java SWT:最有效的layout方法Control.requestLayout()

Eclipse SWT 最新版本中引入了 requestLayout() 方法,该方法被添加到 Control 和 Composite 类中,用于高效地触发布局更新。此方法相较于常用的 Composite.layout() 提供了更好的性能表现,有助于改善应用程序的响应速度。

Eclipse SWT最新的版本中org.eclipse.swt.widgets.Control增加了一个新方法requestLayout()用于更高效的处理layout请求
该方法其实只有一行代码:

public void requestLayout () {
    getShell ().layout (new Control[] {this}, SWT.DEFER);
}

这是SWT当前最高效的触发layout的办法,但是目前大多数开发者还是习惯使用性能更差的 Composite.layout()方法,
下面是说明原文:

SWT has added a new requestLayout() method to the Control and Composite classes. This method does essentially the same thing as
widget.getShell().layout(new Control[] {widget}, SWT.DEFER);
The snippet, above, is currently the most efficient method of triggering layouts in SWT, but most developers are unaware of this. Most Eclipse developers invoke Composite.layout(), which is worse in the sense of performance. This new API is intended to make it easier for developers to adopt the more efficient mechanism as opposed to using Composite#layout().

However, be aware that changing existing invocations of layout() to requestLayout() may break code that assumes that controls are completely sized and positioned at a certain point in time.

参考

《Eclipse Project Neon (4.6) M4 - New and Noteworthy》
《http://www.vogella.com/tutorials/SWT/article.html》

