I am trying to change the orientation of the image (CIImage *myImage) but it looks it did not take any effect.
CIImage *myImage2 = [myImage imageByApplyingOrientation:kCGImagePropertyOrientationUp];
I tried also other ways:
CIImage *myImage2 = [myImage imageByApplyingOrientation:[#"1" intValue]];
CIImage *myImage2 = [myImage imageByApplyingTransform:[myImage imageTransformForOrientation:[#"5" intValue]]];
When I am trying to find out whether the orientation was changed:
NSLog(#"Image orientation %#",[[myImage properties] valueForKey:kCGImagePropertyOrientation]);
I got "null". Tried as well to save "myImage2" to a new image but there is no effect after opening it. It looks that the method "imageByApplyingOrientation" does not work at all.
You might try experimenting with the orientation value. I noticed that using a value of "1" on my image had no effect either, but using something other than "1" did. In my case, the value "6" ('Right, top' according to the docs) turned out to be what I needed. I never checked the ciimage properties attribute, so I can't speak to that.
Related
How to make a distance between the image and the text closer?
In ios 6 the same code displays normally, but in the new version of the distance increased.
I do everything by standard methods
[cell.textLabel setText: .....
// cell.indentationLevel = 0; // this is for test
UIImage * img = [UIImage imageNamed: # "image10.png"];
NSData * imageData = UIImagePNGRepresentation (img);
cell.imageView.image = [UIImage imageWithData: imageData];
attached image
https://www.dropbox.com/s/lt119xgozvzzstd/image01.png
If I remember correctly, the indentation level only affects the text. So when you're changing the indentation level/width you are in fact changing the distance between the imageView and the textLabel.
I tested this an unfortunately you can't make the indentationWidth negative. Thus you will need to subclass the UITableViewCell and set it up with your own views (I would suggest doing that in the Storyboard, with autolayout and make the indentation into a NSLayoutConstraint so that you have a property on your cell indentationConstant, for example which you can change). I have done this for a slightly different purposes, I needed to indent the whole contentView. No way around subclassing and creating custom views in Storyboard, sorry. (I am not even going to suggest some terrible hacks of accessing the subviews and modifying their frame, everything is autolayout today).
I have an NSView that contains an NSScrollView containing a CALayer-backed NSView. I've tried all the usual methods of capturing an NSView into an NSImage (using -dataWithPDFInsideRect, NSBitmapImageRep's -initWithFocusedViewRect, etc.) However, all these methods treat the CALayer-backed NSView as if it doesn't exist. I've already seen this StackOverflow post, but it was a question about rendering just a CALayer tree to an image, not an NSView containing both regular NSView's and layer-backed views.
Any help is appreciated, thanks :)
The only way I found to do this is to use the CGWindow API's, something like:
CGImageRef cgimg = CGWindowListCreateImage(CGRectZero, kCGWindowListOptionIncludingWindow, [theWindow windowNumber], kCGWindowImageDefault);
then clip out the part of that CGImage that corresponds to your view with
-imageByCroppingToRect.
Then make a NSImage from the cropped CGImage.
Be aware this won't work well if parts of that window are offscreen.
This works to draw a view directly to an NSImage, though I haven't tried it with a layer-backed view:
NSImage * i = [[NSImage alloc] initWithSize:[view frame].size];
[i lockFocus];
if ([view lockFocusIfCanDrawInContext:[NSGraphicsContext currentContext]]) {
[view displayRectIgnoringOpacity:[view frame] inContext:[NSGraphicsContext currentContext]];
[view unlockFocus];
}
[i unlockFocus];
NSData * d = [i TIFFRepresentation];
[d writeToFile:#"/path/to/my/test.tiff" atomically:YES];
[i release];
Have you looked at the suggestions in the Cocoa Drawing Guide? ("Creating a Bitmap")
To draw directly into a bitmap, create a new NSBitmapImageRep object with the parameters you want and use the graphicsContextWithBitmapImageRep: method of NSGraphicsContext to create a drawing context. Make the new context the current context and draw. This technique is available only in Mac OS X v10.4 and later.
Alternatively, you can create an NSImage object (or an offscreen window), draw into it, and then capture the image contents. This technique is supported in all versions of Mac OS X.
That sounds similar to the iOS solution I'm familiar with (using UIGraphicsBeginImageContext and UIGraphicsGetImageFromCurrentImageContext) so I'd expect it to work for your view.
Please have a look at the answer on this post: How do I render a view which contains Core Animation layers to a bitmap?
That approach worked for me under similar circumstances to your own.
