me.xiaopan.vpc.ViewPagerCompat.java Source code

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Here is the source code for me.xiaopan.vpc.ViewPagerCompat.java

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/*
 * Copyright (C) 2014 Peng fei Pan <sky@xiaopan.me>
 *
 * 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 me.xiaopan.vpc;

import android.content.Context;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

/**
 * ViewPagerCompat
 * <br>Inherited from the ViewPager, solve api13 and the following, when the ViewPager nested child ViewPager cannot slide
 *
 * @author xiaopan
 * @version 1.1.0
 * @website https://github.com/xiaopansky/ViewPagerCompat
 */
public class ViewPagerCompat extends ViewPager {
    public ViewPagerCompat(Context context) {
        super(context);
    }

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

    @Override
    protected boolean canScroll(View v, boolean checkV, int dx, int x, int y) {
        if (v instanceof ViewGroup) {
            final ViewGroup group = (ViewGroup) v;
            final int scrollX = v.getScrollX();
            final int scrollY = v.getScrollY();
            final int count = group.getChildCount();
            // Count backwards - let topmost views consume scroll distance first.
            for (int i = count - 1; i >= 0; i--) {
                // TODO: Add versioned support here for transformed views.
                // This will not work for transformed views in Honeycomb+
                final View child = group.getChildAt(i);
                if (x + scrollX >= child.getLeft() && x + scrollX < child.getRight()
                        && y + scrollY >= child.getTop() && y + scrollY < child.getBottom() && canScroll(child,
                                true, dx, x + scrollX - child.getLeft(), y + scrollY - child.getTop())) {
                    return true;
                }
            }
        }

        if (checkV) {
            // Direct call ViewPager.canScrollHorizontally(int)
            if (v instanceof ViewPager) {
                return ((ViewPager) v).canScrollHorizontally(-dx);
            } else {
                return ViewCompat.canScrollHorizontally(v, -dx);
            }
        } else {
            return false;
        }
    }
}