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.

slint/internal/backends/android-activity/androidwindowadapter.rs

Lines 326 to 327 in 6e7353c

	// Also send exit to avoid remaining hover state
	self.window.dispatch_event(WindowEvent::PointerExited);

(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.