Strange feeling that if i want to preview a pdf on a controller alongside an image the only way i can get it to work is to use a defined segue from the previous view controller, maybe i'm not clear. How to i get an image to show up on a preview of a QuickLook action without having to segue in and not just modal into the view ? Is this logical ?
I dev an app which generates PDF's, and i'm giving the user the possibility to preview them....but when these have an image....boom the image disappears from the preview...unless i use a segue then no problem, seems weird though. Any suggestions ?....thanks in advance...
- (CFRange)renderPage:(NSInteger)pageNum withTextRange:(CFRange)currentRange
andFramesetter:(CTFramesetterRef)framesetter
{
CGContextRef currentContext = UIGraphicsGetCurrentContext();
// Put the text matrix into a known state. This ensures
// that no old scaling factors are left in place.
CGContextSetTextMatrix(currentContext, CGAffineTransformIdentity);
// Create a path object to enclose the text. Use 72 point
// margins all around the text.
#pragma-----------here to disclose the height of text on pdf preview
CGRect frameRect = CGRectMake(40, 72, 468, 350);
CGMutablePathRef framePath = CGPathCreateMutable();
CGPathAddRect(framePath, NULL, frameRect);
[_imageView1 setImage:theImage1];
CGRect frame = CGRectMake(40, 50, 130, 130);
[ProgramPDFViewController drawImage:theImage1 inRect:frame];
CGSize size = theImage1.size;
CGFloat ratio = 0;
if (size.width > size.height) {
ratio = 44.0 / size.width;
} else {
ratio = 44.0 / size.height;
}
CGRect rect = CGRectMake(0.0, 0.0, ratio * size.width, ratio * size.height);
UIGraphicsBeginImageContext(rect.size);
[theImage1 drawInRect:rect];
UIGraphicsEndImageContext();
CTFrameRef frameRef = CTFramesetterCreateFrame(framesetter, currentRange, framePath, NULL);
CGPathRelease(framePath);
CGContextTranslateCTM(currentContext, 0, kDefaultPageHeight);
CGContextScaleCTM(currentContext, 1.0, -1.0);
CTFrameDraw(frameRef, currentContext);
currentRange = CTFrameGetVisibleStringRange(frameRef);
currentRange.location += currentRange.length;
currentRange.length = 0;
CFRelease(frameRef);
return currentRange;
}
Related
I can make a CGRect with an exact defined PointSize e.g (20x20) and on this way i can exactly calculate the real size (cm or inch) on the Screen.
-(void) drawRect:(CGRect)rect{
[super drawRect:rect];
CGRect rectangle = CGRectMake(0, 0, 20, 20);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetRGBFillColor(context, 1.0, 0.0, 0.0, 1.0);
CGContextSetRGBStrokeColor(context, 1.0, 0.0, 0.0, 1.0);
CGContextFillRect(context, rectangle);
}
I would like to determine the size of the UIFont (always only one Charackter "A..Z" or "1..9") somehow in a simular way, so that i can calculate at least the real height on the Screen.
Is it possible to calculate the Font size from CGSize to UIfont Size, so that it really matches on the screen ?
I have found a Solution for this kind of Problem.
If you want to have an UIFont to fit a CGRect or a Label, it won't fit the CGRect in the most cases. The Reason are the Font specific paddings.
If you want a Font to fit a CGRect, you must know wheter to use a lower or Upper Case Letters, an then to set font.xHeigth or the font.capHeight as font.pointSize. Therefore you'll get a bigger font.pointsize.
This little CodeSnippet solved my Problem:
+(CGFloat) fitFontSize:(UIFont*) font{
CGFloat fontSize = font.pointSize;
bool fontSizeAdjusted = false;
while (!fontSizeAdjusted) {
CGFloat xHeight = font.xHeight;
if( fontSize-xHeight > 0.1 ){
font = [font fontWithSize:font.pointSize+1];
}else{
fontSizeAdjusted = true;
fontSize = font.pointSize;
}
}
return fontSize;
}
This Article helped me to learn more about UIFonts
I'm using standart code to rotate image, but when UIImageRotatation is not equal to 2, the image is rotated not correctly.
