Center the text in a UITextView, vertically and horizontally [duplicate]

Answer 1

I resolve this issue by observing the contentsize of UITextView, when there is any change in the contentSize, update the contentOffset.

Add observer as follows:

[textview addObserver:self forKeyPath:@"contentSize" options:(NSKeyValueObservingOptionNew) context:NULL];

Handle the observer action as follows:

-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
     UITextView *txtview = object;
     CGFloat topoffset = ([txtview bounds].size.height - [txtview contentSize].height * [txtview zoomScale])/2.0;
     topoffset = ( topoffset < 0.0 ? 0.0 : topoffset );
     txtview.contentOffset = (CGPoint){.x = 0, .y = -topoffset};
}

To make the textview text horizontally center, select the textview from .xib class and go to the library and in that set Alignment as center.

Enjoy. :)

Answer 2

Very good solution! This is a Swift + Interface Builder solution so that you can enable it in IB.

I'll put it as part of the LSwift library.

extension UITextView {
    @IBInspectable var align_middle_vertical: Bool {
        get {
            return false    //  TODO
        }
        set (f) {
            self.addObserver(self, forKeyPath:"contentSize", options:.New, context:nil)
        }
    }
    override public func observeValueForKeyPath(keyPath: String, ofObject object: AnyObject, change: [NSObject:AnyObject], context: UnsafeMutablePointer<Void>) {
        if let textView = object as? UITextView {
            var y: CGFloat = (textView.bounds.size.height - textView.contentSize.height * textView.zoomScale)/2.0;
            if y < 0 {
                y = 0
            }
            textView.content_y = -y
        }
    }
}

public extension UIScrollView {
    public var content_x: CGFloat {
        set(f) {
            contentOffset.x = f
        }
        get {
            return contentOffset.x
        }
    }
    public var content_y: CGFloat {
        set(f) {
            contentOffset.y = f
        }
        get {
            return contentOffset.y
        }
    }
}