I am trying to call the method below using [self changeColor]; and getting
"No visible interface for #MyClassViewController declares the selector "changeColor"
I did declare it like that on both .h and .m:
#interface changeColor
- (UIImage *) changeColor:(UIImage *)image;
#end
What I am doing wrong?
Please help
-------------Code-------------
- (UIImage *) changeColor:(UIImage *)image
{
UIGraphicsBeginImageContext(image.size);
CGRect contextRect;
contextRect.origin.x = 0.0f;
contextRect.origin.y = 0.0f;
contextRect.size = [image size];
// Retrieve source image and begin image context
CGSize itemImageSize = [image size];
CGPoint itemImagePosition;
itemImagePosition.x = ceilf((contextRect.size.width - itemImageSize.width) / 2);
itemImagePosition.y = ceilf((contextRect.size.height - itemImageSize.height) );
UIGraphicsBeginImageContext(contextRect.size);
CGContextRef c = UIGraphicsGetCurrentContext();
// Setup shadow
// Setup transparency layer and clip to mask
CGContextBeginTransparencyLayer(c, NULL);
CGContextScaleCTM(c, 1.0, -1.0);
CGContextClipToMask(c, CGRectMake(itemImagePosition.x, -itemImagePosition.y, itemImageSize.width, -itemImageSize.height), [image CGImage]);
CGContextSetRGBFillColor(c, 0, 0, 1, 1);
NSLog(#"--------- METHOD DETECTED");//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> TEST
/*
switch (row)
{
case 0:
CGContextSetRGBFillColor(c, 0, 0, 1, 1);
break;
default:
CGContextSetRGBFillColor(c, 1, 0, 0., 1);
break;
}
*/
contextRect.size.height = -contextRect.size.height;
contextRect.size.height -= 15;
// Fill and end the transparency layer
CGContextFillRect(c, contextRect);
CGContextEndTransparencyLayer(c);
UIImage *img = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return img;
}
The problem is [self changeColor];. changeColor and changeColor: are two different things. If you define it as taking one parameter, you have to call it that way.
Related
I am trying to drag a CGRect, but nothing happens. The rect stays in the same place. Here is my mouseDragged: code:
-(void)mouseDragged:(NSEvent *)theEvent{
NSPoint eventLocation = [theEvent locationInWindow];
NSPoint location = [self convertPoint:eventLocation fromView:self];
int locationX = location.x;
int locationY = location.y;
[self setNeedsDisplay:TRUE];
if(CGRectContainsPoint(myRect, location)){
myRect.origin.x = locationX;
myRect.origin.y = locationY;
}
}
This code is inside of an NSView. I draw the rect myRect in drawRect:
Here is my drawRect:
- (void)drawRect:(NSRect)rect
{
int width = self.bounds.size.width;
int height = self.bounds.size.height;
myRect = CGRectMake((width/2)-50, (height /2)-50, 100, 100);
CGContextRef myContext = [[NSGraphicsContext currentContext] graphicsPort];
CGContextSetRGBFillColor(myContext, 1, 0, 0, 1);
CGContextFillRect(myContext, myRect);
NSLog(#"drawRect: called");
}
Any ideas?
