dispatchTouchEvent事件分发浅析（一）大体代码

dodo_lihao

发布于 2018-09-12 11:03:28

5680

发布于 2018-09-12 11:03:28

文章被收录于专栏：懒人开发

View类很复杂，到今天自己都没有勇气去看，先从事件分发开始吧

题外话，外面调用虽然一样，但是下面源码其实每个版本的实现都是不一样的。

具体代码可以见https://github.com/2954722256/demo_event

大体内容描述：

有1个Activity， 3个相关继承的View （2个是继承LinearLayout的ViewGroup， 1个是Button，也就是单纯的View）
这3个类之间没有继承关系，只是想表达在layout中的嵌套团系
ViewGroup，我们大体知道是组合模式的树形结构，ViewGroup可以添加ViewGroup和View， View本身是不能添加View的

文件大体结构：

R.layout.activity_main：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@android:color/background_light" >

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">

        <com.aohuan.test.dodoevent.view.TouchEventFather
            android:layout_width="300dp"
            android:layout_height="300dp"
            android:background="#468AD7"
            android:layout_centerHorizontal="true"
            android:orientation="vertical"
            android:id="@+id/father">

            <com.aohuan.test.dodoevent.view.TouchEventChilds
                android:id="@+id/childs"
                android:layout_width="200dp"
                android:layout_height="200dp"
                android:layout_margin="50dp"
                android:layout_gravity="center_horizontal"
                android:background="#E1110D">

                <com.aohuan.test.dodoevent.view.TouchEventChilds2
                    android:id="@+id/childs2"
                    android:layout_width="100dp"
                    android:layout_height="100dp"
                    android:layout_margin="50dp" />
            </com.aohuan.test.dodoevent.view.TouchEventChilds>
        </com.aohuan.test.dodoevent.view.TouchEventFather>
    </RelativeLayout>



    <com.aohuan.test.dodoevent.view.EventButton
        android:id="@+id/testBtn"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_margin="50dp"
        />

    <com.aohuan.test.dodoevent.view.EventViewGroup
        android:id="@+id/testLl"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:layout_alignParentBottom="true"
        android:layout_alignParentRight="true"
        android:layout_margin="50dp"
        android:background="@android:color/darker_gray"
        />

</RelativeLayout>

MainActivity：

package com.aohuan.test.dodoevent;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;

import com.aohuan.test.dodoevent.tools.TouchEventUtil;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
//        ((ViewGroup)this.getWindow().getDecorView().getRootView()).getChildAt(0).setOnClickListener(new View.OnClickListener() {
//            @Override
//            public void onClick(View v) {
//                TouchEventUtil.doClick(MainActivity.class);
//            }
//        });
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"onTouchEvent",ev);
        return super.onTouchEvent(ev);
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"dispatchTouchEvent",ev);
        return super.dispatchTouchEvent(ev);
    }
}

EventButton：

package com.aohuan.test.dodoevent.view;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.Button;

import com.aohuan.test.dodoevent.tools.TouchEventUtil;

public class EventButton extends Button{
    public EventButton(Context context) {
        super(context);
    }

    public EventButton(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public EventButton(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"onTouchEvent",ev);
        return super.onTouchEvent(ev);
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"dispatchTouchEvent",ev);
        return super.dispatchTouchEvent(ev);
    }
}

EventViewGroup

package com.aohuan.test.dodoevent.view;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.ViewGroup;
import android.widget.LinearLayout;

import com.aohuan.test.dodoevent.tools.TouchEventUtil;

public class EventViewGroup extends LinearLayout{
    public EventViewGroup(Context context) {
        super(context);
    }

    public EventViewGroup(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public EventViewGroup(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"onTouchEvent",ev);
        return super.onTouchEvent(ev);
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"dispatchTouchEvent",ev);
        return super.dispatchTouchEvent(ev);
    }

}

TouchEventFather:

package com.aohuan.test.dodoevent.view;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.LinearLayout;

import com.aohuan.test.dodoevent.tools.TouchEventUtil;


public class TouchEventFather extends LinearLayout {

    private final Context mContext;

    public TouchEventFather(Context context) {
        super(context);
        this.mContext = context;
    }

    public TouchEventFather(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.mContext = context;
//      this.setOnClickListener(new OnClickListener() {
//          @Override
//          public void onClick(View v) {
//              TouchEventUtil.doClick(TouchEventFather.class);
//          }
//      });
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"dispatchTouchEvent",ev);
        return super.dispatchTouchEvent(ev);
//      return false;
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"onInterceptTouchEvent",ev);
        return super.onInterceptTouchEvent(ev);
//      return true;
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"onTouchEvent",ev);
        return super.onTouchEvent(ev);
    }