I'm trying to create a label programmatically using NSTextField, but it comes out blurry: screenshot
This is my code so far:
NSTextfield *textfield = [[NSTextField alloc] initWithFrame:NSMakeRect(5,5,150,20)];
[texField setStringValue:#"some text here"];
[textField setEditable:NO];
[textField setSelectable:NO];
[textField setBordered:NO]
[textField setDrawsBackground:NO]
I've traced the problem down to the setDrawsBackground line. I've also tried using [textField setBackgroundColor:[NSColor clearColor] as well, but no luck.
By the way, I've adding to a textField to the subview of a view that is a subview of a scrollview. I've also playing with isOpaque on all the view levels, but no luck there again.
Any help is greatly appreciated.
If you have no background (including clear) and your text is a subview of any layer-backed superview (you've turned on "wants layer" in code or in IB to allow animations/transitions), you'll get blurry text. You have to choose either no layer backed view or a label with a solid background color.
I had the same problem, but I have solved it by:
textfield.canDrawSubviewsIntoLayer = true
Make sure you're setting the frame of your NSTextField to something with all integer values.
Use roundf() if necessary.
I was getting a blurry NSTextField, and neither adding a solid background nor removing Core Animation layers from my view hierarchy were options for me. I noticed I was setting the frame of this text field to something with a Y value of 4.5, so the following changes fixed the issue for me:
Blurry label:
_label.frame = NSOffsetRect(_labelFrame,
-0.5 * (someRect.size.width + someConstant),
0.0);
No blur:
_label.frame = NSOffsetRect(_labelFrame,
roundf(-0.5 * (someRect.size.width + someConstant)),
0.0);
(In the above examples, _labelFrame and someRect are NSRects, and someConstant is a CGFloat. As you can see, the calculation I was doing in the second line of the first example was passing a non-integer value to NSOffsetRect).
Since this was my first time subclassing NSView, I had put the above code in the drawRect method instead of the initWithFrame method. I did this because I was following one of the sample applications from Apple's Dev site.
This was also causing my CPU usage to spike when I was scrolling
If you created it via an XIB and it is blurry, I found the fix:
[textField setStringValue:#""];
If I comment this out it goes blurry; if put back it's crystal clear.
Try this below:
textField.drawsBackground = true
textField.backgroundColor = NSColor.white.withAlphaComponent(.leastNormalMagnitude)
Out of the box, but worth to mention. I have wasted by entire day debugging the issue. I am using a non-apple external monitor and this is where the issue is identified. Once i open the app in Mac book pro, it is perfectly fine.
So, the Samsung monitor which i am using might be non-retina.
Simply, add
CanDrawConcurrently = true
property from InterfaceBuilder
I know this seems like a simple task, which is why I don't understand why I can't get the image to render.
When I set up my UIView, I do the following:
myUiView.backgroundColor = [UIColor clearColor];
myUiView.opaque = NO;
I create and retain the UIImage in the init function of my UIView:
image = [[UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"test" ofType:#"png"]] retain];
then my drawRect looks like this:
- (void) drawRect:(CGRect) rect
{
[image drawInRect:self.bounds];
}
Ultimately I'll be manipulating that UIImage via bitmap context, and then in drawRect create a CGImage out of the context, and render that, but for now I'm just trying to get it rendering a known image.
I've been digging through this site, as well as the documentation. I've gone down the CG path and tried drawing it with CGContextDrawImage by following the numerous examples other people have posted, but that didn't work either.
So I've come back to what seems to be the most straightforward way to draw an image, but it isn't working.
Any help would be greatly appreciated.
Thanks in advance.
First of all, verify that the size and position of self.bounds are what you want them to be. If the size is {0,0} nothing will display. Check using this function:
NSLog(#"%#", NSStringFromCGRect(self.bounds));
Also make sure that the image is not nil:
NSLog(#"%#", image);
I'm trying to use the select and copy feature of the IKImageView. If all you want to do is have an app with an image, select a portion and copy it to the clipboard, it's easy. You set the copy menu pick to the first responder's copy:(id) method and magically everything works.
However, if you want something more complicated, like you want to copy as part of some other operation, I can't seem to find the method to do this.
IKImageView doesn't seem to have a copy method, it doesn't seem to have a method that will even tell you the selected rectangle!
I have gone through Hillegass' book, so I understand how the clipboard works, just not how to get the portion of the image out of the view...
Now, I'm starting to think that I made a mistake in basing my project on IKImageView, but it's what Preview is built on (or so I've read), so I figured it had to be stable... and anyway, now it's too late, I'm too deep in this to start over...
