When using a touchscreen, the concept of the double-click does not make sense. When the user is using the systemwide double-click setting, this should be ignored when trying to activate Folder View items with a touchscreen, and they should always be activated with a single touch. Alternatively, if it's deemed critically important to respect the single-click/double-click setting even with touch input, a double-tap should not require that the cursor click the same spot; tapping twice *anywhere* on the item should be sufficient to trigger the double-tap to activate the item.
> a double-tap should not require that the cursor click the same spot Even for mouse clicks a slight tolerance should be accepted (pushing down the button can cause a slight move). Some applications use the startDragDistance() property also for double clicks.
(In reply to Christoph Feck from comment #1) > > a double-tap should not require that the cursor click the same spot > > Even for mouse clicks a slight tolerance should be accepted (pushing down > the button can cause a slight move). Some applications use the > startDragDistance() property also for double clicks. Right. However the tolerance would need to be much higher for touch. I still think single-click/touch-only is what makes the most sense for touch. No other touch-first platform that I'm aware of implement a double-tap-to-open behavior.
The startDragDistance used to be configurable with 'kcmshell5 mouse'. Unfortunately the QML 'port' removed many options.
It wasn't a QML port. Rather, a new QML UI was created to support using the Libinput driver. The missing features are ones not supported by Libinput, not anything that was missed or lost in the process of creating the new UI.
startDragDistance and related values are not input driver features, but Qt features.
Ah, that's true. We should indeed bring that back. However I would not put it in the mouse settings, because it doesn't on;y affect mice (e.g. you duoble-click with a touchpad too). Maybe we need a combined "Mouse & Touchpad" KCM that holds settings common to both (single-click vs double-click; drag distance, etc) and also allows configuring mice and touchpads. That's all material for another bug though. :)
This is being implemented in https://phabricator.kde.org/D25428.
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/170
Git commit a366714231dcdb24e17bf12c39d4457ac5d7dbb7 by David Edmundson, on behalf of Steffen Hartleib. Committed on 30/10/2020 at 21:14. Pushed by davidedmundson into branch 'master'. Allow touch to interact with Icons in FolderView mode * moving icon's on the desktop around with touch * open/launch icons with tap (only singe tap, regardless of mouse workspace behavior) * access the icon's context menu with tap and hold Related: bug 366462 M +29 -1 containments/desktop/package/contents/ui/FolderView.qml https://invent.kde.org/plasma/plasma-desktop/commit/a366714231dcdb24e17bf12c39d4457ac5d7dbb7