I have a UITextView with a lot of text in it. When the subview containing the UITextView is shown the UITextView only appears after the UITextView has been touched and scrolled.
Is there a limit of how much text can be in a UITextView?
Or is this a bug?
attached is a clip explaining this occurrence.
https://dl.dropbox.com/u/8256776/UITextView%20Bug.MOV
Ok, I have looked into it and it seems to be quite a common issue. It seems that the text view doesn't feel that it has to draw the text, but calling setNeedsDisplay doesn't help. I don't know if there is a "real" solution, but you can force it to draw the text by scrolling programmatically:
disclaimerView.contentOffset = CGPointMake(0, 1);
disclaimerView.contentOffset = CGPointMake(0, 0);
An unrelated thing in your code: In your switchView method you have two animations, one for the menu view and one for the view you are sliding into place. This is unnecessary as you can put both setFrame calls in the same animation:
MenuView = (UIView *)[self.view viewWithTag:100];
appView = (UIView *)[self.view viewWithTag:ViewInt];
[MenuView setFrame:CGRectMake(0, 0, 320, 480)];
[appView setFrame:CGRectMake(321, 0, 320, 480)];
[UIView beginAnimations:#"move buttons" context:nil];
[UIView setAnimationDuration:.5];
[MenuView setFrame:CGRectMake(-320, 0, 320, 480)];
[appView setFrame:CGRectMake(0, 0, 320, 480)];
disclaimerView.contentOffset = CGPointMake(0, 1);
disclaimerView.contentOffset = CGPointMake(0, 0);
[UIView commitAnimations];
And one more thing (and then I will back off :) )
You seem to be quite fond of using tags to retrieve elements. While it does work, it is not very understandable. You don't have that many elements so I would just add each of them as IBOutlet with a meaningful name (like you did with your disclaimerView). Also, have seperate switchView methods for the different views you are moving into place. That way you can easily perform additional stuff you might need for just that view, like the force scroll on disclaimerView.
Related
I have a UICollectionView that displays images. My images are size 114x133 but for some reason the actual UICollectionVewCell is bigger than this (I can see this because I set the cell background to red). Because of this the view can display only 2 images and there is a huge gap between the two. I am implementing the following
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
UIImage* img = [UIImage imageNamed:#"thumbnail_frame.png"];
return img.size;
}
- (UIEdgeInsets)collectionView:
(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
return UIEdgeInsetsMake(1, 1, 1, 1);
}
I am creating the cell's contentview programmatically (i.e init imageView etc).
I face the same problem in a different view where I am creating the whole view programmatically. There I do:
UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init];
flowLayout.minimumInteritemSpacing=10;
flowLayout.minimumLineSpacing= 30;
flowLayout.sectionInset = UIEdgeInsetsMake(5, 5, 5, 5);
if(collectionView != nil) {
[collectionView removeFromSuperview];
}
CGRect frm= CGRectMake(45, 80, 250, 230);
collectionView = [[UICollectionView alloc] initWithFrame:frm collectionViewLayout:flowLayout];//(0, 0, self.view.frame.size.width, self.view.frame.size.height) collectionViewLayout:flowLayout];
collectionView.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0.5];
collectionView.clipsToBounds = YES;
collectionView.layer.cornerRadius = 10.0;
collectionView.dataSource = self;
collectionView.delegate = self;
[collectionView registerClass:[YourPicCollectionViewCell class] forCellWithReuseIdentifier:#"YourPicCell"];
Again there is either a big gap between two images, or if I make the width smaller, there are 3 images but the right-most one is half-visible.
I tinkered with spacing but it doesn't seem to work. What could be the problem?
I think instead of resizing the cell.. you should try resizing the collection view. Make sure that the collection view has just enough width to hold 2 items in a row. This is because if the collection view has more width than the cells, then then will stick to the extreme right and left. If it's too short, then only one cell will be displayed at the centre (Assuming that you are trying to keep 2 cells in a row).
The reason that one of your cell was half visible is that the collection view had more width than its super view.
So doing the following would help you get what you want..
Frame your collection view such that its less than its super view and should be equal to (numberOfCells X width) + ((numberOfCells-1) X cellGap).
