I'm making a card game for mac and I'm using a CABasicAnimation to making the card flip around. It's almost working, but it could be a bit better.
As it works now, the card flips inwards (to the left) - Screenshot 1. When the card has moved "flipped" all the way to the left, I change the image of the NSView and flip the card outwards again - Screenshot 2.
Screenshot 1 (flipping in):
Screenshot 2 (flipping out):
Code for flipping in:
- (void)flipAnimationInwards{
// Animate shadow
NSShadow *dropShadow = [[NSShadow alloc] init];
[dropShadow setShadowOffset:NSMakeSize(0, 1)];
[dropShadow setShadowBlurRadius:15];
[dropShadow setShadowColor:[NSColor colorWithCalibratedWhite:0.0 alpha:0.5]];
[[self animator] setShadow:dropShadow];
// Create CAAnimation
CABasicAnimation* rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.y"];
rotationAnimation.fromValue = [NSNumber numberWithFloat: 0.0];
rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI/2];
rotationAnimation.duration = 3.1;
rotationAnimation.repeatCount = 1.0;
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
rotationAnimation.fillMode = kCAFillModeForwards;
rotationAnimation.removedOnCompletion = NO;
[rotationAnimation setValue:#"flipAnimationInwards" forKey:#"flip"];
rotationAnimation.delegate = self;
// Get the layer
CALayer* lr = [self layer];
// Add perspective
CATransform3D mt = CATransform3DIdentity;
mt.m34 = 1.0/-1000;
lr.transform = mt;
// Set z position so the layer will be on top
lr.zPosition = 999;
// Keep cards tilted when flipping
if(self.tiltCard)
self.frameCenterRotation = self.frameCenterRotation;
// Do rotation
[lr addAnimation:rotationAnimation forKey:#"flip"];
}
The code for flipping out:
- (void)flipAnimationOutwards{
// Set correct image
if (self.faceUp){
[self setImage:self.faceImage];
}else{
[self setImage:[NSImage imageNamed:#"Card_Background"]];
}
// Animate shadow
NSShadow *dropShadow = [[NSShadow alloc] init];
[dropShadow setShadowOffset:NSMakeSize(0, 1)];
[dropShadow setShadowBlurRadius:0];
[dropShadow setShadowColor:[NSColor colorWithCalibratedWhite:0.0 alpha:0.0]];
[[self animator] setShadow:dropShadow];
// Create CAAnimation
CABasicAnimation* rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:#"transform.rotation.y"];
rotationAnimation.fromValue = [NSNumber numberWithFloat: M_PI/2];
rotationAnimation.toValue = [NSNumber numberWithFloat: 0.0];
rotationAnimation.duration = 3.1;
rotationAnimation.repeatCount = 1.0;
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
rotationAnimation.fillMode = kCAFillModeForwards;
rotationAnimation.removedOnCompletion = YES;
[rotationAnimation setValue:#"flipAnimationOutwards" forKey:#"flip"];
rotationAnimation.delegate = self;
// Get the layer
CALayer* lr = [self layer];
// Add perspective
CATransform3D mt = CATransform3DIdentity;
mt.m34 = 1.0/1000;
lr.transform = mt;
// Set z position so the layer will be on top
lr.zPosition = 999;
// Keep cards tilted when flipping
if(self.tiltCard)
self.frameCenterRotation = self.frameCenterRotation;
// Commit animation
[lr addAnimation:rotationAnimation forKey:#"flip"];
}
The problem:
The flipping out part looks fine. The right side of the card is taller/stretched than the left side, like it's supposed to be.
Flipping in is not perfect though. Here the right side is smaller/stretched, when it should be the left side that is taller/stretched.
How do I make the left side taller/stretched on flipping in, instead of making the right side smaller/stretched?
You ask:
How do I make the left side taller/stretched on flipping in, instead of making the right side smaller/stretched?
You also say that flipping out works fine but flipping in is wrong.
The difference between the two is in the sign of the perspective:
Flipping out code:
CATransform3D mt = CATransform3DIdentity;
mt.m34 = 1.0/1000; // note the lack of a minus sign
lr.transform = mt;
Flipping in code:
CATransform3D mt = CATransform3DIdentity;
mt.m34 = 1.0/-1000; // note the minus sign
lr.transform = mt;
If you want the two to look the same then they should most likely have the same perspective.
In my experience you usually want the negative perspective value (as you have done in the flipping in example). This has to do with the fact that the value represents the position of the "eye" / "camera" / "observer" or whatever you call it.
If you imagine a 3D scene where the position of the eye is (ex, ey, ez) then the perspective part of the transform is:
Assuming that you are looking at right at the world (i.e. not looking at it from the side) the position would be (0, 0, ez) which is the reason why we usually only set m34 (3rd column, 4th row) when adding perspective to a transform.
You can also see that this is how it is used in the Core Animation Programming Guide:
Listing 5-8 Adding a perspective transform to a parent layer
CATransform3D perspective = CATransform3DIdentity;
perspective.m34 = -1.0/eyePosition;
If the rotation looks wrong to you should probably rotate in the other direction (for example changing a rotation from 0 to π into a rotation from 0 to -π or the other way around: changing a rotation from π to 0 into a rotation from -π to 0.
What about adding some scale while you flip the card?
You could even exaggerate it and it would look as if someone lifted the card in order to flip it.
Some code to scale a view inspired by this answer:
CABasicAnimation *scaleAnimation = [CABasicAnimation animationWithKeyPath:#"transform.scale"];
scaleAnimation.fromValue = [NSNumber numberWithFloat:1.0];
scaleAnimation.toValue = [NSNumber numberWithFloat:1.3];
I understand, this is late answer, but I wrote easy usage solution.
FlipTransition
import Cocoa
public final class FlipTransition: NSObject {
private var srcView, dstView: NSView?