You're always setting myRect to a constant value inside of drawRect:. It seems like what you want is to not set myRect at all in drawRect: and to draw it with its current value. So something like this:
- (void)drawRect:(NSRect)rect
{
CGContextRef myContext = [[NSGraphicsContext currentContext] graphicsPort];
CGContextSetRGBFillColor(myContext, 1, 0, 0, 1);
CGContextFillRect(myContext, myRect);
NSLog(#"drawRect: called");
}
Here with below code PDF gets created but i am able to write in PDF.But i am not able to render NSView in PDF
CGContextRef aCgPDFContextRef = [self createPDFContext:CGRectMake(0, 0, 612, 892) path:(CFStringRef)filepath];
CGContextBeginPage(aCgPDFContextRef,nil);
//Draw view into PDF
NSView *aPageNote=[[NSView alloc]initWithFrame:CGRectMake(0,0, 612, 892)];
CGAffineTransform aCgAffTrans = CGAffineTransformIdentity;
aCgAffTrans = CGAffineTransformMakeTranslation(0,892);
aCgAffTrans = CGAffineTransformScale(aCgAffTrans, 1.0, -1.0);
CGContextConcatCTM(aCgPDFContextRef, aCgAffTrans);
NSString *strText = #"Test 123333333333333333";
[strText drawAtPoint:NSMakePoint(100, 200) withAttributes:[NSDictionary dictionaryWithObjectsAndKeys:[NSFont systemFontOfSize:40.0],NSFontAttributeName,nil]];//drawAtPoint:CGPointMake(200, 300) withFont:[NSFont systemFontOfSize:20]];
[aPageNote setWantsLayer:YES];
[aPageNote.layer renderInContext:aCgPDFContextRef];
CGContextEndPage(aCgPDFContextRef);
CGContextRelease (aCgPDFContextRef);
NSLog(#"Pdf Successfully Created");
The Method :
-(CGContextRef) createPDFContext:(CGRect)aCgRectinMediaBox path:(CFStringRef) aCfStrPath
{
CGContextRef aCgContextRefNewPDF = NULL;
CFURLRef aCfurlRefPDF;
aCfurlRefPDF = CFURLCreateWithFileSystemPath (NULL,aCfStrPath,kCFURLPOSIXPathStyle,false);
if (aCfurlRefPDF != NULL) {
aCgContextRefNewPDF = CGPDFContextCreateWithURL (aCfurlRefPDF,&aCgRectinMediaBox,NULL);
CFRelease(aCfurlRefPDF);
}
return aCgContextRefNewPDF;
}
EDIT : I am able to write in PDF using this code
CGContextBeginPage(aCgPDFContextRef,nil);
NSString *strText1 = #"I am iOS Developer";
CGContextSelectFont (aCgPDFContextRef, "Helvetica", 24, kCGEncodingMacRoman);
CGContextSetTextDrawingMode (aCgPDFContextRef, kCGTextFill);
CGContextSetRGBFillColor (aCgPDFContextRef, 0, 0, 0, 1);
const char *text1 = [strText1 UTF8String];
CGContextShowTextAtPoint (aCgPDFContextRef, 50, 375, text1, strlen(text1));
CGContextEndPage(aCgPDFContextRef);
EDIT : Render NSView and add as image into PDF like this:
//Firstly render NS element into NSImage
NSImage *i = [[NSImage alloc] initWithData:[yourView dataWithPDFInsideRect:[yourView bounds]]];
//Now u can add in PDF
CGImageSourceRef source = CGImageSourceCreateWithData((CFDataRef)[i TIFFRepresentation], NULL);
CGImageRef imageRef = CGImageSourceCreateImageAtIndex(source, 0, NULL);
CGContextDrawImage(aCgPDFContextRef,[yourView bounds], imageRef);
I got a interesting riddle here. My cocos2d project uses a UIView to display nicer popups than the regular alert view. To be more flexible in the size of the popup, I draw the background in the drawRect method.
But first the hierarchy how I implement cocos2d and UIKit:
Every UIKit element is added to the RootViewController. Every CCNode to the EAGLView. (If someone has a better solution to mix those world, don't wait to tell me!) Unfortunately is every UIKit view in front of cocos nodes.
Everything works fine when I add the first popup to the RootViewController. But if I remove the first popup and add a new one to the RootViewController occurs a bad access.
It crashes only in combination with cocos2d.
I use the code from Ray Wenderlichs CoreGraphics 101 tutorial.
context and strokeColor are not nil.
Another important infos: I use ARC and am supporting iOS 4.2 and above.