025-11-27 20:49:13.448 9351-9351 InputEventReceiver com.example.rednotedemo E Exception dispatching input event. 2025-11-27 20:49:13.448 9351-9351 MessageQueue-JNI com.example.rednotedemo E Exception in MessageQueue callback: handleReceiveCallback 2025-11-27 20:49:13.453 9351-9351 MessageQueue-JNI com.example.rednotedemo E java.lang.IndexOutOfBoundsException: Index 0 out of bounds for length 0 at jdk.internal.util.Preconditions.outOfBounds(Preconditions.java:64) at jdk.internal.util.Preconditions.outOfBoundsCheckIndex(Preconditions.java:70) at jdk.internal.util.Preconditions.checkIndex(Preconditions.java:266) at java.util.Objects.checkIndex(Objects.java:385) at java.util.ArrayList.get(ArrayList.java:434) at androidx.recyclerview.widget.StaggeredGridLayoutManager$Span.calculateCachedStart(StaggeredGridLayoutManager.java:2505) at androidx.recyclerview.widget.StaggeredGridLayoutManager$Span.getStartLine(StaggeredGridLayoutManager.java:2522) at androidx.recyclerview.widget.StaggeredGridLayoutManager.checkSpanForGap(StaggeredGridLayoutManager.java:409) at androidx.recyclerview.widget.StaggeredGridLayoutManager.hasGapsToFix(StaggeredGridLayoutManager.java:358) at androidx.recyclerview.widget.StaggeredGridLayoutManager.checkForGaps(StaggeredGridLayoutManager.java:281) at androidx.recyclerview.widget.StaggeredGridLayoutManager.onScrollStateChanged(StaggeredGridLayoutManager.java:316) at androidx.recyclerview.widget.RecyclerView.dispatchOnScrollStateChanged(RecyclerView.java:5726) at androidx.recyclerview.widget.RecyclerView.setScrollState(RecyclerView.java:1690) at androidx.recyclerview.widget.RecyclerView.onTouchEvent(RecyclerView.java:3894) at android.view.View.performOnTouchCallback(View.java:16645) at android.view.View.dispatchTouchEvent(View.java:16598) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3140) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2814) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3146) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2829) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3146) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2829) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3146) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2829) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3146) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2829) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3146) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2829) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3146) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2829) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3146) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2829) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3146) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2829) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3146) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2829) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3146) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2829) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3146) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2829) at com.android.internal.policy.DecorView.superDispatchTouchEvent(DecorView.java:475) at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:2021) at android.app.Activity.dispatchTouchEvent(Activity.java:4604) at androidx.appcompat.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:70) at com.android.internal.policy.DecorView.dispatchTouchEvent(DecorView.java:433) at android.view.View.dispatchPointerEvent(View.java:16938) at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:8228) at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:7987) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:7369) 2025-11-27 20:49:13.453 9351-9351 MessageQueue-JNI com.example.rednotedemo E at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:7426) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:7392) at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:7558) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:7400) at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:7615) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:7373) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:7426) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:7392) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:7400) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:7373) at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:10533) at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:10484) at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:10452) at android.view.ViewRootImpl.processRawInputEvent(ViewRootImpl.java:10897) at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:10655) at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:300) at android.os.MessageQueue.nativePollOnce(Native Method) at android.os.MessageQueue.nextLegacy(MessageQueue.java:913) at android.os.MessageQueue.next(MessageQueue.java:1025) at android.os.Looper.loopOnce(Looper.java:196) at android.os.Looper.loop(Looper.java:338) at android.app.ActivityThread.main(ActivityThread.java:9067) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:593) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:932) 2025-11-27 20:49:13.453 9351-9351 AndroidRuntime com.example.rednotedemo D Shutting down VM
最新发布
11-28
at android.widget.LinearLayout.measureVertical(LinearLayout.java:883) at android.widget.LinearLayout.onMeasure(LinearLayout.java:726) at android.view.View.measure(View.java:29007) at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:7132) at com.android.internal.policy.DecorView.measureChildWithMargins(DecorView.java:3010) at android.widget.FrameLayout.onMeasure(FrameLayout.java:205) at com.android.internal.policy.DecorView.onMeasure(DecorView.java:911) at android.view.View.measure(View.java:29007) at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:5801) at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:3999) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:4393) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:3667) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:12113) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:2459) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:2468) at android.view.Choreographer.doCallbacks(Choreographer.java:1693) at android.view.Choreographer.doFrame(Choreographer.java:1448) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:2284) at android.os.Handler.handleCallback(Handler.java:1014) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loopOnce(Looper.java:250) at android.os.Looper.loop(Looper.java:340) at android.app.ActivityThread.main(ActivityThread.java:9913) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:621) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:957)
