I am drawing on a custom view an NSGradient like this:
- (void)drawRect: (NSRect)dirtyRect
{
NSGradient* g = [[NSGradient alloc] initWithStartingColor: _color endingColor: [NSColor clearColor]];
[g drawInRect: [self bounds] angle: 90];
}
If _color is a normal color, for example [NSColor blueColor], everything is fine. The problem is that _color comes from a pattern image (which in this case is mostly grey with some fancy pixels on it), and when that happens the program keeps logging this error:
*** -[NSGradient initWithColors:atLocations:colorSpace:]: the color NSPatternColorSpace CGImageSource=0x400367d60"
)> cannot be converted into color space Generic RGB colorspace
_color = [NSColor colorWithPatternImage: [NSImage imageNamed: #"mainBG.png"]]
The image is completely opaque and is a png file.
Any ideas? perhaps I should change the file type? I don't know...
EDIT:
If I define _color like this:
_color = [[NSColor colorWithPatternImage: [NSImage imageNamed: #"mainBG.tiff"]] colorUsingColorSpace: [NSColorSpace genericRGBColorSpace]]
then no gradient is displayed. Nothing. Just as if I didn't have the drawRect: method. Any ideas?
An NSGradient doesn't work with a pattern as one of the colors. That's what the exception is telling you. It will only work with an NSColor that can be converted to an RGB color. If you want to make your pattern fade to clear, you'll have to do it another way.
Related
I'm attempting to draw some text onto an NSImage, but I've run into some issues.
Originally I was just drawing an attributed string onto the NSImage, but if the string was too long it would run off the image and I couldn't find a way to wrap the text to a newline.
To solve this I figured that I could just make an NSTextView, place the text in there, and then draw it onto the NSImage.
Unfortunately, when I attempt to draw the NSTextView to the NSImage, the text does not appear. The NSTextView's background color does show up though.
When I set a breakpoint before I lock focus on the NSImage, and preview the NSTextView, the text view has text. After I draw the text view onto the NSImage, it looks like the NSTextView is drawn, just without the text.
If there is a better way to throw text onto an NSImage that has the ability to have multiple lines, please let me know how.
Here's the code I've written for reference:
NSTextView *textToDraw = [[NSTextView alloc] initWithFrame:NSMakeRect(0, 0, input.size.width - 16, 243)];
textToDraw.backgroundColor = [NSColor blueColor];
[textToDraw setAlignment:NSTextAlignmentCenter];
[textToDraw setEditable:YES];
// textOnImage is a regular NSString
[textToDraw insertText:textOnImage replacementRange:NSMakeRange(0, textOnImage.length)];
[textToDraw setTextColor:[NSColor blackColor]];
[textToDraw setFont:font];
[textToDraw setEditable:NO];
// input is an NSImage
[input lockFocus];
[textToDraw drawRect:NSMakeRect(8, inputImage.size.height - textToDraw.frame.size.height - 8, textToDraw.frame.size.width, textToDraw.frame.size.height)];
[input unlockFocus];
Instead of drawing textview on image you can provide the bounded rect in which text should be drawn. If the string is too long it wouldn't run off the image and will automatically enter in new line.
Here is code where inputImage is the image on which you want to draw text
NSImage *newImage = [[NSImage alloc] initWithSize:inputImage.size];
[newImage lockFocus];
[inputImage drawAtPoint:NSZeroPoint fromRect:NSZeroRect operation:NSCompositeSourceOver fraction:1.0];
[textStr drawInRect:boundedRect withAttributes:attrsDictionary];
[newImage unlockFocus];
I am trying to make trivial app, in which I have a sidebar, and I am trying either to get background color based on RGB values from the PSD file, either to use background image as pattern....
I have make attempts in both ways, and nothing work's so far. Any help will be deeply appreciated.
-(void) drawRect:(NSRect)dirtyRect {
CALayer *viewLayer = [CALayer layer];
[viewLayer setBackgroundColor:CGColorCreateGenericRGB(85.0, 179.0, 217.0, 1.0)]; //RGB plus Alpha Channel
[self setWantsLayer:YES]; // view's backing store is using a Core Animation Layer
[self setLayer:viewLayer];
}
This code should show bluish color, result is almost white color...not even close to what I want.
Second code, show black background, even that my png file is in the folder supporting files.
- (void)drawRect:(NSRect)dirtyRect {
NSGraphicsContext* theContext = [NSGraphicsContext currentContext];
[theContext saveGraphicsState];
[[NSGraphicsContext currentContext] setPatternPhase:NSMakePoint(0,[self frame].size.height)];
[self.customBackgroundColour set];
NSRectFill([self bounds]);
[theContext restoreGraphicsState];
}
- (id)initWithFrame:(NSRect)frame {
self = [super initWithFrame:frame];
if (self) {
self.customBackgroundColour = [NSColor colorWithPatternImage:
[NSImage imageNamed:#"buttonBg.png"]];
}
return self;
}
Again, any help will be deeply appreciated.
If I recall correctly CGColorCreateGenericRGB expects a range from 0.0-1.0 and would explain why it is white. This should fix the white issue.
