mono
[BUG] SkiaSharp views do not emit mouse motion events when a mouse button is not clicked
On platforms with a mouse, the only way to track mouse motion is through the Touch events and it only happens when a mouse key is pressed. In many uses cases you still need the mouse motion without any of the mouse keys pressed, for example to prelight objects. For now I have reproduce this error in the Forms views.
From the SKTouchEventArgs API I understand this could be achieved emitting the motion event with the InContact property to false, am I correct? Otherwise this would be a feature instead of bug :)
What platforms are broken? Do you get any events when the mouse moves? I believe it was working, maybe something broke.
It may be that you did not set e.Handled = true. If you don't let the OS know that your are interested in the event, then it won't send the rest.
I do get move events when moving the mouse, but only when a button is pressed. This happens with the SkiaSharp.Views.Forms.SKCanvasView in macOS and in the Android and iOS emulators. I can't remind right now from other applications I wrote, if Android.View or UIKit.UIView emit those events, but in macOS it should.
Here is the code: https://github.com/ylatuya/lienzosharp/blob/master/src/LienzoSharp.Skia.Forms/LienzoFormsView.cs#L104
Looking at the implementation, at least for the macOS/iOS part, it seems it's only handling mouse drag events: https://github.com/mono/SkiaSharp/blob/master/source/SkiaSharp.Views.Forms/SkiaSharp.Views.Forms.Mac/SKTouchHandler.cs
I know this is an old issue, but still valid. Currently the macOS views use a gesture recognizer - which only works when the mouse is pressed.
A better alternative is to override the mouse events on the view itself and/or use a NSTrackingArea.