Some built in AppKit components temporarily "pause" NSTrackingArea updates while their content is being scrolled or resized. For example, if you inspect tracking areas using the Quartz Debug tool, you can see that tracking areas embedded in an NSScrollView don't move onscreen as the content is being scrolled, and only update when scrolling ends. Tracking areas within NSSplitView panes similarly don't update while the panes are being resized. How do these components achieve this behavior?
I'm working on a custom scrolling component that handles scrollWheel events and enters a mouse tracking loop as described here and I'd like to replicate this behavior as a performance improvement.
Related
I have a modal window, which is perfect for iOS 13's drag to dismiss gesture, because this way the user remains in the context, so I don't want to use full screen. The controller contains a UICollectionView which displays a month calendar, which is scrollable vertically.
The problem is, that when the user wants to scroll upwards in the collection view, the dismiss gesture is triggered instead. If I scroll down first, then can I only scroll up.
I've tried to disable the internal UIPanGestureRecognizer (it seems somehow there is no presentedView, so it didn't work), tried to set the UICollectionView's pan gesture recognizer delegate to prevent the system recognizer to fire (it turned out you can't do that), and tried to scroll the collection view on appearing a bit (ugly).
How can I elegantly convince the the modal presentation, that my scrollview isn't scrolled to the top?
I have a window with an opengl view where content ist rendered. The problem I have in macOS is, that when I move the window from one monitor to the other, its content gets messed up. A redraw fixes the issue. Thus I need to redraw the GL Area when it gets moved from one monitor to the other. Is there any way to detect the transition of the window from one monitor to the other?
You can register for notifications that fire when the view's window changes screens: NSWindowDidChangeScreenNotification
Alright here is my issue. I have a Pivot view. Inside that pivot view a scroll viewer containing many stack panels and grids. On some of the grids I have MouseButton Up Events. What is happening is if I flick the scroll it scrolls as expected but when I release my finger most of the time it fires off the event from mousebutton up. Because technically I let up. The problem is these grids completely fill the screen so finding an area without a mousebutton up to scroll is near impossible. What I want to happen is if the user flicked to scroll I would ideally like it to ignore the mousebutton up event. It does this successfully sometimes but pretty rarely and I have noticed I have to flick pretty fast for it to work as expected.
Any ideas on how to prevent this activity. I assume there is as Listboxes work perfect.
i think u should use windows phone toolkit GestureListener to recognize flick event
I ended up setting a bool for when the scrollviewer was scrolling and based on that allowing the mouseup action to run my code. Here is the the site I used to implement the bool based on scrolling status.
http://blogs.msdn.com/b/ptorr/archive/2010/07/23/how-to-detect-when-a-list-is-scrolling-or-not.aspx
I am wanting to implement history navigation in my app that mimics the slide away animation found in Safari on Lion and in XCode where a top view slides away at the speed of swipe to reveal the view underneath it.
I was looking for pointers on how to do this. I know how to detect the swipe. I assume I could implement the animation via a CALayer animation slide transition on the top view revealing a view underneath it. Has anybody else done this and can offer some further pointers?
It's a new NSEvent method, -trackSwipeEventWithOptions:.... You should call it from within your regular scroll/swipe event handler, whenever you decide the gesture should begin. Unfortunately it doesn't automatically handle the page animations — it just gives you updates with the gesture amount, and you have to do the animations yourself (using layers or views or somesuch). You'll probably want to save images of each page so you can animate them around during a gesture.
I am using a custom panel as a ItemsPanel for a ItemsControl in a with a custom template that provides for a scroll viewer. (See Xaml below.) So long as my panel does not implement IScrollInfo, scrolling works in this scenerio.
I implement IScrollInfo and update my viewport and extent sizes in measure override. The scroll bar shows the correct relative size, and if I call the IScrollInfo methods directly, scrolling works as expected. However, the drag and flick gestures no longer scroll the content. Putting a breakpoint on the input of every IScrollInfo method shows that drag and pick are not calling the interface. Removing the IScrollInfo interface declaration restores the scroll on drag and flick behavior.
Is there a simple way to restore the flick and pan gestures to ItemControls with panels that implement IScrollInfo?
An unfortunate answer I received from Eric Sink, A MSFT forum moderator.
I believe that what is happening is that, when you inherit from
IScrollInfo, your panel takes over all of the scroll functionality but
we use an internal interface, as martin mentioned, to control the
flick animation. Since your object does not inherit from this
interface the underlying code will bypass this functionality.
I think that you should still be able to override the OnManipulation*
events and setup your own storyboard animation.
It sounds like if you want to do IScrollInfo, you're on your own for the manipulation.