如何应用长触摸和捏缩放android？

Question

I have issue in applying pinch in zoom for image and long press in view pager. When I zoom in and zoom out the image, long press gets triggered. How to overcome this? When I long touch the image alone, it should be triggered. How to do this? I searched but I couldn't find solution for this.

My code is as follows:

TouchImageView:

public class TouchImageView extends ImageView {

Matrix 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 last = new PointF();
PointF start = new PointF();
float minScale = 1f;
float maxScale = 3f;
float[] m;


int viewWidth, viewHeight;
static final int CLICK = 3;
float saveScale = 1f;
protected float origWidth, origHeight;
int oldMeasuredWidth, oldMeasuredHeight;


ScaleGestureDetector mScaleDetector;

Context context;

public TouchImageView(Context context) {
    super(context);
    sharedConstructing(context);
}

public TouchImageView(Context context, AttributeSet attrs) {
    super(context, attrs);
    sharedConstructing(context);
}
public float getSaveScale() {
    return saveScale;
}

private void sharedConstructing(Context context) {
    super.setClickable(true);
    this.context = context;
    mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
    matrix = new Matrix();
    m = new float[9];
    setImageMatrix(matrix);
    setScaleType(ScaleType.MATRIX);

    setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            boolean defaultResult = v.onTouchEvent(event);
            mScaleDetector.onTouchEvent(event);
            PointF curr = new PointF(event.getX(), event.getY());

            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    last.set(curr);
                    start.set(last);
                    mode = DRAG;
                    break;

                case MotionEvent.ACTION_MOVE:
                    if (mode == DRAG) {
                        float deltaX = curr.x - last.x;
                        float deltaY = curr.y - last.y;
                        float fixTransX = getFixDragTrans(deltaX, viewWidth, origWidth * saveScale);
                        float fixTransY = getFixDragTrans(deltaY, viewHeight, origHeight * saveScale);
                        matrix.postTranslate(fixTransX, fixTransY);
                        fixTrans();
                        last.set(curr.x, curr.y);
                    }
                    break;

                case MotionEvent.ACTION_UP:
                    mode = NONE;
                    int xDiff = (int) Math.abs(curr.x - start.x);
                    int yDiff = (int) Math.abs(curr.y - start.y);
                    if (xDiff < CLICK && yDiff < CLICK)
                        performClick();
                    break;

                case MotionEvent.ACTION_POINTER_UP:
                    mode = NONE;
                    break;
                default:
                    return defaultResult;
            }

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


    });
}

public void setMaxZoom(float x) {
    maxScale = x;
}
public float getMaxScale() {
    return maxScale;
}
public void  reiniciarZoom()
{
    matrix = new Matrix();
    saveScale = 1f;
    setImageMatrix(matrix);
    invalidate();
}

private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
    @Override
    public boolean onScaleBegin(ScaleGestureDetector detector) {
        mode = ZOOM;
        return true;
    }


    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        float mScaleFactor = detector.getScaleFactor();
        float origScale = saveScale;
        saveScale *= mScaleFactor;
        if (saveScale > maxScale) {
            saveScale = maxScale;
            mScaleFactor = maxScale / origScale;
        } else if (saveScale < minScale) {
            saveScale = minScale;
            mScaleFactor = minScale / origScale;
        }

        if (origWidth * saveScale <= viewWidth || origHeight * saveScale <= viewHeight)
            matrix.postScale(mScaleFactor, mScaleFactor, viewWidth / 2, viewHeight / 2);
        else
            matrix.postScale(mScaleFactor, mScaleFactor, detector.getFocusX(), detector.getFocusY());

        fixTrans();
        return true;
    }
}

void fixTrans() {
    matrix.getValues(m);
    float transX = m[Matrix.MTRANS_X];
    float transY = m[Matrix.MTRANS_Y];

    float fixTransX = getFixTrans(transX, viewWidth, origWidth * saveScale);
    float fixTransY = getFixTrans(transY, viewHeight, origHeight * saveScale);

    if (fixTransX != 0 || fixTransY != 0)
        matrix.postTranslate(fixTransX, fixTransY);
}

float getFixTrans(float trans, float viewSize, float contentSize) {
    float minTrans, maxTrans;

    if (contentSize <= viewSize) {
        minTrans = 0;
        maxTrans = viewSize - contentSize;
    } else {
        minTrans = viewSize - contentSize;
        maxTrans = 0;
    }

    if (trans < minTrans)
        return -trans + minTrans;
    if (trans > maxTrans)
        return -trans + maxTrans;
    return 0;
}

float getFixDragTrans(float delta, float viewSize, float contentSize) {
    if (contentSize <= viewSize) {
        return 0;
    }
    return delta;
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    viewWidth = MeasureSpec.getSize(widthMeasureSpec);
    viewHeight = MeasureSpec.getSize(heightMeasureSpec);