private var duration: TimeInterval = 0.3
public func flip(
from srcView: NSView,
to dstView: NSView,
duration: TimeInterval = 0.3
) {
self.duration = duration
self.srcView = srcView
self.dstView = dstView
srcView.isHidden = false
dstView.isHidden = true
// Get super layer
guard let superLayer = srcView.superview?.layer else {
return
}
// Setup super layer 3d perspective
var transform3D = CATransform3DIdentity
transform3D.m34 = -1 / 1000
let translation = CATransform3DMakeTranslation(
superLayer.bounds.midX,
superLayer.bounds.midY,
.zero
)
superLayer.sublayerTransform = CATransform3DConcat(
transform3D,
translation
)
// Set layer anchor & position to center
[srcView, dstView]
.compactMap(\.layer)
.forEach { layer in
layer.anchorPoint = .init(x: 0.5, y: 0.5)
}
// Start src view animation
animate(
srcView,
from: CATransform3DIdentity,
to: CATransform3DMakeRotation(CGFloat.pi / -2, 0, 1, 0)
) { f in
self.startSecondStep()
}
}
private func startSecondStep() {
guard let srcView = srcView, let dstView = dstView else {
return
}
srcView.isHidden = true
dstView.isHidden = false
animate(
dstView,
from: CATransform3DMakeRotation(CGFloat.pi / 2, 0, 1, 0),
to: CATransform3DIdentity
) { f in
self.finish()
}
}
private func finish() {
guard let srcView = srcView, let dstView = dstView else {
return
}
srcView.layer?.removeAllAnimations()
dstView.layer?.removeAllAnimations()
[srcView, dstView]
.compactMap(\.layer)
.forEach { layer in
layer.anchorPoint = .zero
}
srcView.superview?.layer?.sublayerTransform = CATransform3DIdentity
}
// MARK: - Animation Utility
private class AnimationDelegate: NSObject, CAAnimationDelegate {
private let completion: (Bool) -> Void
init(completion: #escaping (Bool) -> Void) {
self.completion = completion
}
func animationDidStart(_ anim: CAAnimation) { }
func animationDidStop(_ anim: CAAnimation, finished flag: Bool) {
completion(flag)
}
}
private func animate(
_ view: NSView,
from: CATransform3D,
to: CATransform3D,
completion: #escaping (Bool) -> Void
) {
let dstRotation = CABasicAnimation(keyPath: "transform")
dstRotation.fromValue = from
dstRotation.toValue = to
dstRotation.duration = duration / 2
dstRotation.fillMode = .forwards
dstRotation.isRemovedOnCompletion = false
dstRotation.delegate = AnimationDelegate(completion: completion)
view.layer?.add(dstRotation, forKey: "flip")
}
}
Usage
FlipTransition().flip(from: srcView, to: dstView)
View Structure
holderView {
srcView,
dstView
}
dstView initially should be hidden (dstView.isHidden = true). holderView, srcView and dstView should have equal sizes.
I want to move an image to the right when a user imports it using uiimagepicker but when I set content mode = .right this occurs: The image enlarges for some reason and it looks like it moves to the left
Is there any way to keep the aspect ratio of the uiimageview and the aspect ratio of the imported image, and while also moving it to the right inside the image view.
This is how I want it to be
Here is one approach: custom view, using a sublayer with the content set to the image...
add a CALayer as a sublayer
calculate the aspect-scaled rectangle for the image inside the view's bounds
set the image layer's frame to that scaled rect
then set the layer's origin based on the desired alignment
A simple example:
class AspectAlignImageView: UIView {
enum AspectAlign {
case top, left, right, bottom, center
}
// this is an array so we can set two options
// if, for example, we don't know if the image will be
// taller or narrower
// for example:
// [.top, .right] will put a
// wide image aligned top
// narrow image aligned right
public var alignment: [AspectAlign] = [.center]
public var image: UIImage?
private let imgLayer: CALayer = CALayer()
override func layoutSubviews() {
super.layoutSubviews()
// make sure we have an image
if let img = image {
// only add the sublayer once
if imgLayer.superlayer == nil {
layer.addSublayer(imgLayer)
}
imgLayer.contentsGravity = .resize
imgLayer.contents = img.cgImage
// calculate the aspect-scaled rect inside our bounds
var scaledImageRect = CGRect.zero
let aspectWidth:CGFloat = bounds.width / img.size.width
let aspectHeight:CGFloat = bounds.height / img.size.height
let aspectRatio:CGFloat = min(aspectWidth, aspectHeight)
scaledImageRect.size.width = img.size.width * aspectRatio
scaledImageRect.size.height = img.size.height * aspectRatio
// set image layer frame to aspect-scaled rect
imgLayer.frame = scaledImageRect
// align as specified
if alignment.contains(.top) {
imgLayer.frame.origin.y = 0
}
if alignment.contains(.left) {
imgLayer.frame.origin.x = 0
}
if alignment.contains(.bottom) {
imgLayer.frame.origin.y = bounds.maxY - scaledImageRect.height
}
if alignment.contains(.right) {
imgLayer.frame.origin.x = bounds.maxX - scaledImageRect.width
}
}
}
}
class TestAlignViewController: UIViewController {
let testView = AspectAlignImageView()
override func viewDidLoad() {
super.viewDidLoad()
testView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(testView)
NSLayoutConstraint.activate([
// constrain test view 240x240 square
testView.widthAnchor.constraint(equalToConstant: 240.0),
testView.heightAnchor.constraint(equalTo: testView.widthAnchor),
// centered in view
testView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
testView.centerYAnchor.constraint(equalTo: view.centerYAnchor),
])
if let img = UIImage(named: "bottle") {
testView.image = img
}
testView.alignment = [.right]
// so we can see the actual view frame
testView.backgroundColor = .green
}
}
Using this image:
in a 240x240 view (view background set green so we can see its frame), we get this result:
Set your UIImage Content mode to aspect fill or aspect fit. Then use auto layout.
I've seen a bunch of examples for changing the size of a UILabel.
Here's what I'd like to do:
Change the font size so that the text will be as large as possible within the new height.
Any clues?
I had the very same problem and, thanks to this thread and Joel's algorithm, I could fix it. :-)
Below is my code in Swift. I'm in iOS 8 + Autolayout.
Problem:
User inputs expenses:
When users tap the 'check' button, a menu appears from bottom, pushing everything to the top of the screen (shrinking stuff, including the label):
After the fix:
Which is exactly what the designer had in mind... :)
I subclassed UILabel and overrode layoutSubviews. Then each time the UILabel gets its size changed, the font size is recalculated:
//
// LabelWithAdaptiveTextHeight.swift
// 123
//
// Created by https://github.com/backslash-f on 12/19/14.
//
/*
Designed with single-line UILabels in mind, this subclass 'resizes' the label's text (it changes the label's font size)
everytime its size (frame) is changed. This 'fits' the text to the new height, avoiding undesired text cropping.
