Abilitazione dello zoom sulla vista di scorrimento

Question

Ho alcuni dati inseriti nel mio ScrollView. Voglio abilitarlo per ingrandire/ridurre. Contiene semplice ImageView e TextView.

Qualsiasi suggerimento sarà utile. Grazie.

Ecco il mio codice:

<ScrollView 
    android:id="@+id/viewSoupMenu" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:background="@drawable/soupback" > 

<LinearLayout 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:orientation="vertical"> 

<LinearLayout 
      android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:orientation="horizontal" 
      android:layout_marginTop="50dp"> 

    <ImageButton 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_marginLeft="35dp" 
     android:layout_marginTop="30dp" 
     android:background="@android:color/transparent" 
     android:src="@drawable/flowericon" /> 

    <ImageButton 
     android:id="@+id/btnVegClearSoup" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_marginLeft="5dp" 
     android:layout_marginTop="20dp" 
     android:background="@android:color/transparent" 
     android:src="@drawable/btnvegsoupclearclickedxml" /> 

    </LinearLayout> 
</ScrollView> 

Answer 1

Provare a utilizzare FrameLayout e dare un'occhiata a questo documento ufficiale: Zooming a View.

Answer 2

È possibile utilizzare la classe indicato di seguito per consentire Pinch Zoom in ImageView e si può creare una classe duplicato di questa classe che si estende TextView invece di ImageView per consentire lo zoom in esso.

public class PinchZoomImageView extends ImageView implements OnTouchListener{ 

    public PinchZoomImageView(Context context) { 
     super(context); 
     _init(); 
    } 

    public PinchZoomImageView(Context context, AttributeSet attrs) { 
     super(context, attrs); 
     _init(); 
    } 

    public PinchZoomImageView(Context context, AttributeSet attrs, int defStyle) { 
     super(context, attrs, defStyle); 
     _init(); 
    } 

    private void _init(){ 
     //setOnTouchListener(this); 

     view = (ImageView) this; 
     view.setOnTouchListener(this); 

     metric = new DisplayMetrics(); 
     // Work around a Cupcake bug 

     d_dpi=((0.52f/(metric.densityDpi))*240.0f)-0.52f; 
     Log.d("ash","dpi= "+d_dpi); 
     if(metric.densityDpi==160) 
     d_dpi=0.34f; 
     matrix.setTranslate(1f, 1f); 
     matrix.setScale((0.52f/800.0f)*metric.widthPixels+d_dpi, (0.52f/480.0f)*metric.heightPixels+d_dpi); 
     view.setImageMatrix(matrix); 
     bMap = BitmapFactory.decodeResource(getResources(), R.drawable.mfigure); 
     btsize = BitmapFactory.decodeResource(getResources(), R.drawable.map); 
    } 

    @Override 
    public void onWindowFocusChanged(boolean hasFocus) { 
     super.onWindowFocusChanged(hasFocus); 
     if(hasFocus){ 
      init(); 
     } 
    } 

    private void init() { 
     maxZoom = (3.0f/480.0f)*metric.heightPixels+d_dpi; 
     minZoom = (0.52f/800.0f)*metric.widthPixels+d_dpi; 
     height = view.getDrawable().getIntrinsicHeight(); 
     width = view.getDrawable().getIntrinsicWidth(); 
     viewRect = new RectF(0, 0, view.getWidth(), view.getHeight()); 
    } 

    @Override 
    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()/metric.widthPixels * 800, event.getY()/metric.heightPixels * 480); 
       Log.d(TAG, "mode=DRAG"); 
       mode = DRAG; 
       click = true; 
       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"); 
       } 
       click = false; 
       break; 
      case MotionEvent.ACTION_UP: 
      case MotionEvent.ACTION_POINTER_UP: 
       mode = NONE; 
       Log.d(TAG, "mode=NONE"); 
       if(click) 
        onClick(event.getX(), event.getY(),true); 
       break; 
      case MotionEvent.ACTION_MOVE: 
       if (mode == DRAG) { 

        temp_x = ((start.x) - ((event.getX()/metric.widthPixels)*800)); 
        temp_y = ((start.y) - ((event.getY()/metric.heightPixels) * 480));    
        if(FloatMath.sqrt(temp_x * temp_x + temp_y * temp_y)< 10) 
         break; 

        matrix.set(savedMatrix); 

        // limit pan 
        matrix.getValues(matrixValues); 
        float currentY = matrixValues[Matrix.MTRANS_Y]; 
        float currentX = matrixValues[Matrix.MTRANS_X]; 
        float currentScale = matrixValues[Matrix.MSCALE_X]; 
        float currentHeight = height * currentScale; 
        float currentWidth = width * currentScale; 
        float dx = (event.getX()/metric.widthPixels * 800) - start.x; 
        float dy = (event.getY()/metric.heightPixels * 480) - start.y; 
        float newX = currentX+dx; 
        float newY = currentY+dy; 

