Am I doing something wrong here?
If I call my class from the awakeFromNib method I can trace, via a NSLog, that the class is being called up to the initWithFrame method, but the drawRect method is not being called. If I instantiate through an IBAction (say a button) it works fine. Here's the code:
-(void) awakeFromNib {
[winMain center];
SplashScreen* newSplashScreen = [[SplashScreen alloc] initWithFrame:NSMakeRect(0.0, 0.0, 737.0, 303.0)];
[[[NSApp mainWindow] contentView] addSubview:newSplashScreen];
}
and my SplashScreen.m file:
#import "SplashScreen.h"
#implementation SplashScreen
- (id)initWithFrame:(NSRect)frame {
self = [super initWithFrame:frame];
if (self) {
// Initialization code here.
}
return self;
}
- (void)drawRect:(NSRect)rect {
NSImage *imageFromBundle = [NSImage imageNamed:#"sheet1.png"];
[self setNeedsDisplay:YES];
[imageFromBundle drawInRect:[self bounds] fromRect:NSMakeRect(0.0, 0.0, 737.0, 303.0) operation: NSCompositeCopy fraction:1.0];
}
#end
Why have you marked the view as needing to be redrawn before you have even drawn anything to the view? This will load the image , mark the view as needing to be redrawn, load the image , mark the view , etc etc etc....
Remove the setNeedsDisplay:
And read up on views and memory management.
Related
I'm trying to figure out how to custom draw Buttons in Cocoa/OSX. Since my view is custom drawn I will not use IB and want to do it all in code. I created a subclass of NSButtonCell and a subclass of NSButton. In the Subclass of NSButtonCell I override the Method drawBezelWithFrame:inView: and in the initWithFrame Method of my subclassed NSButton I use setCell to set my CustomCell in the Button. However, drawBezelWithFrame gets not called and I don't understand why. Can someone point out what I've done wrong or what I miss here?
Subclass of NSButtonCell:
#import "TWIButtonCell.h"
#implementation TWIButtonCell
-(void)drawBezelWithFrame:(NSRect)frame inView:(NSView *)controlView
{
//// General Declarations
[[NSGraphicsContext currentContext] saveGraphicsState];
//// Color Declarations
NSColor* fillColor = [NSColor colorWithCalibratedRed: 0 green: 0.59 blue: 0.886 alpha: 1];
//// Rectangle Drawing
NSBezierPath* rectanglePath = [NSBezierPath bezierPathWithRect: NSMakeRect(8.5, 7.5, 85, 25)];
[fillColor setFill];
[rectanglePath fill];
[NSGraphicsContext restoreGraphicsState];
}
#end
Subclass of NSButton:
#import "TWIButton.h"
#import "TWIButtonCell.h"
#implementation TWIButton
- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self)
{
TWIButtonCell *cell = [[TWIButtonCell alloc]init];
[self setCell:cell];
}
return self;
}
- (void)drawRect:(NSRect)dirtyRect
{
// Drawing code here.
}
#end
Usage:
- (void)addSendButton:(NSRect)btnSendRectRect
{
TWIButton *sendButton = [[TWIButton alloc] initWithFrame:btnSendRectRect];
[self addSubview:sendButton];
[sendButton setTitle:#"Send"];
[sendButton setTarget:self];
[sendButton setAction:#selector(send:)];
}
Following are the things seems to be missing out from your code.
You are not calling the [super drawRect:dirtyRect]
You are not overriding + (Class)cellClass in the Class(TWIButton) which is derived from NSButton.
Below is the code after changes:
#implementation TWIButton
- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self)
{
TWIButtonCell *cell = [[TWIButtonCell alloc]init];
[self setCell:cell];
}
return self;
}
- (void)drawRect:(NSRect)dirtyRect
{
// Drawing code here.
//Changes Added!!!
[super drawRect:dirtyRect];
}
//Changes Added!!!!
+ (Class)cellClass
{
return [TWIButtonCell class];
}
#end
Now keep the break point at drawBezelWithFrame and check it will get called.
One might forgo the NSButton subclass, since it looks like you are ONLY using it to instantiate the Cell type within the initializer.
Simply
NSButton *button ...
[button setCell: [[TWIButtonCell alloc] init] autorelease]];
btw. you will probably have a leak in the previous examples since you init and then call setCell that likely has its own retain.
I know how to do this in iOS but cannot figure it how to it in Cocoa.
I want to capture keyboard events and I think I need to override the acceptsFirstResponder method to accomplish that (keyDown method being triggered). So I created a class extending NSCustomView and tried to add it in the main Window but I just cannot understand how to do it. So far I added a Custom View to the main View then tried to add it programmatically like:
TestView *view = [[TestView alloc] init];
[[_window contentView] addSubview:view];
but this is not working. So how can I do this?
To see if the view has been added to a window, you can override the view's viewDidMoveToWindow method and log the value of [self window] to check (if it's nil then the view has been removed from a window):
- (void)viewDidMoveToWindow
{
NSLog(#"window=%p", [self window]);
[super viewDidMoveToWindow];
}
You should be subclassing NSView, not NSCustomView, and initWithFrame is the designated initializer for NSView, not init.