So, other than not using IKImageView, any suggestions on how to copy the select region to the clipboard manually?
EDIT actually, I have found the copy(id) method, but when I call it, I get
<Error>: CGBitmapContextCreate: unsupported parameter combination: 8 integer bits/component; 16 bits/pixel; 1-component color space; kCGImageAlphaPremultipliedLast; 2624 bytes/row.
Which obviously doesn't happen when I do a normal copy through the first-responder... I understand the error message, but I'm not sure where it's getting those parameters from...
Is there any way to trace through this and see how this is happening? A debugger won't help for obvious reasons, as well as the fact that I'm doing this in Mozilla, so a debugger isn't an option anyway...
EDIT 2 It occurs to me that the copy:(id) method I found may be copying the VIEW rather than copying a chunk of the image to the clipboard, which is what I need.
The reason I thought it was the clipboard copy is that in another project, where I'm copying from an IKImageView to the clipboard straight from the edit menu, it just sends a copy:(id) to the firstResponder, but I'm not actually sure what the firstresponder does with it...
EDIT 3 It appears that the CGBitmapContextCreate error is coming from [imageView image] which, oddly enough, IS a documented method.
It's possible that this is happening because I'm putting the image in there with a setImage:(id) method, passing it an NSImage*... Is there some other, more clever way of getting an NSImage into an IKImageView?
The -copy: method in IKImageView does what every other -copy: method does: it copies the current selection to the clipboard. It is, however, implemented as a private method in IKImageView for some reason.
You can just call it directly:
[imageView copy:nil];
This will copy whatever is currently selected to the clipboard.
I don't think there's a way to directly access the image content of the current selection in IKImageView using public methods, this is a good candidate for a bug report/feature request.
You can, however, use the private method -selectionRect to get a CGRect of the current selection and use that to extract the selected portion of the image:
//stop the compiler from complaining when we call a private method
#interface IKImageView (CompilerSTFU)
- (CGRect)selectionRect
#end
#implementation YourController
//imageView is an IBOutlet connected to your IKImageView
- (NSImage*)selectedImage
{
//get the current selection
CGRect selection = [imageView selectionRect];
//get the portion of the image that the selection defines
CGImageRef selectedImage = CGImageCreateWithImageInRect([imageView image],(CGRect)selection);
//convert it to an NSBitmapImageRep
NSBitmapImageRep* bitmap = [[[NSBitmapImageRep alloc] initWithCGImage:selectedImage] autorelease];
CGImageRelease(selectedImage);
//create an image from the bitmap data
NSImage* image = [[[NSImage alloc] initWithData:[bitmap TIFFRepresentation]] autorelease];
//in 10.6 you can skip converting to an NSBitmapImageRep by doing this:
//NSImage* image = [[NSImage alloc] initWithCGImage:selectedImage size:NSZeroSize];
return image;
}
#end
Ok, so the copy: nil fails, and the [imageView image] fails, but it turns out that I have another copy of the NSImage from when I added it into the view in the first place, so I could that. Also, CGImageCreateWithImageInRect expects a CGImageRef not an NSImage*, so I had to do some conversions.
In addition, for some reason the selection rectangle is flipped, either it's bottom origined, and the image is top, or the other way around, so I had to flip it.
And for some reason, the compiler suddenly started complaining that NSRect isn't the same type as CGRect (Which implies that it suddenly went from 32 to 64 bit or something... not sure why...)
Anyway, here is my copy of selectedImage:
- (NSImage*)selectedImage
{
//get the current selection
CGRect selection = flipCGRect(imageView, [imageView selectionRect]);
//get the portion of the image that the selection defines
struct CGImage * full = [[doc currentImage] CGImageForProposedRect: NULL context: NULL hints: NULL];
CGImageRef selectedImage = CGImageCreateWithImageInRect( full, selection);
//convert it to an NSBitmapImageRep
NSBitmapImageRep* bitmap = [[[NSBitmapImageRep alloc] initWithCGImage:selectedImage] autorelease];
CGImageRelease(selectedImage);
// //create an image from the bitmap data
NSImage* image = [[[NSImage alloc] initWithData:[bitmap TIFFRepresentation]] autorelease];
// //in 10.6 you can skip converting to an NSBitmapImageRep by doing this:
//NSImage* image = [[NSImage alloc] initWithCGImage:selectedImage size:NSZeroSize];
return image;
}
I wrote flipCGRect, and [doc currentImage] returns an NSImage*...