I have a UILabel with right-aligned text that may vary from between three to seven characters in length. I am trying to anchor a button to the left of this text so that when the length of the text increases, the button will stay the same distance from the left of the label.
Is there an anchor setting in Interface Builder, or does it require a code-level solution (e.g. setting the button's x position according to the width of the label)?
You need to do this in code. Interface builder is not build for runtime calculations.
To calculate the width of your text you can use NSString's sizeWithFont: method.
Related
If you take a close look an an iMessage conversation cell, you’ll notice that the preview text is always two lines long. This can’t be a hard coded row height because the rows adjust to dynamic type. How can you always force a label to take up a certain number of lines even if there isn’t enough text to do so?
Set the label's numberOfLines to 2 and end the label's text with a linefeed \n. Set the wrapping to word wrap to prevent the ellipses from appearing.
This guarantees that the label text consists of at least 2 lines worth of material. Thus it can never be less than 2 lines, and since the maximum number of lines is 2, it can never be more than 2 lines. Thus it will always be (wait for it) 2 lines.
One way I think this could be possible is having a UIView as a parent of the UILabel.
Fix the height of the UIView based on device size class. Let's say for example 50 points for Width = Compact and Height = Regular.
Embed UILabel in UIView
Set number of Lines = 0 for UILabel
Now match UILabel leading , trailing ,top edge with the superview and leave the height as it is , also don't set the bottom constraints.
Select the superview i.e the UIView and UILabel together and select Equal Heights.
Open the constraint window and change label height less than or equal to SuperView height.
Short Message
Long Message
Height Constraint of the UILabel with respect to SuperView.
I want to call the action (go to another view) when user tap specific area of image (black dots): . Image fills whole view, content mode is 'Aspect Fit'. The problem is that when I setup it on one screen size (e.g. iPhone 8) on another the 'tap area' is shifted. I've tried to solve this with button and constraints or UITapGestureRecognizer with point conversion using screen resolution (nativeBounds), but nothing helps.
It is possible to use constraints to match the positions of the circles with UIButtons. The trick is to use the multiplier of the constraint to scale the buttons width/height and position to the screen size.
I'll describe how to do it for one button, and then you can repeat it for the others. I assume the image is 657 wide by 918 high. If I have the dimensions reversed, you'll need to substitute the actual values for the ones I have used.
Create a UIView to hold the image and buttons. Give this view an aspect ratio constraint with multiplier 657:918 which is width:height. Add the UIImageView to this view and constrain its 4 edges to the edges of the view with 0 offsets. Give this view constraints to the left and right edges of the main view and give it a vertical constraint to place it on the screen.
Get the width/height of the circle in the image and the horizontal and vertical positions of the right edge and bottom edge. For example, the topmost circle is 106 x 106 and ends at horizontal position 392 and the bottom is at 338.
Set the width of the button equal to the width of the containing view with multiplier 106:657 which is width of circle:width of the image.
Set the height of the button equal to the height of the containing view with multiplier 106:918 which is height of circle:height of the image.
Set the trailing edge of the button equal to the trailing edge of the containing view with multiplier 392:657 which is end of circle:width of image.
Set the bottom edge of the button equal to the bottom edge of the containing view with multiplier 338:918 which is bottom of circle:height of the image.
This will allow the button to stay aligned with the circle on all devices. Repeat steps 2 through 6 for the other circles.
Instead of using an image, you can try creating your own UIView subclass called BlackDotsView.
In the draw(_rect:) method, you can draw the lines. To determine where the lines start and end, you need to do some maths with the view's width and height. You calculate where all the lines end and create UIBezierPaths and then you stroke the paths.
In the initializer of BlackDotsView, you can add the dots as subviews. To make them circular, just set dotView.layer.cornerRadius to half the dot's width. Then, you can add UITapGestureRecognizers to the dot views.
You can follow the delegate pattern by creating a BlackDotsViewDelegate that has a method called dotTapped(index:). When a dot is tapped, you would call the delegate method and pass the index of the dot.
I have an UIView that it should contains UILabels, and these UILabels are not fixed if an UILabel is nil, i don't display it, and if is not i must resize the UILabel to fit text (they can be 2 ligne) and put it under another UILabel, and after i must resize the UIView container for the amount of this UILabels. this the Screen Shot that i want to do programmatically:
UILabels can fit large amounts of text by automatically making the font smaller (see the minimum font size value in the Interface Builder). Instead of labels, I would use UITextViews. They fit large amounts of text by allowing the user to scroll. To make them hidden, use change the hidden selector attribute of the UITextViews. Because the UITextViews will never change in size, you can easily calculate how much to decrease the height of the UIView container by per UITextView. Hope this helps!
I think you have to calculate the height of the labels (more specifically, the addition from the original height) one by one. Of course you should be able to do this systematically by having all the labels in an array.
You can use [NSString sizeWithFont:] methods (there are several with similar names) to calculate the height.
http://developer.apple.com/library/ios/#documentation/UIKit/Reference/NSString_UIKit_Additions/Reference/Reference.html
If you want to keep the same font size then you can calculate the frame size for the label at run time depending upon the length of the text..
See here
You need to used following two properties of label-
lineBreakMode
numberOfLine
when you use both of these properties then you will achieve what you want.
I have this interface with multiple UILabels.
On view loading i populate white labelled values with some data from a db.
The problem is, some of that fields are potentially too long for the interface, so i'd like to compute the total height of one label once the text is word wrapped and reposition the 2 labels below (shifting the Y coordinate) accordingly to the previous label's height.
All of this should go inside a UIScrollView to let the user scroll those labels vertically.
Any chance i can do this easily with some control i still don't know, or do i have to do it manually?
Thanks
You'll need to use the NSString UIKit Additions to compute the height you need to set on your UILabel, and then adjust the other controls appropriately.
Specifically, I think you want to use sizeWithFont:forWidth:lineBreakMode: to get the rect for your UILabel.
Alternatively, you could use a UIWebView and display the information as HTML. I don't know if it's necessarily less work, but you'll get a layout that automatically adjusts to the size of its contents.
I have a UITableViewCell with two subviews, a UILabel on the left, and a random input control on the right. The random input control on the right can vary in size, as can the length of the text, but since I can set the word wrap of the text on the left, I need to be able to adjust the size of the UILabel based on the width of the random input control. To complicate matters, the app needs to work in both portrait and landscape modes, which give the table cells different widths.
This wouldn't be difficult if I could read the width of the table cells and set the widths of its subviews appropriately, but at creation time the width of the cell is 0.
Any ideas?
Nothing easier than that: every UITableViewCell is also a UIView, which has a method designed for just that: layoutSubviews, which is called whenever the view (here: cell) needs a re-layout. This is where you lay out the content.