Calculating UILabel Text Size
The problem with
CGRect r = [text boundingRectWithSize:CGSizeMake(200, 0)
options:NSStringDrawingUsesLineFragmentOrigin
attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:fontSize]}
context:nil];
is boundingRectWithSize which determines the maximum value that CGRect can have.
My solution for this problem is to check if it exceeds, if not then text can fit into the label. I did it by using loops.
NSString *text = @"This is a long sentence. Wonder how much space is needed?";
CGFloat width = 100;
CGFloat height = 100;
bool sizeFound = false;
while (!sizeFound) {
NSLog(@"Begin loop");
CGFloat fontSize = 14;
CGFloat previousSize = 0.0;
CGFloat currSize = 0.0;
for (float fSize = fontSize; fSize < fontSize+6; fSize++) {
CGRect r = [text boundingRectWithSize:CGSizeMake(width, height)
options:NSStringDrawingUsesLineFragmentOrigin
attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:fSize]}
context:nil];
currSize =r.size.width*r.size.height;
if (previousSize >= currSize) {
width = width*11/10;
height = height*11/10;
fSize = fontSize+10;
}
else {
previousSize = currSize;
}
NSLog(@"fontSize = %f\tbounds = (%f x %f) = %f",
fSize,
r.size.width,
r.size.height,r.size.width*r.size.height);
}
if (previousSize == currSize) {
sizeFound = true;
}
}
NSLog(@"Size found with width %f and height %f", width, height);
After each iteration the size of height and width increments 10% of its value.
The reason why I picked 6 is because I did not want the label to be too squishy.
For a solution that does not use loops:
NSString *text = @"This is a long sentence. Wonder how much space is needed?";
CGFloat width = 100;
CGFloat height = 100;
CGFloat currentFontSize = 12;
CGRect r1 = [text boundingRectWithSize:CGSizeMake(width, height)
options:NSStringDrawingUsesLineFragmentOrigin
attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:currentFontSize+6]}
context:nil];
CGRect r2 = [text boundingRectWithSize:CGSizeMake(width, height)
options:NSStringDrawingUsesFontLeading
attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:currentFontSize+6]}
context:nil];
CGFloat firstVal =r1.size.width*r1.size.height;
CGFloat secondVal =r2.size.width*r2.size.height;
NSLog(@"First val %f and second val is %f", firstVal, secondVal);
if (secondVal > firstVal) {
float initRat = secondVal/firstVal;
float ratioToBeMult = sqrtf(initRat);
width *= ratioToBeMult;
height *= ratioToBeMult;
}
NSLog(@"Final width %f and height %f", width, height);
//for verifying
for (NSNumber *n in @[@(12.0f), @(14.0f), @(17.0f)]) {
CGFloat fontSize = [n floatValue];
CGRect r = [text boundingRectWithSize:CGSizeMake(width, height)
options:NSStringDrawingUsesLineFragmentOrigin
attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:fontSize]}
context:nil];
NSLog(@"fontSize = %f\tbounds = (%f x %f) = %f",
fontSize,
r.size.width,
r.size.height,r.size.width*r.size.height);
firstVal =r.size.width*r.size.height;
}
Where the last loop is proof that larger font can give a higher size result.
How to calculate UILabel height dynamically?
Try this
// UILabel *myLabel;
CGSize labelSize = [myLabel.text sizeWithFont:myLabel.font
constrainedToSize:myLabel.frame.size
lineBreakMode:NSLineBreakByWordWrapping];
CGFloat labelHeight = labelSize.height;
int lines = [myLabel.text sizeWithFont:myLabel.font
constrainedToSize:myLabel.frame.size
lineBreakMode:NSLineBreakByWordWrapping].height/16;
// '16' is font size
or
int lines = labelHeight/16;
NSLog(@"lines count : %i \n\n",lines);
or
int lines = [myLabel.text sizeWithFont:myLabel.font
constrainedToSize:myLabel.frame.size
lineBreakMode:UILineBreakModeWordWrap].height /myLabel.font.pointSize; //fetching font size from font
By Using Categories, Just Create the category class named as
UILabel+UILabelDynamicHeight.h
UILabel+UILabelDynamicHeight.m
No more tension about the height calculation. Please review the below implementation.
