Java Code Examples for android.view.ScaleGestureDetector#SimpleOnScaleGestureListener

@Override
protected void onInitialize(@NonNull Context context) {
    super.onInitialize(context);
    mPoints = new PointF[]{new PointF(0, 0), new PointF(0, 0)};
    mDetector = new ScaleGestureDetector(context, new ScaleGestureDetector.SimpleOnScaleGestureListener() {
        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            mNotify = true;
            mFactor = ((detector.getScaleFactor() - 1) * ADD_SENSITIVITY);
            return true;
        }
    });

    if (Build.VERSION.SDK_INT >= 19) {
        mDetector.setQuickScaleEnabled(false);
    }

    // We listen only to the pinch type.
    setGestureType(Gesture.PINCH);
}
 

private void setupZoomGesture() {
    mGestureDetector = new GestureDetector(this, new GestureListener());

    mScaleDetector = new ScaleGestureDetector(this, new ScaleGestureDetector.SimpleOnScaleGestureListener() {
        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            float scale = 1 - detector.getScaleFactor();

            mBoardScale += scale;

            if (mBoardScale < kMinBoardScale) mBoardScale = kMinBoardScale;
            if (mBoardScale > kMaxBoardScale) mBoardScale = kMaxBoardScale;

            mBoardContentView.setScaleX(1f / mBoardScale);
            mBoardContentView.setScaleY(1f / mBoardScale);
            return true;
        }
    });
}
 

private void setupGestures() {
    mGestureDetector = new GestureDetector(getContext(), new GestureListener());

    mScaleDetector = new ScaleGestureDetector(getContext(), new ScaleGestureDetector.SimpleOnScaleGestureListener() {
        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            float scale = 1 - detector.getScaleFactor();

            mBoardScale += scale;

            if (mBoardScale < kMinBoardScale) mBoardScale = kMinBoardScale;
            if (mBoardScale > kMaxBoardScale) mBoardScale = kMaxBoardScale;
            Log.d(TAG, "Board scale: " + mBoardScale);

            mBoardContentView.setScaleX(1f / mBoardScale);
            mBoardContentView.setScaleY(1f / mBoardScale);
            return true;
        }
    });

    mCustomPanningView.setOnTouchListener((view, motionEvent) -> {      // Make the GestureDetectors work: https://stackoverflow.com/questions/11421368/android-fragment-oncreateview-with-gestures/11421565#11421565
        final boolean scaleResult = mGestureDetector.onTouchEvent(motionEvent);
        /*final boolean gestureResult = */
        mScaleDetector.onTouchEvent(motionEvent);
        //Log.d(TAG, "scaleResult: " + scaleResult + " gestureResult: " + gestureResult);
        return scaleResult;// || gestureResult;
    });
}
 

private void init() {
    inflate(getContext(), R.layout.image_viewer, this);

    backgroundView = findViewById(R.id.backgroundView);
    pager = (MultiTouchViewPager) findViewById(R.id.pager);

    dismissContainer = (ViewGroup) findViewById(R.id.container);
    swipeDismissListener = new SwipeToDismissListener(findViewById(R.id.dismissView), this, this);
    dismissContainer.setOnTouchListener(swipeDismissListener);

    directionDetector = new SwipeDirectionDetector(getContext()) {
        @Override
        public void onDirectionDetected(Direction direction) {
            ImageViewerView.this.direction = direction;
        }
    };

    scaleDetector = new ScaleGestureDetector(getContext(),
            new ScaleGestureDetector.SimpleOnScaleGestureListener());

    gestureDetector = new GestureDetectorCompat(getContext(), new GestureDetector.SimpleOnGestureListener() {
        @Override
        public boolean onSingleTapConfirmed(MotionEvent e) {
            if (pager.isScrolled()) {
                onClick(e, isOverlayWasClicked);
            }
            return false;
        }
    });
}
 

public PinchToZoomDraweeView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    mScaleListener = new ScaleGestureDetector.SimpleOnScaleGestureListener() {
        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            float scaleFactor = detector.getScaleFactor();
            float newScale = mCurrentScale * scaleFactor;
            // Prevent from zooming out more than original
            if (newScale > 1.0f) {
                // We initialize this lazily so that we don't have to register (and force the user
                // to unregister) a global layout listener on the view.
                if (mMidX == 0.0f) {
                    mMidX = getWidth() / 2.0f;
                }
                if (mMidY == 0.0f) {
                    mMidY = getHeight() / 2.0f;
                }
                mCurrentScale = newScale;
                mCurrentMatrix.postScale(scaleFactor, scaleFactor, mMidX, mMidY);
                invalidate();
            } else {
                scaleFactor = 1.0f / mCurrentScale;
                reset();
            }

            if (mListener != null && scaleFactor != 1.0f) {
                mListener.onZoomChange(mCurrentScale);
            }

            return true;
        }
    };
    mScaleDetector = new ScaleGestureDetector(getContext(), mScaleListener);
    mCurrentMatrix = new Matrix();
}
 

public SimplePhotoView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    //initialize ScaleGestureDetector. Capture the
    mScaleListener = new ScaleGestureDetector.SimpleOnScaleGestureListener() {
        @Override
        public boolean onScale(ScaleGestureDetector detector) {
            float scaleFactor = detector.getScaleFactor();
            float newScale = mCurrentScale * scaleFactor;
            // LogUtils.d("scaleFactor=" + scaleFactor + ",newScale=" + newScale);
            // Prevent from zooming out more than original
            if (newScale > 1.0f && newScale < SCALE_MAX) {
                if (mMidX == 0.0f) {
                    mMidX = getWidth() / 2;//from center to zoom
                }
                if (mMidY == 0.0f) {
                    mMidY = getHeight() / 2;//from center to zoom
                }
                mCurrentScale = newScale;
                SimplePhotoView.this.postDelayed(new AutoRunableZoom(newScale), 16);
            } else if (newScale > SCALE_MAX) {
                newScale = SCALE_MAX;
                mCurrentScale = newScale;
            }

            return true;
        }
    };
    mScaleDetector = new ScaleGestureDetector(getContext(), mScaleListener);
    mCurrentMatrix = new Matrix();
    //initialize GestureDetector, Capture double tap event
    mGestureDetector = new GestureDetector(context,
            new GestureDetector.SimpleOnGestureListener() {
                @Override
                public boolean onDoubleTap(MotionEvent e) {
                    float newscale = 0.0f;
                    if (mCurrentScale == 1.0f) {
                        newscale = SCALE_MID;
                    } else if (mCurrentScale >= SCALE_MID && mCurrentScale < SCALE_MAX) {
                        newscale = SCALE_MAX;
                    } else if (mCurrentScale >= SCALE_MAX) {
                        newscale = 1.0f;
                    }
                    mCurrentScale = newscale;
                    SimplePhotoView.this.postDelayed(new AutoRunableZoom(newscale), 16);
                    isAutoScale = true;
                    return true;
                }
            });
    this.setOnTouchListener(this);
}