一个方便集成的 Android 右滑返回上级 控件

首先这个需求来着与 一款线上项目 要添加上 右滑返回高级页的一个效果( = = #因为IOS有)；
首先分析下 需求： 任何页面上右滑返回上级。考虑到 Android用栈来处理页面，那需要做的 只是关闭当前页面就哦了。
我们要做到的 :
1/ onInterceptTouchEvent(MotionEvent ev) 中 对不同事件 进行判断 并作拦截处理
2/ 如果拦截到了 则在 onTouchEvent(MotionEvent event) 中 对添加对移动距离 以及相应动画效果。
反之 则交给相应控件自己处理。

主要功能就是这两点了，考虑到viewPager也是比较常见的控件 于是在内做了判断处理；测试阶段 发现自定义控件、BaiduMapVIew 事件上的冲突，添加了 setIgnoreView(View view)、removeIgnoreView(View view)方法。
当然还有最重要的一点要方便 线上集成的 attachToActivity(): 考虑到所有页面的view都绑定在window的RelativeLayout上， 参考系统 setContentView( ) 方法；

最重要的 一句话绑定 集成该控件。

//BaseActivity中 添加if (isOpenSwipeBack()) {    layout = new SwipeBackLayout(this);    layout.attachToActivity(this);}//为了拓展性  对外暴露  isOpenSwipeBack() 方法。

