I have an instance of UITextView. It is actually a box, and when user taps on it, I want to make it bigger. So I implemented CGAffineTransformMakeScale in tap event.
The problem is, the text inside the UITextView gets fuzzy and blurry. I set contentMode = UIViewContentModeRedraw, but didn't affect it.
Any idea? Many thanks in advance.
This is always going to happen. If you scale it like that using the transform it will always get blurry because the whole textview is scaled, including all contents.
The only way to prevent this is not using the transform scale but simply make the textview frame bigger!
Can you try to reset the text after making the font bigger on the tap?
say
NSString *placeholderText = textView.text;
textView.font = // bigger font proportional to scaling
textView.text = placeholderText;
Related
I want to change my UILabel text or UILabel itself's size by using UISlider, I know it's something we don't do it for an normal application. But basically I am trying new and different things to explore Objective -C language and iOS platform.
So far I am able to change colour of a font by UISlider, Which looks really great, So thought of changing it's size too by UISlider. Below I am posting pictures to clarify my thoughts visually!
From ----->
To ------->
While making those images I realised I might have to change size of UILable and Size of font too. Am I right? Is this possible?
textLabel.font = [UIFont boldSystemFontOfSize:slider.value];
CGSize newSize = [textLabel.text sizeWithFont:textLabel.font];
This should make it
an alternative is to set the fram of the label above the complete size above the textField and set textAlignement = center
its quite simple actually
According to slider change value dynamically increase height and width of your label..
There can be many ways you can handle this, one way would be to just change the font size with slider and when you change the font calculate the frame size with sizeWithFont: instance method of NSString.
I have a UITextView on the screen.
This UITextView is covered by a UIView.
When I set the text for this UITextView, if the textView is not visible (UIView is covering it), it doesn't draw the text.
So when I remove the view that is covering my textView there is no text in my textView. If I try scrolling the textview the text will appear suddenly.
any way to force the UITextView to draw the text at all times? (This only happens when I have too much text in it (about 1000 characters))
I tried calling [textView setNeedsDisplay], before and after setting 'text' and it didn't fix the problem
I have the same problem, my UITextView does not draw text until I try scrolling it or its parent. [textView setNeedsDisplay] does not work for me. Finally, I increase textView 1px and the problem's gone.
CGRect frame = textView.frame;
frame.size.height += 1;
textView.frame = frame;
I know this method is ugly but it does work.
Most things in the system will not display when hidden, which would be a waste of resources.
The correct approach is to call setNeedsDisplay: on the UITextView AFTER it has been un-hidden, then it should draw immediatley.
The limit to the number of characters in a UITextView seems to be around relatively low (see the post here).
The poster in the link I posted suggests putting your content into a UIWebView, which can handle a large amount of text.
Same problem. We have a textview that is configured and put into the view while hidden or offscreen. Most likely due to Apple optimizing UITextView so that it doesn't do layout and drawing unless it is onscreen and visible.
Calling setNeedsDisplay doesn't work because of the optimizations. setNeedsDisplay gets called quite often, so imagine a UITextView doing layout and drawing quite often? Thus the solution above is ugly but works: add a pixel to the frame which will trigger the UITextView to re-layout and redraw. We went with this solution.
Since UITextView is a subclass of UIScrollView, I did something like this:
CGPoint offset = self.textView.contentOffset;
offset.y++;
[self.textView setContentOffset:offset];
offset.y--;
[self.textView setContentOffset:offset];
the same as #Tùng Đỗ without changing the frame... still looks ugly.
I have a UIView in which I need to draw text in drawRect:
- (void)drawRect:(CGRect)rect {
...
[#"some text" drawAtPoint:somePoint withFont:someFont];
...
}
Because the text requires special formatting, I cannot just use a UILabel.
It looks fine until I rotate the device. Then the size of my custom UIView changes (in the parent view's layoutSubviews method), and the text becomes stretched in one direction and squished in the other.
When I replace my view with a UILabel, the text always looks great, even when the bounds of the view changes.
How can I get my view to exhibit the same behavior as UILabel?
Some things I have looked into, but have yet to have success with:
Set the view's layer's needsDisplayOnBoundsChange to YES.
Set the view's contentStretch to CGRectZero.
Call setNeedsDisplay in my view's layoutSubviews.
Maybe I'm not doing one of these things right. Has anyone else run into this?
Update: As recommended in James Huddleston's answer, I set the contentMode property of the view to UIViewContentModeRedraw, which got me part of the way there. The text now appears correct at the conclusion of the animation. However, at the start of the animation the text gets squished/stretched to fit the end dimensions and then gets unsquished/unstretched over the course of the animation. This is not the case with UILabel.