The complete code can be found at raywenderlich.com or below
void drawLinearGradient(CGContextRef context, CGRect rect, CGColorRef startColor, CGColorRef endColor)
{
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGFloat locations[] = { 0.0, 1.0 };
NSArray *colors = [NSArray arrayWithObjects:(__bridge id)startColor, (__bridge id)endColor, nil];
CGGradientRef gradient = CGGradientCreateWithColors(colorSpace,
(__bridge CFArrayRef) colors, locations);
CGPoint startPoint = CGPointMake(CGRectGetMidX(rect), CGRectGetMinY(rect));
CGPoint endPoint = CGPointMake(CGRectGetMidX(rect), CGRectGetMaxY(rect));
CGContextSaveGState(context);
CGContextAddRect(context, rect);
CGContextClip(context);
CGContextDrawLinearGradient(context, gradient, startPoint, endPoint, 0);
CGContextRestoreGState(context);
CGGradientRelease(gradient);
CGColorSpaceRelease(colorSpace);
}
CGRect rectFor1PxStroke(CGRect rect)
{
return CGRectMake(rect.origin.x + 0.5, rect.origin.y + 0.5, rect.size.width - 1, rect.size.height -1);
}
- (void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
CGRect frame = CGRectInset(self.bounds, 2, 2);
CGContextSetShadowWithColor(context, CGSizeMake(0, 0), 3.0, shadowColor);
CGRect strokeRect = CGRectInset(frame, -2.0, -2.0);
CGContextSetStrokeColorWithColor(context, strokeColor);
CGContextSetLineWidth(context, 2.0);
CGContextStrokeRect(context, rectFor1PxStroke(strokeRect));
drawLinearGradient(context, frame, gradient1, gradient2);
}
ARC releases the CGColorRef named strokeColor. One fix is to replace it with an CGFloat array and use CGContextSetStrokeColor instead CGContextSetStrokeColorWithColor
This answer solves this issue:
App crashes when using __bridge for CoreGraphics gradient on ARC
I agree with zeiteisen ,ARC releases CGColorRef and the easiest way to solve this by
replacing CGContextSetStrokeColorWithColor with
CGContextSetStrokeColor(context, components)
Change UIColor of strokeColor to 'RGB CGFloat components array' as following:
static CGFloat red, green, blue, alpha;
- (void)getRGBComponents:(CGFloat [4])components forColor:(UIColor *)color {
[color getRed:&red green:&green blue:&blue alpha:&alpha];//To fetch CGFloat RGB components
for (int component = 0; component < 4; component++) {
switch (component) {
case 0:
components[component] = red;
break;
case 1:
components[component] = green;
break;
case 2:
components[component] = blue;
break;
case 3:
components[component] = alpha;
break;
default:
break;
}
}
}
Use this method like this:
CGFloat components[4];
UIColor *strokeColor=[UIColor greyColor];//My color
[self getRGBComponents:components forColor:strokeColor];//'components' will be substituted in CGContextSetStrokeColor
NSLog(#"%f %f %f %f", components[0], components[1], components[2],components[3]);
while working with OpenCV I need to convert a NSImage to an OpenCV multi-channel 2D matrix (cvMat) and vice versa.
What's the best way to do it?
Greets,
Dom
Here's my outcome, which works pretty well.
