VerticalDragLayout
来源：互联网 发布：php项目开发常用方法 编辑：程序博客网 时间：2024/06/15 12:59
package com.eoo.eoodemo.taobao;import android.content.Context;import android.support.v4.view.ViewCompat;import android.support.v4.widget.ViewDragHelper;import android.util.AttributeSet;import android.util.Log;import android.view.GestureDetector;import android.view.MotionEvent;import android.view.View;import android.widget.AbsListView;import android.widget.FrameLayout;/** * Created by llchen.Andy on 2015/12/18. */public class VerticalDragLayout extends FrameLayout { private ViewDragHelper mDragHelper; private GestureDetector mGestureDec; public VerticalDragLayout(Context context) { super(context); init(); } public VerticalDragLayout(Context context, AttributeSet attrs) { super(context, attrs); init(); } public VerticalDragLayout(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(); } private void init() { mDragHelper = ViewDragHelper.create(this, new ViewDragHelper.Callback() { @Override public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) { super.onViewPositionChanged(changedView, left, top, dx, dy); performViewPositionChanged(changedView, dy); } @Override public void onViewReleased(View releasedChild, float xvel, float yvel) { super.onViewReleased(releasedChild, xvel, yvel); performViewReleased(releasedChild, yvel); } @Override public boolean tryCaptureView(View child, int pointerId) { return true; } @Override public int clampViewPositionVertical(View child, int top, int dy) { int finalTop = top; if (child == getChildAt(0)) { finalTop = Math.min(0, top); } else { finalTop = Math.max(0, top); } return (int) (child.getTop() + (finalTop - child.getTop()) * 0.5f); } }); mGestureDec = new GestureDetector(getContext(), new GestureDetector.SimpleOnGestureListener() { @Override public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { if (getChildAt(0).getBottom() > 0) { if (canChildScrollDown(getChildAt(0))) { return false; } } else if (canChildScrollDown(getChildAt(1)) && distanceY > 0) { return false; } else if (canChildScrollUp(getChildAt(1)) && distanceY < 0) { return false; } return Math.abs(distanceY) > Math.abs(distanceX); } }); } private void performViewPositionChanged(View changedView, int dy) { View targetView = null; if (changedView == getChildAt(1)) { targetView = getChildAt(0); } else { targetView = getChildAt(1); } targetView.offsetTopAndBottom(dy); invalidate(); } private void performViewReleased(View changedView, float yvel) { if (changedView == getChildAt(0)) { log("Top: " + changedView.getTop()); if (yvel < -1200 || changedView.getTop() < -100) { mDragHelper.smoothSlideViewTo(changedView, changedView.getLeft(), -changedView.getMeasuredHeight()); } else { mDragHelper.smoothSlideViewTo(changedView, changedView.getLeft(), 0); } } else if (changedView == getChildAt(1)) { if (yvel > 1200 || changedView.getTop() > 100) { mDragHelper.smoothSlideViewTo(changedView, changedView.getLeft(), changedView.getMeasuredHeight()); } else { mDragHelper.smoothSlideViewTo(changedView, changedView.getLeft(), 0); } } ViewCompat.postInvalidateOnAnimation(this); } @Override public void computeScroll() { super.computeScroll(); if (mDragHelper.continueSettling(true)) { ViewCompat.postInvalidateOnAnimation(this); } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); } @Override protected void onLayout(boolean changed, int left, int top, int right, int bottom) {// super.onLayout(changed, left, top, right, bottom); int topOffset = top; for (int i = 0; i < getChildCount(); i++) { View childView = getChildAt(i); int height = childView.getMeasuredHeight(); childView.layout(left, topOffset, right, topOffset + height); topOffset += childView.getMeasuredHeight(); } } @Override public boolean onInterceptTouchEvent(MotionEvent ev) {// if (getChildAt(0).getBottom() > 0 && getChildAt(0).getTop() < 0) {// // view粘到顶部或底部，正在动画中的时候，不处理touch事件// return false;// } boolean shouldIntercept = mDragHelper.shouldInterceptTouchEvent(ev); boolean isMoved = mGestureDec.onTouchEvent(ev);// log("shouldIntercept: " + shouldIntercept);// log("isMoved: " + isMoved); if (ev.getAction() == MotionEvent.ACTION_DOWN) { // action_down时就让mDragHelper开始工作，否则有时候导致异常 他大爷的 mDragHelper.processTouchEvent(ev); } return isMoved & shouldIntercept; } protected boolean canChildScrollDown(View mTargetView) { if (android.os.Build.VERSION.SDK_INT < 14) { if (mTargetView instanceof AbsListView) { final AbsListView absListView = (AbsListView) mTargetView; return absListView.getChildCount() > 0 && (absListView.getLastVisiblePosition() < absListView.getChildCount() - 1 || absListView.getChildAt(absListView.getChildCount() - 1).getBottom() > absListView.getPaddingBottom()); } else { return ViewCompat.canScrollVertically(mTargetView, 1) || mTargetView.getScrollY() < 0; } } else { return ViewCompat.canScrollVertically(mTargetView, 1); } } public boolean canChildScrollUp(View mTargetView) { if (android.os.Build.VERSION.SDK_INT < 14) { if (mTargetView instanceof AbsListView) { final AbsListView absListView = (AbsListView) mTargetView; return absListView.getChildCount() > 0 && (absListView.getFirstVisiblePosition() > 0 || absListView.getChildAt(0) .getTop() < absListView.getPaddingTop()); } else { return ViewCompat.canScrollVertically(mTargetView, -1) || mTargetView.getScrollY() > 0; } } else { return ViewCompat.canScrollVertically(mTargetView, -1); } } @Override public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) { super.requestDisallowInterceptTouchEvent(disallowIntercept); } @Override public boolean onTouchEvent(MotionEvent event) { mDragHelper.processTouchEvent(event); return true; } @Override protected void onFinishInflate() { super.onFinishInflate(); } private void log(String msg) { Log.i("TEST", msg); }} 0 0