Kudos to this Stack Overflow thread: bit.ly/setFontSizeToFillUILabelHeight
*/
import Foundation
import UIKit
class LabelWithAdaptiveTextHeight: UILabel {
override func layoutSubviews() {
super.layoutSubviews()
font = fontToFitHeight()
}
// Returns an UIFont that fits the new label's height.
private func fontToFitHeight() -> UIFont {
var minFontSize: CGFloat = DISPLAY_FONT_MINIMUM // CGFloat 18
var maxFontSize: CGFloat = DISPLAY_FONT_BIG // CGFloat 67
var fontSizeAverage: CGFloat = 0
var textAndLabelHeightDiff: CGFloat = 0
while (minFontSize <= maxFontSize) {
fontSizeAverage = minFontSize + (maxFontSize - minFontSize) / 2
// Abort if text happens to be nil
guard text?.characters.count > 0 else {
break
}
if let labelText: NSString = text {
let labelHeight = frame.size.height
let testStringHeight = labelText.sizeWithAttributes(
[NSFontAttributeName: font.fontWithSize(fontSizeAverage)]
).height
textAndLabelHeightDiff = labelHeight - testStringHeight
if (fontSizeAverage == minFontSize || fontSizeAverage == maxFontSize) {
if (textAndLabelHeightDiff < 0) {
return font.fontWithSize(fontSizeAverage - 1)
}
return font.fontWithSize(fontSizeAverage)
}
if (textAndLabelHeightDiff < 0) {
maxFontSize = fontSizeAverage - 1
} else if (textAndLabelHeightDiff > 0) {
minFontSize = fontSizeAverage + 1
} else {
return font.fontWithSize(fontSizeAverage)
}
}
}
return font.fontWithSize(fontSizeAverage)
}
}
Refer to this Pastebin for execution logs (println() of each
iteration).
There is a simpler solution. Just add below lines and magically, the label adjusts its font size to fit the height of the label too:
SWIFT 3:
label.minimumScaleFactor = 0.1 //or whatever suits your need
label.adjustsFontSizeToFitWidth = true
label.lineBreakMode = .byClipping
label.numberOfLines = 0
Here's how I did it, since DGund's answer didn't work for me, it fit the width, but I wanted it to fit the height.
+ (UIFont *)findAdaptiveFontWithName:(NSString *)fontName forUILabelSize:(CGSize)labelSize withMinimumSize:(NSInteger)minSize
{
UIFont *tempFont = nil;
NSString *testString = #"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
NSInteger tempMin = minSize;
NSInteger tempMax = 256;
NSInteger mid = 0;
NSInteger difference = 0;
while (tempMin <= tempMax) {
mid = tempMin + (tempMax - tempMin) / 2;
tempFont = [UIFont fontWithName:fontName size:mid];
difference = labelSize.height - [testString sizeWithFont:tempFont].height;
if (mid == tempMin || mid == tempMax) {
if (difference < 0) {
return [UIFont fontWithName:fontName size:(mid - 1)];
}
return [UIFont fontWithName:fontName size:mid];
}
if (difference < 0) {
tempMax = mid - 1;
} else if (difference > 0) {
tempMin = mid + 1;
} else {
return [UIFont fontWithName:fontName size:mid];
}
}
return [UIFont fontWithName:fontName size:mid];
}
This will take a font name, a size (it doesn't have to be a UILabel, theoretically, but I always used it with a UILabel), and a minimum size (you could also use a max size, just replace the 256 with the max size parameter). This will essentially test every font size between the minimum and maximum font sizes and return the one that is at or just underneath the target height.
Usage is self explanatory, but looks like this:
self.myLabel.font = [self findAdaptiveFontWithName:#"HelveticaNeue-UltraLight" forUILabelSize:self.myLabel.frame.size withMinimumSize:30];
You can also make this a class method category on UIFont (which is what I did).
EDIT: On suggestion, I removed the for loop and spent a little time making it more efficient with a Binary Search routine. I did several checks to make absolutely sure that the font will end up fitting within the label. In initial testing it appears to work.
Edit: Check out Joel Fischer's great answer to programmatically obtain the correct size!
You can set the font to automatically fill the size of a label, and optionally not go below a minimum font size. Just set adjustsFontSizeToFitWidth to YES. Check out the UILabel Class Reference if you need more information.
Although the boolean is called "adjustsFontSizeToFitWidth," it really means the largest size for the height of the label, that will stay on one line of the label (or however many lines you specify).
to adapt the text according to the height of my label I have adapt Joel method to swift
func optimisedfindAdaptiveFontWithName(fontName:String, label:UILabel!, minSize:CGFloat,maxSize:CGFloat) -> UIFont!
{
var tempFont:UIFont
var tempHeight:CGFloat
var tempMax:CGFloat = maxSize
var tempMin:CGFloat = minSize
while (ceil(tempMin) != ceil(tempMax)){
let testedSize = (tempMax + tempMin) / 2
tempFont = UIFont(name:fontName, size:testedSize)
let attributedString = NSAttributedString(string: label.text!, attributes: [NSFontAttributeName : tempFont])
let textFrame = attributedString.boundingRectWithSize(CGSize(width: label.bounds.size.width, height: CGFloat.max), options: NSStringDrawingOptions.UsesLineFragmentOrigin , context: nil)
let difference = label.frame.height - textFrame.height
println("\(tempMin)-\(tempMax) - tested : \(testedSize) --> difference : \(difference)")
if(difference > 0){
tempMin = testedSize
}else{
tempMax = testedSize
}
}
//returning the size -1 (to have enought space right and left)
return UIFont(name: fontName, size: tempMin - 1)
}
and I use it this way :
myLabel.font = optimisedfindAdaptiveFontWithName("Helvetica", label: myLabel, minSize: 10, maxSize: 38)
println("\(myLabel.font)")
Good news,
Performing a binary search is completely unnecessary!
You need only iterate (a couple of times) using a ratio search.
guess = guess * ( desiredHeight / guessHeight )
Here's a full total IBDesignable solution.
Note: when working with designers or typographers, you will need to set the tracking / stretching for fonts. (It's absurd Apple do not include this.) StyledLabel also includes tracking / stretching.
StyledLabel.swift
It sets tracking, stretching, AND it sets the point size to match the view frame height on all devices.
In storyboard: just make the frame of the UILabel, the height you want the text to be - end of story!
// the call fontToFitHeight FINDS THE POINT SIZE TO "FILL TO HEIGHT".
// Just use autolayout to make the frame THE ACTUAL HEIGHT
// you want the type ON ANY DEVICE
// ADDITIONALLY you can set:
// the tracking (that's the overall amount of space between all letters)
// and streching (actually squeeze or stretch the letters horizontally)
// Note: tracking and stretching IS SHOWN IN STORYBOARD LIVE
// WTT crazyrems http://stackoverflow.com/a/37300130/294884
import UIKit
#IBDesignable
class StyledLabel: UILabel
{
#IBInspectable var tracking:CGFloat = 0.8
// values between about 0.7 to 1.3. one means normal.
