Blank pixels left when NSWindow with opaque set to NO - objective-c

I have a NSWindow where I set opaque attribute to NO. The problem is that when I put any view inside that window it's corners has blank pixels.
Everything works well when opaque attribue is left with YES value, however, window's corners are not rounded anymore. See picture:
I've created repository with simple example project at bitbucket: https://bitbucket.org/lukaszb/animationartifacts
Is there a way I can fix this (remain window's corners rounded and blank pixels not appearing)? Or should I try another solution (without setOapque:NO at NSWindow subclass)?

Try enabling the Core Animation layer for your RoundedView, i.e., open MainMenu.xib, select RoundedView and in the “View Effects” tab (rightmost one) check the view under “Core Animation Layer”.
Alternatively you can do it programmatically, e.g., in RoundedView add:
- (void)awakeFromNib {
self.wantsLayer = YES;
self.layer = [CALayer layer];
self.layer.backgroundColor = [[NSColor blackColor] CGColor];
self.layer.cornerRadius = RADIUS;
}
Also #import <QuartzCore/QuartzCore.h> and add QuartzCore.framework to the project. You can then delete the drawRect method since CALayer already does rounded corners for you. (Actually you can delete your whole RoundedView class if you just set up this layer for a regular NSView that you use in its place.)

You can create a Subclass of NSView, make a custom drawing using NSBezierPath in it's drawRect: method, and then set it as the content view of the window.

Related

outside border for UIImageView

I know I can create border using below code.
[[myImageView layer] setBorderWidth:2.0f];
[[myImageView layer] setBorderColor:[UIColor greenColor].CGColor];
However this draw border inside image.
What I was looking is draw border outside ImageView.
Note:
I search online for this and found below.
Can be done by using another image which will have border.
Can be done by drawing another view which is little bigger then current image.
Is there quick way (especially in-built in iOS), where I can draw border outside UIImageView? Any views?
Why don't you try border with using imageview's frame ?
CGFloat borderWidth = 5.0f;
self.imgview.frame = CGRectInset(self.imgview. frame, -borderWidth, -borderWidth);
self.imgview. layer.borderColor = [UIColor blueColor].CGColor;
self.imgview. layer.borderWidth = borderWidth;
There is no quickway in-built in iOS, there is no margin that you could set on the image layer.
If I were you, I'd develop a new class that inherit from UIView (ex UIImageWithBorderView) and which include a UIImageView and making the "UIImageWithBorderView" bigger than the UIImageView (and think about NOT to autoresize the UIImageView with the UIView parent, otherwise your UIImageView will be stretched, and prevent the UIImageWithBorderView from being smaller than the UIImageView frame), and then add borders to the "UIImageWithBorderView".
This way, your UIImageView will be intact and you'll have a specific, reusable composant for your needs.
Hope it helps !