Try:
TestView *view = [[TestView alloc] initWithFrame:NSMakeRect(0, 0, 100, 200)];
[[_window contentView] addSubview:view];
I've got a custom NSView subclass which I want to have rounded corners. I use the following code in the .m file:
#import "ItemImageSelectionView.h"
#implementation ItemImageSelectionView
- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self) {
self.wantsLayer = YES;
self.layer.frame = self.frame;
}
return self;
}
- (void)drawRect:(NSRect)dirtyRect
{
[[NSColor colorWithCalibratedRed:0.0 green:0.5 blue:1 alpha:1] set];
NSRectFill(dirtyRect);
[self.layer setCornerRadius:5.0];
}
#end
I use this code to initialize the view, pretty default:
NSView *imageSelectionView = [[ItemImageSelectionView alloc] initWithFrame:CGRectMake(imageView.frame.origin.x - 2, imageView.frame.origin.y - 2, imageView.frame.size.width + 4, imageView.frame.size.height + 4)];
[self addSubview:imageSelectionView positioned:NSWindowBelow relativeTo:imageView];
But it doesn't set any rounded corners! What am I doing wrong?
You don't need to set rounded corners in the drawrect method; set that in the init. Also, you should probably call the super method, [super drawRect:dirtyRect] in your overrided method. I'm not sure how your fill custom will interact with the layers, though. You may need to set [self.layer setMasksToBounds:YES];
I am confused about why this code does not display any image:
In the app delegate:
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
NSRect rect = window.frame;
rect.origin.x = 0;
rect.origin.y = 0;
BlueImageView *blueImageView = [[BlueImageView alloc]initWithFrame:rect];
window.contentView = blueImageView; // also tried [window.contentView addSubview: blueImageView];
}
BlueImageView.h:
#interface BlueImageView : NSImageView {
}
#end
BlueImageView.m:
#implementation BlueImageView
- (id)initWithFrame:(NSRect)frame {
self = [super initWithFrame:frame];
if (self) {
[self setImage: [NSImage imageNamed:#"imagefile.png"]];
NSAssert(self.image, #"");
NSLog (#"Initialized");
}
return self;
}
- (void)drawRect:(NSRect)dirtyRect {
}
#end
The file imagefile.png exists. The NSAssert is not causing an exception. The NSLog is firing. But no image shows up in the window.
The drawRect: method is called to draw the view, and your implementation immediately returns. To get NSImageView to draw the image for you, call [super drawRect:dirtyRect]; in your implementation of drawRect:. If you aren't going to do any other drawing in drawRect:, just remove the method to speed up drawing.
I'm trying to subclass NSScroller in order to draw my own scroller knob. To do this, I've subclassex NSScrollView and usex the following code to instantiate my custom NSScrollers:
- (void)awakeFromNib;
{
NSRect horizontalScrollerFrame = [[self horizontalScroller] frame];
NSRect verticalScrollerFrame = [[self verticalScroller] frame];
NSString *scrollBarVariant = [[[NSUserDefaults standardUserDefaults] persistentDomainForName:NSGlobalDomain] valueForKey:#"AppleScrollBarVariant"];
if (![scrollBarVariant isEqualToString:#"DoubleBoth"]) {
[self setVerticalScroller:[[[TRScroller alloc] initWithFrame:verticalScrollerFrame] autorelease]];
[self setHorizontalScroller:[[[TRScroller alloc] initWithFrame:horizontalScrollerFrame] autorelease]];
}
}
This works and my NSScrollers display correctly. But I'm occasionally seeing rendering issues upon first loading my application. Within Interface Builder I have laid out a number of NSScrollViews with their scrollbars set to hide automatically. The issue I'm seeing is that when the application first loads, the scrollbar backgrounds are rendered across the NSScrollViews contents.
alt text http://www.freeimagehosting.net/uploads/1d3fc75db8.png
I believe this is because I instantiate my NSScroll subclass (TRSubclass) via awakeFromNib, which means that the scrollbars are given the frame of the NSScrollView before it is automatically resized to meet the windows saved location and size (in other words, it's using the frame that's assigned by default within Interface Builder). What's the best way around this?
I've tried forcing the NSScrollView to redisplay (using setNeedsDisplay: and display:) but with no luck. Has anyone else come across a similar issue?
I'm using the same schema in my applications and I fighted this issues a lot. I use the same trick: scrollers are substituted in [scrollView awakeFromNib] methods, but I don't face such rendering issues at the moment. You can try to play with "draws background" property of the NSScrollView - it really helps sometimes
- (void)changeSubs
{
// change clip view
// ...
// change scrollers
NSRect horizontalScrollerFrame = [[self horizontalScroller] frame];
NSRect verticalScrollerFrame = [[self verticalScroller] frame];
if (![[self verticalScroller] isKindOfClass:[CRScroller class]])
[self setVerticalScroller:[[[CRScroller alloc] initWithFrame:verticalScrollerFrame] autorelease]];
if (![[self horizontalScroller] isKindOfClass:[CRScroller class]])
[self setHorizontalScroller:[[[CRScroller alloc] initWithFrame:horizontalScrollerFrame] autorelease]];
}
- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self)
{
[self changeSubs];
}
return self;
}
- (id)initWithCoder:(NSCoder *)aDecoder
{
NSKeyedUnarchiver* unpacker = (id)aDecoder;
[unpacker setClass:[CRClipView class] forClassName:[NSClipView className]];
[unpacker setClass:[CRScroller class] forClassName:[NSScroller className]];
self = [super initWithCoder:aDecoder];
if (self)
{
}
return self;
}
- (void)awakeFromNib
{
[self changeSubs];
}
There are few tricks here, they work depending on a way NSScrollView is created. 'isKindOfClass' check helps to avoid double-swap.