How can I get the height of my custom control?
The idea is I will use it to dynamically set the height of some buttons inside the custom control. I've set the Placeholder height to 44 in the Xcode size inspector.
Working off Apple's Start Developing iOS Apps (Swift) tutorial, I am attempting to access frame.size.height and it gives a value of 1000 while the tutorial seems to suggest it should be 44.
class RatingControl: UIView {
...
override public var intrinsicContentSize: CGSize {
let buttonSize = Int(frame.size.height)
print(buttonSize) // prints 1000
let width = (buttonSize * starCount) + (spacing * (starCount - 1))
return CGSize(width: width, height: buttonSize)
}
...
You should never access frame inside intrinsicContentSize. intrinsicContentSize should return the size that perfectly fits the contents of the view, regardless of its current frame.
In your case, I think you can just use 44 for your buttonSize.
The placeholder intrinsic size is just that, placeholder, so that IB interpreter is has some value to work with and can layout the rest of the scene. But in your intrinsicContentSize getter, you implement the real size, which will be used in runtime by the AutoLayout engine. Since you return 1000 as the intrinsic content height, that's what you will see in runtime.
Related
In the XCode storyboard, I have set up my ViewController as a bunch of stackviews and everything is relative -- view dimensions are expressed as fractions of other view dimensions... lots of constraints, etc.
This is to make sure it looks decent on all IOS devices (phones and Ipads, anyway).
It does look acceptable in different aspect ratios, but I've noticed that the font size of my UILabels and TextViews are NOT changing -- not getting LARGER along with their containing views.
So, for example, if I switch from an iPhone to an iPad preview, a UILabel size may increase drastically and yet the text that it contains stays the same... so it's tiny text in a big box.
SO... the question is:
Is there a way to express font/text sizes as relative to the view that contains the text?
Something like this:
text.height = 0.7 * container.height
text.width = maintain aspect ratio with height
Thanks.
The same problem i had when i was designing an application for both iPhone and iPad and i tried this solution which is working fine but took a little efforts to manage. You need to create a custom label class which will inherits from UILabel class. There in your awakeFromNib function you can check the device and you can multiply whatever the font size with a ratio you feel ok for iPhone and iPad. You can also add checking for different iPhone sizes. If you wish to use different ratios for different label, make a IBDesignable property named dynamicRatio in your custom class and take that value to increase font. You can play around this. The effort is assigning the class to all your labels and setting properties which i use to do parallel during designing.
Below are the set of code which am using.
import UIKit
class MyLabel: UILabel {
#IBInspectable var autoFont: Bool = false
#IBInspectable var fontSize: CGFloat = 0
override open func awakeFromNib() {
super.awakeFromNib()
let baseHeight: CGFloat = (((UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiom.pad)) ?1024.0:568.0)
if autoFont == true {
if (isDevice() == DEVICES.iPhoneX) {
let size: CGFloat = 667.0 * (fontSize / baseHeight)
self.font = UIFont(name: self.font!.fontName, size: size)
} else {
let size: CGFloat = UIScreen.main.bounds.size.height * (fontSize / baseHeight)
self.font = UIFont(name: self.font!.fontName, size: size)
}
}
}
}
Hope this idea helps.
Increase text font size of UILabels or UITextFields as you can, then set MinimumFontScale or MinimumFontSize attribute for them in "Attributes Inspector" tab, now font size increases as the UITextFields or UILabels size increases.
UILabel
UITextField
Background
I am making a vertical label to use with traditional Mongolian script. Before I was just rotating a UILabel but there were some performance issues and other complications with this. Now I am working on making a label from scratch. However, I need the vertical label to tell auto layout when its height adjusts (based on string length).
What I have read
I read the Intrinsic Content Size and Views with Intrinsic Content Size documentation. These were more about how to use it, though, and not how to define it in a custom view.
Searching for "ios intrinsic content size for a custom view" only gives me
Proper usage of intrinsicContentSize and sizeThatFits: on UIView Subclass with autolayout
in Stack Overflow. This particular question didn't even need intrinsic content size because their view was just an assembly of standard views.
What I am trying
What I am trying is my answer below. I am adding this Q&A pair so that it won't take other people as long to find the answer as it took me with the search keywords that I used.
Setting the intrinsic content size of a custom view lets auto layout know how big that view would like to be. In order to set it, you need to override intrinsicContentSize.
override var intrinsicContentSize: CGSize {
return CGSize(width: x, height: y)
}
Then call
invalidateIntrinsicContentSize()
Whenever your custom view's intrinsic content size changes and the frame should be updated.
Notes
Swift 3 update: Easier Auto Layout: Coding Constraints in iOS 9
Just because you have the intrinsic content size set up in your custom view doesn't mean it will work as you expect. Read the documentation for how to use it, paying special attention to Content-Hugging and Compression-Resistance.
Thanks also to this Q&A for putting me on the right track: How can I add padding to the intrinsic content size of UILabel?
Thanks also to this article and the documentation for help with invalidateIntrinsicContentSize().
Example of a "view with intrinsic height" ...
#IBDesignable class HView: UIView {
#IBInspectable var height: CGFloat = 100.0
override var intrinsicContentSize: CGSize {
return CGSize(width: 99, height: height)
// if using in, say, a vertical stack view, the width is ignored
}
override func prepareForInterfaceBuilder() {
invalidateIntrinsicContentSize()
}
}
which you can set as an inspectable
Since it has an intrinsic height, it can (for example) be immediately inserted in a stack view in code:
stack?.insertArrangedSubview(HView(), at: 3)
In contrast, if it was a normal view with no intrinsic height, you'd have to add a height anchor or it would crash:
let v:UIView = HView()
v.heightAnchor.constraint(equalToConstant: 100).isActive = true
stack?.insertArrangedSubview(v, at: 3)
Note that in ...
the important special case of a stack view:
you set only ONE anchor (for vertical stack view, the height; for horizontal the width)
so, setting the intrinsic height works perfectly, since:
the intrinsic height indeed means that the height anchor specifically will be set automatically if needed.
