Android11 ， Launcher3 切换阿拉伯语，最近应用(后台)不能滑动

Launcher3 切换阿拉伯语，最近应用(后台)不能滑动

Launcher3QuickStep.apk

quickstep/recents_ui_overrides/src/com/android/quickstep/views/RecentsView.java
src/com/android/launcher3/PagedView.java

思路：
找到负责滑动的类，在其对应的函数中，加入日志。
切换成中文，点击Recent 键，进入最近应用界面, 滑动一次，抓取日志。
然后切换成阿拉伯语，执行和上面相同的操作，再一次抓取日志，然后对比日志，看看是否存在差异.

中文日志：

10-01 16:07:19.324 31445 31445 D tang25  : getScrollForPage mPageScrolls == nullfalse----true
10-01 16:07:19.324 31445 31445 D tang25  : computeMaxScroll mIsRtl: true
10-01 16:07:19.324 31445 31445 D tang25  : mDisallowScrollToClearAll: false
10-01 16:07:19.324 31445 31445 D tang25  : computeMaxScroll mTaskViewStartIndex: 0
10-01 16:07:19.324 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.324 31445 31445 D tang25  : updateMinAndMaxScrollX->mMaxScroll:0
10-01 16:07:19.324 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.325 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.325 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.328 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.328 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.332 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.332 31445 31445 D tang25  : computeMaxScroll mIsRtl: true
10-01 16:07:19.332 31445 31445 D tang25  : mDisallowScrollToClearAll: true
10-01 16:07:19.332 31445 31445 D tang25  : computeMaxScroll mTaskViewStartIndex: 0
10-01 16:07:19.332 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.332 31445 31445 D tang25  : updateMinAndMaxScrollX->mMaxScroll:0
10-01 16:07:19.350 31445 31445 D tang25  : getScrollForPage mPageScrolls == nullfalse----true
10-01 16:07:19.350 31445 31445 D tang25  : computeMaxScroll mIsRtl: true
10-01 16:07:19.350 31445 31445 D tang25  : mDisallowScrollToClearAll: false
10-01 16:07:19.350 31445 31445 D tang25  : computeMaxScroll mTaskViewStartIndex: 0
10-01 16:07:19.350 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.350 31445 31445 D tang25  : updateMinAndMaxScrollX->mMaxScroll:0
10-01 16:07:19.372 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.372 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.408 31445 31445 D tang25  : getScrollForPage mPageScrolls == nullfalse----true
10-01 16:07:19.408 31445 31445 D tang25  : computeMaxScroll mIsRtl: true
10-01 16:07:19.408 31445 31445 D tang25  : mDisallowScrollToClearAll: false
10-01 16:07:19.408 31445 31445 D tang25  : computeMaxScroll mTaskViewStartIndex: 0
10-01 16:07:19.408 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.408 31445 31445 D tang25  : updateMinAndMaxScrollX->mMaxScroll:5828
10-01 16:07:19.408 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.408 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.446 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.446 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.460 31445 31445 D tang25  : getScrollForPage mPageScrolls == nullfalse----true
10-01 16:07:19.460 31445 31445 D tang25  : computeMaxScroll mIsRtl: true
10-01 16:07:19.460 31445 31445 D tang25  : mDisallowScrollToClearAll: false
10-01 16:07:19.460 31445 31445 D tang25  : computeMaxScroll mTaskViewStartIndex: 0
10-01 16:07:19.460 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:07:19.460 31445 31445 D tang25  : updateMinAndMaxScrollX->mMaxScroll:5828

阿拉伯语日志：

10-01 16:08:24.982 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:24.982 31445 31445 D tang25  : computeMaxScroll mIsRtl: false
10-01 16:08:24.982 31445 31445 D tang25  : mDisallowScrollToClearAll: false
10-01 16:08:24.982 31445 31445 D tang25  : computeMaxScroll mTaskViewStartIndex: 0
10-01 16:08:24.982 31445 31445 D tang25  : computeMaxScroll final indexOfChild:x2 :1
10-01 16:08:24.982 31445 31445 D tang25  : getScrollForPage mPageScrolls == nullfalse----true
10-01 16:08:24.982 31445 31445 D tang25  : updateMinAndMaxScrollX->mMaxScroll:0
10-01 16:08:24.983 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:24.983 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:24.983 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:24.984 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:24.985 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:24.985 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:24.985 31445 31445 D tang25  : computeMaxScroll mIsRtl: false
10-01 16:08:24.985 31445 31445 D tang25  : mDisallowScrollToClearAll: true
10-01 16:08:24.985 31445 31445 D tang25  : computeMaxScroll mTaskViewStartIndex: 0
10-01 16:08:24.985 31445 31445 D tang25  : computeMaxScroll before indexOfChild x1:0
10-01 16:08:24.985 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:24.985 31445 31445 D tang25  : updateMinAndMaxScrollX->mMaxScroll:0
10-01 16:08:24.988 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:24.988 31445 31445 D tang25  : computeMaxScroll mIsRtl: false
10-01 16:08:24.988 31445 31445 D tang25  : mDisallowScrollToClearAll: false
10-01 16:08:24.988 31445 31445 D tang25  : computeMaxScroll mTaskViewStartIndex: 0
10-01 16:08:24.988 31445 31445 D tang25  : computeMaxScroll final indexOfChild:x2 :1
10-01 16:08:24.988 31445 31445 D tang25  : getScrollForPage mPageScrolls == nullfalse----true
10-01 16:08:24.988 31445 31445 D tang25  : updateMinAndMaxScrollX->mMaxScroll:0
10-01 16:08:25.012 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:25.012 31445 31445 D tang25  : computeMaxScroll mIsRtl: false
10-01 16:08:25.012 31445 31445 D tang25  : mDisallowScrollToClearAll: false
10-01 16:08:25.012 31445 31445 D tang25  : computeMaxScroll mTaskViewStartIndex: 0
10-01 16:08:25.012 31445 31445 D tang25  : computeMaxScroll final indexOfChild:x2 :1
10-01 16:08:25.012 31445 31445 D tang25  : getScrollForPage mPageScrolls == nullfalse----true
10-01 16:08:25.012 31445 31445 D tang25  : updateMinAndMaxScrollX->mMaxScroll:0
10-01 16:08:25.023 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:25.023 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:25.033 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:25.033 31445 31445 D tang25  : computeMaxScroll mIsRtl: false
10-01 16:08:25.033 31445 31445 D tang25  : mDisallowScrollToClearAll: false
10-01 16:08:25.033 31445 31445 D tang25  : computeMaxScroll mTaskViewStartIndex: 0
10-01 16:08:25.033 31445 31445 D tang25  : computeMaxScroll final indexOfChild:x2 :6
10-01 16:08:25.033 31445 31445 D tang25  : getScrollForPage mPageScrolls == nullfalse----true
10-01 16:08:25.033 31445 31445 D tang25  : updateMinAndMaxScrollX->mMaxScroll:0
10-01 16:08:25.033 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0
10-01 16:08:25.033 31445 31445 D tang25  : getScrollForPage mPageScrolls index:0

