Android Open Source - PhotoView Eclair Gesture Detector

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License

The source code is released under:

Apache License

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Java Source Code

/*******************************************************************************
 * Copyright 2011, 2012 Chris Banes.//from w w w  .  ja  v a 2  s  .  co  m
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *******************************************************************************/
package uk.co.senab.photoview.gestures;

import android.annotation.TargetApi;
import android.content.Context;
import android.view.MotionEvent;

import uk.co.senab.photoview.Compat;

@TargetApi(5)
public class EclairGestureDetector extends CupcakeGestureDetector {

    private static final int INVALID_POINTER_ID = -1;
    private int mActivePointerId = INVALID_POINTER_ID;
    private int mActivePointerIndex = 0;

    public EclairGestureDetector(Context context) {
        super(context);
    }

    @Override
    float getActiveX(MotionEvent ev) {
        try {
            return ev.getX(mActivePointerIndex);
        } catch (Exception e) {
            return ev.getX();
        }
    }

    @Override
    float getActiveY(MotionEvent ev) {
        try {
            return ev.getY(mActivePointerIndex);
        } catch (Exception e) {
            return ev.getY();
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        final int action = ev.getAction();
        switch (action & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_DOWN:
                mActivePointerId = ev.getPointerId(0);
                break;
            case MotionEvent.ACTION_CANCEL:
            case MotionEvent.ACTION_UP:
                mActivePointerId = INVALID_POINTER_ID;
                break;
            case MotionEvent.ACTION_POINTER_UP:
                // Ignore deprecation, ACTION_POINTER_ID_MASK and
                // ACTION_POINTER_ID_SHIFT has same value and are deprecated
                // You can have either deprecation or lint target api warning
                final int pointerIndex = Compat.getPointerIndex(ev.getAction());
                final int pointerId = ev.getPointerId(pointerIndex);
                if (pointerId == mActivePointerId) {
                    // This was our active pointer going up. Choose a new
                    // active pointer and adjust accordingly.
                    final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
                    mActivePointerId = ev.getPointerId(newPointerIndex);
                    mLastTouchX = ev.getX(newPointerIndex);
                    mLastTouchY = ev.getY(newPointerIndex);
                }
                break;
        }

        mActivePointerIndex = ev
                .findPointerIndex(mActivePointerId != INVALID_POINTER_ID ? mActivePointerId
                        : 0);
        return super.onTouchEvent(ev);
    }
}

Java Source Code List