I'm trying to create a custom NSButton with a 50% opaque black background and white text. To do this I've subclassed NSButton and overloaded DrawRect:
- (void) drawRect:(NSRect)dirtyRect
{
[self setBordered:NO];
//REMED since it has same effect as NSRectFill below
//[[self cell] setBackgroundColor:[NSColor colorWithCalibratedRed:0 green:0 blue:0 alpha:0.2]];
NSColor* backgroundColor = [NSColor colorWithCalibratedWhite:0 alpha:0.3f];
[backgroundColor setFill];
NSRectFill(dirtyRect);
[super drawRect:dirtyRect];
}
The white text appears fine but the button's background is always 100% opaque. The alpha value is not interpreted.
Any ideas? Thanks!
The default operation of NSRectFill() is copy which is not what you want. Replace it with
NSRectFillUsingOperation(dirtyRect, NSCompositeSourceAtop);
Another solution I found was to keep my code the same but turn on the Core Animation Layer for each button in Interface Builder. I don't know enough about Core Animation Layer to know why this worked. I had previously turned CAL off because it was making my fonts look very jagged.
Related
I am trying to add a shadow to a NSImageView on an MAC application.
I created a custom NSImageView class "ShadowView.h" and modified the drawRect: like so:
- (void)drawRect:(NSRect)dirtyRect {
[super drawRect:dirtyRect];
NSShadow *shadow = [[NSShadow alloc] init];
[shadow setShadowBlurRadius:5];
[shadow setShadowOffset:NSMakeSize(30.0, 3.0)];
[shadow setShadowColor:[NSColor redColor]];
[shadow set];
[self setWantsLayer:YES];
[self setShadow:shadow];
}
However nothing happens. Also, when I debug I can see the above code being called. I looked at this question from 5 years ago but it seems to not work anymore
Adding a Shadow to a NSImageView
Thank you!
When adding a shadow to a view, that view's superview also needs to have layer-backing enabled. If it doesn't, the view's shadow gets clipped at its own bounds, as seen in this sample app:
Make sure you call -setWantsLayer:YES on your view's superview (or check the "Core Animation Layer" checkbox in Interface Builder) in order to make sure the shadow is completely visible:
You should set these somewhere else like, initWithFrame: take them out of the drawRect:
[self setWantsLayer:YES];
[self setShadow:shadow];
I am getting into app development and just started using NSScrollViews to display large chunks of text.
I am able to set the background colour by writing the following:
[_HeadersScrollView setBackgroundColor:[NSColor darkGrayColor]];
But not set the foreground colour by doing something similar to:
[_HeadersScrollView setTextColor:[NSColor whiteColor]]; // nope
[_HeadersScrollView setForegroundColor:[NSColor whiteColor]]; // nope
[_HeadersScrollView setForeground:[NSColor whiteColor]]; // nope
Is there a method or any other way that I could get this type of setup to work? I'd really appreciate it.
The NSScrollView contains an NSClipView (a helper for scrolling) which contains the NSTextView. If you want to operate on the text view you either need an outlet to that or you can request the documentView from the scroll view.
You can do either:
[_HeadersScrollView.documentView setTextColor:[NSColor whiteColor]];
Or, if you have an outlet to the text view (called _textView in my example), you can do:
_textView.textColor = [NSColor whiteColor];
In this case, you would probably want to set the background color on the text view, too, rather than the scroll view. And tell it to draw its background by setting drawsBackground.
There is no setting like that for changing foreground color in scrollview.
_HeadersScrollView.tintColor = [NSColor whiteColor];
or
[_HeadersScrollView setTintColor:[NSColor whiteColor]];
I want to set the NSSegmentedControl background image not the icon image.I subclass the NSSegmentedCell and rewrite the drawSegment: inFrame: withView: function.But this works bad.How can I do that?
update:
I want to set the half rect dark or light color background image.
Subclassing and overriding drawSegment: inFrame: withView works fine
- (void)drawSegment:(NSInteger)segment inFrame:(NSRect)frame withView:(NSView *)controlView
{
NSImage* image = [NSImage imageNamed:NSImageNameBonjour];
[image drawInRect:frame fromRect:NSZeroRect operation:NSCompositeSourceOver fraction:1.0];
[super drawSegment:segment inFrame:frame withView:controlView];
}
What else did you try?
Did you set the cell class for your segmented control correctly in Interface Builder?