Updates for iOS7 & Above,iOS 7 below : Dynamically calculate the UILabel height
#define SYSTEM_VERSION_EQUAL_TO(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedSame)
#define SYSTEM_VERSION_GREATER_THAN(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedDescending)
#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)
#define SYSTEM_VERSION_LESS_THAN(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedAscending)
#define SYSTEM_VERSION_LESS_THAN_OR_EQUAL_TO(v) ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedDescending)
#define iOS7_0 @"7.0"
UILabel+UILabelDynamicHeight.h
#import
@interface UILabel (UILabelDynamicHeight)
#pragma mark - Calculate the size the Multi line Label
/*====================================================================*/
/* Calculate the size of the Multi line Label */
/*====================================================================*/
/**
* Returns the size of the Label
*
* @param aLabel To be used to calculte the height
*
* @return size of the Label
*/
-(CGSize)sizeOfMultiLineLabel;
@end
UILabel+UILabelDynamicHeight.m
#import "UILabel+UILabelDynamicHeight.h"
@implementation UILabel (UILabelDynamicHeight)
#pragma mark - Calculate the size,bounds,frame of the Multi line Label
/*====================================================================*/
/* Calculate the size,bounds,frame of the Multi line Label */
/*====================================================================*/
/**
* Returns the size of the Label
*
* @param aLabel To be used to calculte the height
*
* @return size of the Label
*/
-(CGSize)sizeOfMultiLineLabel{
//Label text
NSString *aLabelTextString = [self text];
//Label font
UIFont *aLabelFont = [self font];
//Width of the Label
CGFloat aLabelSizeWidth = self.frame.size.width;
if (SYSTEM_VERSION_LESS_THAN(iOS7_0)) {
//version < 7.0
return [aLabelTextString sizeWithFont:aLabelFont
constrainedToSize:CGSizeMake(aLabelSizeWidth, MAXFLOAT)
lineBreakMode:NSLineBreakByWordWrapping];
}
else if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(iOS7_0)) {
//version >= 7.0
//Return the calculated size of the Label
return [aLabelTextString boundingRectWithSize:CGSizeMake(aLabelSizeWidth, MAXFLOAT)
options:NSStringDrawingUsesLineFragmentOrigin
attributes:@{
NSFontAttributeName : aLabelFont
}
context:nil].size;
}
return [self bounds].size;
}
@end
How to calculate the width of a text string of a specific font and font-size?
You can do exactly that via the various sizeWithFont: methods in NSString UIKit Additions. In your case the simplest variant should suffice (since you don't have multi-line labels):
NSString *someString = @"Hello World";
UIFont *yourFont = // [UIFont ...]
CGSize stringBoundingBox = [someString sizeWithFont:yourFont];
There are several variations of this method, eg. some consider line break modes or maximum sizes.
Figure out size of UILabel based on String in Swift
Use an extension on String
Swift 3
extension String {
func height(withConstrainedWidth width: CGFloat, font: UIFont) -> CGFloat {
let constraintRect = CGSize(width: width, height: .greatestFiniteMagnitude)
let boundingBox = self.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
return ceil(boundingBox.height)
}
func width(withConstrainedHeight height: CGFloat, font: UIFont) -> CGFloat {
let constraintRect = CGSize(width: .greatestFiniteMagnitude, height: height)
let boundingBox = self.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
return ceil(boundingBox.width)
}
}
and also on NSAttributedString (which is very useful at times)
extension NSAttributedString {
func height(withConstrainedWidth width: CGFloat) -> CGFloat {
let constraintRect = CGSize(width: width, height: .greatestFiniteMagnitude)
let boundingBox = boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, context: nil)
return ceil(boundingBox.height)
}
func width(withConstrainedHeight height: CGFloat) -> CGFloat {
let constraintRect = CGSize(width: .greatestFiniteMagnitude, height: height)
let boundingBox = boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, context: nil)
return ceil(boundingBox.width)
}
}
Swift 4 & 5
Just change the value for attributes in the extension String methods
from
[NSFontAttributeName: font]
to
[.font : font]
Determine font size or scale of a UILabel
You can calculate font size according to the text and width of the label.
titleLabel.text = ""
titleLabel.alpha = 0
var charIndex = 0.0
let titleText = "Some App Title"
//You can use your custom font here.
titleLabel.font = UIFont.systemFont(ofSize: self.calculateOptimalFontSize(textLength: CGFloat(titleText.count), boundingBox: self.titleLabel.bounds))
for letter in titleText
{
Timer.scheduledTimer(withTimeInterval: (0.1 * charIndex), repeats: false)
{ (timer) in
self.titleLabel.text?.append(letter)
self.titleLabel.alpha += 0.1
}
charIndex += 1
}
You can create a similar function or extension.
func calculateOptimalFontSize(textLength:CGFloat, boundingBox:CGRect) -> CGFloat
{
let area:CGFloat = boundingBox.width * boundingBox.height
return sqrt(area / textLength)
}
How to calculate UILabel width based on text length?
