一、前言：
需求：一个ViewGroup中有多个控件，类似于常见的底部Tab布局，这几个子布局之间既可以点击切换，也可以左右滑动切换
实现：自定义父控件，在onInterceptTouchEvent方法中判断是否点击还是滑动，如果判断是点击，则直接交给child来响应点击事件去；如果是滑动，则
拦截事件，并通过回调传递给调用者处理。
优点：该控件只对触摸事件的分发做了相应处理，适用于各种滑动与点击冲突的情况....
使用：直接将该控件作为父布局即可，通过setmSetOnSlideListener回调处理对应滑动事件
二、使用：
1、代码
import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.ViewConfiguration;
import android.widget.RelativeLayout;
public class MyRadioRelativeLayout extends RelativeLayout {
public MyRadioRelativeLayout(Context context) {
this(context, null);
}
public MyRadioRelativeLayout(Context context, AttributeSet attrs,
int defStyleAttr) {
super(context, attrs, defStyleAttr);
initView();
}
public MyRadioRelativeLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
private void initView() {
}
private boolean mScrolling;
private float touchDownX;
@Override
public boolean onInterceptTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touchDownX = event.getX();
mScrolling = false;
break;
case MotionEvent.ACTION_MOVE:
if (Math.abs(touchDownX - event.getX()) >= ViewConfiguration.get(
getContext()).getScaledTouchSlop()) {
mScrolling = true;
} else {
mScrolling = false;
}
break;
case MotionEvent.ACTION_UP:
mScrolling = false;
break;
}
return mScrolling;
}
float x1 = 0;
float x2 = 0;
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
return true;
case MotionEvent.ACTION_MOVE:
break;
case MotionEvent.ACTION_UP:
x2 = event.getX();
if (touchDownX - x2 > DensityUtil.dip2px(getContext(), 40)) {
if(mSetOnSlideListener!=null){
mSetOnSlideListener.onRightToLeftSlide();
}
}
if (touchDownX - x2 < -DensityUtil.dip2px(getContext(), 40)) {
if(mSetOnSlideListener!=null){
mSetOnSlideListener.onLeftToRightSlide();
}
}
break;
}
return super.onTouchEvent(event);
}
private setOnSlideListener mSetOnSlideListener;
public setOnSlideListener getmSetOnSlideListener() {
return mSetOnSlideListener;
}
public void setmSetOnSlideListener(setOnSlideListener mSetOnSlideListener) {
this.mSetOnSlideListener = mSetOnSlideListener;
}
public interface setOnSlideListener{
void onRightToLeftSlide();
void onLeftToRightSlide();
}
}
2、解析：
ViewConfiguration.getScaledTouchSlop () 用法
getScaledTouchSlop是一个距离，表示滑动的时候，手的移动要大于这个距离才开始移动控件。如果小于这个距离就不触发移动控件，如viewpager就是用这个距离来判断用户是否翻页。
ViewConfiguration滑动参数设置类：
/**
* 包含了方法和标准的常量用来设置UI的超时、大小和距离
*/
public class ViewConfiguration {
// 设定水平滚动条的宽度和垂直滚动条的高度，单位是像素px
private static final int SCROLL_BAR_SIZE = 10;
//定义滚动条逐渐消失的时间，单位是毫秒
private static final int SCROLL_BAR_FADE_DURATION = 250;
// 默认的滚动条多少秒之后消失，单位是毫秒
private static final int SCROLL_BAR_DEFAULT_DELAY = 300;
// 定义边缘地方褪色的长度
private static final int FADING_EDGE_LENGTH = 12;
//定义子控件按下状态的持续事件
private static final int PRESSED_STATE_DURATION = 125;
//定义一个按下状态转变成长按状态的转变时间
private static final int LONG_PRESS_TIMEOUT = 500;
//定义用户在按住适当按钮，弹出全局的对话框的持续时间
private static final int GLOBAL_ACTIONS_KEY_TIMEOUT = 500;
//定义一个touch事件中是点击事件还是一个滑动事件所需的时间，如果用户在这个时间之内滑动，那么就认为是一个点击事件
private static final int TAP_TIMEOUT = 115;
/**
* Defines the duration in milliseconds we will wait to see if a touch event
* is a jump tap. If the user does not complete the jump tap within this interval, it is
* considered to be a tap.
*/
//定义一个touch事件时候是一个点击事件。如果用户在这个时间内没有完成这个点击，那么就认为是一个点击事件
private static final int JUMP_TAP_TIMEOUT = 500;
//定义双击事件的间隔时间
private static final int DOUBLE_TAP_TIMEOUT = 300;
//定义一个缩放控制反馈到用户界面的时间
private static final int ZOOM_CONTROLS_TIMEOUT = 3000;
/**
* Inset in pixels to look for touchable content when the user touches the edge of the screen
*/
private static final int EDGE_SLOP = 12;
/**
* Distance a touch can wander before we think the user is scrolling in pixels
*/
private static final int TOUCH_SLOP = 16;
/**
* Distance a touch can wander before we think the user is attempting a paged scroll
* (in dips)
*/
private static final int PAGING_TOUCH_SLOP = TOUCH_SLOP * 2;
/**
* Distance between the first touch and second touch to still be considered a double tap
*/
private static final int DOUBLE_TAP_SLOP = 100;
/**
* Distance a touch needs to be outside of a window's bounds for it to
* count as outside for purposes of dismissing the window.
*/
private static final int WINDOW_TOUCH_SLOP = 16;
//用来初始化fling的最小速度，单位是每秒多少像素
private static final int MINIMUM_FLING_VELOCITY = 50;
//用来初始化fling的最大速度，单位是每秒多少像素
private static final int MAXIMUM_FLING_VELOCITY = 4000;
//视图绘图缓存的最大尺寸，以字节表示。在ARGB888格式下，这个尺寸应至少等于屏幕的大小
@Deprecated
private static final int MAXIMUM_DRAWING_CACHE_SIZE = 320 * 480 * 4; // HVGA screen, ARGB8888
//flings和scrolls摩擦力度大小的系数
private static float SCROLL_FRICTION = 0.015f;
/**
* Max distance to over scroll for edge effects
*/
private static final int OVERSCROLL_DISTANCE = 0;
/**
* Max distance to over fling for edge effects
*/
private static final int OVERFLING_DISTANCE = 4;
}
