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这是一个复杂的控件,双层布局,可滑动,可拖拽
Demo下载:我的Github DoublePull
格瓦拉实际效果图:
简单分析:
- 根部局使用了RelativeLayout,有两个子布局:外层布局与内层布局。
- 外层布局。根布局为自定义ScrollView,有两子布局:HeaderFrameLayout与PullRelativeLayout
- 内层布局。根部局为RelativeLayout,有两子布局:RecyclerView与ImageButton
外层布局如图:
内层布局如图:
实现难点:
- 初始化,事件由ScrollView处理和消耗。当滚动到顶部,若继续往下滑动,事件由子View PullRelativeLayout处理和消耗
- 若PullRelativeLayout处理和消耗事件,拖拽距离过小,移动到原来位置。反之,则向下滑动隐藏布局
- HeaderFrameLayout随着PullRelativeLayout的变化而变化。隐藏则一起隐藏,打开则一起打开
- PullRelativeLayout隐藏后,ScrollView将不能处理和消耗事件,事件应由RecyclerView处理和消耗
- RecyclerView头布局滚动高度超过,头的70%,PullRelativeLayout做动画。HeaderFrameLayout做打开动画
- HeaderFrameLayout自定义View内部需要有打开功能,可使用Scroller来完成
- PullRelativeLayout自定义View内部需要有打开和隐藏功能,可使用Scroller来完成
- View的滑动也可使用动画的形式,但是由于需要设置一些Visibility属性,这里就使用Scroller来完成滑动
- 自定义View之间的状态获取和数据交互,使用了对外提供回调接口的形式和对象直接注入的形式
- 调试布局效果会花掉一些时间
自定义View分析:
OutScrollView
public class OutScrollView extends ScrollView {private int mPullRelativeLayoutState = PullRelativeLayout.SHOW;private int mDownY;private int mMoveY;private OnScrollStateChangeListener mOnScrollStateChangeListener;public OutScrollView(Context context) {super(context);}public OutScrollView(Context context, AttributeSet attrs) {super(context, attrs);}public OutScrollView(Context context, AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);}public void setPullRelativeLayoutState(int state) {mPullRelativeLayoutState = state;}@Overrideprotected void onScrollChanged(int l, int t, int oldl, int oldt) {super.onScrollChanged(l, t, oldl, oldt);if (mOnScrollStateChangeListener != null) {mOnScrollStateChangeListener.onScrollChange(l, t, oldl, oldt);}}@Overridepublic boolean onInterceptTouchEvent(MotionEvent ev) {switch (ev.getAction()) {case MotionEvent.ACTION_DOWN:mDownY = (int) ev.getRawY();break;case MotionEvent.ACTION_MOVE:mMoveY = (int) ev.getRawY();break;case MotionEvent.ACTION_CANCEL:case MotionEvent.ACTION_UP:mDownY = 0;mMoveY = 0;break;}if(mMoveY - mDownY < 0) {return super.onInterceptTouchEvent(ev);}if (getScrollY() == 0) {if (mPullRelativeLayoutState == PullRelativeLayout.SHOW) {return false;}if (mPullRelativeLayoutState == PullRelativeLayout.MOVE) {return false;}}return super.onInterceptTouchEvent(ev);}@Overridepublic boolean onTouchEvent(MotionEvent ev) {if (mPullRelativeLayoutState == PullRelativeLayout.HIDE) {return false;}return super.onTouchEvent(ev);}public interface OnScrollStateChangeListener {void onScrollChange(int l, int t, int oldl, int oldt);}public void setOnScrollStateChangeListener(OnScrollStateChangeListener listener) {mOnScrollStateChangeListener = listener;}}
- 获取PullRelativeLayoutState的状态值,根据它来判断是否处理事件:自己处理,子View处理,不处理等
- OnScrollStateChangeListener把ScrollView滚动高度状态回调出去,给外面使用
HeaderFrameLayout
public class HeaderFrameLayout extends FrameLayout {private Scroller mScroller;private int mHeight;private boolean isOpen;public HeaderFrameLayout(Context context) {super(context);init();}public HeaderFrameLayout(Context context, AttributeSet attrs) {super(context, attrs);init();}public HeaderFrameLayout(Context context, AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);init();}private void init() {mScroller = new Scroller(getContext());}@Overridepublic void computeScroll() {if (mScroller.computeScrollOffset()) {scrollTo(mScroller.getCurrX(), mScroller.getCurrY());postInvalidate();}}@Overrideprotected void onSizeChanged(int w, int h, int oldw, int oldh) {super.onSizeChanged(w, h, oldw, oldh);mHeight = getMeasuredHeight();}public void setOpen(boolean flag) {isOpen = flag;}public boolean isOpen() {return isOpen;}public void open() {if (!isOpen) {return;}smoothScrollTo(0, mHeight, 0, -mHeight, 800);isOpen = false;}private void smoothScrollTo(int startX, int startY,int dx, int dy, int duration) {mScroller.startScroll(startX, startY, dx, dy, duration);invalidate();}}