        RectF drawingRect = new RectF(newX, newY, newX+currentWidth, newY+currentHeight); 
        float diffUp = Math.min(viewRect.bottom-drawingRect.bottom, viewRect.top-drawingRect.top); 
        float diffDown = Math.max(viewRect.bottom-drawingRect.bottom, viewRect.top-drawingRect.top); 
        float diffLeft = Math.min(viewRect.left-drawingRect.left, viewRect.right-drawingRect.right); 
        float diffRight = Math.max(viewRect.left-drawingRect.left, viewRect.right-drawingRect.right); 
        if(diffUp > 0){ 
         dy +=diffUp; 
        } 
        if(diffDown < 0){ 
         dy +=diffDown; 
        } 
        if(diffLeft> 0){ 
         dx += diffLeft; 
        } 
        if(diffRight < 0){ 
         dx += diffRight; 
        } 
        matrix.postTranslate(dx, dy); 
        //selection.set(selection.x + dx, selection.y + dy); 
        click = false; 
       } 
       else if (mode == ZOOM) { 
        float newDist = spacing(event); 
        Log.d(TAG, "newDist=" + newDist); 
        if (newDist > 10f) { 
         matrix.set(savedMatrix); 
         float scale = newDist/oldDist; 

         matrix.getValues(matrixValues); 
         float currentScale = matrixValues[Matrix.MSCALE_X]; 

         // limit zoom 
         if (scale * currentScale > maxZoom) { 
          scale = maxZoom/currentScale; 
         } else if (scale * currentScale < minZoom) { 
          scale = minZoom/currentScale; 
         } 
         matrix.postScale(scale, scale, mid.x, mid.y); 
        } 
       } 
       break; 
     } 
     float mv[] = new float[9]; 
     matrix.getValues(mv); 

     Log.d("PV", "Click x " + mv[Matrix.MTRANS_X] + " y " + mv[Matrix.MTRANS_Y] + " cx " + event.getX() + " cy " + event.getY()); 

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

    public void onClick(float x, float y,boolean state){ 
     Log.d("TAG","x="+x+" y "+y); 
     float mv[] = new float[9]; 
     matrix.getValues(mv); 

     if(btsize != null) 
      btsize.recycle(); 

     btsize = BitmapFactory.decodeResource(getResources(), R.drawable.map); 

     if(btSel != null) 
      btSel.recycle(); 

     btSel = BitmapFactory.decodeResource(getResources(), R.drawable.mfigure); 

     Canvas canvas; 
     try{ 
      canvas = new Canvas(btsize); 
     } 
     catch(Exception e){ 
      btsize = BitmapFactory.decodeResource(getResources(), R.drawable.map).copy(Config.ARGB_8888,true); 
      canvas = new Canvas(btsize); 
     } 

     x -= mv[Matrix.MTRANS_X]; 
     y -= mv[Matrix.MTRANS_Y]; 

     float wdt = btsize.getWidth() * mv[Matrix.MSCALE_X]; 
     float ht = btsize.getHeight() * mv[Matrix.MSCALE_Y]; 

     float tw = x/wdt; 
     float th = y/ht; 

     selPoint.set(tw, th); 
     if(state) 
      canvas.drawBitmap(btSel, (tw * btsize.getWidth()) - (btSel.getWidth()/2), (th * btsize.getHeight()) - (btSel.getHeight()/2), null); 
     else 
      canvas.drawBitmap(btSel, (x * btsize.getWidth()) - (btSel.getWidth()/2), (y * btsize.getHeight()) - (btSel.getHeight()/2), null); 

     setImageBitmap(btsize); 

    } 

    /** Determine the space between the first two fingers */ 
    private float spacing(MotionEvent event) { 
     float x = ((event.getX(0)/metric.widthPixels)*800) - ((event.getX(1)/metric.widthPixels)*800); 
      float y = ((event.getY(0)/metric.heightPixels) * 480) - ((event.getY(1)/metric.heightPixels) * 480); 
     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)/metric.widthPixels) * 800) + ((event.getX(1)/metric.widthPixels)*800); 
      float y = ((event.getY(0)/metric.heightPixels) * 480) + ((event.getY(1)/metric.heightPixels) * 480); 
     point.set(x/2, y/2); 
    } 

    private static final String TAG = "Touch"; 
    // These matrices will be used to move and zoom image 
    Matrix matrix = new Matrix(); 
    Matrix savedMatrix = new Matrix(); 

    // 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; 

    // Limit zoomable/pannable image 
    private ImageView view; 
    private float[] matrixValues = new float[9]; 
    private float maxZoom; 
    private float minZoom; 
    private float height; 
    private float width; 
    private RectF viewRect; 
    private float temp_x,temp_y; 
    private boolean click = false; 
    public PointF selPoint = new PointF(); 
    Bitmap bMap; 
    private float d_dpi; 
    Paint paint = new Paint(); 
    Canvas canvas = new Canvas(); 
    private DisplayMetrics metric; 
    Bitmap bt = null; 
    Bitmap btsize = null; 
    Bitmap btSel = null; 

}