Android: double-clicked callback not work on TouchArea

[heng30]

• platform: Android
• Android target sdk version: 32
• language: Rust
• slint version: v1.5.1
• style: material

• code snippets

  TouchArea {
      moved => {
          debug("move ok");
      }
  
      pointer-event(evt) => {
          debug("pointer-event ok");
      }
  
      clicked => {
          debug("clicked ok");
      }
  
      double-clicked => {
          debug("double-clicked not work");
      }
  }

[ogoffart]

Thanks for reporting an issue.

The problem is that we send a MouseExit event on finger release, which cause the double click state to be reset.

https://github.com/slint-ui/slint/blob/6e7353cf1182712b53a7ed5de3b004ad5507911f/internal/backends/android-activity/androidwindowadapter.rs#L326-L327

(I've actually done the same on some MCU platform)

I think we have the following options:

1. Don't send MouseExit on release in the android backend.
2. Somehow not resetting the click_count on MouseExit. We have other mechanisms to find out it was done on the same item anyway.
3. Have specific events for touch that wouldn't set the has_hover anyway without exit. But that's a bigger change.

[tronical]

Don't send MouseExit on release in the android backend.

Perhaps that could be done with a delay? So that there's still a chance of doing a double tap.