QGesture issues on OS X and Ubuntu
-
Hi everyone,
I just started developing with Qt to write a minimal browser supporting multitouch.
The final platform is an ARMv7-based embedded device with a 7inch multitouch display; the software stack consists of the Linux kernel (I wrote the multitouch display device driver myself) and the Ubuntu 13.10 root file system.As of now, I'm developing on both OS X (and I'm trying with Ubuntu too) on my MacBook Pro with a Magic Trackpad.
I extended QGraphicsWebView to grab Qt::PanGesture, Qt::PinchGesture, and Qt::SwipeGesture and handle the gesture properly.
The code I wrote to handle the QPinchGesture works fine, the "zoom" operates as in mobile devices (and as in Apple Safari), not as in most of desktop browsers; I used setTransformOriginPoint() and setScale() to achieve the behavior.
As a side effect, this kind of zoom breaks scrolling as it is implemented by QGraphicsWebView.Apart from QPinchGesture, the browser doesn't intercept QPanGesture and QSwipeGesture on OS X and I can't understand why this is the case. In addition, neither of the gesture seems to work on Ubuntu.
You can find a full example here: https://github.com/filipposironi/qtbrowser-gesture/tree/pinchablewebview .
If anyone as suggestions, you are more than welcome. -
For the records, the same issues occurs on OS X when using the imagegesture example (<Qt_install_directory>/5.2.1/clang_64/examples/gestures/imagegestures).
The application supports Q{Pan|Pinch|Swipe}Gesture, however, only the QPinchGesture gets triggered, the others go unobserved. -
I modified my system settings in OS X to avoid grabbing most of the gestures.
The net result is that now gestures get to my Qt browser!
Unfortunately, the "pan" gesture (putting 2 or more fingers on the trackpad) is recognized as a QTapAndHoldGesture and occasionally the sequence of QTapAndHoldGesture is interrupted by a QPanGesture.
It seems it has something to do with "speed", if I tap and move slowly I see a QPanGesture the first event I see is a QPanGesture followed by 4 QTapAndHoldGesture (I get 4 of them every time).PS: I had to grab QTapAndHoldGesture in the constructure of PinchableWebView, which I derived from QGraphicsWebView.
Up to now, I'm unable to produce any QSwipeGesture, I always get a sequence of QTapAndHoldGesture.
-
Hi and welcome to devnet,
You may have found something for OS X. You should have a look at the "bug report system":http://bugreports.qt-project.org to see if you find something similar. If so please consider updating the report with your findings, if not open please create a new report with as much information you can.
-
[quote author="SGaist" date="1396425394"]Hi and welcome to devnet,
You may have found something for OS X. You should have a look at the "bug report system":http://bugreports.qt-project.org to see if you find something similar. If so please consider updating the report with your findings, if not open please create a new report with as much information you can.[/quote]
I didn't find any bug that was reporting anything similar to my issue on OS X. I opened a new one: https://bugreports.qt-project.org/browse/QTBUG-38046 .
I'm also making additional experiments to better understand where Qt is behaving as expected. The weird thing is that on top of Linux/X11 (no window manager or desktop environment, just xinit to start X11), I don't see any gesture and all touch examples don't seem to behave as expected, even though xinput test-xi2, evtest, and mtdev-test report multi-touch events correctly (in fact Linux/X11/Unity recognizes at least 3-fingers panning).
-
Thanks for the bug report !
You might want to go to the interest mailing list to continue this. You'll find there Qt's developers/maintainers (this forum is more user oriented)
