Resize font size to fill UITextView?

Question

How would I set the font size of text in a UITextView such that it fills the entire UITextView? I'd like the user to type in their text, then have the text fill the entire UITextView.

Any help is appreciated!

score 25 · Answer 1 · edited Sep 29 '20 at 23:48

I have converted dementiazz's answer to Swift:

func updateTextFont() {
    if (textView.text.isEmpty || CGSizeEqualToSize(textView.bounds.size, CGSizeZero)) {
        return;
    }

    let textViewSize = textView.frame.size;
    let fixedWidth = textViewSize.width;
    let expectSize = textView.sizeThatFits(CGSizeMake(fixedWidth, CGFloat(MAXFLOAT)));

    var expectFont = textView.font;
    if (expectSize.height > textViewSize.height) {
        while (textView.sizeThatFits(CGSizeMake(fixedWidth, CGFloat(MAXFLOAT))).height > textViewSize.height) {
            expectFont = textView.font!.fontWithSize(textView.font!.pointSize - 1)
            textView.font = expectFont
        }
    }
    else {
        while (textView.sizeThatFits(CGSizeMake(fixedWidth, CGFloat(MAXFLOAT))).height < textViewSize.height) {
            expectFont = textView.font;
            textView.font = textView.font!.fontWithSize(textView.font!.pointSize + 1)
        }
        textView.font = expectFont;
    }
}

Swift 3.0+ Update:

func updateTextFont() {
    if (textView.text.isEmpty || textView.bounds.size.equalTo(CGSize.zero)) {
        return;
    }

    let textViewSize = textView.frame.size;
    let fixedWidth = textViewSize.width;
    let expectSize = textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT)));

    var expectFont = textView.font;
    if (expectSize.height > textViewSize.height) {
        while (textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT))).height > textViewSize.height) {
            expectFont = textView.font!.withSize(textView.font!.pointSize - 1)
            textView.font = expectFont
        }
    }
    else {
        while (textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT))).height < textViewSize.height) {
            expectFont = textView.font;
            textView.font = textView.font!.withSize(textView.font!.pointSize + 1)
        }
        textView.font = expectFont;
    }
}

Also you can add the min and max font size to avoid unexpected sizes. (too big or too small) I just added the condition " && (textView.font!.pointSize > CGFloat(minSize))" to your while — RubenVot, Dec 07 '15 at 15:51
Not Working for me. Is there anything do i need to taking care for ? — PinkeshGjr, Jan 12 '19 at 11:29
Important is to run it in the right moment. After UITextView gets the right frame. In my case in `viewDidLayoutSubviews` — Radek Wilczak, May 22 '19 at 11:25
this doesn't deal with line orphan letters, does anyone know how i can do that? — nsleche, May 23 '19 at 16:28
The "Swift 3.0+ Update" solution has given me exactly what I wanted. Thank you so much Matt. — mansoor.khan, Jan 25 '23 at 15:28

score 8 · Answer 2 · edited May 23 '17 at 11:52

This, in a category on UITextView, should do the trick. For why you need the fudgefactor, see this post

#define kMaxFieldHeight 9999 

-(BOOL)sizeFontToFit:(NSString*)aString minSize:(float)aMinFontSize maxSize:(float)aMaxFontSize 
{   
float fudgeFactor = 16.0;
float fontSize = aMaxFontSize;

self.font = [self.font fontWithSize:fontSize];

CGSize tallerSize = CGSizeMake(self.frame.size.width-fudgeFactor,kMaxFieldHeight);
CGSize stringSize = [aString sizeWithFont:self.font constrainedToSize:tallerSize lineBreakMode:UILineBreakModeWordWrap];

while (stringSize.height >= self.frame.size.height)
       {
       if (fontSize <= aMinFontSize) // it just won't fit
           return NO;

       fontSize -= 1.0;
       self.font = [self.font fontWithSize:fontSize];
       tallerSize = CGSizeMake(self.frame.size.width-fudgeFactor,kMaxFieldHeight);
       stringSize = [aString sizeWithFont:self.font constrainedToSize:tallerSize lineBreakMode:UILineBreakModeWordWrap];
       }

return YES; 
}

in iOS >7.0 you need to change UILineBreakModeWordWrap to NSLineBreakByWordWrapping — Vlad Z., Jan 05 '14 at 15:41
just curious, how do you know "fudgeFactor = 16.0"? I believe this value should be smaller when text size is smaller — LiangWang, May 01 '15 at 03:08

score 7 · Answer 3 · answered Mar 16 '14 at 11:01

Similar approach to Arie Litovsky's answer but without sub-classing (or use of a category) and not using contentSize which didn't return the correct height of the rendered text for me. Tested on iOS 7:

while (((CGSize) [_textView sizeThatFits:_textView.frame.size]).height > _textView.frame.size.height) {
    _textView.font = [_textView.font fontWithSize:_textView.font.pointSize-1];
}

The approach is to keep reducing the font size until the text just fits inside the frame of the text view.