Try setting the contentMode property of your view to UIViewContentModeRedraw.
This seems to work OK:
self.contentMode = UIViewContentModeRedraw;
self.contentStretch = CGRectMake(1, 1, 0.5, 0.5);
And then ensure that the bottom-right pixel is the background color. To do that, I put one pixel of padding around the contents of the view. It seems like UILabel doesn't have the one pixel border restriction, so it must be doing something different. But as far as I can tell, this has the same effect.
Use a UIWebView
Sounds a bit overkill but it seems the recommended way to get formatted text that's more complicated than a UILabel can cope with.
There is some source code created by Kevin Ballard called FontLabel. (code.google.com)
The good thing about this, it subclasses UILabel and you can use your own Font ;)
//EDIT: ok ok, as told I will update my answer to recommend subclassing UILabel "to get all the UILabel goodness" ^^
I have a UITextView with scrolling disabled, and I am using the page-curl transition to change the text inside. This is the code I'm using:
myView.text = nextString;
[UIView transitionWithView:myView duration:PAGE_CURL_DURATION options:UIViewAnimationOptionTransitionCurlDown animations:nil completion:nil];
Everything works fine, except if the new text string has more lines than the old one, it will be clipped until the animation is complete. It looks as though the contentSize is changing AFTER the animation. I tried adding myView.contentSize = myView.bounds.size; but that didn't change anything. I also turned off "clip subviews" to no avail.
This is what it looks like immediately after the animation:
a moment later the text is no longer clipped.
Any ideas how to prevent clipping?
The easy way is to do what Bjarne said - use the clipsToBounds property. But watch out - this will make the text expand downwards indefinitely. So you will also need to surround your text field with a container view that DOES clip to bounds to set an upper limit.
If that doesn't do the trick, you will have to do some work to manually expand your text view's bounds and reposition it before animating if the new text is larger.
To get the size of a text, check out UIStringDrawing.h in the UIKit framework. Specifically, I'm thinking of using:
- (CGSize)sizeWithFont:(UIFont *)font forWidth:(CGFloat)width lineBreakMode:(UILineBreakMode)lineBreakMode;
together with UILineBreakModeWordWrap.
another alternative to getting the size may be this function in UILabel:
- (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines;
and passing in the bounds of the largest possible text view.
For extra credit, you may also want to consider animating the change in your view's bounds for a smoother transition.
This is rather odd. The contentSize should not clip contents, but only determine scrolling behavior. This however is the only thing changing from pre- to post-animation. And unchecking Clip Subviews always worked for me.
A few options:
I assume your UITextView.frame is large enough to contain the largest of both texts initially? If you set it just before the animation kicks in, you might be too late. In such cases tricks like [self performSelector(continueWithStuff:) withObject:object afterDelay:0.01] do wonders, because you give the UI the time needed to effectuate your changes before the animation will determine the initial state.
But the easiest fix by far will be to add a bunch of newlines to every text. Since you're not scrolling anyway this should not be a problem.
Another angle may be to embed your UITextView in a UIView which you then animate. Reading the docs, the view argument should be "The container view that contains the views involved in the transition." Ignoring this fact may be giving your surprising results.
The easiest way to fix you problem is to set the UITextView's property "clipsToBounds" to NO. This will make your text view available to draw outside of its bounds
I have a custom UIImageView class which I use to handle multi-touch events on the UIImageView. When the user touch begins, I want to increase the UIImageView's frame but keep the UIImage size fixed.
I tried changing the UIImageView's frame and then calling the drawInRect: method of UIImage to keep the UIImage's size fixed. But this is not working.
The contentMode for the UIImageView is set as ScaleAspectFit and as soon as I increase the frame size of the UIImageView, the UIImage size also increases (and is not affected by the drawInRect:)
Can someone please tell me how I can achieve this?
Thanks.
Adding more details
What I am trying to do is this
Place a UIImageView on the screen with the size same as the size of the image
When the user selects the image, anywhere he touches, the image edits as if the user is doing multi-touch with the image
If I increase the size of the imageview to detect touches any where, the image size also increases... Hope that makes things clearer!
Thanks
There may well be other ways to do it, but I think the UIImageView is doing what it's intended to do here.
What do you want the area of the view not covered by the image to look like? Be transparent? Have a solid colour?
Why do you want to do this? Is it to capture touch events from a wider area than that under the image itself?
If you have a good reason for needing to do this I would create a new view, probably just a plain UIView (with background set to transparent colour), and add the UIImageView to that. Make the plain view the one you resize.
I haven't specifically tried this, but I think it would work:
imageView.contentMode = UIViewContentModeCenter;