My UIView structure:
I have a "master" UIView (actually UIScrollView, but it's only purpose scrolling per pagination).
As a subView on this "master" I have my "pageView" (subclass of UIScrollView). This UIScrollView can have any content (e.g. a UIImageView).
The "master" has another subView: PaintView (subclass of UIView). With this view, I track the finger movements and draw it.
The structure looks like this:
[master.view addSubview: pageView];
[master.view addSubview: paintView];
I know when the user zooms in (pageView is responsible for this) and over delegate/method calls I change the frame of paintView according to the zoom change, during the zoom action.
After zooming (scrollViewDidEndZooming:withView:atScale) I call a custom redraw method of paintView.
Redraw method and drawRect:
-(void)redrawForScale:(float)scale {
for (UIBezierPath *path in _pathArray) {
//TransformMakeScale...
}
[self setNeedsDisplay];
}
-(void)drawRect:(CGRect)rect {
for (UIBezierPath *path in _pathArray) {
[path strokeWithBlendMode:kCGBlendModeNormal alpha:1.0];
}
}
The problem:
When I zoom-in, I receive a memory warning and the app crashes.
In the Allocations profiler I can see that the app own a lot of memory, but I can't see why.
When I don't call 'setNeedDisplay' after my 'redrawForScale' method the app isn't crashing.
When I log the rect in drawRect I see values like this: {{0, 0.299316}, {4688, 6630}}.
The problem is (re)drawing such a huge CGRect (correct me if this is wrong).
The solution for me is to avoid calling a custom drawRect method. In some stackoverflow answers (and I think somewhere in the Appls docs) it was mentioned that a custom drawRect: will reduce the performance (because iOS can't do some magic on a custom drawRect method).
My solution:
Using a CAShapeLayer. For every UIBezierPath I create a CAShapeLayer instance, add the UIBezierPath to the path attribute of the layer and add the layer as a sublayer to my view.
CAShapeLayer *shapeLayer = [[CAShapeLayer alloc] initWithLayer:self.layer];
shapeLayer.lineWidth = 10.0;
shapeLayer.strokeColor = [UIColor blackColor].CGColor;
shapeLayer.fillColor = [UIColor clearColor].CGColor;
shapeLayer.path = myBezierPath.CGPath;
[self.layer addSublayer:shapeLayer];
With this solution I don't need to implement drawRect. So the App won't crash, even with a big maximumZoomScale.
After changing the UIBezierPath (translate, scale, change color) I need to set the changed bezierPath to the shapeLayer again (set the path attribute of shapeLayer again).
I'm looking for a way to draw a fade effect on a table view (and outline view, but I think it will be the same) when the content is scrolled. Here is an example from the Fantastical app:
Also a video of a similar fade on QuickLook windows here.
To make this I tried subclassing the scrollview of a tableview with this code:
#define kFadeEffectHeight 15
#implementation FadingScrollView
- (void)drawRect: (NSRect)dirtyRect
{
[super drawRect: dirtyRect];
NSGradient* g = [[NSGradient alloc] initWithStartingColor: [NSColor blackColor] endingColor: [NSColor clearColor]];
NSRect topRect = self.bounds;
topRect.origin.y = self.bounds.size.height - kFadeEffectHeight;
topRect.size.height = kFadeEffectHeight;
NSRect botRect = self.bounds;
botRect.size.height = kFadeEffectHeight;
[NSGraphicsContext saveGraphicsState];
[[NSGraphicsContext currentContext] setCompositingOperation: NSCompositeDestinationAtop];
// Tried every compositing operation and none worked. Please specify wich one I should use if you do it this way
[g drawInRect: topRect angle: 90];
[g drawInRect: botRect angle: 270];
[NSGraphicsContext restoreGraphicsState];
}
...but this didn't fade anything, probably because this is called before the actual table view is drawn. I have no idea on how to do this :(
By the way, both the tableview and the outlineview I want to have this effect are view-based, and the app is 10.7 only.
In Mac OS X (as your question is tagged), there are several gotchas that make this difficult. This especially true on Lion with elastic scrolling.
I've (just today) put together what I think is a better approach than working on the table or outline views directly: a custom NSScrollView subclass, which keeps two "fade views" tiled in the correct place atop its clip view. JLNFadingScrollView can be configured with the desired fade height and color and is free/open source on Github. Please respect the license and enjoy. :-)