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!

Answer 1

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.

Answer 2

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;
    }
}

Answer 3

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
    }
}

Answer 4

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.

Answer 5

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
    }
}

}

Answer 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];
}