Customizing tableView: Corner radius, decreased width and shadow

This is what I want to do:
As you can see i want to:
Decrease the width of the tableView (I want more margin on the sides than the grouped tableView provides)
Corner radius (bigger radius than the default for grouped tableView)
Drop shadow around the table and a special shadow beneath the last cell
You can do this by "drawing" the backgroundView of the cells yourself.
I'd recommend getting an image to use as the background (if the cells are all the same height).
You'll need three images.
A "top" image with the top corners rounded.
A "bottom" image with the bottom corners rounded and the drop shadow how you want it.
And a "middle" image with no rounded corners.
If the cells don't have any texture or gradient within them then you can use stretchable images to reduce the memory footprint of them.
Then I would subclass the UITableViewCell and override the backgroundView to add a UIImageView. I'd also provide an accessor method to change the type (top, middle, bottom) of the cell.
Each cell can then have three placeHolder properties of a UIImage (topImage, bottomImage and middleImage). When the type of the cell is changed these can be accessed (use lazy instantiation to make sure they are only loaded once and only when needed) and then set the backgroundVIew image to be the required image.
Something like this...
In the UITableViewCell subclass define a type enum...
typedef enum {
CellTypeTop,
CellTypeMiddle,
CellTypeBottom
} cellType;
Then a property for the type...
#property (nonatomic) cellType cellType
Then in the .m ...
Define some more internal properties...
#property UIImageView *bgImageView;
#property UIImage *topImage;
#property UIImage *middleImage;
#property UIImage *bottomImage;
Then add the imageView (only once)...
- (void)awakeFromNib //or in the init depends how you are initialising the cell
{
self.bgImageView = [[UIImageView alloc] initWithFrame:blah];
[self.backgroundView addSubView:self.bgImageView];
}
Now when the type is changed...
- (void)setCellType:(cellType)cellType
{
switch(cellType) {
case CellTypeTop:
self.bgImageView.image = self.topImage;
break;
case CellTypeMiddle:
self.bgImageView.image = self.middleImage;
break;
case CellTypeBottom:
self.bgImageView.image = self.bottomImage;
break;
}
}
Finally a lazy instantiation of the images...
- (UIImage *)topImage
{
if (_topImage == nil) {
_topImage = [UIImage imageNamed:#"topImage"];
//alternatively...
_topImage = [[UIImage imageNamed:#"topImage"] stretchableImageWith...
}
return _topImage;
}
Now repeat these for the other images.
This will be more performant (by a long way) than using a CALayer alternative and, especially if using the stretchable images, will have a very small memory footprint.
Several other users have said that this is not good for performance, memory, design, whatever, but it really is the best way to get the best performance for UserExperience than CALayers. Yes, it will use more memory than CALayers but only marginally and it will get to a limit as there are only a few dequeueable cells created.
A couple of links explaining performance issues when using CALayers in scrollViews...
http://www.quora.com/iOS-Development/What-is-the-best-way-to-optimize-the-performance-of-a-non-paging-but-view-recycling-UIScrollView-involving-loading-potentially-caching-and-displaying-bundled-images
Bad performance on scroll view loaded with 3 view controllers, drawn with CALayer
::EDIT:: Edit to answer Michael's question.
In the storyboard create a UITableViewController (rename the Class in the inspector so that it matches your subclass UITableViewController - I'll call it MyTableViewController).
Create a subclass of UITableViewCell (I'll call mine MyTableViewCell) in the code (i.e. the .h and .m).
Add the above code to do with properties and types and imageViews to your MyTableViewCell.h file.
In the storyboard select the cell in the TableViewController and rename the class to MyTableViewCell. Also set the reuse identifier on it.
In the MyTableViewController code you will need a function like this...
-(UITableViewCell*)tableView:(UITabelView*)tableView cellForRowAtIndexPath:(NSIndexPath*)indexPath
{
MyTableViewCell *cell = [tableView dequeueCellWithReuseIdentifier:#"Cell"];
cell.cellType = CellTypeTop; //or whichever it needs to be
cell.textLabel.text = #"Blah";
return cell;
}
Oh, another thing, in the storyboard you will be able to layout your cell how you want it to look and link up all the labels and imageviews etc... Make sure you add IBOutlet to the UIImageView so that you can link it up in the storyboard.
make sure you have #import <QuartzCore/QuartzCore.h> imported, then you can start accessing the layers of the UITableView like.
UITableView *yourTable = [[UITableView alloc] initWithStyle:UITableViewStyleGrouped];
[[yourTable layer] setCornerRadius:10.0f];
[[yourTable layer] setShadowColor:[[UIColor blackColor] CGColor]];
[[yourTable layer] setShadowOffset:CGSizeMake([CALayer ShadowOffSetWidthWithFloat:10.0f], [CALayer ShadowOffSetWidthWithFloat:10.0f])];
[[yourTable layer] setShadowOpacity:[CALayer ShadowOpacity:1]];
[[yourTable layer] setMasksToBounds:NO];
UIBezierPath *path = [UIBezierPAth bezierPathWithRect:yourTable.bounds];
[[yourTable layer] setShadowPath:[path CGPath]];
This will add shadow affect to your table view with the shadow not masked to the bounds of the UITableView, at setCornerRadius you can set the corners of the table to whatever you want. You can also set the frame of the UITableView by doing
[yourTable setFrame:CGRectMake(CGFloat x, CGFloat y, CGFloat width, CGFloat height)];
EDIT
As another user has tried to point out that CALayer is very slow, this is not the case
CALayer was introduced to help performance issues around animation. Please read documentation. Loading an image straight in may seem like a good idea but in the long run will take up more memory. Please this question about memory allocation for images. As you can see it may seem faster, but it takes up 2.25 MByte of memory per image which after loading each image so many times your app will start to become slow.

