UITextView alignment to bottom

Question

I wondered how to set the UITextView so that the text inside aligns to the bottom? Like, if you start typing, you will always type in the lowest row?

Solution

I don't believe there is a built-in way to vertically align the text in a UITextView, but you should be able to use the contentOffset property of the UITextView class to accomplish this. See this blog post for more details:

http://imagineric.ericd.net/2011/03/10/ios-vertical-aligning-text-in-a-uitextview/

Update: since the above link appears to be dead, I used the Wayback Machine to retrieve an archived copy and have pasted the text of the article below.

The default and expected behavior of a UITextView (multi-line text) out of the box in iOS is to align the text top left in it’s container. That works well most of the time. However I recently had need to either center the text vertically within the control or have all the text align to the bottom of the control.

You can add an observer to the control and when it’s content size changes (text is set), fire a method. The method can then handle how the text is actually positioned in the control. If it doesn’t make sense to do the alignment, it will default to the normal behavior of the control (top vertical alignment).

Here we go:

- (void) viewDidLoad {
   [textField addObserver:self forKeyPath:@"contentSize" options:(NSKeyValueObservingOptionNew) context:NULL];
   [super viewDidLoad];
}

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

   //Bottom vertical alignment
   CGFloat topCorrect = ([tv bounds].size.height - [tv contentSize].height);
    topCorrect = (topCorrect <0.0 ? 0.0 : topCorrect);
    tv.contentOffset = (CGPoint){.x = 0, .y = -topCorrect};
}

You can decide which you’d like to use, or flush the method out to take an argument for which type of vertical alignment you’d like to use. This works quite well and it would have been nice if the properties were built into the control to begin with.

If you can use it, enjoy.

Comments

[Isaac Overacker]

The UILabel class cannot be directly typed into, though. You could do some work to manually update the UILabel instance as the user types, but I don't think this is what @Urban is asking for.

[Michael M]

Ah ok didnt read the typing part, could he not use a UITextField and then something like the following: textField.contentVerticalAlignment = UIControlContentVerticalAlignmentBottom;

[Schultz9999]

I had to use CGSize contentSize = [tv sizeThatFits:CGSizeMake(tv.frame.size.width, FLT_MAX)]; because contentSize was giving me full height of the control. Other than that, that's a good solution.

[Jan]

You should include the code in your answer so we don't miss it if the blog ever goes down

[Isaac Overacker]

@biomiker I have updated the answer with the text of the article retrieved from the Wayback Machine. Cheers.