CGSize expectedLabelSize = [yourString sizeWithFont:yourLabel.font
constrainedToSize:maximumLabelSize
lineBreakMode:yourLabel.lineBreakMode];
What is -[NSString sizeWithFont:forWidth:lineBreakMode:] good for?
this question might have your answer, it worked for me.
For 2014, I edited in this new version, based on the ultra-handy comment by Norbert below! This does everything. Cheers
// yourLabel is your UILabel.
float widthIs =
[self.yourLabel.text
boundingRectWithSize:self.yourLabel.frame.size
options:NSStringDrawingUsesLineFragmentOrigin
attributes:@{ NSFontAttributeName:self.yourLabel.font }
context:nil]
.size.width;
NSLog(@"the width of yourLabel is %f", widthIs);
iOS how to determine the size of UILabel dynamically
just use
UILabel *myLabel = [[UILabel alloc] init];
myLabel.font = [UIFont fontWithName:@"BentonSansComp-Medium" size:50.0];
myLabel.text = @"This is a string example"
[myLabel sizeToFit]; //it will resize the label to just the text is set
CGRectMake size = myLabel.frame; // u will get the frame of the label once is resized
float height = size.size.height; //to get the height of the label
float width = size.size.width; //to get the width of the label
hope it helps
Make sure evrytime you change the text u call the [myLabel sizeToFit]; method
How do I calculate the UILabel height dynamically
Use following method to calculate dynamic UILabel height:
- (CGFloat)getLabelHeight:(UILabel*)label
{
CGSize constraint = CGSizeMake(label.frame.size.width, CGFLOAT_MAX);
CGSize size;
NSStringDrawingContext *context = [[NSStringDrawingContext alloc] init];
CGSize boundingBox = [label.text boundingRectWithSize:constraint
options:NSStringDrawingUsesLineFragmentOrigin
attributes:@{NSFontAttributeName:label.font}
context:context].size;
size = CGSizeMake(ceil(boundingBox.width), ceil(boundingBox.height));
return size.height;
}
Adjust UILabel height depending on the text
sizeWithFont constrainedToSize:lineBreakMode: is the method to use. An example of how to use it is below:
//Calculate the expected size based on the font and linebreak mode of your label
// FLT_MAX here simply means no constraint in height
CGSize maximumLabelSize = CGSizeMake(296, FLT_MAX);
CGSize expectedLabelSize = [yourString sizeWithFont:yourLabel.font constrainedToSize:maximumLabelSize lineBreakMode:yourLabel.lineBreakMode];
//adjust the label the the new height.
CGRect newFrame = yourLabel.frame;
newFrame.size.height = expectedLabelSize.height;
yourLabel.frame = newFrame;
Get size of UILabel after setting text programmatically
Try implementing the following method in your ViewController with the tableView:
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return HeightCalculator.height(with: text, inViewController: self)
}
Then add the following class:
import UIKit
class HeightCalculator {
let title: String
let viewController: UIViewController
class func height(with title: String, inViewController viewController: UIViewController) -> CGFloat {
let calculator = HeightCalculator(title: title, viewController: viewController)
return calculator.height
}
init(title: String, viewController: UIViewController) {
self.title = title
self.viewController = viewController
}
var height: CGFloat {
let contentHeight = title.heightWithConstrainedWidth(width: defaultWidth, font: UIFont.preferredFont(forTextStyle: UIFontTextStyle.title1))
}
}
You need the following extension on your String to get the height:
import UIKit
extension String {
func heightWithConstrainedWidth(width: CGFloat, font: UIFont) -> CGFloat {
let constraintRect = CGSize(width: width, height: .greatestFiniteMagnitude)
let boundingBox = self.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
return boundingBox.height
}
}
Use heightForRowAt to calculate the height, the calculator class calculating it (contentHeight) and the extension to get the height. You can adjust the calculator class to pass the font in so it can use this font to pass it to the heightWithConstrainedWidth method.
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