I have a book app. User choose a book and UITextView show it. Every book has a caption. I need to add 55px offset to the top of UITextView. I want that every caption has 55px offset. But I don't know how to do this?
1)My text height is 22px. I can add 2 or 3 empty line of text, but it doesn't suit me because I need 55px.
2)I can add contentOffset.y = 55. But I have a problem. contentOffset will be zero if an user scroll to top.
Have you tried using contentInset in UIScrollView?
textView.contentInset = UIEdgeInsetsMake(55.0, 0, 0, 0);
Related
I have a TextField in my storyboard with a height of 100 .
When I'm clicking the TextField the cursor is placed in center :
I would like to set the cursor position in the top left corner.
I tried :
let startPosition: UITextPosition = textField.beginningOfDocument
But it seems that the position is already at the beginning and when the height is extended the cursor stay in center.
How can it be done ?
Seems like you want a multiline UITextField. In that case you might want to take a look at UITextView, which should allow for what you want (docs)
I am tying to modify the height of a UITextView dynamically (up to a max height) while the user enters text. I am experiencing a very strange behavior when there are an even number of lines in the text view.
I am using autolayout and the text view has a height constraint. I respond to calls to the text view's delegate (textViewDidChange(_:)), where I calculate and adjust the height constraint based on the contentSize.
Here is the code:
func textViewDidChange(_ textView: UITextView) {
let newHeight = textView.contentSize.height
let newConstraintConst = max(MinTextViewHeight, min(MaxTextViewHeight, newHeight))
self.textViewHeightConstraint.constant = newConstraintConst
}
This works well, it resizes the frame up to MaxTextViewHeight and then the text view can scroll. However, when there are an even number of lines in the text view, the text view adds a kind of offset to the bottom of its NSTextContainer, causing the top line to be cut off:
However, when there are odd lines the NSTextContainer is no longer offset:
At first I thought it was somehow being controlled by the text view's textContainerInset but that is only used to pad the space inside the NSTextContainer, as setting it to .zero removes the space inside but does not affect the offset (and incidentally makes it even worse, as the top line almost completely disappears):
I have looked through the UITextView class reference and I don't see any property that would let me manipulate or even get the value of this offset.
As a workaround I am increasing the text container's top inset and removing the bottom inset:
textView.textContainerInset = UIEdgeInsetsMake(10, 0, 0, 0)
This works so far, but I arrived at a value of 10 by trial-and-error, and so far I've only tested it on a single device.
I am not interested in more hacky workarounds that require fragile, fixed values; I am trying to understand how this offset is being set and a proper way to fix it. I'm hoping that someone can provide some insight, thanks!
Just a speculation, but I think the problem is that the text view assumes that the height of itself does not change while calling textViewDidChange, so it scrolls when it thinks it has to, regardless of you changing its frame.
Not sure if you think my solution is too hacky, but this will stop it from scrolling when you don't want it. I simply pin the content offset to the top as long as the wanted content size is smaller than your max size.
Just add this:
func scrollViewDidScroll(scrollView: UIScrollView) {
if textView.contentSize.height <= MaxTextViewHeight && textView.contentOffset.y > 0.0 {
textView.contentOffset.y = 0.0;
}
}
I use this open source library called ReadMoreTextView to display a bunch of text. The library enables me to toggle between displaying an excerpt of the text and showing the full length content (the button is a normal UIButton added by me, not the library).
This works as expected.
My problem arises when I have to display a smaller amount of text. If I add some content that doesn't exceed the height of the UITextView, I want to hide the more/less toggle button. So I thought of taking the full content height and if only it's larger than the text view's height, show the toggle button.
In the above example, I aded a long couple of paragraphs that exceeds the text view bounds. The text view's height comes up as 128. But the content height also returns 128. There's a library specific method called boundingRectForCharacterRange which is supposed to return the content height also returns a wrong value (100).
print("TEXTVIEW HEIGHT: \(textView.bounds.height)") // 128
print("CONTENT HEIGHT: \(textView.contentSize.height)") // 128
let rect = textView.layoutManager.boundingRectForCharacterRange(range: NSRange(location: 0, length: textView.text.count), inTextContainer: textView.textContainer)
print("TEXT HEIGHT: \(rect.height)") // 100
I opened an issue at the library's Github page but the owner asked to ask it here.
Why does the content height return a wrong value?
Here is the project I'm using in the above example by the way.
You can simply use following method to get the content size:
let contentSize = self.textView.sizeThatFits(self.textView.bounds.size)
Then update the textview frame accordingly:
self.textView.frame = CGRect(width: contentSize.width, height: contentSize.height)
So I have a label that I've made in Xcode's storyboard which I want to later edit in my code. I want it to simulate something like a vertical bar so I am editing its height by doing:
answerE.frame.size.height = -200
The problem comes from the negative number, I want the label to "grow" up so the height has to be negative from its original position... I have the line in code in a simple action on button press, but each time the line is executed the label moves "up" and eventually after 3-4 clicks is out of the screen.
I just want to edit its height, what is the correct way and what am I doing wrong?
My exact line in code is:
label.frame.size.height = -CGFloat(Double(x)/Double(y) * (200))
If you have added the label in storyboard, why not you use constraints to get the result.
Add leading, trailing , bottom and fixed height constraint and connect IBOutlet to height constraint. Change the constant value of height constraint at the event which you want to perform.
If I'm right, you want the label to gain height, keeping the same bottom edge, but the top edge moving up.
In order to do this, you want to change the frame.origin.y as you change the frame.size.height at the same amount, as its placement (and so top edge) is determined by its origin. So maybe make it zero height, place it where you want it in storyboard, and then when you want it to 'grow' by x:
label.frame.size.height = label.frame.height + x
label.frame.origin.y = label.frame.origin.y - x
I have a UITextField that shrinks and expands when user input text. If the textfield's width reach the screen width, I want it to be right-aligned so user can see the last input characters. In other circumstance, I want it to be left-aligned.
Because the textfield's maximum width is not exactly the same with screen, I need to find a way to check if it has characters out of visible area.
Is there anyway to achieve this?
You could try checking the width of the string that is in the field and comparing it to the width of the field itself. It would look something like this -
CGSize textSize = [self.field.text sizeWithAttributes:#{NSFontAttributeName:self.field.font}];
// If the text is larger than the field
if (textSize.width > self.field.bounds.size.width) {
// There is text that is not visible in the field.
}
This is fairly rough, but should get you close.