If you were going to use this in production you would still need to:

Handle the case where even with the smallest-possible font size the text still won't fit.
Use a similar approach to increase the font size if you would also like to scale text up to fit the frame.

score 6 · Answer 4 · edited Jan 18 '22 at 01:31

6

Try this, it's a lot simpler:

while (self.contentSize.height > self.frame.size.height)
{
    self.font = [self.font fontWithSize:self.font.pointSize -1];
    [self layoutSubviews];//force .contentSize to update
}

edited Jan 18 '22 at 01:31

Albert Renshaw

17,282
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answered Aug 06 '12 at 19:56

Arie Litovsky

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@BradMoore, you need to add one more line: [textView layoutSubviews]; – LiangWang Mar 09 '14 at 23:43
@Jacky, good to know! If I revisit this code I'll see if its worth updating. – Brad Moore Mar 10 '14 at 23:57
@Jacky - it's actually [textView layoutIfNeeded] you want to call – amergin May 31 '16 at 15:22
@BradMoore This should be top answer. I also noticed this was answered in 2012, resolution is so high these days that fractional font sizes should be considered. I used -0.5 instead -1 and it worked very smoothly on all device sizes. – Albert Renshaw Jan 18 '22 at 01:32

nahung89 · Answer 5 · 2014-08-12T05:07:25.480

3

Here is my sample code. Basically, I check the expect size to know if font size need to increase or decrease. You need to add UITextViewDelegate to your class to make sure it workings

- (void)updateTextFont:(UITextView *)textView
{
    // Only run if has text, otherwise it will make infinity loop
    if (textView.text.length == 0 || CGSizeEqualToSize(textView.bounds.size, CGSizeZero)) return;

    /*
     - Update textView font size
     If expectHeight > textViewHeight => descrease font size n point until it reach textViewHeight
     If expectHeight < textViewHeight => inscrease font size n point until it reach textViewHeight
     */
    CGSize textViewSize = textView.frame.size;
    CGFloat fixedWidth = textViewSize.width;
    CGSize expectSize = [textView sizeThatFits:CGSizeMake(fixedWidth, MAXFLOAT)];

    UIFont *expectFont = textView.font;
    if (expectSize.height > textViewSize.height) {
        while ([textView sizeThatFits:CGSizeMake(fixedWidth, MAXFLOAT)].height > textViewSize.height) {
            expectFont = [textView.font fontWithSize:(textView.font.pointSize-1)];
            textView.font = expectFont;
        }
    } else {
        while ([textView sizeThatFits:CGSizeMake(fixedWidth, MAXFLOAT)].height < textViewSize.height) {
            expectFont = textView.font;
            textView.font = [textView.font fontWithSize:(textView.font.pointSize+1)];
        }
        textView.font = expectFont;
    }
}

edited Aug 12 '14 at 05:07

answered Jul 22 '14 at 10:31

nahung89

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I'm curious what the else clause is doing here. You set an `expectFont` to the `textView's` `font` before you modify it... then you set it back to the unmodified `font`? Is that to prevent the jumping up and down of the text size? – Stephen Paul Feb 16 '18 at 09:44
@StephenPaul in else clause, if while doesn't run, the `textView.font` doesn't change (because `expectFont` is actually original `textView.font`). But if while run at least 1 time, `expectFont` is changed and we need to update it after finish the loop. I could make a flag to determine while run or not, but I didn't. Instead, I group it into last line `textView.font = expectFont` – nahung89 Feb 20 '18 at 05:17
if the while loop runs at least 1 time, you store the current font in a variable `expectFont`. Then you increase the `textView`'s font by one point, but then when that while loop exits, you see that `textView` font back to what it was... – Stephen Paul Feb 28 '18 at 10:08
you set*, I meant. – Stephen Paul Feb 28 '18 at 23:41
Yes, because the last time `textView.font` is setted, the while condition is false (I'm using textView to calculate the condition directly). That mean the font I'm setting is not correct, and I have to roll back to expect font. – nahung89 Mar 01 '18 at 03:11

score 3 · Answer 6 · answered Jan 13 '17 at 11:41

I have converted dementiazz's & Matt Frear's answer to Swift 3:

func updateTextFont() {
        if (textView.text.isEmpty || textView.bounds.size.equalTo(CGSize.zero)) {
            return
        }

    let textViewSize = textView.frame.size
    let fixedWidth = textViewSize.width
    let expectSize = textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT)))

    var expectFont = textView.font
    if (expectSize.height > textViewSize.height) {
        while (textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT))).height > textViewSize.height) {
            expectFont = textView.font!.withSize(textView.font!.pointSize - 1)
            textView.font = expectFont
        }
    }
    else {
        while (textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT))).height < textViewSize.height) {
            expectFont = textView.font
            textView.font = textView.font!.withSize(textView.font!.pointSize + 1)
        }
        textView.font = expectFont
    }
}