#IBInspectable var stretching:CGFloat = -0.1
// values between about -.5 to .5. zero means normal.
override func awakeFromNib()
{
tweak()
}
override func prepareForInterfaceBuilder()
{
tweak()
}
override func layoutSubviews()
{
super.layoutSubviews()
font = fontToFitHeight()
}
private func fontToFitHeight() -> UIFont
{
/* Apple have failed to include a basic thing needed in handling text: fitting the text to the height. Here's the simplest and fastest way to do that:
guess = guess * ( desiredHeight / guessHeight )
That's really all there is to it. The rest of the code in this routine is safeguards. Further, the routine iterates a couple of times, which is harmless, to take care of any theoretical bizarre nonlinear sizing issues with strange typefaces. */
guard text?.characters.count > 0 else { return font }
let desiredHeight:CGFloat = frame.size.height
guard desiredHeight>1 else { return font }
var guess:CGFloat
var guessHeight:CGFloat
print("searching for... ", desiredHeight)
guess = font.pointSize
if (guess>1&&guess<1000) { guess = 50 }
guessHeight = sizeIf(guess)
if (guessHeight==desiredHeight)
{
print("fluke, exact match within float math limits, up front")
return font.fontWithSize(guess)
}
var iterations:Int = 4
/* It is incredibly unlikely you would need more than four iterations, "two" would rarely be needed. You could imagine some very strange glyph handling where the relationship is non-linear (or something weird): That is the only theoretical reason you'd ever need more than one or two iterations. Note that when you watch the output of the iterations, you'll sometimes/often see same or identical values for the result: this is correct and expected in a float iteration. */
while(iterations>0)
{
guess = guess * ( desiredHeight / guessHeight )
guessHeight = sizeIf(guess)
if (guessHeight==desiredHeight)
{
print("unbelievable fluke, exact match within float math limits while iterating")
return font.fontWithSize(guess)
}
iterations -= 1
}
print("done. Shame Apple doesn't do this for us!")
return font.fontWithSize(guess)
}
private func sizeIf(pointSizeToTry:CGFloat)->(CGFloat)
{
let s:CGFloat = text!.sizeWithAttributes(
[NSFontAttributeName: font.fontWithSize(pointSizeToTry)] )
.height
print("guessing .. ", pointSizeToTry, " .. " , s)
return s
}
private func tweak()
{
let ats = NSMutableAttributedString(string: self.text!)
let rg = NSRange(location: 0, length: self.text!.characters.count)
ats.addAttribute(
NSKernAttributeName, value:CGFloat(tracking), range:rg )
ats.addAttribute(
NSExpansionAttributeName, value:CGFloat(stretching), range:rg )
self.attributedText = ats
}
}
One line called in viewWillAppear does the trick:
testLabel.font = testLabel.font.fontWithSize(testLabel.frame.height * 2/3)
In storyboard, I set all of my label heights relative to the overall height of the view, and this allows the font size to scale dynamically with them.
Notice that the font size is actually 2/3 the height of the label. If the font you are using has tails that dip below the line (as in y, g, q, p, or j), you will want to make the font size a ratio of the label height so that those tails aren't chopped off. 2/3 works well for Helvetica Neue, but try other ratios depending on the font you're using. For fonts without tails, numbers, or all-caps text, a 1:1 ratio may suffice.
Based on #Conaaando's great answer, I've updated it to a version with IBDesignable parameters included, which makes it possible to edit it throughout the Interface builder:
And the code:
//
// TIFFitToHeightLabel.swift
//
import Foundation
import UIKit
#IBDesignable class TIFFitToHeightLabel: UILabel {
#IBInspectable var minFontSize:CGFloat = 12 {
didSet {
font = fontToFitHeight()
}
}
#IBInspectable var maxFontSize:CGFloat = 30 {
didSet {
font = fontToFitHeight()
}
}
override func layoutSubviews() {
super.layoutSubviews()
font = fontToFitHeight()
}
// Returns an UIFont that fits the new label's height.
private func fontToFitHeight() -> UIFont {
var minFontSize: CGFloat = self.minFontSize
var maxFontSize: CGFloat = self.maxFontSize
var fontSizeAverage: CGFloat = 0
var textAndLabelHeightDiff: CGFloat = 0
while (minFontSize <= maxFontSize) {
fontSizeAverage = minFontSize + (maxFontSize - minFontSize) / 2
if let labelText: NSString = text {
let labelHeight = frame.size.height
let testStringHeight = labelText.sizeWithAttributes(
[NSFontAttributeName: font.fontWithSize(fontSizeAverage)]
).height
textAndLabelHeightDiff = labelHeight - testStringHeight
if (fontSizeAverage == minFontSize || fontSizeAverage == maxFontSize) {
if (textAndLabelHeightDiff < 0) {
return font.fontWithSize(fontSizeAverage - 1)
}
return font.fontWithSize(fontSizeAverage)
}
if (textAndLabelHeightDiff < 0) {
maxFontSize = fontSizeAverage - 1
} else if (textAndLabelHeightDiff > 0) {
minFontSize = fontSizeAverage + 1
} else {
return font.fontWithSize(fontSizeAverage)
}
}
}
return font.fontWithSize(fontSizeAverage)
}
}
This borrows heavily from Joel Fischer's answer. His answer takes into account label height only -- I've made some changes to take into account label width as well (given an input string), which I wanted:
typedef enum
{
kDimensionHeight,
kDimensionWidth,
} DimensionType;
#implementation UIFont (AdaptiveFont)
+ (UIFont *)_adaptiveFontWithName:(NSString *)fontName minSize:(NSInteger)minSize labelDimension:(CGFloat)labelDimension testString:(NSString *)testString dimension:(DimensionType)dimension
{
UIFont *tempFont = nil;
NSInteger tempMin = minSize;
NSInteger tempMax = 256;
NSInteger mid = 0;
NSInteger difference = 0;
CGFloat testStringDimension = 0.0;
while (tempMin <= tempMax) {
#autoreleasepool {
mid = tempMin + (tempMax - tempMin) / 2;
tempFont = [UIFont fontWithName:fontName size:mid];
// determine dimension to test
if (dimension == kDimensionHeight) {
testStringDimension = [testString sizeWithFont:tempFont].height;
} else {
testStringDimension = [testString sizeWithFont:tempFont].width;
}
difference = labelDimension - testStringDimension;
if (mid == tempMin || mid == tempMax) {
if (difference < 0) {
return [UIFont fontWithName:fontName size:(mid - 1)];
}
return [UIFont fontWithName:fontName size:mid];
}
if (difference < 0) {
tempMax = mid - 1;
} else if (difference > 0) {
tempMin = mid + 1;
} else {
return [UIFont fontWithName:fontName size:mid];
}
}
}
return [UIFont fontWithName:fontName size:mid];
}
+ (UIFont *)adaptiveFontWithName:(NSString *)fontName minSize:(NSInteger)minSize labelSize:(CGSize)labelSize string:(NSString *)string
{
UIFont *adaptiveFont = nil;
NSString *testString = nil;
// get font, given a max height
testString = #"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
UIFont *fontConstrainingHeight = [UIFont _adaptiveFontWithName:fontName minSize:minSize labelDimension:labelSize.height testString:testString dimension:kDimensionHeight];
CGSize boundsConstrainingHeight = [string sizeWithFont:fontConstrainingHeight];
CGSize boundsConstrainingWidth = CGSizeZero;
// if WIDTH is fine (while constraining HEIGHT), return that font
if (boundsConstrainingHeight.width <= labelSize.width) {
adaptiveFont = fontConstrainingHeight;
} else {
// get font, given a max width
// i.e., fontConstrainingWidth
testString = string;
adaptiveFont = [UIFont _adaptiveFontWithName:fontName minSize:minSize labelDimension:labelSize.width testString:testString dimension:kDimensionWidth];
// TEST comparison
boundsConstrainingWidth = [string sizeWithFont:adaptiveFont];
}
return adaptiveFont;
}
Combining answers by #DGund and #Kashif, here's a simple IB solution:
This fits text by height as low as you specify in Autoshrink parameter.
