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.
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 have a custom PDFView subclass and have overridden -mouseDown, -mouseDragged etc to draw a rectangle over the view. Here is the code I am using:
#implementation MyPDFView {
NSPoint clickLocation;
NSRect selection;
}
- (void)mouseDown:(NSEvent *)theEvent {
NSPoint clickLocationOnWindow = [self.window mouseLocationOutsideOfEventStream];
clickLocation = [self convertPoint:clickLocationOnWindow fromView:nil];
NSLog(#"%#", NSStringFromPoint(clickLocation));
}
- (void)mouseDragged:(NSEvent *)theEvent {
NSPoint mouseLocationOnWindow = [self.window mouseLocationOutsideOfEventStream];
NSPoint currentLocation = [self convertPoint:mouseLocationOnWindow fromView:nil];
CGFloat lowerX = fmin(clickLocation.x, currentLocation.x);
CGFloat lowerY = fmin(clickLocation.y, currentLocation.y);
CGFloat upperX = fmax(clickLocation.x, currentLocation.x);
CGFloat upperY = fmax(clickLocation.y, currentLocation.y);
selection = NSMakeRect(lowerX, lowerY, upperX-lowerX, upperY-lowerY);
[self setNeedsDisplay:YES];
NSLog(#"%#", NSStringFromRect(selection));
}
- (void)drawRect:(NSRect)dirtyRect
{
// Drawing code here.
NSLog(#"drawRect");
NSBezierPath *bp = [NSBezierPath bezierPathWithRect:selection];
[[NSColor blueColor] set];
[bp fill];
}
#end
The NSRect is calculated correctly, but when I call [self setNeedsDisplay], -drawRect is never called, and the rectangle is never drawn.
Is there any reason why -drawRect is never called on a PDFView subclass?
I have a similar use case. According to the docs, override PDFView's drawPage method instead. Continue to call setNeedsDisplay on the PDFView. It works, but it's a little slow. Working on overlaying a view right now instead.
I have this in a custom class on my NSView and when I press a button using my drawMyRec IBAction I want to change the color of my NSRect however this is not working, can anyone help?
#import "myView.h"
#implementation myView
- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self) {
RectColor = [[NSColor blackColor] init];
}
return self;
}
- (IBAction)drawMyRec:(id)sender;
{
NSLog(#"pressed");
RectColor = [[NSColor blueColor] init];
[self setNeedsDisplay:YES];
}
- (void)drawRect:(NSRect)dirtyRect
{
NSRectFill(dirtyRect);
[RectColor set];
}
#end
Your drawRect function is incorrect. change to this:
- (void)drawRect:(NSRect)dirtyRect
{
[RectColor set];
NSRectFill(dirtyRect);
}
First, why are you calling -init on an NSColor? Second, you're setting the color after you've drawn the rect, so it won't take affect until the next redraw. 3rd, what's dirtyRect when -drawRect: is called? Why not just fill the entire rect regardless of what's dirty?
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 have a class called ServerImage (sub of NSView) which I am calling from my AppController but for some reason it won't draw to the screen. I have other views which I am able to draw and add images to but for some reason not this one. I'm sure I am missing something in my code but am just not seeing it. Here's the relevant code from AppController:
//loop through masterServerDict and get server status
NSMutableString* key;
for(key in masterServerDict) {
ServerImage* newImage = [[ServerImage alloc] initWithFrame:NSMakeRect(200.0, 0.0, 48.0, 48.0)];
[newImage setServerName:key];
[[[NSApp mainWindow] contentView] addSubview:newImage];
[newImage setNeedsDisplay:YES];
}
masterServerDict is a mutable dictionary, the key is the name of a server, the object is an array, it holds the smb and afp paths to the server and whether it is mounted or not.
Here is ServerImage.h
#import <Cocoa/Cocoa.h>
#interface ServerImage : NSView {
NSString * serverName;
}
- (void) setServerName : (NSString* ) s;
#end
and ServerImage.m
#import "ServerImage.h"
#implementation ServerImage
- (id)initWithFrame:(NSRect)frame {
self = [super initWithFrame:frame];
if (self) {
// Initialization code here.
NSLog(#"%f", self.frame.origin.x);
}
return self;
}
- (void)drawRect:(NSRect)rect {
NSLog(#"drawrect");
[[NSColor redColor] set];
NSRectFill(rect);
}
- (void) setServerName : (NSString* ) s {
NSLog(#"method");
serverName = s;
}
I can get the init and setServerName methods to log but not drawRect...
Check if [[NSApp mainWindow] contentView] is non-nil. Also check if it refers to the right window and that the coordinate is good (visible).