NSImage+OpenCV.h:
//
// NSImage+OpenCV.h
//
#import <AppKit/AppKit.h>
#interface NSImage (NSImage_OpenCV) {
}
+(NSImage*)imageWithCVMat:(const cv::Mat&)cvMat;
-(id)initWithCVMat:(const cv::Mat&)cvMat;
#property(nonatomic, readonly) cv::Mat CVMat;
#property(nonatomic, readonly) cv::Mat CVGrayscaleMat;
#end
NSImage+OpenCV.mm:
//
// NSImage+OpenCV.mm
//
#import "NSImage+OpenCV.h"
static void ProviderReleaseDataNOP(void *info, const void *data, size_t size)
{
return;
}
#implementation NSImage (NSImage_OpenCV)
-(CGImageRef)CGImage
{
CGContextRef bitmapCtx = CGBitmapContextCreate(NULL/*data - pass NULL to let CG allocate the memory*/,
[self size].width,
[self size].height,
8 /*bitsPerComponent*/,
0 /*bytesPerRow - CG will calculate it for you if it's allocating the data. This might get padded out a bit for better alignment*/,
[[NSColorSpace genericRGBColorSpace] CGColorSpace],
kCGBitmapByteOrder32Host|kCGImageAlphaPremultipliedFirst);
[NSGraphicsContext saveGraphicsState];
[NSGraphicsContext setCurrentContext:[NSGraphicsContext graphicsContextWithGraphicsPort:bitmapCtx flipped:NO]];
[self drawInRect:NSMakeRect(0,0, [self size].width, [self size].height) fromRect:NSZeroRect operation:NSCompositeCopy fraction:1.0];
[NSGraphicsContext restoreGraphicsState];
CGImageRef cgImage = CGBitmapContextCreateImage(bitmapCtx);
CGContextRelease(bitmapCtx);
return cgImage;
}
-(cv::Mat)CVMat
{
CGImageRef imageRef = [self CGImage];
CGColorSpaceRef colorSpace = CGImageGetColorSpace(imageRef);
CGFloat cols = self.size.width;
CGFloat rows = self.size.height;
cv::Mat cvMat(rows, cols, CV_8UC4); // 8 bits per component, 4 channels
CGContextRef contextRef = CGBitmapContextCreate(cvMat.data, // Pointer to backing data
cols, // Width of bitmap
rows, // Height of bitmap
8, // Bits per component
cvMat.step[0], // Bytes per row
colorSpace, // Colorspace
kCGImageAlphaNoneSkipLast |
kCGBitmapByteOrderDefault); // Bitmap info flags
CGContextDrawImage(contextRef, CGRectMake(0, 0, cols, rows), imageRef);
CGContextRelease(contextRef);
CGImageRelease(imageRef);
return cvMat;
}
-(cv::Mat)CVGrayscaleMat
{
CGImageRef imageRef = [self CGImage];
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
CGFloat cols = self.size.width;
CGFloat rows = self.size.height;
cv::Mat cvMat = cv::Mat(rows, cols, CV_8UC1); // 8 bits per component, 1 channel
CGContextRef contextRef = CGBitmapContextCreate(cvMat.data, // Pointer to backing data
cols, // Width of bitmap
rows, // Height of bitmap
8, // Bits per component
cvMat.step[0], // Bytes per row
colorSpace, // Colorspace
kCGImageAlphaNone |
kCGBitmapByteOrderDefault); // Bitmap info flags
CGContextDrawImage(contextRef, CGRectMake(0, 0, cols, rows), imageRef);
CGContextRelease(contextRef);
CGColorSpaceRelease(colorSpace);
CGImageRelease(imageRef);
return cvMat;
}
+ (NSImage *)imageWithCVMat:(const cv::Mat&)cvMat
{
return [[[NSImage alloc] initWithCVMat:cvMat] autorelease];
}
- (id)initWithCVMat:(const cv::Mat&)cvMat
{
NSData *data = [NSData dataWithBytes:cvMat.data length:cvMat.elemSize() * cvMat.total()];
CGColorSpaceRef colorSpace;
if (cvMat.elemSize() == 1)
{
colorSpace = CGColorSpaceCreateDeviceGray();
}
else
{
colorSpace = CGColorSpaceCreateDeviceRGB();
}
CGDataProviderRef provider = CGDataProviderCreateWithCFData((__bridge CFDataRef)data);
CGImageRef imageRef = CGImageCreate(cvMat.cols, // Width
cvMat.rows, // Height
8, // Bits per component
8 * cvMat.elemSize(), // Bits per pixel
cvMat.step[0], // Bytes per row
colorSpace, // Colorspace
kCGImageAlphaNone | kCGBitmapByteOrderDefault, // Bitmap info flags
provider, // CGDataProviderRef
NULL, // Decode
false, // Should interpolate
kCGRenderingIntentDefault); // Intent
NSBitmapImageRep *bitmapRep = [[NSBitmapImageRep alloc] initWithCGImage:imageRef];
NSImage *image = [[NSImage alloc] init];
[image addRepresentation:bitmapRep];
CGImageRelease(imageRef);
CGDataProviderRelease(provider);
CGColorSpaceRelease(colorSpace);
return image;
}
#end
Example usage:
Just import it like this:
#import "NSImage+OpenCV.h"
And use it like this:
cv::Mat cvMat_test;
NSImage *image = [NSImage imageNamed:#"test.jpg"];
cvMat_test = [image CVMat];
[myImageView setImage:[NSImage imageWithCVMat:cvMat_test]];
In -(id)initWithCVMat:(const cv::Mat&)cvMat, shouldn't you be adding the representation to self, rather than a new NSImage?
