Whole-word swipe-deletion crashes app when swiping text with only numbers and symbols

Edit by @patrickgold : This issue is the main discussion area for fixing word deletion related stuff all at once, which have piled up. Below you can still see the original issue comment.

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Description

When swipe-deleting in a text box that exclusively contains numbers and symbols, the keyboard crashes. If the text box contains any single letter, the keyboard doesn’t immediately crash. The error doesn’t occur on per-character swipe-deletion.

Somehow related to #547. This issue is also somehow related to #1076, which is likely sufficiently different to this issue that this issue being a separate one is justified.

Steps to reproduce

1. Go to a text box where typing text is possible.
2. Type 123456789@#$%&-+()/*"':;!?.
3. Focus the cursor on the very end of the text box.
4. Swipe the delete button to the left.

Environment information

• FlorisBoard Version: 0.3.13-beta08 (51)
• Android: 10 (cn=Q sdk=29)

Features enabled

smartbar = true
suggestions = false
suggestions_clipboard = true
suggestions_next_word = false
glide = false
clipboard_internal = false
clipboard_history = false

Attached stacktrace files

1628111146794.stacktrace

java.util.NoSuchElementException: List is empty.
	at kotlin.collections.CollectionsKt___CollectionsKt.last(_Collections.kt:416)
	at dev.patrickgold.florisboard.ime.core.EditorInstance.leftAppendWordToSelection(EditorInstance.kt:419)
	at dev.patrickgold.florisboard.ime.text.keyboard.TextKeyboardView.handleDeleteSwipe(TextKeyboardView.kt:651)
	at dev.patrickgold.florisboard.ime.text.keyboard.TextKeyboardView.onSwipe(TextKeyboardView.kt:585)
	at dev.patrickgold.florisboard.ime.text.gestures.SwipeGesture$Detector.onTouchMove(SwipeGesture.kt:136)
	at dev.patrickgold.florisboard.ime.text.keyboard.TextKeyboardView.onTouchEventInternal(TextKeyboardView.kt:330)
	at dev.patrickgold.florisboard.ime.keyboard.KeyboardView$1.invokeSuspend(KeyboardView.kt:52)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTaskKt.resume(DispatchedTask.kt:227)
	at kotlinx.coroutines.DispatchedTaskKt.resumeUnconfined(DispatchedTask.kt:190)
	at kotlinx.coroutines.DispatchedTaskKt.dispatch(DispatchedTask.kt:161)
	at kotlinx.coroutines.CancellableContinuationImpl.dispatchResume(CancellableContinuationImpl.kt:362)
	at kotlinx.coroutines.CancellableContinuationImpl.completeResume(CancellableContinuationImpl.kt:479)
	at kotlinx.coroutines.channels.AbstractChannel$ReceiveHasNext.completeResumeReceive(AbstractChannel.kt:940)
	at kotlinx.coroutines.channels.ArrayChannel.offerInternal(ArrayChannel.kt:84)
	at kotlinx.coroutines.channels.AbstractSendChannel.offer(AbstractChannel.kt:141)
	at kotlinx.coroutines.channels.ChannelsKt__ChannelsKt.sendBlocking(Channels.kt:21)
	at kotlinx.coroutines.channels.ChannelsKt.sendBlocking(Unknown Source:1)
	at dev.patrickgold.florisboard.ime.keyboard.KeyboardView.onTouchEvent(KeyboardView.kt:83)
	at android.view.View.dispatchTouchEvent(View.java:13620)
	at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3125)
	at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2774)
	at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3131)
	at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2788)
	at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3131)
	at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2788)
	at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3131)
	at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2788)
	at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3131)
	at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2788)
	at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3131)
	at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2788)
	at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3131)
	at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2788)
	at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3131)
	at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2788)
	at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3131)
	at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2788)
	at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3131)
	at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2788)
	at com.android.internal.policy.DecorView.superDispatchTouchEvent(DecorView.java:506)
	at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1857)
	at android.app.Dialog.dispatchTouchEvent(Dialog.java:873)
	at android.inputmethodservice.SoftInputWindow.dispatchTouchEvent(SoftInputWindow.java:152)
	at com.android.internal.policy.DecorView.dispatchTouchEvent(DecorView.java:456)
	at android.view.View.dispatchPointerEvent(View.java:13884)
	at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:6202)
	at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:5940)
	at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:5393)
	at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:5453)
	at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:5412)
	at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:5577)
	at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:5420)
	at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:5634)
	at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:5393)
	at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:5453)
	at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:5412)
	at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:5420)
	at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:5393)
	at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:8343)
	at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:8312)
	at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:8263)
	at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:8482)
	at android.view.InputEventReceiver.dispatchInputEvent(InputEventReceiver.java:188)
	at android.view.InputEventReceiver.nativeConsumeBatchedInputEvents(Native Method)
	at android.view.InputEventReceiver.consumeBatchedInputEvents(InputEventReceiver.java:178)
	at android.view.ViewRootImpl.doConsumeBatchedInput(ViewRootImpl.java:8429)
	at android.view.ViewRootImpl$ConsumeBatchedInputRunnable.run(ViewRootImpl.java:8506)
	at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1056)
	at android.view.Choreographer.doCallbacks(Choreographer.java:880)
	at android.view.Choreographer.doFrame(Choreographer.java:800)
	at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1041)
	at android.os.Handler.handleCallback(Handler.java:883)
	at android.os.Handler.dispatchMessage(Handler.java:100)
	at android.os.Looper.loop(Looper.java:227)
	at android.app.ActivityThread.main(ActivityThread.java:7822)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1026)

[patrickgold]

Other than that, I’ve changed #548’s title, as I’ve now just realized that its title makes it sound like a bug when the issue itself sounds more like a proposal (and an opinionated one at that) for partial/precise symbol selection.

Perfect, we will work on #548 on a later stage then. As for the word deletion, I will merge the changes now in so I can work on fixing some other things for 0.3.13 stable next week, thanks for testing the debug build out!

[Glitchy-Tozier]

@Glitchy-Tozier do you know any other issues regarding current word/precise word deletion which are not on above list? I tried my best at searching all but I may have missed some.

I checked but couldn’t remember/find any additional ones.