Drag image creation for NSView with CALayer in NSCollectionView calls drawRect:?
I have an NSCollectionView with NSCollectionViewItems that have, amongst other things, a layer-hosting NSView with CALayers. The collectionView has wantsLayers set, and everything there is working nicely - draw, scroll, reorder animation. The trouble comes when I try to drag them. The collectionView builds the drag image for me, and all the collectionViewItem's children draw except the one with the CALayers. Some digging and logging revealed that the drag image creation code is calling drawRect: on my layer-hosting NSView. I can work around it by implementing a drawRect: that creates a placeholder drag image, but the question I have is: Is there something I'm missing that would cause it to create the right drag image for me? Or is this an Apple bug? If so, is my workaround good or bad? Is there a case where it will call drawRect: for some other legit reason, or should it just never call it and so when it's fixed my drawRect: will be ignored?___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Drag image creation for NSView with CALayer in NSCollectionView calls drawRect:?
On Mon, Mar 14, 2011 at 1:15 PM, Lee Ann Rucker lruc...@vmware.com wrote: Is there something I'm missing that would cause it to create the right drag image for me? If you think about it, you pretty much have to use the old raster drawing path to generate drag images. Even if you don't call -drawRect: (which NSCollectionView presumably does to insulate you from its implementation details), the drag image is a static bitmap. I suppose you could use a CARenderer to produce a static bitmap from within -drawRect:. I believe we've determined that the window update machinery does not call -drawRect: if you have set up your layer-hosting view correctly. Printing, and apparently NSCollectionView, will call it directly. --Kyle Sluder ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Drag image creation for NSView with CALayer in NSCollectionView calls drawRect:?
On Mar 14, 2011, at 1:29 PM, Kyle Sluder wrote: On Mon, Mar 14, 2011 at 1:15 PM, Lee Ann Rucker lruc...@vmware.com wrote: Is there something I'm missing that would cause it to create the right drag image for me? If you think about it, you pretty much have to use the old raster drawing path to generate drag images. Even if you don't call -drawRect: (which NSCollectionView presumably does to insulate you from its implementation details), the drag image is a static bitmap. I suppose you could use a CARenderer to produce a static bitmap from within -drawRect:. It's a CAOpenGLLayer, so as far as I can tell CARenderer is not going to help. But I'm fine with having a placeholder image, I just wanted to be sure I was making it in the right place. The first thing I thought looked promising was cacheDisplayInRect:toBitmapImageRep: which is called by NSCollectionView's drag, but that just calls drawRect on the top level view. I believe we've determined that the window update machinery does not call -drawRect: if you have set up your layer-hosting view correctly. Printing, and apparently NSCollectionView, will call it directly. --Kyle Sluder ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