There is a much simpler way to do it. Just calculate point per pixel of the screen and multiply it to the height of your label, and you'll get the desiered font size.
Here are custom methods for this. Choose whatever you want.
TYPE 1. Hardoded single-line version:
- (CGFloat) fontSizeFromHeight:(CGFloat)height
{
return ceilf(height * (10.0 / [#"Tg" sizeWithAttributes:#{NSFontAttributeName:[UIFont systemFontOfSize:10.0]}].height));
}
TYPE 2. Cleaner version:
- (CGFloat)fontSizeFromHeight:(CGFloat)height
{
static CGFloat const testFontSize = 12.0;
static NSString * const testText = #"TestString";
UIFont *testFont = [UIFont systemFontOfSize:testFontSize];
CGFloat pixelHeight = [testText sizeWithAttributes:#{NSFontAttributeName:testFont}].height;
CGFloat pointPerPixel = testFontSize / pixelHeight;
CGFloat desiredFontSize = ceilf(height * pointPerPixel);
return desiredFontSize;
}
Usage examples:
myLabel.font = [UIFont systemFontOfSize:[self fontSizeFromHeight:myLabel.frame.size.height]];
myLabel.font = [myLabel.font fontWithSize:[self fontSizeFromHeight:myLabel.frame.size.height]];
Expanding on #Joe Blow's answer, here is an Objective-C category UILabel+FitToHeight which allows you to easily import and toggle a adjustsFontSizeToFitHeight much like you can already adjustsFontSizeToFitWidth.
UILabel+FitToHeight.h
#import <UIKit/UIKit.h>
#interface UILabel (FitToHeight)
#property (nonatomic, assign) BOOL adjustsFontSizeToFitHeight;
#end
UILabel+FitToHeight.m
#import "UILabel+FitToHeight.h"
#import <objc/runtime.h>
#implementation UILabel (FitToHeight)
-(BOOL)adjustsFontSizeToFitHeight {
NSNumber *number = objc_getAssociatedObject(self, #selector(adjustsFontSizeToFitHeight));
return [number boolValue];
}
-(void)setAdjustsFontSizeToFitHeight:(BOOL)adjustsFontSizeToFitHeight {
NSNumber *number = [NSNumber numberWithBool:adjustsFontSizeToFitHeight];
objc_setAssociatedObject(self, #selector(adjustsFontSizeToFitHeight), number, OBJC_ASSOCIATION_ASSIGN);
}
-(UIFont *)fontToFitHeight {
float desiredHeight = [self frame].size.height;
float guess;
float guessHeight;
guess = [[self font] pointSize];
guessHeight = [self sizeIf:guess];
if(guessHeight == desiredHeight) {
return [[self font] fontWithSize:guess];
}
int attempts = 4;
while(attempts > 0) {
guess = guess * (desiredHeight / guessHeight);
guessHeight = [self sizeIf:guess];
if(guessHeight == desiredHeight) {
return [[self font] fontWithSize:guess];
}
attempts--;
}
return [[self font] fontWithSize:guess];
}
-(float)sizeIf:(float)sizeToTry {
CGSize size = [[self text] sizeWithAttributes:#{ NSFontAttributeName : [[self font] fontWithSize:sizeToTry] }];
return size.height;
}
-(void)layoutSubviews {
[super layoutSubviews];
if([self adjustsFontSizeToFitHeight]) {
[self setFont:[self fontToFitHeight]];
}
}
Import as you would any other category...
#import "UILabel+FitToHeight.h"
and use as follows...
UILabel *titleLabel = [[UILabel alloc] init];
[titleLabel setAdjustsFontSizeToFitHeight:YES];
[titleLabel setAdjustsFontSizeToFitWidth:YES];
It's worth noting that this still works with [titleLabel setAdjustsFontSizeToFitWidth:YES]; so the using the two in conjunction is entirely possible.
SWIFT variation:
I managed to do it with an extension. Works fine, min font size is 5.
I subtract 10 from the height, so I leave a "margin" also, but you can delete it or modify it.
extension UILabel {
//Finds and sets a font size that matches the height of the frame.
//Use in case the font size is epic huge and you need to resize it.
func resizeToFitHeight(){
var currentfontSize = font.pointSize
let minFontsize = CGFloat(5)
let constrainedSize = CGSizeMake(frame.width, CGFloat.max)
while (currentfontSize >= minFontsize){
let newFont = font.fontWithSize(currentfontSize)
let attributedText: NSAttributedString = NSAttributedString(string: text!, attributes: [NSFontAttributeName: newFont])
let rect: CGRect = attributedText.boundingRectWithSize(constrainedSize, options: .UsesLineFragmentOrigin, context: nil)
let size: CGSize = rect.size
if (size.height < frame.height - 10) {
font = newFont
break;
}
currentfontSize--
}
//In case the text is too long, we still show something... ;)
if (currentfontSize == minFontsize){
font = font.fontWithSize(currentfontSize)
}
}
}
Building off of Joel Fisher's epic answer but written as a Swift 4 extension:
extension String {
/// Attempts to return the font specified by name of the appropriate point
/// size for this string to fit within a particular container size and
/// constrained to a lower and upper bound point size.
/// - parameter name: of the font.
/// - parameter containerSize: that this string should fit inside.
/// - parameter lowerBound: minimum allowable point size of this font.
/// - parameter upperBound: maximum allowable point size of this font.
