mobi.cangol.mobile.navigation.PagerEnabledSlidingPaneLayout.java Source code

Introduction

Here is the source code for mobi.cangol.mobile.navigation.PagerEnabledSlidingPaneLayout.java

Source

/**
 * Copyright (c) 2013 Cangol
 * <p/>
 * 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
 * <p/>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p/>
 * 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 mobi.cangol.mobile.navigation;

import android.content.Context;
import android.support.v4.view.MotionEventCompat;
import android.support.v4.widget.SlidingPaneLayout;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.ViewConfiguration;

/**
 * SlidingPaneLayout that, if closed, checks if children can scroll before it intercepts
 * touch events.  This allows it to contain horizontally scrollable children without
 * intercepting all of their touches.
 *
 * To handle cases where the user is scrolled very far to the right, but should still be
 * able to open the pane without the need to scroll all the way back to the start, this
 * view also adds edge touch detection, so it will intercept edge swipes to open the pane.
 */
public class PagerEnabledSlidingPaneLayout extends SlidingPaneLayout {

    private float mInitialMotionX;
    private float mInitialMotionY;
    private float mEdgeSlop;

    public PagerEnabledSlidingPaneLayout(Context context) {
        this(context, null);
    }

    public PagerEnabledSlidingPaneLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        ViewConfiguration config = ViewConfiguration.get(context);
        mEdgeSlop = config.getScaledEdgeSlop();
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {

        switch (MotionEventCompat.getActionMasked(ev)) {
        case MotionEvent.ACTION_DOWN: {
            mInitialMotionX = ev.getX();
            mInitialMotionY = ev.getY();
            break;
        }

        case MotionEvent.ACTION_MOVE: {
            final float x = ev.getX();
            final float y = ev.getY();
            // The user should always be able to "close" the pane, so we only check
            // for child scrollability if the pane is currently closed.
            if (mInitialMotionX > mEdgeSlop && !isOpen()
                    && canScroll(this, false, Math.round(x - mInitialMotionX), Math.round(x), Math.round(y))) {

                // How do we set super.mIsUnableToDrag = true?

                // send the parent a cancel event
                MotionEvent cancelEvent = MotionEvent.obtain(ev);
                cancelEvent.setAction(MotionEvent.ACTION_CANCEL);
                return super.onInterceptTouchEvent(cancelEvent);
            }
        }
        }

        return super.onInterceptTouchEvent(ev);
    }
}