On Fri, 19 Feb 2021 15:56:02 GMT, Kevin Rushforth <k...@openjdk.org> wrote:
>> The issue is reproduced on Raspberry Pi 3 B+ with Touchscreen display. >> >> To reproduce the issue run the >> [ScrollPaneSample](https://bugs.openjdk.java.net/secure/attachment/93270/ScrollPaneSample.java) >> with Monocle: >>> sudo jdk/bin/java -Dprism.verbose=true -Djavafx.platform=monocle >>> -Dembedded=monocle -Dglass.platform=Monocle ScrollPaneSample >> >> >> An application consists of a ScrollPane with buttons. if a button is touched >> by a finger, moved up/down and released, the button is scrolled and the >> button's action is fired. >> >> This happens because Monocle generates mouse pressed, mouse dragged, scroll, >> mouse released events when touch events are received. >> Even a button is scrolled on a ScrollPane it still fires the button's >> action on the synthesized mouse release event. >> >> My first attempt was to add a scroll event listener to a ButtonBehavior >> class and disarm the button when the scroll event is received. >> This does work not in the case where buttons are small and scrolling buttons >> leads that a finger is released on the next button (the scrolling process is >> remained a slightly behind the touched finger so the finger is touched on >> one button and released on another). >> In this case all scroll events goes to the first button and the second >> button still fires its action (it does not disarmed because it does not >> receive scroll events). >> >> The current fix adds drag event listener to ButtonBehavior to disarm the >> button. Drag events goes to the touched and released buttons. >> >> Than I checked the fix on the same Raspberry Pi using GTK with touchscreen. >>> sudo jdk/bin/java -Dprism.verbose=true -Djavafx.platform=gtk >>> ScrollPaneSample >> >> I have not seen scroll events using GTK (even using >> -Dgtk.com.sun.javafx.gestures.scroll=true option), but GTK sends mouse drag >> events on a button touch. >> The mouse drag event between a button touch and release events would disarm >> the button in the proposed ButtonBehavior drag event handler. So I added the >> check if the mouse drag is synthesized. If the mouse drag is synthesized >> (Monocle case on touchscreen) it disarms the button, otherwise (GTK case) >> not. >> >> I checked the fix for the following controls placed on a ScrollPane (see >> [ScrollPaneControlsSample](https://bugs.openjdk.java.net/secure/attachment/93271/ScrollPaneControlsSample.java) >> sample) : >> - Fixed in corresponding behavior classes or its parents: Button, >> ToggleButton, CheckBox, ComboBox, ChoiceBox, ColorPicker, DatePicker, >> RadioButton >> - Works because an action is not fired on mouse release event: TextField >> - Does not work: Slider >> >> The Slider control does not work with the fix because it reacts not only on >> mouse release event but on mouse drag event as well. It requires a separate >> fix. >> >> I checked the Ensemble8 sample with the fix. It works with Monocle on >> Raspberry Pi 3B+ on Touchscreen. Scrolling the main page by a finger does >> not makes it to be pressed. >> >> The Ensemble8 sample does not work with GTK on Raspberry Pi 3B+ with >> Touchscreen. I see it generates scroll events ( it has its own >> [ScrollEventSynthesizer](https://github.com/openjdk/jfx/blob/master/apps/samples/Ensemble8/src/app/java/ensemble/ScrollEventSynthesizer.java)) >> and action events and it can makes the Ensemble8 buttons on a ScrollPane to >> be pressed. > > Can you provide an automated test for this? > > Since this is touching common code, what testing have you done to ensure no > regressions on other platforms when not using Monocle? > > This will need careful review and testing. I have Touchscreen only on Raspberry Pi so I checked the touch events only on JavaFX on arm with Monocle and GTK. I also checked the fix with ScrollPaneControlsSample on Linux and Windows with ordinary screen and using only mouse (press, release, scroll) and the sample works with and without the fix. I run all but webkit automated tests with the fix on Ubuntu `gradle test` and they passed. I will look the way to provide an automated test. I am interested if there is a better way to fix this. Handling scroll event would be straightforward (because the ScrollPane is used) but unfortunately it does not work when two controls are scrolled. ------------- PR: https://git.openjdk.java.net/jfx/pull/406