/// - returns: the font specified by name of the appropriate point
/// size for this string to fit within a particular container size and
/// constrained to a lower and upper bound point size; `nil` if no such
/// font exists.
public func font(named name: String,
toFit containerSize: CGSize,
noSmallerThan lowerBound: CGFloat = 1.0,
noLargerThan upperBound: CGFloat = 256.0) -> UIFont? {
let lowerBound = lowerBound > upperBound ? upperBound : lowerBound
let mid = lowerBound + (upperBound - lowerBound) / 2
guard let tempFont = UIFont(name: name, size: mid) else { return nil }
let difference = containerSize.height -
self.size(withAttributes:
[NSAttributedStringKey.font : tempFont]).height
if mid == lowerBound || mid == upperBound {
return UIFont(name: name, size: difference < 0 ? mid - 1 : mid)
}
return difference < 0 ? font(named: name,
toFit: containerSize,
noSmallerThan: mid,
noLargerThan: mid - 1) :
(difference > 0 ? font(named: name,
toFit: containerSize,
noSmallerThan: mid,
noLargerThan: mid - 1) :
UIFont(name: name, size: mid))
}
/// Returns the system font of the appropriate point size for this string
/// to fit within a particular container size and constrained to a lower
/// and upper bound point size.
/// - parameter containerSize: that this string should fit inside.
/// - parameter lowerBound: minimum allowable point size of this font.
/// - parameter upperBound: maximum allowable point size of this font.
/// - returns: the system font of the appropriate point size for this string
/// to fit within a particular container size and constrained to a lower
/// and upper bound point size.
public func systemFont(toFit containerSize: CGSize,
noSmallerThan lowerBound: CGFloat = 1.0,
noLargerThan upperBound: CGFloat = 256.0) -> UIFont {
let lowerBound = lowerBound > upperBound ? upperBound : lowerBound
let mid = lowerBound + (upperBound - lowerBound) / 2
let tempFont = UIFont.systemFont(ofSize: mid)
let difference = containerSize.height -
self.size(withAttributes:
[NSAttributedStringKey.font : tempFont]).height
if mid == lowerBound || mid == upperBound {
return UIFont.systemFont(ofSize: difference < 0 ? mid - 1 : mid)
}
return difference < 0 ? systemFont(toFit: containerSize,
noSmallerThan: mid,
noLargerThan: mid - 1) :
(difference > 0 ? systemFont(toFit: containerSize,
noSmallerThan: mid,
noLargerThan: mid - 1) :
UIFont.systemFont(ofSize: mid))
}
}
Usage:
let font = "Test string".font(named: "Courier New",
toFit: CGSize(width: 150.0, height: 30.0),
noSmallerThan: 12.0,
noLargerThan: 20.0)
let sysfont = "Test string".systemFont(toFit: CGSize(width: 150.0, height: 30.0),
noSmallerThan: 12.0,
noLargerThan: 20.0)
For UILabels that resize proportionally for larger/smaller devices:
Most effective solution for me has been to set the font's point-size to some ratio of the label's height +/- an adjustment factor. Assuming use of auto-layout constraints, position it's y vertical-center aligned to the bottom of the superview, multiplied by a ratio. Similarly in IB, constrain label's width to a proportion of screen's width.
Optionally, you may lock in the label's height/width ratio with an aspect constraint, however this may cause clipping if you don't get the font's point-size calculation right. The only reason to lock aspect ratio is if other controls/views' positions are relative to this label. However I highly recommend placing such controls/views relative to the superview's height/width so that they are not dependent on this label.
I understand this isn't exactly an encapsulated solution, but it has consistently caused me the least amount of grief. The only other solution that came close made use of while loops, however in my case I couldn't deal with the delays they imposed for upon every layout/refresh system call.
My apologies, if I have missed something here in all the text.
I followed #Crazyrems suggestions for autoshrinking the label's font. This does scale the font based on width as others have observed.
Then I just set 'Lines' to 0 in the UILabel's font section of Xcode. In code, that should be numberOfLines. That's all.
Credit goes to #Mikrasya, who hinted on this solution in one of the comments above.
Tested on Xcode 7.3 and iOS 9.3.2.
Forgive me if I am wrong but everything mentioned here is unnecessary. Set your font again just after the change with a new fontSize of yourLabel.height
You can also check for a conditional comparison between these values (yourLabel.height and fontSize) to prevent unnecessary updates.
All you need to do is:
[yourLabel setFont:[UIFont fontWithName:#"*your fontname*" size:yourLabel.frame.size.height]];
I made a macro to do this for you
///Scales FontSize up (or down) until the text fits within the height of the label, will not auto-update, must be called any time text is updated. Label Frame must be set prior to calling
#define scaleFontSizeToFillHeight(__label) {\
__label.font = [UIFont fontWithName:__label.font.fontName size:__label.frame.size.height*2.0f];\
UIFont *__currentFont = __label.font;\
CGFloat __originalFontSize = __currentFont.pointSize;\
CGSize __currentSize = [__label.text sizeWithAttributes:#{NSFontAttributeName : __currentFont}];\
while (__currentSize.height > __label.frame.size.height && __currentFont.pointSize > (__originalFontSize * __label.minimumScaleFactor)) {\
__currentFont = [__currentFont fontWithSize:__currentFont.pointSize - 1];\
__currentSize = [__label.text sizeWithAttributes:#{NSFontAttributeName : __currentFont}];\
}\
__label.font = __currentFont;\
}
The accepted answer has a bug in it. The variable distance must be a float, or it can return a font size that is too big. Also, the use of "- (CGSize)sizeWithFont:(UIFont *)font;" is deprecated. Here's the code with these 2 issues fixed.
+ (UIFont *)findAdaptiveFontWithName:(NSString *)fontName forUILabelSize:(float)maxHeight withMaxFontSize:(int)maxFontSize
{
UIFont *tempFont = nil;
NSString *testString = #"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
NSInteger tempMin = 0;
NSInteger tempMax = maxFontSize;
NSInteger mid = 0;
float difference = 0;
while (tempMin <= tempMax) {
mid = tempMin + (tempMax - tempMin) / 2;
tempFont = [UIFont fontWithName:fontName size:mid];
UILabel* dummyLabel = [[UILabel alloc] initWithFrame:CGRectZero];
dummyLabel.text = testString;
dummyLabel.font = tempFont;
[dummyLabel sizeToFit];
difference = maxHeight - dummyLabel.bounds.size.height;
if (mid == tempMin || mid == tempMax) {
if (difference < 0) {
return [UIFont fontWithName:fontName size:(mid - 1)];
}
return [UIFont fontWithName:fontName size:mid];
}
if (difference < 0) {
tempMax = mid - 1;
} else if (difference > 0) {
tempMin = mid + 1;
} else {
return [UIFont fontWithName:fontName size:mid];
}
}
return [UIFont fontWithName:fontName size:mid];
}
This seemed to work for me, I've subclassed UILabel and in the layoutSubviews i've checked for the actual height and adjusted the font size accordingly.
import UIKit
class HeightAdjustableLabel: UILabel {
override func layoutSubviews() {
super.layoutSubviews()
if frame.height < font.pointSize + 2 {
font = font.withSize(frame.height - 2)
}
}
}
Yeah, go to interface builder, (your .xib file) and go to the third tab from the right in the attributes inspector and you may set the size of the font there!