Any code to fix UIImageRotation and rotate image by X degrees? Try nearly everything.
NSLog(#"Image orientation %d",self.imageOrientation);
CGSize rotatedSize = CGSizeApplyAffineTransform(self.size, CGAffineTransformMakeRotation(rad(degrees)));
if (rotatedSize.width < 0) {
rotatedSize.width *= -1;
}
if (rotatedSize.height < 0) {
rotatedSize.height *= -1;
}
// Create the bitmap context
UIGraphicsBeginImageContextWithOptions(rotatedSize, YES, 0.0);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
// Move the origin to the middle of the image so we will rotate and scale around the center.
CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);
// // Rotate the image context
CGContextRotateCTM(bitmap, rad(degrees));
// Now, draw the rotated/scaled image into the context
CGContextScaleCTM(bitmap, 1.0, -1.0);
CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2, self.size.width, self.size.height), [self CGImage]);
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
I'm developing an iOS app for iPad. Is there any way to rotate a UIImage 90ยบ and then add it to a UIImageView? I've tried a lot of different codes but none worked...
Thanks!
You may rotate UIImageView itself with:
UIImageView *iv = [[UIImageView alloc] initWithImage:image];
iv.transform = CGAffineTransformMakeRotation(M_PI_2);
Or if you really want to change image, you may use code from this answer, it works.
To rotate the pixels you can use the following. This creates an intermediate UIImage with rotated metadata and renders it into a image context with width/height dimensions transposed. The resulting image has the pixels rotated (i.e the underlying CGImage)
- (UIImage*)rotateUIImage:(UIImage*)sourceImage clockwise:(BOOL)clockwise
{
CGSize size = sourceImage.size;
UIGraphicsBeginImageContext(CGSizeMake(size.height, size.width));
[[UIImage imageWithCGImage:[sourceImage CGImage] scale:1.0 orientation:clockwise ? UIImageOrientationRight : UIImageOrientationLeft] drawInRect:CGRectMake(0,0,size.height ,size.width)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
There are other possible values that can be passed for the orientation parameter to achieve 180 degree rotation and flips etc.
This will rotate an image by any given degrees.
Note this works 2x and 3x retina as well
- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees {
CGFloat radians = DegreesToRadians(degrees);
UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0, self.size.width, self.size.height)];
CGAffineTransform t = CGAffineTransformMakeRotation(radians);
rotatedViewBox.transform = t;
CGSize rotatedSize = rotatedViewBox.frame.size;
UIGraphicsBeginImageContextWithOptions(rotatedSize, NO, [[UIScreen mainScreen] scale]);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(bitmap, rotatedSize.width / 2, rotatedSize.height / 2);
CGContextRotateCTM(bitmap, radians);
CGContextScaleCTM(bitmap, 1.0, -1.0);
CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2 , self.size.width, self.size.height), self.CGImage );
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
There is also imageWithCIImage:scale:orientation if you wanted to rotate the UIImage not the UIImageView
with one of these orientations:
typedef enum {
UIImageOrientationUp,
UIImageOrientationDown, // 180 deg rotation
UIImageOrientationLeft, // 90 deg CW
UIImageOrientationRight, // 90 deg CCW
UIImageOrientationUpMirrored, // vertical flip
UIImageOrientationDownMirrored, // horizontal flip
UIImageOrientationLeftMirrored, // 90 deg CW then perform horizontal flip
UIImageOrientationRightMirrored, // 90 deg CCW then perform vertical flip
} UIImageOrientation;
Here is the swift version of #RyanG's Objective C code as an extension to UIImage:
extension UIImage {
func rotate(byDegrees degree: Double) -> UIImage {
let radians = CGFloat(degree*M_PI)/180.0 as CGFloat
let rotatedViewBox = UIView(frame: CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height))
let t = CGAffineTransform(rotationAngle: radians)
rotatedViewBox.transform = t
let rotatedSize = rotatedViewBox.frame.size
let scale = UIScreen.main.scale
UIGraphicsBeginImageContextWithOptions(rotatedSize, false, scale)
let bitmap = UIGraphicsGetCurrentContext()
CGContextTranslateCTM(bitmap, rotatedSize.width / 2, rotatedSize.height / 2);
bitmap!.rotate(by: radians);
bitmap!.scaleBy(x: 1.0, y: -1.0);
CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2 , self.size.width, self.size.height), self.CGImage );
let newImage = UIGraphicsGetImageFromCurrentImageContext()
return newImage
}
}
The usage is image.rotate(degree).