Tarek hemdan · Answer 7 · 2019-01-22T15:08:48.027

for swift 3

    func updateTextFont(textView: UITextView) {
     if (textView.text.isEmpty || textView.bounds.size.equalTo(CGSize.zero)) {
        return
     }
     let textViewSize = textView.frame.size
     let fixedWidth = textViewSize.width
     let expectSize = textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT)))
     var expectFont = textView.font;
     if (expectSize.height > textViewSize.height) {
        while (textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT))).height > textViewSize.height) {
            expectFont = textView.font!.withSize(textView.font!.pointSize - 1)
            textView.font = expectFont
        }
     }
     else {
        while (textView.sizeThatFits(CGSize(width: fixedWidth,height: CGFloat(MAXFLOAT))).height < textViewSize.height) {
            expectFont = textView.font
            textView.font = textView.font!.withSize(textView.font!.pointSize + 1)
        }
        textView.font = expectFont
     }
 }

score 3 · Answer 8 · edited May 08 '20 at 07:55

I have converted Matt Frear's answer to Swift 4.1 as extension for UITextView:

extension UITextView {
func updateTextFont() {
    if (self.text.isEmpty || self.bounds.size.equalTo(CGSize.zero)) {
        return;
    }

    let textViewSize = self.frame.size;
    let fixedWidth = textViewSize.width;
    let expectSize = self.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT)))


    var expectFont = self.font
    if (expectSize.height > textViewSize.height) {

        while (self.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT))).height > textViewSize.height) {
            expectFont = self.font!.withSize(self.font!.pointSize - 1)
            self.font = expectFont
        }
    }
    else {
        while (self.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT))).height < textViewSize.height) {
            expectFont = self.font
            self.font = self.font!.withSize(self.font!.pointSize + 1)
        }
        self.font = expectFont
    }
}
}

score 3 · Answer 9 · answered Apr 05 '22 at 19:01

Max Font Size

If you would like the size of the font in your UITextView to not exceed a certain point size, I added that functionality to Matt's answer. I also put it in an extension of UITextView to make it easier to use.

extension UITextView {
    /// Autosizes the font to fit the UITextView's text in its frame
    /// - Parameter max: The maximum point size the font should get
    func updateTextFont(max: CGFloat) {
        if (self.text!.isEmpty || self.bounds.size.equalTo(CGSize.zero)) {
            return;
        }
        
        let textViewSize = self.frame.size;
        let fixedWidth = textViewSize.width;
        let expectSize = self.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT)));
        
        var expectFont = self.font;
        if (expectSize.height > textViewSize.height) {
            while (self.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT))).height > textViewSize.height) && (self.font!.pointSize <= max) {
                expectFont = self.font!.withSize(self.font!.pointSize - 1)
                self.font = expectFont
            }
        } else {
            while (self.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT))).height < textViewSize.height) && (self.font!.pointSize <= max) {
                expectFont = self.font;
                self.font = self.font!.withSize(self.font!.pointSize + 1)
            }
            self.font = expectFont;
        }
    }
}

I found it best to call in UITextView's delegate method textViewDidChange

class UIViewController: UIViewController, UITextViewDelegate {
    
    @IBOutlet var textView: UITextView!
    
    func textViewDidChange(_ textView: UITextView) {
        textView.updateTextFont(max: 40)
    }
}

This has also been updated for Swift 5.1

score 2 · Answer 10 · answered Jan 11 '10 at 01:20

2

This property is only available on UITextFields. To do this in a UITextView, you'd have to constantly watch the text and manually adjust the font size as that changed.

answered Jan 11 '10 at 01:20

Ben Gottlieb

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Ah, is there any sample code out there that does this? I looked around and couldn't find anything. Thanks so much! – Johnny Tee Jan 11 '10 at 02:56
I'm not aware of any sample code; I've never heard of anyone trying to do this before. – Ben Gottlieb Jan 11 '10 at 12:37

score 2 · Answer 11 · answered Nov 22 '19 at 09:55

Hope that's clearer:

extension UITextView {
    @objc public func fitText() {
        fitText(into: frame.size)
    }

