package com.wise.extend;
/**
* 自定义首页滑动控件
*/
import com.wise.extend.OnViewChangeListener;
import android.content.Context;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.widget.Scroller;
public class HScrollLayout extends ViewGroup {
private static final String TAG = "HScrollLayout";
private VelocityTracker velocityTracker;// 判断手势
private static final int SNAP_VELOCITY = 600; // 滑动速度
private int mCurScreen = 0; // 当前所在屏幕
private float downMotionX; // 按下x坐标
OnViewChangeListener mOnViewChangeListener;
Scroller scroller;
Context mContext;
public HScrollLayout(Context context) {
super(context);
init(context);
}
public HScrollLayout(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
private void init(Context context) {
scroller = new Scroller(context);
mContext = context;
mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
}
int desireWidth;
int desireHeight;
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
desireWidth = 0;
desireHeight = 0;
int count = getChildCount();
for (int i = 0; i < count; ++i) {
View v = getChildAt(i);
if (v.getVisibility() != View.GONE) {
measureChild(v, widthMeasureSpec,heightMeasureSpec);
desireWidth += v.getMeasuredWidth();
desireHeight = Math.max(desireHeight, v.getMeasuredHeight());
}
}
desireWidth += getPaddingLeft() + getPaddingRight();
desireHeight += getPaddingTop() + getPaddingBottom();
desireWidth = Math.max(desireWidth, getSuggestedMinimumWidth());
desireHeight = Math.max(desireHeight, getSuggestedMinimumHeight());
setMeasuredDimension(resolveSize(desireWidth, widthMeasureSpec),
resolveSize(desireHeight, heightMeasureSpec));
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
int childLeft = 0;
final int count = getChildCount();
for (int i = 0; i < count; i++) {
final View childView = getChildAt(i);
final int width = childView.getMeasuredWidth();
childView.layout(childLeft, 0, childLeft + width,
childView.getMeasuredHeight());
childLeft += width;
}
}
private float mLastMotionX;
private int mTouchSlop = 10;
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
//Log.d(TAG, "onInterceptTouchEvent = " + ev.getAction());
boolean xMoved = false;
final float x = ev.getX();
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
mLastMotionX = x;
downMotionX = ev.getX();
break;
case MotionEvent.ACTION_MOVE:
final int xDiff = (int) Math.abs(x - mLastMotionX);
xMoved = xDiff > mTouchSlop;
if ((mLastMotionX - x) <= 0 && getScrollX() <= 0){
}else{
//Log.d(TAG, "父控件停止感应");
getParent().requestDisallowInterceptTouchEvent(true);
}
break;
case MotionEvent.ACTION_UP:
break;
}
// true滑动容器里感应不到点击事件，false，滑动容器里控件感应到点击事件
//return mTouchState != TOUCH_STATE_REST;
//Log.d(TAG, "xMoved = " + xMoved);
return xMoved;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
//Log.d(TAG, "onTouchEvent = " + event.getAction());
float x = event.getX();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
if (velocityTracker == null) {
velocityTracker = VelocityTracker.obtain();
}
velocityTracker.addMovement(event);
if (!scroller.isFinished()) { // 解决在松开手滚动时，按下无效
scroller.abortAnimation();
}
downMotionX = x;
break;
case MotionEvent.ACTION_MOVE:
int deltaX = (int) (downMotionX - x);
downMotionX = x;
if (deltaX <= 0) {// 向右滑
if (getScrollX() <= 0) {
//Log.d(TAG, "划不动");
} else {
//Log.d(TAG, "不应该啊");
getParent().requestDisallowInterceptTouchEvent(true);
scrollBy(deltaX, 0);// 画面跟随指尖
if (velocityTracker == null) {
velocityTracker = VelocityTracker.obtain();
}
velocityTracker.addMovement(event);
}
} else {// 像左滑
//Log.d(TAG, "父控件停止感应");
getParent().requestDisallowInterceptTouchEvent(true);
scrollBy(deltaX, 0);// 画面跟随指尖
if (velocityTracker == null) {
velocityTracker = VelocityTracker.obtain();
}
velocityTracker.addMovement(event);
}
break;
case MotionEvent.ACTION_UP:
getParent().requestDisallowInterceptTouchEvent(false);
int velocityX = 0;
if (velocityTracker != null) {
velocityTracker.addMovement(event);
velocityTracker.computeCurrentVelocity(1000);
velocityX = (int) velocityTracker.getXVelocity();// 计算x方向速度
velocityTracker.recycle();
velocityTracker = null;
}
if (velocityX > SNAP_VELOCITY && mCurScreen > 0) { // 速度快且不是第一屏
snapToScreen(mCurScreen - 1);
} else if (velocityX < -SNAP_VELOCITY
&& mCurScreen < getChildCount() - 1) {// 速度快且不是最后一屏
snapToScreen(mCurScreen + 1);
} else {
snapToDestination(); // 判断是否翻转
}
break;
case MotionEvent.ACTION_CANCEL:
getParent().requestDisallowInterceptTouchEvent(false);
snapToDestination(); // 判断是否翻转
break;
}
return true;
}
/**
* 跳转到那个屏幕
*
* @param whichScreen
*/
public void snapToScreen(int whichScreen) {
if (whichScreen > (getChildCount() - 1)) {
addView();
}
whichScreen = Math.max(0, Math.min(whichScreen, (getChildCount() - 1)));// 防止输入不再范围内的数字
if (getScrollX() != getWidth() * whichScreen) {// 时候需要移动
int delta = whichScreen * getWidth() - getScrollX(); // 还有多少没有显示
scroller.startScroll(getScrollX(), 0, delta, 0, Math.abs(delta) * 2);// 滚动完剩下的距离
mCurScreen = whichScreen;
invalidate();
if (mOnViewChangeListener != null) {
mOnViewChangeListener.OnViewChange(whichScreen);
}
}
}
public void snapFastToScreen(int whichScreen){
whichScreen = Math.max(0, Math.min(whichScreen, (getChildCount() - 1)));// 防止输入不再范围内的数字
if (getScrollX() != getWidth() * whichScreen) {// 时候需要移动
int delta = whichScreen * getWidth() - getScrollX(); // 还有多少没有显示
scroller.startScroll(getScrollX(), 0, delta, 0);// 滚动完剩下的距离
mCurScreen = whichScreen;
invalidate();
if (mOnViewChangeListener != null) {
mOnViewChangeListener.OnViewChange(whichScreen);
}
}
}
/**
* 滑动速度过慢的话调用这个方法判断是否滑动了半个屏幕，并计算出当前显示那个屏幕
*/
private void snapToDestination() {
int screenWidth = getWidth();
int destScreen = (getScrollX() + screenWidth / 2) / screenWidth;
snapToScreen(destScreen);
}
@Override
public void computeScroll() {// 需要，不然松手后不会滑动
if (scroller.computeScrollOffset()) {
scrollTo(scroller.getCurrX(), scroller.getCurrY());
postInvalidate();
}
}
public void setOnViewChangeListener(
OnViewChangeListener onViewChangeListener) {
mOnViewChangeListener = onViewChangeListener;
}
public void addView() {
if (mOnViewChangeListener != null) {
mOnViewChangeListener.OnLastView();
}
}
}