On Fri, 19 Feb 2021 14:19:35 GMT, Alexander Scherbatiy <alex...@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. This pull request has been closed without being integrated. ------------- PR: https://git.openjdk.org/jfx/pull/406