If it's a custom collection view cell try adding constraints to the imageView such that the image sticks to the cells edges.
I'm getting crazy while trying to merge two UIImageView.
The situation:
a background UIImageView
(userPhotoImageView)
an overlayed
UIImageView (productPhotoImageView)
that can be streched, pinched and
rotated
I call my function on the UIImages but I can take coords and new stretched size from the UIImageView containing them (they are synthesized in my class)
- (UIImage *)mergeImage:(UIImage *)bottomImg withImage:(UIImage *)topImg;
Maybe simplest way would be rendering the layer of the top UIImageView in a the new CGContextRef like this:
[bottomImg drawInRect:CGRectMake(0, 0, bottomImg.size.width, bottomImg.size.height)];
[productPhotoImageView.layer renderInContext:ctx];
But in this way I loose the rotation effect previosly applied by gestures.
A second way would be trying to apply AffineTransformation to UIImage to reproduce GestureEffects and then draw it in the context like this:
UIImage * scaledTopImg = [topImg imageByScalingProportionallyToSize:productPhotoView.frame.size];
UIImage * rotatedScaledTopImg = [scaledTopImg imageRotatedByDegrees:ANGLE];
[rotatedScaledTopImg drawAtPoint:CGPointMake(productPhotoView.frame.origin.x, productPhotoView.frame.origin.y)];
The problem of this second approach is that I'm not able to exactly get the final rotation degrees (the ANGLE parameter that should be filled in the code above) amount since the user started to interact, this because the RotationGesture is reset to 0 after applying so the next callback is a delta from the current rotation.
For sure the most easy way would be the first one, freezing the two UIImageViews as they are displayed in that very moment but actually I still didn't find anyway to do it.
Ok basically there is another workaround for all this crazy merging stuff, but it's definitively not an elegant solution. For avoid handling any kind of AffineTransformation just capture the ImageScreen and then crop it.
CGImageRef screenImage = UIGetScreenImage();
CGRect fullRect = [[UIScreen mainScreen] applicationFrame];
CGImageRef saveCGImage = CGImageCreateWithImageInRect(screenImage, fullRect);
CGRect cropRect = CGRectMake(x,y,width,height);
CGImageRef saveCGImage = CGImageCreateWithImageInRect(screenImage, cropRect);
Told you it wasnt elegant, but for someone it could be useful.
Great that was helpful and so too much workaroundy ;)
so since i see it's pretty hard to find around some code examples to merge pics after a manipulation here goes mine, hope it can be helpful:
- (UIImage *)mergeImage:(UIImage *)bottomImg withImage:(UIImage *)topImg {
UIImage * scaledTopImg = [topImg imageByScalingProportionallyToSize:productPhotoView.frame.size];
UIGraphicsBeginImageContext(scaledTopImg.size);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, scaledTopImg.size.width * 0.5f, scaledTopImg.size.height * 0.5f);
CGFloat angle = atan2(productPhotoView.transform.b, productPhotoView.transform.a);
CGContextRotateCTM(ctx, angle);
[scaledTopImg drawInRect:CGRectMake(- scaledTopImg.size.width * 0.5f, -(scaledTopImg.size.height * 0.5f), scaledTopImg.size.width, scaledTopImg.size.height)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIGraphicsBeginImageContext(bottomImg.size);
[bottomImg drawInRect:CGRectMake(0, 0, bottomImg.size.width, bottomImg.size.height)];
[newImage drawInRect:CGRectMake(productPhotoView.frame.origin.x, productPhotoView.frame.origin.y, newImage.size.width, newImage.size.height)];
UIImage *newImage2 = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage2;
}
Since I got a background image it was easier first create a context just to apply tranformation to the overlayview, than save it and write on top of the bottom layer.
Take care of the CTM translation before rotating the overlayview or it will rotate around an axis placed at {0,0} while I want to rotate my image around its center.
Regards
I have the same problem.
I only have problem with rotation.
I use gesture recognizers for move, scale and rotation.
At the beginning when I save the image tha scale was right, the position was right but never apply rotation to the saved image.
