Determining maximum font size for UITextView

Question

Is it possible to determine maximum font size for UITextView which keeps all texts inside without cropping, while its containing text is already set and constant.

Note: I'm using custom fonts, and Swift.

Answer 1

Try this:

- (void)ff
{
    int minSize = 12; //define a minimum font size
    int maxSize = 60; //define a maximum font size
    int size = minSize;
    for (size = minSize; size < maxSize; size++) {
        UIFont *font = [UIFont fontWithName:@"your_font_name" size:size]; // init your font
        textView.font = font;
        [textView.layoutManager glyphRangeForTextContainer:textView.textContainer];
        NSRange visibleRange = [self visibleRangeOfTextView:textView];
        if (visibleRange.length < textView.text.length) {
            size--;
            break;
        }
    }

    NSLog(@"%d", size);

    return YES;
}

- (NSRange)visibleRangeOfTextView:(UITextView *)textView {
    CGRect bounds = textView.bounds;
    UITextPosition *start = [textView characterRangeAtPoint:bounds.origin].start;
    UITextPosition *end = [textView characterRangeAtPoint:CGPointMake(CGRectGetMaxX(bounds), CGRectGetMaxY(bounds))].end;
    return NSMakeRange([textView offsetFromPosition:textView.beginningOfDocument toPosition:start],
                       [textView offsetFromPosition:start toPosition:end]);
}

For the best results I suggest you to reset textview's paddings:

[textView setTextContainerInset:UIEdgeInsetsZero];
textView.textContainer.lineFragmentPadding = 0;