With Swift, you can rotate an image by doing:
var image: UIImage = UIImage(named: "headerBack.png")
var imageRotated: UIImage = UIImage(CGImage: image.CGImage, scale:1, orientation: UIImageOrientation.UpMirrored)
UIImage *img = [UIImage imageWithName#"aaa.png"];
UIImage *image = [UIImage imageWithCGImage:img.CGImage scale:1.0 orientation:UIImageOrientationRight];
Another way of doing this would be to render the UIImage again using Core Graphics.
Once you have the context, use CGContextRotateCTM.
More info on this Apple Doc
Thanks Jason Crocker this solved my problem. Only one minor correction, interchange height and width in both locations and no distortion occurs, ie,
UIGraphicsBeginImageContext(CGSizeMake(size.width, size.height));
[[UIImage imageWithCGImage:[sourceImage CGImage] scale:1.0 orientation:clockwise ? UIImageOrientationRight : UIImageOrientationLeft] drawInRect:CGRectMake(0,0,size.width,size.height)];
My problem could not be solved by CGContextRotateCTM, I don't know why. My issue is that I'm transmitting my image to a server and it was alway displayed off by 90 degrees. You can easily test if your images are going to work in the non apple world by copying the image to an MS Office Program that you are running on your mac.
This is what i've done when i wanted to change the orientation of an image (rotate 90 degree clockwise).
//Checking for the orientation ie, image taken from camera is in portrait or not.
if(yourImage.imageOrientation==3)
{
//Image is in portrait mode.
yourImage=[self imageToRotate:yourImage RotatedByDegrees:90.0];
}
- (UIImage *)image:(UIImage *)imageToRotate RotatedByDegrees:(CGFloat)degrees
{
CGFloat radians = degrees * (M_PI / 180.0);
UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0, image.size.height, image.size.width)];
CGAffineTransform t = CGAffineTransformMakeRotation(radians);
rotatedViewBox.transform = t;
CGSize rotatedSize = rotatedViewBox.frame.size;
UIGraphicsBeginImageContextWithOptions(rotatedSize, NO, [[UIScreen mainScreen] scale]);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(bitmap, rotatedSize.height / 2, rotatedSize.width / 2);
CGContextRotateCTM(bitmap, radians);
CGContextScaleCTM(bitmap, 1.0, -1.0);
CGContextDrawImage(bitmap, CGRectMake(-image.size.width / 2, -image.size.height / 2 , image.size.height, image.size.width), image.CGImage );
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
The rotated image may be of size >= 15MB (from my experience). So you should compress it and use it. Otherwise, you may met with crash causing memory pressure. Code I used for compressing is given below.
NSData *imageData = UIImageJPEGRepresentation(yourImage, 1);
//1 - it represents the quality of the image.
NSLog(#"Size of Image(bytes):%d",[imageData length]);
//Here I used a loop because my requirement was, the image size should be <= 4MB.
//So put an iteration for more than 1 time upto when the image size is gets <= 4MB.
for(int loop=0;loop<100;loop++)
{
if([imageData length]>=4194304) //4194304 = 4MB in bytes.
{
imageData=UIImageJPEGRepresentation(yourImage, 0.3);
yourImage=[[UIImage alloc]initWithData:imageData];
}
else
{
NSLog(#"%d time(s) compressed.",loop);
break;
}
}
Now your yourImage can be used for anywhere..
Happy coding...