How do I enable zooming in a UIScrollView?
Answer is here:
A scroll view also handles zooming and panning of content. As the user makes a pinch-in or pinch-out gesture, the scroll view adjusts the offset and the scale of the content. When the gesture ends, the object managing the content view should update subviews of the content as necessary. (Note that the gesture can end and a finger could still be down.) While the gesture is in progress, the scroll view does not send any tracking calls to the subview.
The UIScrollView class can have a delegate that must adopt the UIScrollViewDelegate protocol. For zooming and panning to work, the delegate must implement both viewForZoomingInScrollView: and scrollViewDidEndZooming:withView:atScale:; in addition, the maximum (maximumZoomScale) and minimum (minimumZoomScale) zoom scale must be different.
So:
You need a delegate that implements UIScrollViewDelegate and is set to delegate on your UIScrollView instance
On your delegate you have to implement one method: viewForZoomingInScrollView: (which must return the content view you're interested in zooming). You can also implement scrollViewDidEndZooming:withView:atScale: optionally.
On your UIScrollView instance, you have to set the minimumZoomScale and the maximumZoomScale to be different (they are 1.0 by default).
Note: The interesting thing about this is what if you want to break zooming. Is it enough to return nil in the viewForZooming... method? It does break zooming, but some of the gestures will be messed up (for two fingers). Therefore, to break zooming you should set the min and max zoom scale to 1.0.
Have a read through this Ray Wenderlich tutorial:
http://www.raywenderlich.com/76436/use-uiscrollview-scroll-zoom-content-swift
If you follow through the section 'Scrolling and Zooming a Larger Image' it will get a image up and enable you to pinch and zoom.
In case the link gets altered, here's the main info:
Put this code in your view controller (this sets the main functionality):
override func viewDidLoad() {
super.viewDidLoad()
// 1
let image = UIImage(named: "photo1.png")!
imageView = UIImageView(image: image)
imageView.frame = CGRect(origin: CGPoint(x: 0, y: 0), size:image.size)
scrollView.addSubview(imageView)
// 2
scrollView.contentSize = image.size
// 3
var doubleTapRecognizer = UITapGestureRecognizer(target: self, action: "scrollViewDoubleTapped:")
doubleTapRecognizer.numberOfTapsRequired = 2
doubleTapRecognizer.numberOfTouchesRequired = 1
scrollView.addGestureRecognizer(doubleTapRecognizer)
// 4
let scrollViewFrame = scrollView.frame
let scaleWidth = scrollViewFrame.size.width / scrollView.contentSize.width
let scaleHeight = scrollViewFrame.size.height / scrollView.contentSize.height
let minScale = min(scaleWidth, scaleHeight);
scrollView.minimumZoomScale = minScale;
// 5
scrollView.maximumZoomScale = 1.0
scrollView.zoomScale = minScale;
// 6
centerScrollViewContents()
}
Add this to the class:
func centerScrollViewContents() {
let boundsSize = scrollView.bounds.size
var contentsFrame = imageView.frame
if contentsFrame.size.width < boundsSize.width {
contentsFrame.origin.x = (boundsSize.width - contentsFrame.size.width) / 2.0
} else {
contentsFrame.origin.x = 0.0
}
if contentsFrame.size.height < boundsSize.height {
contentsFrame.origin.y = (boundsSize.height - contentsFrame.size.height) / 2.0
} else {
contentsFrame.origin.y = 0.0
}
imageView.frame = contentsFrame
}
And then this if you want the double tap gesture to be recognised:
func scrollViewDoubleTapped(recognizer: UITapGestureRecognizer) {
// 1
let pointInView = recognizer.locationInView(imageView)
// 2
var newZoomScale = scrollView.zoomScale * 1.5
newZoomScale = min(newZoomScale, scrollView.maximumZoomScale)
// 3
let scrollViewSize = scrollView.bounds.size
let w = scrollViewSize.width / newZoomScale
let h = scrollViewSize.height / newZoomScale
let x = pointInView.x - (w / 2.0)
let y = pointInView.y - (h / 2.0)
let rectToZoomTo = CGRectMake(x, y, w, h);
// 4
scrollView.zoomToRect(rectToZoomTo, animated: true)
}
If you want more detail read the tutorial, but that pretty much covers it.
Make sure you set your viewController as the scrollViews delegate and implement:
func viewForZooming(in scrollView: UIScrollView) -> UIView? {
return imageView
}
I don't think this is working for iOS 5.0 and Xcode 4.3+
Im looking for the same here, I found this its for images but it may help you.
http://www.youtube.com/watch?v=Ptm4St6ySEI
I'm creating a custom UISlider to test out some interface ideas. Mostly based around making the thumb image larger.
I found out how to do that, like so:
UIImage *thumb = [UIImage imageNamed:#"newThumbImage_64px.png"];
[self.slider setThumbImage:thumb forState:UIControlStateNormal];
[self.slider setThumbImage:thumb forState:UIControlStateHighlighted];
[thumb release];
To calculate a related value I need to know where the center point of the thumb image falls when it's being manipulated. And the point should be in it's superview's coordinates.
Looking at the UISlider docs, I didn't see any property that tracked this.
Is there some easy way to calculate this or can it be derived from some existing value(s)?
This will return the correct X position of center of thumb image of UISlider in view coordinates:
- (float)xPositionFromSliderValue:(UISlider *)aSlider {
float sliderRange = aSlider.frame.size.width - aSlider.currentThumbImage.size.width;
float sliderOrigin = aSlider.frame.origin.x + (aSlider.currentThumbImage.size.width / 2.0);
float sliderValueToPixels = (((aSlider.value - aSlider.minimumValue)/(aSlider.maximumValue - aSlider.minimumValue)) * sliderRange) + sliderOrigin;
return sliderValueToPixels;
}
Put it in your view controller and use it like this: (assumes property named slider)
float x = [self xPositionFromSliderValue:self.slider];
I tried this after reading the above suggestion -
yourLabel = [[UILabel alloc]initWithFrame:....];
//Call this method on Slider value change event
-(void)sliderValueChanged{
CGRect trackRect = [self.slider trackRectForBounds:self.slider.bounds];
CGRect thumbRect = [self.slider thumbRectForBounds:self.slider.bounds
trackRect:trackRect
value:self.slider.value];
yourLabel.center = CGPointMake(thumbRect.origin.x + self.slider.frame.origin.x, self.slider.frame.origin.y - 20);
}
For Swift version
func sliderValueChanged() -> Void {
let trackRect = self.slider.trackRect(forBounds: self.slider.bounds)
let thumbRect = self.slider.thumbRect(forBounds: self.slider.bounds, trackRect: trackRect, value: self.slider.value)
yourLabel.center = CGPoint(x: thumbRect.origin.x + self.slider.frame.origin.x + 30, y: self.slider.frame.origin.y - 60)
}
I could get most accurate value by using this snippet.
