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

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;
    }
}

Answer 2

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
}