I am currently working on drawing app, in which have a slider to increase and decrease line width. I just want to do a simple thing that a circle in front of slider to present a width. I easily did that but its not growing and shrinking from centre, its growing and shrinking from top x, y, here is the code
- (UIImage *)circleOnImage:(int)size
{
UIGraphicsBeginImageContext(CGSizeMake(25, 25));
CGContextRef ctx = UIGraphicsGetCurrentContext();
[[UIColor blackColor] setFill];
CGContextTranslateCTM(ctx, 12, 12);//also try to change the coordinate but didn't work
CGRect circleRect = CGRectMake(0, 0, size, size);
CGContextFillEllipseInRect(ctx, circleRect);
UIImage *retImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return retImage;
}
Try
CGContextTranslateCTM(ctx, 12.5, 12.5);
CGRect circleRect = CGRectMake(-size/2., -size/2., size, size);
Is there any way to draw an NSImage like images in NSButtons or other cocoa interface elements?
Here are examples:
Apple uses pdf's with black icons:
If you simply want this effect to be applied when you use your own images in a button, use [myImage setTemplate:YES]. There is no built-in way to draw images with this effect outside of a button that has the style shown in your screenshots.
You can however replicate the effect using Core Graphics. If you look closely, the effect consists of a horizontal gradient, a white drop shadow and a dark inner shadow (the latter is the most difficult).
You could implement this as a category on NSImage:
//NSImage+EtchedDrawing.h:
#interface NSImage (EtchedImageDrawing)
- (void)drawEtchedInRect:(NSRect)rect;
#end
//NSImage+EtchedDrawing.m:
#implementation NSImage (EtchedImageDrawing)
- (void)drawEtchedInRect:(NSRect)rect
{
NSSize size = rect.size;
CGFloat dropShadowOffsetY = size.width <= 64.0 ? -1.0 : -2.0;
CGFloat innerShadowBlurRadius = size.width <= 32.0 ? 1.0 : 4.0;
CGContextRef c = [[NSGraphicsContext currentContext] graphicsPort];
//save the current graphics state
CGContextSaveGState(c);
//Create mask image:
NSRect maskRect = rect;
CGImageRef maskImage = [self CGImageForProposedRect:&maskRect context:[NSGraphicsContext currentContext] hints:nil];
//Draw image and white drop shadow:
CGContextSetShadowWithColor(c, CGSizeMake(0, dropShadowOffsetY), 0, CGColorGetConstantColor(kCGColorWhite));
[self drawInRect:maskRect fromRect:NSMakeRect(0, 0, self.size.width, self.size.height) operation:NSCompositeSourceOver fraction:1.0];
//Clip drawing to mask:
CGContextClipToMask(c, NSRectToCGRect(maskRect), maskImage);
//Draw gradient:
NSGradient *gradient = [[[NSGradient alloc] initWithStartingColor:[NSColor colorWithDeviceWhite:0.5 alpha:1.0]
endingColor:[NSColor colorWithDeviceWhite:0.25 alpha:1.0]] autorelease];
[gradient drawInRect:maskRect angle:90.0];
CGContextSetShadowWithColor(c, CGSizeMake(0, -1), innerShadowBlurRadius, CGColorGetConstantColor(kCGColorBlack));
//Draw inner shadow with inverted mask:
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef maskContext = CGBitmapContextCreate(NULL, CGImageGetWidth(maskImage), CGImageGetHeight(maskImage), 8, CGImageGetWidth(maskImage) * 4, colorSpace, kCGImageAlphaPremultipliedLast);
CGColorSpaceRelease(colorSpace);
CGContextSetBlendMode(maskContext, kCGBlendModeXOR);
CGContextDrawImage(maskContext, maskRect, maskImage);
CGContextSetRGBFillColor(maskContext, 1.0, 1.0, 1.0, 1.0);
CGContextFillRect(maskContext, maskRect);
CGImageRef invertedMaskImage = CGBitmapContextCreateImage(maskContext);
CGContextDrawImage(c, maskRect, invertedMaskImage);
CGImageRelease(invertedMaskImage);
CGContextRelease(maskContext);
//restore the graphics state
CGContextRestoreGState(c);
}
#end
Example usage in a view:
- (void)drawRect:(NSRect)dirtyRect
{
[[NSColor colorWithDeviceWhite:0.8 alpha:1.0] set];
NSRectFill(self.bounds);
NSImage *image = [NSImage imageNamed:#"MyIcon.pdf"];
[image drawEtchedInRect:self.bounds];
}
This would give you the following result (shown in different sizes):
You may need to experiment a bit with the gradient colors and offset/blur radius of the two shadows to get closer to the original effect.