Swift 3
extension UISlider {
var thumbCenterX: CGFloat {
let trackRect = self.trackRect(forBounds: frame)
let thumbRect = self.thumbRect(forBounds: bounds, trackRect: trackRect, value: value)
return thumbRect.midX
}
}
I would like to know why none of you provide the simplest answer which consist in reading the manual. You can compute all these values accurately and also MAKING SURE THEY STAY THAT WAY, by simply using the methods:
- (CGRect)trackRectForBounds:(CGRect)bounds
- (CGRect)thumbRectForBounds:(CGRect)bounds trackRect:(CGRect)rect value:(float)value
which you can easily find in the developer documentation.
If thumb image changes and you want to change how it's positioned, you subclass and override these methods. The first one gives you the rectangle in which the thumb can move the second one the position of the thumb itself.
It's better to use -[UIView convertRect:fromView:] method instead. It's cleaner and easier without any complicated calculations:
- (IBAction)scrub:(UISlider *)sender
{
CGRect _thumbRect = [sender thumbRectForBounds:sender.bounds
trackRect:[sender trackRectForBounds:sender.bounds]
value:sender.value];
CGRect thumbRect = [self.view convertRect:_thumbRect fromView:sender];
// Use the rect to display a popover (pre iOS 8 code)
[self.popover dismissPopoverAnimated:NO];
self.popover = [[UIPopoverController alloc] initWithContentViewController:[UIViewController new]];
[self.popover presentPopoverFromRect:thumbRect inView:self.view
permittedArrowDirections:UIPopoverArrowDirectionDown|UIPopoverArrowDirectionUp animated:YES];
}
I approached it by first mapping the UISlider's value interval in percents and then taking the same percent of the slider's size minus the percent of the thumb's size, a value to which I added half of the thumb's size to obtain its center.
- (float)mapValueInIntervalInPercents: (float)value min: (float)minimum max: (float)maximum
{
return (100 / (maximum - minimum)) * value -
(100 * minimum)/(maximum - minimum);
}
- (float)xPositionFromSliderValue:(UISlider *)aSlider
{
float percent = [self mapValueInIntervalInPercents: aSlider.value
min: aSlider.minimumValue
max: aSlider.maximumValue] / 100.0;
return percent * aSlider.frame.size.width -
percent * aSlider.currentThumbImage.size.width +
aSlider.currentThumbImage.size.width / 2;
}
Swift 3.0
Please refer if you like.
import UIKit
extension UISlider {
var trackBounds: CGRect {
return trackRect(forBounds: bounds)
}
var trackFrame: CGRect {
guard let superView = superview else { return CGRect.zero }
return self.convert(trackBounds, to: superView)
}
var thumbBounds: CGRect {
return thumbRect(forBounds: frame, trackRect: trackBounds, value: value)
}
var thumbFrame: CGRect {
return thumbRect(forBounds: bounds, trackRect: trackFrame, value: value)
}
}
AFter a little playing with IB and a 1px wide thumb image, the position of the thumb is exactly where you'd expect it:
UIImage *thumb = [UIImage imageNamed:#"newThumbImage_64px.png"];
CGRect sliderFrame = self.slider.frame;
CGFloat x = sliderFrame.origin.x + slideFrame.size.width * slider.value + thumb.size.width / 2;
CGFloat y = sliderFrame.origin.y + sliderFrame.size.height / 2;
return CGPointMake(x, y);
Here is a Swift 2.2 solution, I created an extension for it. I have only tried this with the default image.
import UIKit
extension UISlider {
var thumbImageCenterX: CGFloat {
let trackRect = trackRectForBounds(bounds)
let thumbRect = thumbRectForBounds(bounds, trackRect: trackRect, value: value)
return thumbRect.origin.x + thumbRect.width / 2 - frame.size.width / 2
}
}
Above solution is useful when UISlider is horizontal. In a recent project,we need to use UISlider with angle. So I need to get both x and y position. Using below to calculate the x,y axis:
- (CGPoint)xyPositionFromSliderValue:(UISlider *)aSlider WithAngle:(double)aangle{
//aangle means the dextrorotation angle compare to horizontal.
float xOrigin = 0.0;
float yOrigin = 0.0;
float xValueToaXis=0.0;
float yValueToaXis=0.0;
float sliderRange = slider_width-aSlider.currentThumbImage.size.width;
xOrigin = aSlider.frame.origin.x+slider_width*fabs(cos(aangle/180.0*M_PI));
yOrigin = aSlider.frame.origin.y;
xValueToaXis = xOrigin + ((((((aSlider.value-aSlider.minimumValue)/(aSlider.maximumValue-aSlider.minimumValue)) * sliderRange))+(aSlider.currentThumbImage.size.width / 2.0))*cos(aangle/180.0*M_PI)) ;
yValueToaXis = yOrigin + ((((((aSlider.value-aSlider.minimumValue)/(aSlider.maximumValue-aSlider.minimumValue)) * sliderRange))+(aSlider.currentThumbImage.size.width / 2.0))*sin(aangle/180.0*M_PI));
CGPoint xyPoint=CGPointMake(xValueToaXis, yValueToaXis);
return xyPoint;
}
Besides, can I Create a Ranger Slider based on UISlider? Thanks.
This will work for the UISlider being placed anywhere on the screen. Most of the other solutions will only work when the UISlider is aligned with the left edge of the screen. Note, I used frame rather than bounds for the thumbRect, to achieve that. And I show two variations, based on using frame or bounds for the trackRect
extension UISlider {
//this version will return the x coordinate in relation to the UISlider frame
var thumbCenterX: CGFloat {
return thumbRect(forBounds: frame, trackRect: trackRect(forBounds: bounds), value: value).midX
}
//this version will return the x coordinate in relation to the UISlider's containing view
var thumbCenterX: CGFloat {
return thumbRect(forBounds: frame, trackRect: trackRect(forBounds: frame), value: value).midX
}
}
step 1 :get View for detect position (use same extension top commet of# Ovi Bortas)
#IBOutlet weak var sliderView: UIView!
step 2 : set label frame for add sub view
func setLabelThumb(slider:UISlider,value:Float){
slider.value = value
let label = UILabel(frame: CGRect(x: slider.thumbCenterX - 20, y: slider.frame.origin.y - 25, width: 50, height: 30))
label.font = UIFont.systemFont(ofSize: 10.0)
label.textColor = UIColor.red
label.textAlignment = .center
label.text = "\(value) kg."
sliderView.addSubview(label)
}