对比日志，发现差异 updateMinAndMaxScrollX->mMaxScroll:0，中文可以滑动，它这个mMaxScroll 不是一直为0的，
找到相应函数，打印退栈，查看调用流程，Log.d(TAG, Log.getStackTraceString(new Throwable()));

at com.android.launcher3.PagedView.getScrollForPage(PagedView.java:1062)
        at com.android.quickstep.views.RecentsView.computeMaxScroll(RecentsView.java:2370)
        at com.android.launcher3.PagedView.updateMinAndMaxScrollX(PagedView.java:712)
        at com.android.launcher3.PagedView.onLayout(PagedView.java:647)
        at com.android.quickstep.views.RecentsView.onLayout(RecentsView.java:1879)
        at android.view.View.layout(View.java:22905)
        at android.view.ViewGroup.layout(ViewGroup.java:6389)
        at com.android.quickstep.views.RecentsView.showCurrentTask(RecentsView.java:1240)
        at com.android.quickstep.AppToOverviewAnimationProvider.onActivityReady(AppToOverviewAnimationProvider.java:77)
        at com.android.quickstep.OverviewCommandHelper$RecentsActivityCommand.onActivityReady(OverviewCommandHelper.java:234)
        at com.android.quickstep.OverviewCommandHelper$RecentsActivityCommand.lambda$QLBi40m2HnRcFakJUh6rtde_WJM(Unknown Source:0)
        at com.android.quickstep.-$$Lambda$OverviewCommandHelper$RecentsActivityCommand$QLBi40m2HnRcFakJUh6rtde_WJM.test(Unknown Source:4)
        at com.android.quickstep.FallbackActivityInterface.lambda$createActivityInitListener$0(FallbackActivityInterface.java:97)
        at com.android.quickstep.-$$Lambda$FallbackActivityInterface$5yFo4vs3bnvBoGmsaVSWVYH888g.test(Unknown Source:6)
        at com.android.quickstep.util.ActivityInitListener.handleInit(ActivityInitListener.java:56)
        at com.android.quickstep.util.ActivityInitListener.init(ActivityInitListener.java:52)
        at com.android.launcher3.util.ActivityTracker.handleIntent(ActivityTracker.java:81)
        at com.android.launcher3.util.ActivityTracker.handleCreate(ActivityTracker.java:68)
        at com.android.quickstep.RecentsActivity.onCreate(RecentsActivity.java:262)
        at android.app.Activity.performCreate(Activity.java:7994)
        at android.app.Activity.performCreate(Activity.java:7978)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1310)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3405)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3596) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2067) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loop(Looper.java:223) 
        at android.app.ActivityThread.main(ActivityThread.java:7705) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:952) 
        
流程 RecentsView.onLayout() -> PagedView.updateMinAndMaxScrollX() -> RecentsView.computeMaxScroll() -> PagedView.getScrollForPage()

RecentsView 继承了PagedView，复现了其computeMaxScroll()函数，切换语言后导致mMaxScroll 为0！

改动

方案：不让其走子类的computeMaxScroll(), 走父类的，强制为mMaxScroll赋值！！！

PagedView.java

protected void updateMinAndMaxScrollX() {
        mMinScroll = computeMinScroll();
        //add start 
        if(mIsRtl){
            mMaxScroll = computeMaxScroll();
        }else {
            int childCount = getChildCount();
            if (childCount > 0) {
                final int index = false ? 0 : childCount - 1;
                mMaxScroll = getScrollForPage(index);
            } else {
                mMaxScroll = 0;
            }
        }
        Log.d("TAG","updateMinAndMaxScrollX->mMaxScroll:"+mMaxScroll);
        //add end
    }