> -----Original Message----- > From: J-P Nurmi > Sent: Sunday, 16 October 2016 4:06 PM > To: Mitch Curtis <mitch.cur...@qt.io>; Qt Project <interest@qt-project.org> > Subject: Re: Mouse event propagation in Qt Quick > > Hey Mitch,
Hey! > > > - In example #2, why is Flickable happy to steal events that it doesn't do > anything with? Shouldn't it see that it wasn't a "flick" and ignore the > event, so > that it goes to the next highest item in the stacking order (the mouse area)? > > An interactive Flickable always accepts mouse press events, because it needs > to become the "mouse grabber item" ie. the item that receives the > consequent mouse move events. This way Flickable can detect drags and > flicks. I was about to reply to myself after realising exactly this, hahaha. It would be too late to propagate press events by the time it receives the final release... > > - Why aren't the scroll bars blocked by the mouse area in example #3? > > The MouseArea is under the ScrollBar, because its parent is under the > ScrollBar. The MouseArea is a child of Flickable::contentItem, whereas > ScrollBars are children of the Flickable they are attached to. ScrollBar and > Flickable::contentItem are siblings, ScrollBar being higher in the stacking > order. Ahhhh. That makes perfect sense, thanks! > > - Why does example #3 work if I remove "preventStealing: true"? > > What do you mean? That's the exact use case "preventStealing" is meant for. > :) When the MouseArea's preventStealing is true, Flickable honors it and > won't be able to flick or drag since it's not allowed to steal events from the > MouseArea. When preventStealing is false, Flickable's > childMouseEventFilter() steals the press from the MouseArea when it > detects a flick or drag. Because of the other misunderstandings that I had, I thought that preventStealing was the only thing allowing the MouseArea to get events, which is why I thought it was strange that leaving it as false allowed the example to continue working. :D > -- > J-P Nurmi > [snip] > _______________________________________________ > Interest mailing list > Interest@qt-project.org > http://lists.qt-project.org/mailman/listinfo/interest _______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