If you don't mind calling a private API, you can let the operating system (CoreUI) do the shading for you. You need a few declarations:
typedef CFTypeRef CUIRendererRef;
extern void CUIDraw(CUIRendererRef renderer, CGRect frame, CGContextRef context, CFDictionaryRef object, CFDictionaryRef *result);
#interface NSWindow(CoreUIRendererPrivate)
+ (CUIRendererRef)coreUIRenderer;
#end
And for the actual drawing:
CGRect drawRect = CGRectMake(x, y, width, height);
CGImageRef cgimage = your_image;
CFDictionaryRef dict = (CFDictionaryRef) [NSDictionary dictionaryWithObjectsAndKeys:
#"backgroundTypeRaised", #"backgroundTypeKey",
[NSNumber numberWithBool:YES], #"imageIsGrayscaleKey",
cgimage, #"imageReferenceKey",
#"normal", #"state",
#"image", #"widget",
[NSNumber numberWithBool:YES], #"is.flipped",
nil];
CUIDraw ([NSWindow coreUIRenderer], drawRect, cg, dict, nil);
CGImageRelease (cgimage);
This will take the alpha channel of cgimage and apply the embossing effect as seen on toolbar buttons. You may or may not need the "is.flipped" line. Remove it if your result is upside-down.
There are a bunch of variations:
kCUIPresentationStateKey = kCUIPresentationStateInactive: The window is not active, the image will be lighter.
state = rollover: Only makes sense with the previous option. This means you are hovering over the image, the window is inactive, but the button is sensitive (click-through is enabled). It will become darker.
state = pressed: Occurs when the button is pressed. The icon gets slightly darker.
Bonus tip: To find out stuff like this, you can use the SIMBL plugin CUITrace. It prints out all the CoreUI invocations of a target app. This is a treasure trove if you have to draw your own native-looking UI.
Here's a much simpler solution: just create a cell and let it draw. No mucking around with private APIs or Core Graphics.
Code could look similar to the following:
NSButtonCell *buttonCell = [[NSButtonCell alloc] initImageCell:image];
buttonCell.bordered = YES;
buttonCell.bezelStyle = NSTexturedRoundedBezelStyle;
// additional configuration
[buttonCell drawInteriorWithFrame: someRect inView:self];
You can use different cells and configurations depending on the look you want to have (eg. NSImageCell with NSBackgroundStyleDark if you want the inverted look in a selected table view row)
And as a bonus, it will automatically look correct on all versions of OS X.
To get to draw correctly within any rect, the CGContextDrawImage and CGContextFillRect for the inner mask must have the origin of (0,0). then when you draw the image for the inner shadow you can then reuse the mask rect. So ends up looking like:
CGRect cgRect = CGRectMake( 0, 0, maskRect.size.width, maskRect.size.height );
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef maskContext = CGBitmapContextCreate( NULL, CGImageGetWidth( maskImage ), CGImageGetHeight( maskImage ), 8, CGImageGetWidth( maskImage ) * 4, colorSpace, kCGImageAlphaPremultipliedLast );
CGColorSpaceRelease( colorSpace );
CGContextSetBlendMode( maskContext , kCGBlendModeXOR );
CGContextDrawImage( maskContext, cgRect, maskImage );
CGContextSetRGBFillColor( maskContext, 1.0, 1.0, 1.0, 1.0 );
CGContextFillRect( maskContext, cgRect );
CGImageRef invertedMaskImage = CGBitmapContextCreateImage( maskContext );
CGContextDrawImage( context, maskRect, invertedMaskImage );
CGImageRelease( invertedMaskImage );
CGContextRelease( maskContext );
CGContextRestoreGState( context );
You also have to leave a 1px border around the outside of the image or the shadows won't work correctly.