Android input专题--触摸事件中Split相关课程笔记

Posted 2022-12-11 Android高级知识分享官

android input专题–触摸事件中Split相关课程笔记

1. 应用层面Activity的Window最常见控制可以通过设置windowEnableSplitTouch
   在values/styles.xml中的theme中设置, 可将theme设置给Application或者Activity,但是这个属性控制的是Window的属性。

<resources>
    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>

    <style name="AppTheme.NoActionBar">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
        <item name="android:windowEnableSplitTouch">true</item>    <!-- 加入的配置-->
    </style>

    <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />

    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

</resources>

其实Activity默认是有设置的：

  protected DecorView generateDecor(int featureId) 
        // System process doesn't have application context and in that case we need to directly use
        // the context we have. Otherwise we want the application context, so we don't cling to the
        // activity.
        Context context;
        if (mUseDecorContext) 
            Context applicationContext = getContext().getApplicationContext();
            if (applicationContext == null) 
                context = getContext();
             else 
                context = new DecorContext(applicationContext, getContext());
                if (mTheme != -1) 
                    context.setTheme(mTheme);
                
            
         else 
            context = getContext();
        
        return new DecorView(context, featureId, this, getAttributes());
    

    protected ViewGroup generateLayout(DecorView decor) 
        // Apply data from current theme.

     //省略部分
        if (a.getBoolean(R.styleable.Window_windowShowWallpaper, false)) 
            setFlags(FLAG_SHOW_WALLPAPER, FLAG_SHOW_WALLPAPER&(~getForcedWindowFlags()));
        

        if (a.getBoolean(R.styleable.Window_windowEnableSplitTouch,
                getContext().getApplicationInfo().targetSdkVersion
                        >= android.os.Build.VERSION_CODES.HONEYCOMB)) 
            setFlags(FLAG_SPLIT_TOUCH, FLAG_SPLIT_TOUCH&(~getForcedWindowFlags()));
        
//省略部分
        

这里只是应用层面的控制，那么InputDispatcher部分是桌面处理的呢？
其实这一部分主要逻辑集中在findTouchedWindowTargetsLocked方法中对isSplit处理，
总结为以下2点：
1、只有当多指时候才存在对触摸事件进行分离的情况，如果单指压根不涉及
2、只有当触摸的原window和新window都同时支持FLAG_SPLIT_TOUCH才可以达到两个window都响应触摸事件，不然只会传递给原window