下面是最重要的 控件的方法

import java.lang.ref.WeakReference;import java.util.ArrayList;import java.util.LinkedList;import java.util.List;import android.app.Activity;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Canvas;import android.graphics.Rect;import android.graphics.drawable.Drawable;import android.support.v4.view.ViewPager;import android.util.AttributeSet;import android.util.Log;import android.view.MotionEvent;import android.view.View;import android.view.ViewConfiguration;import android.view.ViewGroup;import android.widget.FrameLayout;import android.widget.Scroller;import com.sino.fanxq.R;public class SwipeBackLayout extends FrameLayout {    private static final String TAG = SwipeBackLayout.class.getSimpleName();    private View mContentView;    private int mTouchSlop;    private int downX;    private int downY;    private int tempX;    private Scroller mScroller;    private int viewWidth;    private boolean isSilding;    private boolean isFinish;    private Drawable mShadowDrawable;    private Activity mActivity;    private List<ViewPager> mViewPagers = new LinkedList<ViewPager>();    public SwipeBackLayout(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }    public SwipeBackLayout(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        //触发移动事件的距离        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();        mScroller = new Scroller(context);        mShadowDrawable = getResources().getDrawable(R.drawable.shadow_left);    }    public void attachToActivity(Activity activity) {        mActivity = activity;        TypedArray a = activity.getTheme().obtainStyledAttributes(new int[] { android.R.attr.windowBackground });        int background = a.getResourceId(0, 0);        a.recycle();        ViewGroup decor = (ViewGroup) activity.getWindow().getDecorView();        ViewGroup decorChild = (ViewGroup) decor.getChildAt(0);        decorChild.setBackgroundResource(background);        decor.removeView(decorChild);        addView(decorChild);        setContentView(decorChild);        decor.addView(this);    }    private void setContentView(View decorChild) {        mContentView = (View) decorChild.getParent();    }    /**     * 事件拦截操作     */    @Override    public boolean onInterceptTouchEvent(MotionEvent ev) {        // 处理ViewPager冲突问题        ViewPager mViewPager = getTouchViewPager(mViewPagers, ev);        // Log.i(TAG, "mViewPager = " + mViewPager);        if (mViewPager != null && mViewPager.getCurrentItem() != 0) {            return super.onInterceptTouchEvent(ev);        }        View ignoreView = getTouchIgnoreView(ignoreViews, ev);        if (ignoreView != null) {            Log.i(TAG, "ignoreView》》》》》》》》》》》》》》》》ignoreView");            return false;        }        switch (ev.getAction()) {        case MotionEvent.ACTION_DOWN:            downX = tempX = (int) ev.getRawX();            downY = (int) ev.getRawY();            break;        case MotionEvent.ACTION_MOVE:            int moveX = (int) ev.getRawX();            // 满足此条件屏蔽SildingFinishLayout里面子类的touch事件            if (moveX - downX > mTouchSlop && Math.abs((int) ev.getRawY() - downY) < mTouchSlop) {                return true;            }            break;        }        return super.onInterceptTouchEvent(ev);    }    private List<WeakReference<View>> ignoreViews = new ArrayList<WeakReference<View>>();    public void setIgnoreView(View view) {        if (view == null) {            return;        }        WeakReference<View> mReference = new WeakReference<View>(view);        if (!ignoreViews.contains(view)) {            ignoreViews.add(mReference);        }    }    public void removeIgnoreView(View view) {        if (view == null) {            return;        }        WeakReference<View> mReference = new WeakReference<View>(view);        if (ignoreViews.contains(mReference)) {            ignoreViews.remove(mReference);        }    }    private View getTouchIgnoreView(List<WeakReference<View>> ignoreViews, MotionEvent ev) {        if (ignoreViews == null || ignoreViews.size() == 0) {            return null;        }        Rect mRect = new Rect();        for (WeakReference<View> v : ignoreViews) {            v.get().getGlobalVisibleRect(mRect);            // v.getHitRect(mRect);            if (mRect.contains((int) ev.getX(), (int) ev.getY())) {                return v.get();            }        }        return null;    };    @Override    public boolean onTouchEvent(MotionEvent event) {        switch (event.getAction()) {        case MotionEvent.ACTION_MOVE:            int moveX = (int) event.getRawX();            int deltaX = tempX - moveX;            tempX = moveX;            if (moveX - downX > mTouchSlop && Math.abs((int) event.getRawY() - downY) < mTouchSlop) {                isSilding = true;            }            if (moveX - downX >= 0 && isSilding) {                mContentView.scrollBy(deltaX, 0);            }            break;        case MotionEvent.ACTION_UP:            isSilding = false;            if (mContentView.getScrollX() <= -viewWidth / 2) {                isFinish = true;                scrollRight();            } else {                scrollOrigin();                isFinish = false;            }            break;        }        return true;    }    /**     * 获取SwipeBackLayout里面的ViewPager的集合     *      * @param mViewPagers     * @param parent     */    private void getAlLViewPager(List<ViewPager> mViewPagers, ViewGroup parent) {        int childCount = parent.getChildCount();        for (int i = 0; i < childCount; i++) {            View child = parent.getChildAt(i);            if (child instanceof ViewPager) {                mViewPagers.add((ViewPager) child);            } else if (child instanceof ViewGroup) {                getAlLViewPager(mViewPagers, (ViewGroup) child);            }        }    }    /**     * 返回我们touch的ViewPager     *      * @param mViewPagers     * @param ev     * @return     */    private ViewPager getTouchViewPager(List<ViewPager> mViewPagers, MotionEvent ev) {        if (mViewPagers == null || mViewPagers.size() == 0) {            return null;        }        Rect mRect = new Rect();        for (ViewPager v : mViewPagers) {            v.getGlobalVisibleRect(mRect);            // v.getHitRect(mRect);            if (mRect.contains((int) ev.getX(), (int) ev.getY())) {                return v;            }        }        return null;    }    @Override    protected void onLayout(boolean changed, int l, int t, int r, int b) {        super.onLayout(changed, l, t, r, b);        if (changed) {            viewWidth = this.getWidth();            getAlLViewPager(mViewPagers, this);            // Log.i(TAG, "ViewPager size = " + mViewPagers.size());        }    }    @Override    protected void dispatchDraw(Canvas canvas) {        super.dispatchDraw(canvas);        if (mShadowDrawable != null && mContentView != null) {            int left = mContentView.getLeft() - mShadowDrawable.getIntrinsicWidth();            int right = left + mShadowDrawable.getIntrinsicWidth();            int top = mContentView.getTop();            int bottom = mContentView.getBottom();            mShadowDrawable.setBounds(left, top, right, bottom);            mShadowDrawable.draw(canvas);        }    }    /**     * 滚动出界面     */    private void scrollRight() {        final int delta = (viewWidth + mContentView.getScrollX());        // 调用startScroll方法来设置一些滚动的参数，我们在computeScroll()方法中调用scrollTo来滚动item        mScroller.startScroll(mContentView.getScrollX(), 0, -delta + 1, 0, Math.abs(delta));        postInvalidate();    }    /**     * 滚动到起始位置     */    private void scrollOrigin() {        int delta = mContentView.getScrollX();        mScroller.startScroll(mContentView.getScrollX(), 0, -delta, 0, Math.abs(delta));        postInvalidate();    }    @Override    public void computeScroll() {        // 调用startScroll的时候scroller.computeScrollOffset()返回true，        if (mScroller.computeScrollOffset()) {            mContentView.scrollTo(mScroller.getCurrX(), mScroller.getCurrY());            postInvalidate();            if (mScroller.isFinished() && isFinish) {                mActivity.finish();            }        }    }}