Now it works
if you want to know the rotation angle I get it with:
CGFloat angle = atan2(overlay.transform.b, overlay.transform.a);
And rotation with:
CGContextRotateCTM(context, angle);
If you have a different approach please let me know.
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
UIWebView on iPad size
- (void)viewDidLoad {
[super viewDidLoad];
UINavigationController *naviController = [[UINavigationController alloc]init];
[self.view addSubview:naviController.view];
}
If I add navigation controller in the view, it appears about 20 pixels below status bar.
I want it appears just below status bar. How do I fix this?
I've experienced this same issue.
This discussion was helpful: UIWebView on iPad size
Tony's answer helped me discover this trick:
naviController.view.frame = self.view.bounds;
Turns out setting the view height fixes this problem. You can do it in the nib (xib) file or progammatically when creating the view setting the view.frame = CGRect(0, 0, 320.0 460.0); or whatever it's supposed to be (in your case it looks like it should be 460.0 since you have the status bar on).
The main point is that if the view size is smaller than the height of the screen, there are no guarantees where your controls will show up.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
CGRect frame = CGRectMake(0, 0, 320.0, 480.0);
viewController.view.frame = frame;
[self.window addSubview:viewController.view];
[self.window makeKeyAndVisible];
return YES;
}
I changed like above. It works. So far so good. If height was 460, there would have been blank line at the bottom. View's absolute coordinate is (0, 20). So, Navigation bar's coordinate is (0, 40). I think that was the problem. I will encounter another problem.
Maybe there is way to change coordinate before displaying navigation view. Thank you.
I'm trying to scroll up my UISCrollView when the keyboard is shown
I use setContentOffset to shift the uiview up.
At the same time I want to decrease the height of my UISCrollView to (view height - keyboard height), so that the entire content view can be scrolled.
I apply both the changes in keyboardWillShow notification
When I actually bring the keyboard up in my app, the contents first get pushed up and then they are pushed down (which gives a flickering effect). I'm trying to smooth out both the transformations in one go..
Is it possible?
Code Below ---
- (void) keyboardWillShow {
CGPoint contentOffset = scrollView.contentOffset;
CGRect scrollViewFrame = scrollView.frame;
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.3];
if (contentOffset.y >= 0 && contentOffset.x >= 0) {
isContentOffset = YES;
contentOffset.y += screenShift;
[scrollView setContentOffset:contentOffset animated: NO];
}
scrollViewFrame.size.height = keyboardOrigin.y - self.view.frame.origin.y - toolbarHeight;
scrollView.frame = scrollViewFrame;
[UIView commitAnimations];
}
There is an option for animation when you setContentOffset for animation. here is the code that i use all the time
- (void)textViewDidBeginEditing:(UITextView *)textView
{
svos = scrollView.contentOffset;
CGRect rect = [textView bounds];
rect = [textView convertRect:rect toView:self.scrollView];
CGPoint point = rect.origin ;
point.x = 0 ;
[self.scrollView setContentOffset:point animated:YES];
doneButton.enabled = YES;
}
- (IBAction)donePressed
{
[scrollView setContentOffset:svos animated:YES];
[textview resignFirstResponder];
doneButton.enabled = NO;
}
It works fine for me.
Are you wrapping these changes in an animation block?
[UIView beginAnimations:#"resizeScroll" context:nil];
// make your changes to set and content offset
[UIView commitAnimations];
I think I have got a solution for this. You can handle the resize of the view in textViewDidBeginEditing method. You can just change the frame size of the scrollView to half by
CGRect tframe = myscrollView.frame;
tframe.size.height/=2;
myscrollView.frame = tframe;
and to initialize or handle the total length of the scrollview you can set the contentSize of the scrollView in the similar fashion as the frame was set in above snippet. for example
CGSize tsize = self.view.frame.size;
//here you can change the height and width of the scrollView
myscrollView.contentSize = tsize;
I hope this should do the trick for you. If it does please communicate.
Figured out the issue...
When the keyboard button was clicked, I was doing a becomeFirstResponder followed by a resignFirstResponder on keyboard view. This caused keyboardWillShow followed by keyboardWillHide and another keyboardWillShow notification, which brought the keyboard up, brought it back down and then up again.