-(id)initWithCVMat:(const cv::Mat *)iMat
{
if(self = [super init]) {
NSData *tData = [NSData dataWithBytes:iMat->data length:iMat->elemSize() * iMat->total()];
CGColorSpaceRef tColorSpace;
if(iMat->elemSize() == 1) {
tColorSpace = CGColorSpaceCreateDeviceGray();
} else {
tColorSpace = CGColorSpaceCreateDeviceRGB();
}
CGDataProviderRef tProvider = CGDataProviderCreateWithCFData((CFDataRef) tData);
CGImageRef tImage = CGImageCreate(
iMat->cols,
iMat->rows,
8,
8 * iMat->elemSize(),
iMat->step[0],
tColorSpace,
kCGImageAlphaNone | kCGBitmapByteOrderDefault,
tProvider,
NULL,
false,
kCGRenderingIntentDefault);
NSBitmapImageRep *tBitmap = [[NSBitmapImageRep alloc] initWithCGImage:tImage];
[self addRepresentation:tBitmap];
[tBitmap release];
CGImageRelease(tImage);
CGDataProviderRelease(tProvider);
CGColorSpaceRelease(tColorSpace);
}
return self;
}
I have a CALayer (containerLayer) that I'm looking to convert to a NSBitmapImageRep before saving the data out as a flat file. containerLayer has its geometryFlipped property set to YES, and this seems to be causing issues. The PNG file that is ultimately generated renders the content correctly, but doesn't seem to takes the flipped geometry into account. I'm obviously looking for test.png to accurately represent the content shown to the left.
Attached below is a screenshot of the problem and the code I'm working with.
- (NSBitmapImageRep *)exportToImageRep
{
CGContextRef context = NULL;
CGColorSpaceRef colorSpace;
int bitmapByteCount;
int bitmapBytesPerRow;
int pixelsHigh = (int)[[self containerLayer] bounds].size.height;
int pixelsWide = (int)[[self containerLayer] bounds].size.width;
bitmapBytesPerRow = (pixelsWide * 4);
bitmapByteCount = (bitmapBytesPerRow * pixelsHigh);
colorSpace = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
context = CGBitmapContextCreate (NULL,
pixelsWide,
pixelsHigh,
8,
bitmapBytesPerRow,
colorSpace,
kCGImageAlphaPremultipliedLast);
if (context == NULL)
{
NSLog(#"Failed to create context.");
return nil;
}
CGColorSpaceRelease(colorSpace);
[[[self containerLayer] presentationLayer] renderInContext:context];
CGImageRef img = CGBitmapContextCreateImage(context);
NSBitmapImageRep *bitmap = [[NSBitmapImageRep alloc] initWithCGImage:img];
CFRelease(img);
return bitmap;
}
For reference, here's the code that actually saves out the generated NSBitmapImageRep:
NSData *imageData = [imageRep representationUsingType:NSPNGFileType properties:nil];
[imageData writeToFile:#"test.png" atomically:NO];
You need to flip the destination context BEFORE you render into it.
Update your code with this, I have just solved the same problem:
CGAffineTransform flipVertical = CGAffineTransformMake(1, 0, 0, -1, 0, pixelsHigh);
CGContextConcatCTM(context, flipVertical);
[[[self containerLayer] presentationLayer] renderInContext:context];