- 使用Scroller来滑动,让自己拥有打开滑动的效果,初始化位移高度等
- 一个boolean值来限制是否做打开滑动的效果
PullRelativeLayout
public class PullRelativeLayout extends RelativeLayout {public static final int SHOW = 1000;public static final int HIDE = 2000;public static final int MOVE = 3000;public static final int OPEN_START = 4000;public static final int OPEN_FINISH = 5000;private static final int NORMAL_TIME = 600;private int mMaxOffset;private int mState = SHOW;private float mLastY;private int mMoveY;private Scroller mScroller;private OnStateChangeListener mOnStateChangeListener;public PullRelativeLayout(Context context) {super(context);init();}public PullRelativeLayout(Context context, AttributeSet attrs) {super(context, attrs);init();}public PullRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);init();}private void init() {mScroller = new Scroller(getContext());}@Overridepublic void computeScroll() {if (mScroller.computeScrollOffset()) {scrollTo(mScroller.getCurrX(), mScroller.getCurrY());postInvalidate();}}public void setMaxOffset(int offset) {mMaxOffset = offset;}public void setState(int state) {mState = state;}public int getState() {return mState;}@Overridepublic boolean onTouchEvent(MotionEvent event) {if (mState == HIDE) {return false;}float y = event.getY();switch (event.getAction()) {case MotionEvent.ACTION_DOWN:mLastY = y;break;case MotionEvent.ACTION_MOVE:int moveY = (int) (y - mLastY);if (getScrollY() <= 0 && moveY > 0) {int offset = moveY / 2;move(offset);}mLastY = y;break;case MotionEvent.ACTION_CANCEL:case MotionEvent.ACTION_UP:changeState();break;}return true;}private void move(int offset) {mState = MOVE;if (mOnStateChangeListener != null) {mOnStateChangeListener.pullViewMove(mState, -offset);}scrollBy(0, -offset);}private void hide() {mState = HIDE;if (mOnStateChangeListener != null) {mOnStateChangeListener.pullViewHide(mState);}mMoveY = getMeasuredHeight() + Math.abs(getScrollY());smoothScrollTo(0, getScrollY(), 0, -mMoveY, NORMAL_TIME * 3);}public void hide(int time) {mState = HIDE;if (mOnStateChangeListener != null) {mOnStateChangeListener.pullViewHide(mState);}mMoveY = getMeasuredHeight() + Math.abs(getScrollY());smoothScrollTo(0, getScrollY(), 0, -mMoveY, time);}private void show() {mState = SHOW;if (mOnStateChangeListener != null) {mOnStateChangeListener.pullViewShow(mState);}smoothScrollTo(0, getScrollY(), 0, -getScrollY(), getScrollY());}private void changeState() {if (Math.abs(getScrollY()) > mMaxOffset + 50) {hide();} else {show();}}public void open() {mState = OPEN_START;if (mOnStateChangeListener != null) {mOnStateChangeListener.pullViewOpenStart();}smoothScrollTo(0, -mMoveY, 0, mMoveY, NORMAL_TIME);postDelayed(new Runnable() {@Overridepublic void run() {mState = OPEN_FINISH;if (mOnStateChangeListener != null) {mOnStateChangeListener.pullViewOpenFinish();}}}, NORMAL_TIME);}private void smoothScrollTo(int startX, int startY,int dx, int dy, int duration) {mScroller.startScroll(startX, startY, dx, dy, duration);invalidate();}public interface OnStateChangeListener {void pullViewShow(int state);void pullViewHide(int state);void pullViewMove(int state, int offset);void pullViewOpenStart();void pullViewOpenFinish();}public void setOnStateChangeListener(OnStateChangeListener listener) {mOnStateChangeListener = listener;}}
- 使用Scroller来滑动,设置打开,隐藏,手指拖拽的方法。将View的各种状态回调出去,用于同步其他View的状态
- 设置状态监听器
再来看一次效果图:
Demo下载:我的Github DoublePull
2016年7月09日 03:57:12
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