06-13
E DCS>CommonEventRuleListManager[main#dcs-thread-DcsWorker]: getUploadPolicy: cache does not have 20110 201101 launch_time_consuming 08-06 15:26:25.541040 6101 6267 D DCS>CommonRecorder[main#dcs-thread-DcsWorker]: Common Record event failed. DCS reject event: [appId=20110,logTag=201101,eventId=launch_time_consuming] . Pls check server config. 08-06 15:26:25.541095 6191 6191 D StackPagedViewEx[u0]: requestLayout com.oplus.quickstep.layout.grid.OplusGridRecentsView.requestLayout:0 android.view.ViewExtImpl.hookRequestLayout:656 android.view.View.requestLayout:28958 android.view.ViewExtImpl.hookRequestLayout:656 android.view.View.requestLayout:28958 android.view.ViewExtImpl.hookRequestLayout:656 android.view.View.requestLayout:28958 08-06 15:26:25.541152 6191 6191 D StackPagedViewEx[u0]: mIsLayoutValid true->false caller=com.oplus.quickstep.views.StackPagedViewEx.requestLayout:20 com.oplus.quickstep.layout.grid.OplusGridRecentsView.requestLayout:0 android.view.ViewExtImpl.hookRequestLayout:656 android.view.View.requestLayout:28958 android.view.ViewExtImpl.hookRequestLayout:656 android.view.View.requestLayout:28958 android.view.ViewExtImpl.hookRequestLayout:656 08-06 15:26:25.541457 3384 3543 D CompactWindowManagerService: triggerCompatWindowState canEnterCompactWindowMode: false 08-06 15:26:25.541470 3384 3543 D OplusVFXScreenEffectFeature: notifySFCompatWindowStateChange entered false 08-06 15:26:25.541516 3384 3543 D FSS_FoldScreenBlackCoverController: displayChangeToOn, dc:Display{#0 state=ON size=1264x2780 ROTATION_0} 08-06 15:26:25.541595 6191 22197 I NotificationListener[u0]: title and text is null, title:null,text:null,notification:StatusBarNotification(pkg=com.oplus.olc user=UserHandle{0} id=0 tag=null key=0|com.oplus.olc|0|null|1000: Notification(channel=LOGKIT_CHANNEL shortcut=null contentView=null vibrate=null sound=null defaults=0 flags=ONGOING_EVENT|GROUP_SUMMARY|CAN_COLORIZE color=0x00000000 groupKey=com.oplus.olc.notification vis=PRIVATE)) 08-06 15:26:25.541603 3384 3543 D FSS_FoldScreenBlackSurfaceStrategy: checkFinishFolding post clearBlackCover, triggerByAllDrawn:false, deviceFolding=false, waitingForHintMaskShown = false, foldingScreenAllDrawn:true, display.state=2, screenOnFully=true, isMatchDefaultState:false, aodShowing:false, screenOn:true, dc:Display{#0 state=ON size=1264x2780 ROTATION_0}, call by:com.android.server.wm.FoldScreenBlackCoverPolicy.checkFinishFolding:66 com.android.server.wm.FoldScreenBlackCoverController.checkFinishFolding:146 com.android.server.wm.FoldScreenBlackCoverController.displayChangeToOn:69 com.android.server.wm.FoldScreenSwitchingManager.displayChangeToOn:188 com.android.server.wm.DisplayContentExtImpl.displayChangeToOn:1072 08-06 15:26:25.541609 6191 6191 D LauncherRootView[u0]: LauncherRootView onLayout 08-06 15:26:25.541630 6191 6191 D StackPagedViewEx[u0]: PagedView.onLayout() 08-06 15:26:25.541797 2120 2547 D [PREVIEW]: SF obtain preview_adapter: 0 08-06 15:26:25.541806 2120 2547 D [PREVIEW]: TabletPreviewAdapter::parallel world 0 08-06 15:26:25.541848 6191 6191 D StackPagedViewEx[u0]: mIsLayoutValid false->true caller=com.oplus.quickstep.views.StackPagedViewEx.onLayout:14 com.android.quickstep.views.RecentsView.onLayout:39 com.android.quickstep.views.OplusRecentsViewImpl.onLayout:46 android.view.View.layout:26209 android.view.ViewGroup.layout:6664 android.widget.FrameLayout.layoutChildren:332 android.widget.FrameLayout.onLayout:270 08-06 15:26:25.541942 6191 6191 I LauncherRecentsView[u0]: setCurrentPageIfNeed mScroller.isFinished=false,pageScrollChanged=false,orientationChange=false 08-06 15:26:25.541950 6191 11157 D OplusTaskIconCacheImpl[u0]: OplusTaskIconCacheImpl#getCacheEntry(), task=[com.oplus.logkit.collect.activity.CollectActivity id=1574 m=1 u=0 lAT=171313478 dId=0] null getBitmapInfo, icon=com.oplus.icons.OplusFastBitmapDrawable@8c4fd6a, defaultWidth=210, defaultHeight=210, width=210, height=210 08-06 15:26:25.542048 3384 3552 D AppProfilerExtImpl: Skipped pss collection for CPU busy 08-06 15:26:25.542119 6191 22197 I NotificationListener[u0]: isGroupHeader is true, notification:StatusBarNotification(pkg=com.oplus.olc user=UserHandle{0} id=0 tag=null key=0|com.oplus.olc|0|null|1000: Notification(channel=LOGKIT_CHANNEL shortcut=null contentView=null vibrate=null sound=null defaults=0 flags=ONGOING_EVENT|GROUP_SUMMARY|CAN_COLORIZE color=0x00000000 groupKey=com.oplus.olc.notification vis=PRIVATE)) 08-06 15:26:25.542166 6101 6267 D DCS>AbandonEventRuleTableHelper[main#dcs-thread-DcsWorker]: insert package: 20110_201101_launch_time_consuming true 08-06 15:26:25.542228 6191 22197 I Launcher.Badge[u0]: BadgeDataProviderCompatVP#onNotificationFullRefreshInner, activeNotifications size = 2activeNotifications = [StatusBarNotification(pkg=com.oplus.olc user=UserHandle{0} id=1 tag=null key=0|com.oplus.olc|1|null|1000: Notification(channel=LOGKIT_CHANNEL shortcut=null contentView=null vibrate=null sound=null defaults=0 flags=ONGOING_EVENT|NO_CLEAR|FOREGROUND_SERVICE|CAN_COLORIZE color=0x00000000 groupKey=com.oplus.olc.notification vis=PRIVATE)), StatusBarNotification(pkg=com.oplus.olc user=UserHandle{0} id=2 tag=null key=0|com.oplus.olc|2|null|1000: Notification(channel=SCREENRECORD_CHANNEL shortcut=null contentView=null vibrate=null sound=null defaults=0 flags=ONGOING_EVENT|NO_CLEAR|FOREGROUND_SERVICE|CAN_COLORIZE color=0x00000000 groupKey=com.oplus.olc.notification vis=PRIVATE))] 08-06 15:26:25.542237 6191 6191 I OplusPageIndicator[u0]: onGlobalLayout isFolderHost = false, disableUpdatePivot = falsemPressFeedbackHelper.isPressingAnim() false 08-06 15:26:25.542255 6191 6191 I OplusPageIndicator[u0]: updatePivot() getExtraIndicatorPivotY = 0 08-06 15:26:25.542343 6191 6191 D OplusPageIndicator[u0]: setPivotY -1133.0; caller = com.android.la 解释
08-13
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