[viewLayer setBackgroundColor:CGColorCreateGenericRGB(85.0/255.0, 179.0/255.0, 217.0/255.0, 1.0)]; //RGB plus Alpha Channel
Hopefully that helps.
I'm trying to fill a circle in Objective-C with a custom RGB color. Here is my drawRect method:
- (void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
UIColor *color = [UIColor colorWithRed:10.0 green:131.0 blue:254.0 alpha:1.0];
CGContextSetStrokeColorWithColor(context, [color CGColor]);
CGContextSetLineWidth(context, 1.0);
CGContextAddEllipseInRect(context, [ball getRect]);
CGContextStrokePath(context);
}
Whenever I specify anything in place of [color CGColor] like greenColor it works fine, but with the above code nothing gets rendered (an invisible object). I know it is moving around the page because my update method is NSLog'ing a string for every update.
So, I want to fill and get the outer line of the circle to be the specified RGB color above. What am I doing wrong?
Thanks
[UIColor colorWithRed:green:blue:alpha] accept values between 0.0 to 1.0 (Apple Docs Reference) try changing the code like this:
UIColor *color = [UIColor colorWithRed:10.0/255.0 green:131.0/255.0 blue:254.0/255.0 alpha:1.0];
The value for each parameter in this method call:
[UIColor colorWithRed:10.0 green:131.0 blue:254.0 alpha:1.0];
should be between 0.0 and 1.0.
I am making a pdf in an iPad app. Now i can make the pdf however want to add a picture with a rounded corner border. For example to achieve the effect i want on the border on a simple view item i use the following code.
self.SaveButtonProp.layer.cornerRadius=8.0f;
self.SaveButtonProp.layer.masksToBounds=YES;
self.SaveButtonProp.layer.borderColor=[[UIColor blackColor]CGColor];
self.SaveButtonProp.layer.borderWidth= 1.0f;
With the pdf i am using the following method to add the picture with the border to the pdf.
CGContextRef currentContext = UIGraphicsGetCurrentContext();
UIImage * demoImage = [UIImage imageWithData : Image];
UIColor *borderColor = [UIColor blackColor];
CGRect rectFrame = CGRectMake(20, 125, 200, 200);
[demoImage drawInRect:rectFrame];
CGContextSetStrokeColorWithColor(currentContext, borderColor.CGColor);
CGContextSetLineWidth(currentContext, 2);
CGContextStrokeRect(currentContext, rectFrame);
How do i round the corners?
Thanks
While drawing you can set clipping masks. For example, it's relatively easy to create a Bezier path with the shape of a rounded rectangle and apply that as clipping mask to your graphics context. Everything subsequently drawn will be clipped.
If you want remove the clipping mask later (for example because you have an image with rounded corners but follow that by other elements) you'll have to save the graphic state first, then apply your clipping mask and restore the graphics state when you're done with your rounded corners.
You can see actual code that comes pretty close to what I think you need here:
UIImage with rounded corners
You can use a method to get any UIView/UIImageView to PDF NSData:
UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
NSData *data = [self makePDFfromView:imageView];
Method:
- (NSData *)makePDFfromView:(UIView *)view
{
NSMutableData *pdfData = [NSMutableData data];
UIGraphicsBeginPDFContextToData(pdfData, view.bounds, nil);
UIGraphicsBeginPDFPage();
CGContextRef pdfContext = UIGraphicsGetCurrentContext();
[view.layer renderInContext:pdfContext];
UIGraphicsEndPDFContext();
return pdfData;
}
Maybe you can change or use this code to help you with your problem.
OK, this is what I'm trying to do :
Get an NSImage containing, let's say a photo (1000+ x 1000+ dimensions).
Get another NSImage containing just a tranparent background and a simple black border (500x500).
"Combine" the 2 images, so that the resulting image is the photo with a border.
This is what I've achieved so far :
NSImage* resultImage = [[[self drop] image] copy];
[resultImage lockFocus];
NSRect newRect = NSMakeRect(0, 0, [[[self drop] image] size].width, [[[self drop] image] size].height);
[[[self drop2] image] drawInRect:newRect
fromRect:NSZeroRect
operation:NSCompositeSourceOver
fraction:1.0];
[resultImage unlockFocus];
[[self drop] setImage:resultImage];
Where [self drop] is an ImageWell containing the photo, and [self drop2] an ImageWell containing the border.
The thing is that it IS working. However, the resulting image is - quite obviously - showing a somewhat "stretched" border.
How could I resolve that? Given that the original photo should be of ANY dimensions, how could I make it to use a border (of some fixed dimensions) and still avoid stretching?
How about doing the border directly with CALayer, e.g.:
#import <QuartzCore/QuartzCore.h>
CALayer *layer = imageView.layer;
layer.borderColor = [[NSColor blackColor] CGColor];
layer.borderWidth = 10;
I would do this differently. Just size the image as desired and then add the border. You could do this just by having a simple view with black background, or a suitable image (assuming you want to have customizable image borders, like frames), sized to always keep the resulting border constant. Then you can generate a new image from that view, if you need to.