}

TouchEventChilds:

package com.aohuan.test.dodoevent.view;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.LinearLayout;

import com.aohuan.test.dodoevent.tools.TouchEventUtil;


public class TouchEventChilds extends LinearLayout {

    private final Context mContext;

    public TouchEventChilds(Context context) {
        super(context);
        this.mContext = context;
    }

    public TouchEventChilds(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.mContext = context;
//      this.setClickable(false);
//      this.setOnClickListener(new OnClickListener() {
//          @Override
//          public void onClick(View v) {
//              TouchEventUtil.doClick(TouchEventChilds.class);
//          }
//      });
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"onInterceptTouchEvent",ev);
        return super.onInterceptTouchEvent(ev);
//      return true;
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"dispatchTouchEvent",ev);
        return super.dispatchTouchEvent(ev);
//      return true;
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"onTouchEvent",ev);
        return super.onTouchEvent(ev);
    }

}

TouchEventChilds2:

package com.aohuan.test.dodoevent.view;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;

import com.aohuan.test.dodoevent.tools.TouchEventUtil;


public class TouchEventChilds2 extends Button {

    Context mContext;

    public TouchEventChilds2(Context context) {
        super(context);
        this.mContext = context;
    }

    public TouchEventChilds2(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.mContext = context;
//        this.setClickable(false);
//        this.setOnClickListener(new OnClickListener() {
//            @Override
//            public void onClick(View v) {
//                TouchEventUtil.doClick(TouchEventChilds2.class);
//            }
//        });
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"dispatchTouchEvent",ev);
        return super.dispatchTouchEvent(ev);
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        TouchEventUtil.logActionMsg(getClass(),"onTouchEvent",ev);
        return super.onTouchEvent(ev);
    }


}

TouchEventUtil:(打印的帮助类，简单过滤MotionEvent的种类)

package com.aohuan.test.dodoevent.tools;

import android.util.Log;
import android.view.MotionEvent;

public class TouchEventUtil {

    public static void logActionMsg(Class cls, String functionName, MotionEvent ev) {
        logActionMsg(cls, functionName, ev, "noMsg");
    }

    enum LogType {
        Down, Up, Move, All
    }

    static LogType mLogType = LogType.Down;


    public static void logActionMsg(Class cls, String functionName, MotionEvent ev, String msg) {
        switch (mLogType) {
            case Down:
                if (ev.getAction() == MotionEvent.ACTION_DOWN)
                    doPrint(cls, functionName, ev, msg);
                break;
            case Up:
                if (ev.getAction() == MotionEvent.ACTION_UP)
                    doPrint(cls, functionName, ev, msg);
                break;
            case Move:
                if (ev.getAction() == MotionEvent.ACTION_MOVE)
                    doPrint(cls, functionName, ev, msg);
                break;
            case All:
                doPrint(cls, functionName, ev, msg);
                break;
            default:
                break;
        }
    }

    private static void doPrint(Class cls, String functionName, MotionEvent ev, String msg) {
        Log.e("touch", cls.getSimpleName() + "\t----\t" + functionName + "\t---->\t" + getTouchAction(ev.getAction()) + "\t---->\t" + msg);
    }

    private static String getTouchAction(int actionId) {
        String actionName = "Unknow:id=" + actionId;
        switch (actionId) {
            case MotionEvent.ACTION_DOWN:
                actionName = "ACTION_DOWN";
                break;
            case MotionEvent.ACTION_MOVE:
                actionName = "ACTION_MOVE";
                break;
            case MotionEvent.ACTION_UP:
                actionName = "ACTION_UP";
                break;
            case MotionEvent.ACTION_CANCEL:
                actionName = "ACTION_CANCEL";
                break;
            case MotionEvent.ACTION_OUTSIDE:
                actionName = "ACTION_OUTSIDE";
                break;
        }
        return actionName;
    }

    public static void doClick(Class cls){
        Log.e("【click】", cls.getSimpleName() + " is  clicked!!");
    }


}

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原始发表：2016.08.22 ，如有侵权请联系 cloudcommunity@tencent.com 删除

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dispatchTouchEvent事件分发浅析（一）大体代码

dispatchTouchEvent事件分发浅析（一）大体代码

具体代码可以见https://github.com/2954722256/demo_event

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