Windows 7中使用Qt / QML应用程序的自定义触摸行为

Question

I am developing a touch application for Windows 7 with Qt/QML. The end-user-device has Windows 7's native touch behavior, ie: When touching the screen, a point appears on the last-touched-point, and when ending the physical touch, Windows puts that point on the now-touched point and runs in the on-clicked-Event.

Compared to the behavior one knows from standard Windows mouse-usage, this leads to a different behavior as soon as it comes to eg clicking some button: A mouse user will expect that the button changes color to the pressed-down-color when mouse button goes down, while the color changes to the default color again when the mouse button goes up.

In my application, I want to have a customized way of touch feedback: What is currently being touched should be marked using changed colors of buttons, imitating a "mouse goes down" when the actual physical touch begins and imitating a "mouse goes up" when the actual physical touch ends.

My application will run fullscreen, so an actual possibility would be to change the system's behavior on application start and change it back to default on applications end.

Such a behavior would effectively be the same as the standard behavior on eg all Android devices I know.

I searched through all the MouseArea and MultiPointTouchArea elements, trying to find a way to just make the click-reaction behavior different to the standard behavior. However I did not even find a way to capture the begin of the actual touch ... All the things which I want to happen at the begin of the touch actually happen when the touching ends.

Edit: It does not matter if I use a QML button or a mousearea plus the MouseArea.pressed property: Nothing will be "pressed" before the finger leaves the touch and the onClicked() even is called.

Possibly related: Adobe AIR: touch screen doesn't trigger mouse down event correctly - but I did not find a way to access the functions like Multitouch.inputMode (which are mentioned in the first reply) from a native Qt application.

How can I achieve the described behavior for my application?

Answer 1

The solution for this issue is to disable "Press and Hold" for the application. This is what can be done in a system-wide setting using ... Control Panel -> Pen and Touch -> Touch -> Press and Hold -> Settings -> uncheck 'Enable press and hold for right-clicking'

The only solution I found to to this in native code can be found here: http://msdn.microsoft.com/en-us/library/ms812373.aspx

I checked that this is at least still working for Windows 7. To get it working for QML, I searched for the QWindow* in QQmlApplicationEngine::rootObjects() and used its winId as a HWND. With that HWND, I called the TogglePressAndHold function from the link before app.exec().