I don't know what's going on exactly, but I have reports from a few people with touchscreens now that if the main scrollbar is visible, dragging on their touchscreen scrolls the output. But if they hide the scrollbar with SetScroll(-2, false) then their touchscreens are no longer able to scroll the display and dragging highlights text instead.
Hiding the scrollbar makes touchscreens no longer able to scroll output?
Posted by Fiendish on Sun 23 Aug 2020 09:56 PM — 3 posts, 13,959 views.
This is probably an OS issue - if there is no scrollbar then the dragging of the finger has nowhere to direct the movement to.
Ah, allowing touchscreen scrolling at all seems like a legacy fallback behavior. By default Windows 7+ converts WM_GESTURE into WM_*SCROLL but only if a scrollbar is present. It seems like it may be possible to restore touchscreen scrolling even without a scrollbar by registering for WM_GESTURE as well if it's available?
https://docs.microsoft.com/en-us/windows/win32/wintouch/legacy-support-for-panning-with-scrollbars
https://docs.microsoft.com/en-us/windows/win32/wintouch/improving-the-single-finger-panning-experience
https://docs.microsoft.com/en-us/windows/win32/wintouch/windows-touch-gestures-overview#legacy-support
https://docs.microsoft.com/en-us/windows/win32/wintouch/legacy-support-for-panning-with-scrollbars
https://docs.microsoft.com/en-us/windows/win32/wintouch/improving-the-single-finger-panning-experience
https://docs.microsoft.com/en-us/windows/win32/wintouch/windows-touch-gestures-overview#legacy-support