor = null; 
    // Bitmap bitmap = Bitmap.getBitmapResource("wallpaper_bold.jpg"); 
    Bitmap bitmap = Bitmap.getBitmapResource("wallpaper_storm.jpg"); 
    BitmapField mBitmapField = new BitmapField(bitmap); 

    public Scr() { 
     add(mBitmapField); 
     mCoursor = new XYPoint(bitmap.getWidth() >> 1, 
       bitmap.getHeight() >> 1); 
    } 

    protected void makeMenu(Menu menu, int instance) { 
     super.makeMenu(menu, instance); 
     if (mLeftUp != null && mRightBottom != null) { 
      menu.add(new MenuItem("crop", 0, 0) { 
       public void run() { 
        XYRect rect = null; 
        if (mLeftUp.x > mRightBottom.x 
          && mLeftUp.y > mRightBottom.y) { 
         rect = new XYRect(mRightBottom, mLeftUp); 
        } else { 
         rect = new XYRect(mLeftUp, mRightBottom); 
        } 
        Bitmap crop = cropImage(bitmap, rect.x, rect.y, 
          rect.width, rect.height); 
        mBitmapField.setBitmap(crop); 
        mCoursor = new XYPoint(crop.getWidth() >> 1, crop 
          .getHeight() >> 1); 
        mLeftUp = null; 
        mRightBottom = null; 
        invalidate(); 
       } 
      }); 

      menu.add(new MenuItem("reset", 0, 0) { 
       public void run() { 
        mBitmapField.setBitmap(bitmap); 
        mCoursor = new XYPoint(bitmap.getWidth() >> 1, bitmap 
          .getHeight() >> 1); 
        invalidate(); 
       } 
      }); 
     } 
    } 

    protected void paint(Graphics graphics) { 
     super.paint(graphics); 
     if (mCoursor != null) { 
      graphics.setColor(Color.RED); 
      graphics.drawLine(mCoursor.x - 4, mCoursor.y - 4, 
        mCoursor.x + 4, mCoursor.y + 4); 
      graphics.drawLine(mCoursor.x + 4, mCoursor.y - 4, 
        mCoursor.x - 4, mCoursor.y + 4); 
     } 
     if (mLeftUp != null && mRightBottom != null) { 
      graphics.setColor(Color.RED); 
      graphics.drawPoint(mLeftUp.x, mLeftUp.y); 
      graphics.drawPoint(mRightBottom.x, mRightBottom.y); 
      graphics.drawPoint(mLeftUp.x, mRightBottom.y); 
      graphics.drawPoint(mRightBottom.x, mLeftUp.y); 
      graphics.setColor(Color.WHITESMOKE); 
      XYRect redRect = null; 
      if (mLeftUp.x > mRightBottom.x && mLeftUp.y > mRightBottom.y) { 
       redRect = new XYRect(mRightBottom, mLeftUp); 
      } else { 
       redRect = new XYRect(mLeftUp, mRightBottom); 
      } 
      graphics.drawRect(redRect.x, redRect.y, redRect.width, 
        redRect.height); 
     } 
    } 

    // comment block for Bold 
    protected boolean touchEvent(TouchEvent message) { 
     int x1 = message.getX(1); 
     int y1 = message.getY(1); 
     int x2 = message.getX(2); 
     int y2 = message.getY(2); 
     switch (message.getEvent()) { 
     case TouchEvent.DOWN: 
      if (x1 != -1) { 
       mLeftUp = new XYPoint(x1, y1); 
      } else if (x2 != -1) { 
       mRightBottom = new XYPoint(x2, y2); 
      } 
      break; 
     case TouchEvent.MOVE: 
      if (x1 != -1) { 
       mLeftUp = new XYPoint(x1, y1); 
      } 
      if (x2 != -1) { 
       mRightBottom = new XYPoint(x2, y2); 
      } 
      break; 
     case TouchEvent.UNCLICK: 
      mLeftUp = null; 
      mRightBottom = null; 
     default: 
      break; 
     } 
     invalidate(); 
     return true; 
    } 

    protected boolean navigationMovement(int dx, int dy, int status, 
      int time) { 
     moveCoursor(dx, dy); 
     return true; 
    } 

    private void moveCoursor(int dx, int dy) { 
     mCoursor.translate(dx, dy); 
     if (mLeftUp != null) { 
      mRightBottom = new XYPoint(mCoursor); 
     } 
     invalidate(); 
    } 

    protected boolean navigationUnclick(int status, int time) { 
     clickCoursor(); 
     return true; 
    } 

    private void clickCoursor() { 
     if (mLeftUp != null && mLeftUp.equals(mCoursor)) { 
      mLeftUp = null; 
      mRightBottom = null; 
     } else { 
      mLeftUp = new XYPoint(mCoursor); 
     } 
     invalidate(); 
    } 

    public static Bitmap cropImage(Bitmap image, int x, int y, int width, 
      int height) { 
     Bitmap result = new Bitmap(width, height); 
     Graphics g = Graphics.create(result); 
     g.drawBitmap(0, 0, width, height, image, x, y); 
     return result; 
    } 
}