Remembering that in all normal cases of a subview, many other anchors are needed.
I am looking to layout multiple components in a stack view. The layout is working perfectly until I add a custom control, which is removing all elements below it in the stack. I'm not sure what could be causing this (perhaps it's from constraints?), any ideas would be appreciated!
Storyboard (the custom control is "Rating Control", in between the Name Text Field and the Photo Image View):
Simulator without custom control:
Simulator with custom control:
This was caused by the following function in my custom control:
override var intrinsicContentSize : CGSize {
let buttonSize = Int(frame.size.height)
let width = (buttonSize + spacing) * stars
return CGSize(width: width, height: buttonSize)
}
Background
I am making a vertical label to use with traditional Mongolian script. Before I was just rotating a UILabel but there were some performance issues and other complications with this. Now I am working on making a label from scratch. However, I need the vertical label to tell auto layout when its height adjusts (based on string length).
What I have read
I read the Intrinsic Content Size and Views with Intrinsic Content Size documentation. These were more about how to use it, though, and not how to define it in a custom view.
Searching for "ios intrinsic content size for a custom view" only gives me
Proper usage of intrinsicContentSize and sizeThatFits: on UIView Subclass with autolayout
in Stack Overflow. This particular question didn't even need intrinsic content size because their view was just an assembly of standard views.
What I am trying
What I am trying is my answer below. I am adding this Q&A pair so that it won't take other people as long to find the answer as it took me with the search keywords that I used.
Setting the intrinsic content size of a custom view lets auto layout know how big that view would like to be. In order to set it, you need to override intrinsicContentSize.
override var intrinsicContentSize: CGSize {
return CGSize(width: x, height: y)
}
Then call
invalidateIntrinsicContentSize()
Whenever your custom view's intrinsic content size changes and the frame should be updated.
Notes
Swift 3 update: Easier Auto Layout: Coding Constraints in iOS 9
Just because you have the intrinsic content size set up in your custom view doesn't mean it will work as you expect. Read the documentation for how to use it, paying special attention to Content-Hugging and Compression-Resistance.
Thanks also to this Q&A for putting me on the right track: How can I add padding to the intrinsic content size of UILabel?
Thanks also to this article and the documentation for help with invalidateIntrinsicContentSize().
Example of a "view with intrinsic height" ...
#IBDesignable class HView: UIView {
#IBInspectable var height: CGFloat = 100.0
override var intrinsicContentSize: CGSize {
return CGSize(width: 99, height: height)
// if using in, say, a vertical stack view, the width is ignored
}
override func prepareForInterfaceBuilder() {
invalidateIntrinsicContentSize()
}
}
which you can set as an inspectable
Since it has an intrinsic height, it can (for example) be immediately inserted in a stack view in code:
stack?.insertArrangedSubview(HView(), at: 3)
In contrast, if it was a normal view with no intrinsic height, you'd have to add a height anchor or it would crash:
let v:UIView = HView()
v.heightAnchor.constraint(equalToConstant: 100).isActive = true
stack?.insertArrangedSubview(v, at: 3)
Note that in ...
the important special case of a stack view:
you set only ONE anchor (for vertical stack view, the height; for horizontal the width)
so, setting the intrinsic height works perfectly, since:
the intrinsic height indeed means that the height anchor specifically will be set automatically if needed.
Remembering that in all normal cases of a subview, many other anchors are needed.
I'm new to iPhone developing. I have a screen with image, title and content:
Image has dynamic size and also all text can have any length. What I want to achievie is to fit the image exactly in screen and make all labels to be only as long as they should be.
Afterk about 5 hours of work I have:
Working labels length, achieved by setting Lines=0 and Preferred Width=content width
Not working image, which lefts blank spaces
I have read a lot, I understand Content Hugging Priority and Content Compression Resistance Priority. I know differences in UIViewContentMode. I know that I can manually set UIImage.frame=CGRectMake(...). Nothing works. My image is more wider than higher (lets assume that width/height = 3). If I have UIViewContentMode=Aspect Fit then I will have blank space above and below the image. If set to Aspect fill then image is too high and also cropped. Changing frame in code doesn't change anything in view. What I want is to have image with size that was made using Aspect fit, but without blank space.
Finally I dit it. First of all, everyone writes that UIImageView.Frame should be modified to shrink the image, but be aware, that if your view is UITableViewCell then you should do that in layoutSubviews method (remember to invoke super.layoutSubviews() at the begging).
Secondly, make in IB a height constraint for your UIImageView for temporary value (for example 100). You will change that constraint in layoutSubviews method.
And finally: fitting image is NOT about its ratio. Set UIViewContentMode=Aspect Fit. Then the case with blank top and bottom areas occurs only when the initial image is wider than screen. Calculating the proper height should also take place in layoutSubviews.
Example implementation:
override func layoutSubviews() {
super.layoutSubviews()
var imageWidth = (imageViewObject.image?.size.width)!
var imageHeight = (imageViewObject.image?.size.height)!
var frameWidth = UIScreen.mainScreen().bounds.width
var properHeight: CGFloat
if imageWidth > frameWidth {
var ratio = frameWidth / imageWidth
properHeight = imageHeight * ratio
}
else {
properHeight = imageHeight
}
imageHeightConstraint.constant = properHeight
imageViewObject.frame = CGRectMake(0, 0, frameWidth, properHeight)
}