    //
    // Rescales image on rotation
    //
    if (oldMeasuredHeight == viewWidth && oldMeasuredHeight == viewHeight
            || viewWidth == 0 || viewHeight == 0)
        return;
    oldMeasuredHeight = viewHeight;
    oldMeasuredWidth = viewWidth;

    if (saveScale == 1) {
        //Fit to screen.
        float scale;

        Drawable drawable = getDrawable();
        if (drawable == null || drawable.getIntrinsicWidth() == 0 || drawable.getIntrinsicHeight() == 0)
            return;
        int bmWidth = drawable.getIntrinsicWidth();
        int bmHeight = drawable.getIntrinsicHeight();

        Log.d("bmSize", "bmWidth: " + bmWidth + " bmHeight : " + bmHeight);

        float scaleX = (float) viewWidth / (float) bmWidth;
        float scaleY = (float) viewHeight / (float) bmHeight;
        scale = Math.min(scaleX, scaleY);
        matrix.setScale(scale, scale);

        // Center the image
        float redundantYSpace = (float) viewHeight - (scale * (float) bmHeight);
        float redundantXSpace = (float) viewWidth - (scale * (float) bmWidth);
        redundantYSpace /= (float) 2;
        redundantXSpace /= (float) 2;

        matrix.postTranslate(redundantXSpace, redundantYSpace);

        origWidth = viewWidth - 2 * redundantXSpace;
        origHeight = viewHeight - 2 * redundantYSpace;
        setImageMatrix(matrix);
    }
    fixTrans();
}

} and in MainActivity:

 //here Iused longclicklistener to handle overlay
    TouchImageView prodImage = (TouchImageView) itemView.findViewById(R.id.product_image);
    prodImage.setOnLongClickListener(new OnLongClickListener() {

            @Override
            public boolean onLongClick(View v) {

                overlayLink.setVisibility(View.VISIBLE);
                overlayLink.postDelayed(new Runnable() {

                    @Override
                    public void run() {
                        if (overlayLink != null) {
                            overlayLink.setVisibility(View.GONE);
                        }
                    }
                }, 5000);

                return true;
            }
        });

But problem is when I zoom the image, overlay is displaying ie which should display only in long touch. The screen :

How to solve this?

Answer 1

What you can do is:

Keep a boolean isZoomed in your class TouchImageView along with getter setters.

Set it to true in onScaleBegin method. Set it to false in onScaleEnd method:

See below snippet:

Inside TouchImageView:

boolean isZoomed;
private class ScaleListener extends
        ScaleGestureDetector.SimpleOnScaleGestureListener {
    @Override
    public boolean onScaleBegin(ScaleGestureDetector detector) {
        isZoomed = true;
        mode = ZOOM;
        return true;
    }

    @Override
    public boolean onScale(ScaleGestureDetector detector) {

        float mScaleFactor = detector.getScaleFactor();
        float origScale = saveScale;
        saveScale *= mScaleFactor;
        if (saveScale > maxScale) {
            saveScale = maxScale;
            mScaleFactor = maxScale / origScale;
        } else if (saveScale < minScale) {
            saveScale = minScale;
            mScaleFactor = minScale / origScale;
        }

        if (origWidth * saveScale <= viewWidth
                || origHeight * saveScale <= viewHeight)
            matrix.postScale(mScaleFactor, mScaleFactor, viewWidth / 2,
                    viewHeight / 2);
        else
            matrix.postScale(mScaleFactor, mScaleFactor,
                    detector.getFocusX(), detector.getFocusY());

        fixTrans();

        return true;
    }

    @Override
    public void onScaleEnd(ScaleGestureDetector detector) {
        // TODO Auto-generated method stub
        isZoomed = false;
        super.onScaleEnd(detector);
    }
}

public boolean isZoomed() {
    return isZoomed;
}

public void setZoomed(boolean isZoomed) {
    this.isZoomed = isZoomed;
}

Now in your MainActivity:

Check in onLongClick event: If imageview's isZoomed is false, then only handle that long click event. Else don't handle.

tiv = (TouchImageView) findViewById(R.id.timg);
tiv.setOnLongClickListener(new OnLongClickListener() {

    @Override
    public boolean onLongClick(View v) {
        // TODO Auto-generated method stub
        if (!tiv.isZoomed()) {
            Toast.makeText(getApplicationContext(), "long clicked",
                    Toast.LENGTH_LONG).show();
            return true;
        }
        return false;
    }
});

Hope this helps.