Thanks to everybody who tried to help out.. and sorry the issue was pretty different...
I've made a CALayer with an added CATextLayer and the text comes out blurry. In the docs, they talk about "sub-pixel antialiasing", but that doesn't mean much to me. Anyone have a code snippet that makes a CATextLayer with a bit of text that is clear?
Here's the text from Apple's documentation:
Note: CATextLayer disables sub-pixel antialiasing when rendering text.
Text can only be drawn using sub-pixel antialiasing when it is
composited into an existing opaque background at the same time that
it's rasterized. There is no way to draw subpixel-antialiased text by
itself, whether into an image or a layer, separately in advance of
having the background pixels to weave the text pixels into. Setting
the opacity property of the layer to YES does not change the rendering
mode.
The second sentence implies that one can get good looking text if one composites it into an existing opaque background at the same time that it's rasterized. That's great, but how do I composite it and how do you give it an opaque background and how do you rasterize it?
The code they use in their example of a Kiosk Menu is as such: (It's OS X, not iOS, but I assume it works!)
NSInteger i;
for (i=0;i<[names count];i++) {
CATextLayer *menuItemLayer=[CATextLayer layer];
menuItemLayer.string=[self.names objectAtIndex:i];
menuItemLayer.font=#"Lucida-Grande";
menuItemLayer.fontSize=fontSize;
menuItemLayer.foregroundColor=whiteColor;
[menuItemLayer addConstraint:[CAConstraint
constraintWithAttribute:kCAConstraintMaxY
relativeTo:#"superlayer"
attribute:kCAConstraintMaxY
offset:-(i*height+spacing+initialOffset)]];
[menuItemLayer addConstraint:[CAConstraint
constraintWithAttribute:kCAConstraintMidX
relativeTo:#"superlayer"
attribute:kCAConstraintMidX]];
[self.menuLayer addSublayer:menuItemLayer];
} // end of for loop
Thanks!
EDIT: Adding the code that I actually used that resulted in blurry text. It's from a related question I posted about adding a UILabel rather than a CATextLayer but getting a black box instead. http://stackoverflow.com/questions/3818676/adding-a-uilabels-layer-to-a-calayer-and-it-just-shows-black-box
CATextLayer* upperOperator = [[CATextLayer alloc] init];
CGColorSpaceRef space = CGColorSpaceCreateDeviceRGB();
CGFloat components1[4] = {1.0, 1.0, 1.0, 1.0};
CGColorRef almostWhite = CGColorCreate(space,components1);
CGFloat components2[4] = {0.0, 0.0, 0.0, 1.0};
CGColorRef almostBlack = CGColorCreate(space,components2);
CGColorSpaceRelease(space);
upperOperator.string = [NSString stringWithFormat:#"13"];
upperOperator.bounds = CGRectMake(0, 0, 100, 50);
upperOperator.foregroundColor = almostBlack;
upperOperator.backgroundColor = almostWhite;
upperOperator.position = CGPointMake(50.0, 25.0);
upperOperator.font = #"Helvetica-Bold";
upperOperator.fontSize = 48.0f;
upperOperator.borderColor = [UIColor redColor].CGColor;
upperOperator.borderWidth = 1;
upperOperator.alignmentMode = kCAAlignmentCenter;
[card addSublayer:upperOperator];
[upperOperator release];
CGColorRelease(almostWhite);
CGColorRelease(almostBlack);
EDIT 2: See my answer below for how this got solved. sbg.
Short answer — You need to set the contents scaling:
textLayer.contentsScale = [[UIScreen mainScreen] scale];
A while ago I learned that when you have custom drawing code, you have to check for the retina display and scale your graphics accordingly. UIKit takes care of most of this, including font scaling.
Not so with CATextLayer.
My blurriness came from having a .zPosition that was not zero, that is, I had a transform applied to my parent layer. By setting this to zero, the blurriness went away, and was replaced by serious pixelation.
After searching high and low, I found that you can set .contentsScale for a CATextLayer and you can set it to [[UIScreen mainScreen] scale] to match the screen resolution. (I assume this works for non-retina, but I haven't checked - too tired)
After including this for my CATextLayer the text became crisp. Note - it's not necessary for the parent layer.
