What about use qt's built-in QGesture?

[xiaoyifang]

goldendict-ng/src/ui/mainwindow.cc

Lines 875 to 878 in 7669316

	#ifndef Q_OS_MACOS
	ui.centralWidget->grabGesture( Gestures::GDPinchGestureType );
	ui.centralWidget->grabGesture( Gestures::GDSwipeGestureType );
	#endif

[shenlebantongying]

Current reality:

• Yes, Qt now has better built-in gestures, and it is not hard to do clean: replace gestures.cc with Qt's built-ins #1407. However, real hardware is needed to test and connect gestures to actions.
• The webengine widget on macOS has rich gestures built-in. Just don't add/touch/modify them.

For GD's in-house implementation, there are maybe some bugs if user has unusual setups (unusual to 10 years ago), such as:

• Wayland -> GD's implementation simply doesn't work because the screen coordinate cannot be obtained, and the relevant methods are deprecated.
  • Wayland appears to implement gesture recognition on the system's side (via libinput?) simliar to macOS instead of letting apps do it on their own.
• Hi-Dpi or large screen -> GD's implementation only needs very small movement to trigger the gestures. Again, deprecated methods are used.
• The webengine widget appears to have some built-in gestures for Linux/Windows like on macOS too. Conflict?

(BTW, I welcome sponsorship to buy me a high-precision trackpad/touchscreen that supports 3-figures to improve gesture support 😅)