NSScrollView with fixed background texture

I have an IKImageBrowserView that is the document view of an NSScrollView. How can I set a background image (a texture) so that the background remains fixed when the user scrolls.
I have tried a variety of things but either they just don't work or it doesn't remain fixed.
I have tried making the IKImageBrowserView and NSScrollView transparent, but this doesn't work, the background is black.
I have tried adding the texture as the background layer of the image browser:
NSColor* browserBackgroundColor = [NSColor colorWithPatternImage:[NSImage imageNamed:#"linenTile"]];
CALayer *layer = [CALayer layer];
[layer setBackgroundColor:[browserBackgroundColor CGColor]];
[self.imageBrowserView setBackgroundLayer:layer];
It remains fixed when scrolling down, but when scrolling up. This is the closest I have got it.
If your scrollView is full screen, you can just set you image to be the background of your self.view, and then set the background of your scrollView transparent.
Or you can just add a separate NSView beneath your scrollView, make it cover the same area as your scrollView, and set its background.
Finally got the combination correct.
Subclass NSScrollView and draw the pattern image in drawRect:
- (void)drawRect:(NSRect)rect {
[[NSColor colorWithPatternImage:[NSImage imageNamed:#"linenTile"]] set];
NSRectFill(rect);
}
Set the background of the document view to clear (for IKImageBrowserView like this):
[self.imageBrowserView setValue:[NSColor clearColor] forKey:IKImageBrowserBackgroundColorKey];
And also the Draw Background check box in interface builder on the scroll view must be unchecked. Or set the value to NO in code.
If you want the pattern to scroll with the content. Don't subclass the NSScrollView and just set the background color of the scrollview to the pattern, and the background color of the document view to clear.
Subclassing and -drawRect: is unnecessary, simply use the backgroundColor property of NSScrollView. The docs say "This color is used to paint areas inside the content view that aren’t covered by the document view."
scollView.backgroundColor = [[NSColor colorWithPatternImage:[NSImage imageNamed:#"linenTile"]] set];

How to create a "stretchable" UIView

I have a UIView that contains another UIView. The outer UIView draws a border around the inner UIView via drawRect. (The border is too complicated to be drawn via CALayer properties.)
At present, when I animate the resizing of the outer UIView, its drawRect method is called once at the beginning of the animation and the result is stretched or shrunk. This does not look good.
I am looking for a way to either redraw the content at every step of the animation, or find a way to achieve the same visual effect. (The result should be similar to the resizing of a stretchable UIImage.)
You should change view's content type to:
your_view.contentMode = UIViewContentModeRedraw;
And it will redraw each time its frame changes.
I ended up adding subviews with autoresizing masks that kept them positioned correctly during the animation.
You need to send a [UIView setNeedsToDisplay] to the view for every time the frame size is changed, you could try overriding the setFrame: method like
- (void)setFrame:(CGRect)r
{
[super setFrame:r];
[self setNeedsToDisplay];
}

Custom NSView Fill Paints Over Bottom Bar

I have a window which has a custom NSView and has a bottom bar with controls on it, one of which is an NSColorWheel.
For simplicity sake the Window is 332px high, with the custom NSView being 300px high and the bottom bar being 32px high.
The bottom bar is created as part of my awakeFromNib when the app loads the window using the following code:
[[self window] setAutorecalculatesContentBorderThickness:YES forEdge:NSMinYEdge];
[[self window] setContentBorderThickness: 32.0 forEdge: NSMinYEdge];
In my custom NSView class I fill the rectangle with color. Everything works fine when the app loads using the following in my NSView class:
- (void)drawRect:(NSRect)dirtyRect
{
dirtyRect = [self bounds];
NSColor * mNewColor = [NSColor blackColor];
[mNewColor set];
[NSBezierPath fillRect:dirtyRect];
}
However, if I subsequently call a method that changes the color of the custom NSView when a color wheel in the bottom bar is changed, the bottom bar gets overwritten with the color. The following code illustrates this method (this code is in the custom NSView class:
- (void)changeBackgroundColor:(NSNotification *)notification
{
NSLog(#"Changed background color");
NSRect mRect = [self bounds];
NSColor * mNewColor = [theColorWell color];
[mNewColor set];
[NSBezierPath fillRect:mRect];
[self setNeedsDisplay:YES];
}
Resizing the window instantly corrects the problem, but obviously I don't want the user to have to resize the window for an obvious bug!
What I don't understand is why my bounds appear to be mapping to the parent window and not the custom NSView when I call setNeedsDisplay and yet the bound correctly adjust when I resize the window using the mouse (even if just by 1 pixel).
Do I somehow need to account for the bottom bar on the redraw?
Any and all help much appreciated.
You should do all your drawing in the drawRect: method of your custom NSView. Cocoa automatically sets up the graphics context for you when it calls this method - things may not draw correctly if you perform drawing operations in other methods.
Your code in drawRect: could set the colour to the the current background colour as specified by your NSColorWell and fill the dirtyRect rectangle with this.
Then in the other method just call [self setNeedsDisplay:YES]; and then drawRect: will automatically be called to redraw the view.
See here for more information: http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/CocoaViewsGuide/SubclassingNSView/SubclassingNSView.html#//apple_ref/doc/uid/TP40002978-CH7-SW4 (in particular the Drawing View Content section)