Re: problem getting CALayer to draw an image
Sorry about the mysterious blank posts. Let's see if I can do it with plain text rather than HTML. On 4/5/2018 11:05 AM, David Duncan wrote: >> On Apr 5, 2018, at 10:53 AM, James Walker wrote: >> >> I have a generic NSView that contains some subviews, and I'd like to add a background image. I tried code like this: >> >> NSImage* backgroundImage = [NSImage imageNamed: @"blueprint controls.png"]; >> CALayer* holderLayer = [CALayer layer]; >> _throttleHolder.layer = holderLayer; >> _throttleHolder.wantsLayer = YES; >> holderLayer.zPosition = 4.0f; >> holderLayer.contents = backgroundImage; >> holderLayer.hidden = NO; >> holderLayer.bounds = NSRectToCGRect( _throttleHolder.bounds ); >> [holderLayer setNeedsDisplay]; > You don’t need to call -setNeedsDisplay here, and it may be what is destroying your content (when a layer displays, its stores the result of drawing in contents – you don’t want that since you are setting the contents directly). Thank you (and also thanks to Rob Petrovec). I think my first try didn't have that line, but when it didn't work, I started making desperate changes. In my first attempt, I tried using the layer that the view already owned by virtue of being marked layer-backed in the nib, rather than adding my own layer. For the record, I get correct results with just this: NSImage* backgroundImage = [NSImage imageNamed: @"blueprint controls.png"]; _throttleHolder.layer = [CALayer layer]; _throttleHolder.layer.contents = backgroundImage; ___ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: problem getting CALayer to draw an image (repost)
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Re: problem getting CALayer to draw an image
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Re: problem getting CALayer to draw an image
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Re: problem getting CALayer to draw an image
> On Apr 5, 2018, at 10:53 AM, James Walker wrote: > > I have a generic NSView that contains some subviews, and I'd like to add a > background image. I tried code like this: > > NSImage* backgroundImage = [NSImage imageNamed: @"blueprint controls.png"]; > CALayer* holderLayer = [CALayer layer]; > _throttleHolder.layer = holderLayer; > _throttleHolder.wantsLayer = YES; > holderLayer.zPosition = 4.0f; > holderLayer.contents = backgroundImage; > holderLayer.hidden = NO; > holderLayer.bounds = NSRectToCGRect( _throttleHolder.bounds ); > [holderLayer setNeedsDisplay]; You don’t need to call -setNeedsDisplay here, and it may be what is destroying your content (when a layer displays, its stores the result of drawing in contents – you don’t want that since you are setting the contents directly). Overall however, I think AppKit has an NSView method (something like updateLayer I think) that you want to override to do this. The layer’s geometry should already be set by AppKit and you should not modify it if I recall correctly. Geometry includes things such as center/bounds/frame and hidden. > > But no background image shows up. On the other hand, if I add the line > > holderLayer.backgroundColor = CGColorGetConstantColor( kCGColorWhite ); > > then I get a white background, so apparently the layer is there and capable > of drawing. And yes, I have made sure that backgroundImage is not nil. > > At this point, it probably would have been quicker to just go ahead and > subclass NSView, but I'm curious about what dumb mistake I'm making. > ___ > > 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: > https://lists.apple.com/mailman/options/cocoa-dev/david.duncan%40apple.com > > This email sent to david.dun...@apple.com -- David Duncan ___ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: problem getting CALayer to draw an image
If you take out the setNeedsDisplay it draws ok. —Rob > On Apr 5, 2018, at 11:53 AM, James Walker wrote: > > I have a generic NSView that contains some subviews, and I'd like to add a > background image. I tried code like this: > > NSImage* backgroundImage = [NSImage imageNamed: @"blueprint controls.png"]; > CALayer* holderLayer = [CALayer layer]; > _throttleHolder.layer = holderLayer; > _throttleHolder.wantsLayer = YES; > holderLayer.zPosition = 4.0f; > holderLayer.contents = backgroundImage; > holderLayer.hidden = NO; > holderLayer.bounds = NSRectToCGRect( _throttleHolder.bounds ); > [holderLayer setNeedsDisplay]; > > But no background image shows up. On the other hand, if I add the line > > holderLayer.backgroundColor = CGColorGetConstantColor( kCGColorWhite ); > > then I get a white background, so apparently the layer is there and capable > of drawing. And yes, I have made sure that backgroundImage is not nil. > > At this point, it probably would have been quicker to just go ahead and > subclass NSView, but I'm curious about what dumb mistake I'm making. > ___ > > 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: > https://lists.apple.com/mailman/options/cocoa-dev/petrock%40mac.com > > This email sent to petr...@mac.com ___ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
problem getting CALayer to draw an image
I have a generic NSView that contains some subviews, and I'd like to add a background image. I tried code like this: NSImage* backgroundImage = [NSImage imageNamed: @"blueprint controls.png"]; CALayer* holderLayer = [CALayer layer]; _throttleHolder.layer = holderLayer; _throttleHolder.wantsLayer = YES; holderLayer.zPosition = 4.0f; holderLayer.contents = backgroundImage; holderLayer.hidden = NO; holderLayer.bounds = NSRectToCGRect( _throttleHolder.bounds ); [holderLayer setNeedsDisplay]; But no background image shows up. On the other hand, if I add the line holderLayer.backgroundColor = CGColorGetConstantColor( kCGColorWhite ); then I get a white background, so apparently the layer is there and capable of drawing. And yes, I have made sure that backgroundImage is not nil. At this point, it probably would have been quicker to just go ahead and subclass NSView, but I'm curious about what dumb mistake I'm making. ___ 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