    @objc public func fitText(into originalSize: CGSize) {
        let originalWidth = originalSize.width
        let expectedSize = sizeThatFits(CGSize(width: originalWidth, height: CGFloat(MAXFLOAT)))

        if expectedSize.height > originalSize.height {
            while let font = self.font, sizeThatFits(CGSize(width: originalWidth, height: CGFloat(MAXFLOAT))).height > originalSize.height {
                self.font = font.withSize(font.pointSize - 1)
            }
        } else {
            var previousFont = self.font
            while let font = self.font, sizeThatFits(CGSize(width: originalWidth, height: CGFloat(MAXFLOAT))).height < originalSize.height {
                previousFont = font
                self.font = font.withSize(font.pointSize + 1)
            }
            self.font = previousFont
        }
    }
}

score 1 · Answer 12 · answered Dec 29 '16 at 16:39

In viewDidLoad:

textView.textContainer.lineFragmentPadding = 0;
textView.textContainerInset = UIEdgeInsetsMake(0, 0, 0, 0);

You need to add UITextViewDelegate:

- (void)updateTextFont:(UITextView *)textView {

    CGSize textViewSize = textView.frame.size;
    CGSize sizeOfText = [textView.text sizeWithAttributes:@{NSFontAttributeName: textView.font}];

    CGFloat fontOfWidth = floorf(textView.font.pointSize / sizeOfText.height * textViewSize.height);
    CGFloat fontOfHeight = floorf(textView.font.pointSize / sizeOfText.width * textViewSize.width);

    textView.font = [textView.font fontWithSize:MIN(fontOfHeight, fontOfWidth)];
}

score 0 · Answer 13 · answered May 31 '16 at 15:25

An updated version of @Arie Litovsky's code. This works in iOS7 and later and stretches the font size both up and down so the text fits.

- (void) stretchFontToFit:(UITextView*)textView
{

    while( textView.contentSize.height < textView.frame.size.height )
    {
        textView.font = [textView.font fontWithSize:textView.font.pointSize +1];
        [textView layoutIfNeeded];
    }

    while( textView.contentSize.height > textView.frame.size.height )
    {
        textView.font = [textView.font fontWithSize:textView.font.pointSize -1];
        [textView layoutIfNeeded];
    }
}

score 0 · Answer 14 · answered Aug 04 '19 at 04:13

Here is a conversion of dementiazz's and Matt Frear's answer to Swift 5. Put this function into viewDidLayoutSubviews, referencing the UITextView's who's font you want to dynamically resize.

func updateTextFont(textView: UITextView) {
    if (textView.text.isEmpty || textView.bounds.size.equalTo(CGSize.zero)) {
        return;
    }

    let textViewSize = textView.frame.size;
    let fixedWidth = textViewSize.width;
    let expectSize = textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT)))

    var expectFont = textView.font;
    if (expectSize.height > textViewSize.height) {
        while (textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT))).height > textViewSize.height) {
            expectFont = textView.font!.withSize(textView.font!.pointSize - 1)
            textView.font = expectFont
        }
    }
    else {
        while (textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat(MAXFLOAT))).height < textViewSize.height) {
            expectFont = textView.font;
            textView.font = textView.font!.withSize(textView.font!.pointSize + 1)
        }
        textView.font = expectFont;
    }
}

score -2 · Answer 15 · answered May 30 '17 at 22:47

-2

U can easily do this by using

self.textview.font =

self.textview.font = UIFont(name: self.textview.font!.fontName,
size: self.textview.frame.size.height / 10)!

divide textview.frame.size.height upon some constant based on your requirement..

answered May 30 '17 at 22:47

Amit Verma

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4
6

score -2 · Answer 16 · answered Jan 30 '18 at 09:55

Here is a solution for Swift 4 (based on Arie Litovsky answer), you can put this code into textViewDidChange(_ textView: UITextView) delegate method :

Scaling down the font :

    while (textView.contentSize.height > textView.frame.size.height) {
        guard let fontName = textView.font?.fontName, let fontSize = textView.font?.pointSize else {return}
        if fontSize < 12 {
            return
        }
        textView.font = UIFont(name: fontName, size: fontSize - 1)
        textView.layoutIfNeeded()
    }

And scaling up the font:

        while (textView.contentSize.height < textView.frame.size.height) {
        guard let fontName = textView.font?.fontName, let fontSize = textView.font?.pointSize else {return}
        if fontSize > 15 {
            return
        }
        textView.font = UIFont(name: fontName, size: fontSize + 1)
        textView.layoutIfNeeded()
    }

You can change the fontSize < 12 and fontSize > 15 to fit your needs in minimum and maximum font size.

Resize font size to fill UITextView?

16 Answers16

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