And the blurriness? It comes back when you're rotating in 3D, but you don't notice it because the text starts out clear and while it's in motion, you can't tell.
Problem solved!
Swift
Set the text layer to use the same scale as the screen.
textLayer.contentsScale = UIScreen.main.scale
Before:
After:
Before setting shouldRasterize, you should:
set the rasterizationScale of the base layer you are going to rasterize
set the contentsScale property of any CATextLayers and possibly other types of layers(it never hurts to do it)
If you don't do #1, then the retina version of sub layers will look blurry, even for normal CALayers.
- (void)viewDidLoad {
[super viewDidLoad];
CALayer *mainLayer = [[self view] layer];
[mainLayer setRasterizationScale:[[UIScreen mainScreen] scale]];
CATextLayer *messageLayer = [CATextLayer layer];
[messageLayer setForegroundColor:[[UIColor blackColor] CGColor]];
[messageLayer setContentsScale:[[UIScreen mainScreen] scale]];
[messageLayer setFrame:CGRectMake(50, 170, 250, 50)];
[messageLayer setString:(id)#"asdfasd"];
[mainLayer addSublayer:messageLayer];
[mainLayer setShouldRasterize:YES];
}
First off I wanted to point out that you've tagged your question with iOS, but constraint managers are only available on OSX, so I'm not sure how you're getting this to work unless you've been able to link against it in the simulator somehow. On the device, this functionality is not available.
Next, I'll just point out that I create CATextLayers often and never have the blurring problem you're referring to so I know it can be done. In a nutshell this blurring occurs because you are not positioning your layer on the whole pixel. Remember that when you set the position of a layer, you use a float values for the x and y. If those values have numbers after the decimal, the layer will not be positioned on the whole pixel and will therefore give this blurring effect--the degree of which depending upon the actual values. To test this, just create a CATextLayer and explicitly add it to the layer tree ensuring that your position parameter is on a whole pixel. For example:
CATextLayer *textLayer = [CATextLayer layer];
[textLayer setBounds:CGRectMake(0.0f, 0.0f, 200.0f, 30.0f)];
[textLayer setPosition:CGPointMake(200.0f, 100.0f)];
[textLayer setString:#"Hello World!"];
[[self menuLayer] addSublayer:textLayer];
If your text is still blurry, then there is something else wrong. Blurred text on your text layer is an artifact of incorrectly written code and not an intended capability of the layer. When adding your layers to a parent layer, you can just coerce the x and y values to the nearest whole pixel and it should solve your blurring problem.
You should do 2 things, the first was mentioned above:
Extend CATextLayer and set the opaque and contentsScale properties to properly support retina display, then render with anti aliasing enabled for text.
+ (TextActionLayer*) layer
{
TextActionLayer *layer = [[TextActionLayer alloc] init];
layer.opaque = TRUE;
CGFloat scale = [[UIScreen mainScreen] scale];
layer.contentsScale = scale;
return [layer autorelease];
}
// Render after enabling with anti aliasing for text
- (void)drawInContext:(CGContextRef)ctx
{
CGRect bounds = self.bounds;
CGContextSetFillColorWithColor(ctx, self.backgroundColor);
CGContextFillRect(ctx, bounds);
CGContextSetShouldSmoothFonts(ctx, TRUE);
[super drawInContext:ctx];
}
If you came searching here for a similar issue for a CATextLayer in OSX, after much wall head banging, I got the sharp clear text by doing:
text_layer.contentsScale = self.window!.backingScaleFactor
(I also set the views background layer contentsScale to be the same).
This is faster and easier: you just need to set contentsScale
CATextLayer *label = [[CATextLayer alloc] init];
[label setFontSize:15];
[label setContentsScale:[[UIScreen mainScreen] scale]];
[label setFrame:CGRectMake(0, 0, 50, 50)];
[label setString:#"test"];
[label setAlignmentMode:kCAAlignmentCenter];
[label setBackgroundColor:[[UIColor clearColor] CGColor]];
[label setForegroundColor:[[UIColor blackColor] CGColor]];
[self addSublayer:label];