Dynamic UILabel Sizing

[ScottishPirate]

Hi All,

I have a very simple app (frankly because I don't know how to create anything more complicated) in which a UILabel, contained within a scroll view, takes on a new string of text when the user touches any 1 of 8 buttons.

My problem is that these strings of text are all of different lengths. I would like to somehow code the UILabel so that it's size is dependent upon the length of text that inhabits it.

I've googled this like crazy, and have found several threads of the same topic, but can't quite seem to get it to work. Could someone please tell me what I need to enter in my .m and .h files in order for this to work properly?

Thank you in advance!

[baja_yu]

One thing you could use is the sizeWithFont:constrainedToSize:lineBreakMode: method of NSString. You send it to the string you want to put in the label, give it the font and size you will be using in the label, the constraint rect (the size you do not want to go over, for example 300 width and 150 height), and line break mode (word wrap) and it will return you a size of the rectangle in which that text would fit. Based on that you can set the size of the label and calculate the number of lines you need to set.

Now, I'm not sure if there is any easier way, maybe you can dig around the NSString and UILabel class references in the docs and see if you can find something.

[Duncan C]

Originally Posted by baja_yu

One thing you could use is the sizeWithFont:constrainedToSize:lineBreakMode: method of NSString. You send it to the string you want to put in the label, give it the font and size you will be using in the label, the constraint rect (the size you do not want to go over, for example 300 width and 150 height), and line break mode (word wrap) and it will return you a size of the rectangle in which that text would fit. Based on that you can set the size of the label and calculate the number of lines you need to set.

Now, I'm not sure if there is any easier way, maybe you can dig around the NSString and UILabel class references in the docs and see if you can find something.

I haven't mucked with this in quite a while. (I'm off working on a Mac OS project.) UIView has a -sizeToFit method. Will a label resize itself if you call that method? You'd need to set the numberOfLines property to 0 first, so the label will use as many lines as needed.

If that doesn't work, baja_yu's method will work. I've used that approach to create custom table view cells that size themselves to the text they are displaying.

[ScottishPirate]

So you think I need to manually calculate the size of the frame, based on the string length and font size? There's no good way to create a dynamically sized UILabel?

[ScottishPirate]

Originally Posted by Duncan C

I haven't mucked with this in quite a while. (I'm off working on a Mac OS project.) UIView has a -sizeToFit method. Will a label resize itself if you call that method? You'd need to set the numberOfLines property to 0 first, so the label will use as many lines as needed.

If that doesn't work, baja_yu's method will work. I've used that approach to create custom table view cells that size themselves to the text they are displaying.

I could be wrong (very likely), but I thought sizetofit resized the text to fit the label, and not the label to fit the text.

[ScottishPirate]

I found a thread that discusses how to vertically align text in a UILabel here:

https://discussions.apple.com/thread...art=0&tstart=0

Does anyone know how to use the .h and .m files that ivan.m has provided?

[dany_dev]

Originally Posted by ScottishPirate

I found a thread that discusses how to vertically align text in a UILabel here:

https://discussions.apple.com/thread...art=0&tstart=0

Does anyone know how to use the .h and .m files that ivan.m has provided?

VerticallyAlignedLabel.h

//
// VerticallyAlignedLabel.h
//

#import <Foundation/Foundation.h>


typedef enum VerticalAlignment {
 VerticalAlignmentTop,
 VerticalAlignmentMiddle,
 VerticalAlignmentBottom,
} VerticalAlignment;

@interface VerticallyAlignedLabel : UILabel {
@private
 VerticalAlignment verticalAlignment_;
}

@property (nonatomic, assign) VerticalAlignment verticalAlignment;

@end

VerticallyAlignedLabel.m

//
// VerticallyAlignedLabel.m
//

#import "VerticallyAlignedLabel.h"


@implementation VerticallyAlignedLabel

@synthesize verticalAlignment = verticalAlignment_;

- (id)initWithFrame:(CGRect)frame {
 if (self = [super initWithFrame:frame]) {
 self.verticalAlignment = VerticalAlignmentMiddle;
 }
 return self;
}

- (void)setVerticalAlignment:(VerticalAlignment)verticalAlignment {
 verticalAlignment_ = verticalAlignment;
 [self setNeedsDisplay];
}

- (CGRect)textRectForBounds:(CGRect)bounds limitedToNumberOfLines:(NSInteger)numberOfLines {
 CGRect textRect = [super textRectForBounds:bounds limitedToNumberOfLines:numberOfLines];
 switch (self.verticalAlignment) {
 case VerticalAlignmentTop:
 textRect.origin.y = bounds.origin.y;
 break;
 case VerticalAlignmentBottom:
 textRect.origin.y = bounds.origin.y + bounds.size.height - textRect.size.height;
 break;
 case VerticalAlignmentMiddle:
 // Fall through.
 default:
 textRect.origin.y = bounds.origin.y + (bounds.size.height - textRect.size.height) / 2.0;
 }
 return textRect;
}

-(void)drawTextInRect:(CGRect)requestedRect {
 CGRect actualRect = [self textRectForBounds:requestedRect limitedToNumberOfLines:self.numberOfLines];
 [super drawTextInRect:actualRect];
}

@end

yourDidLoad or everywhere you like in your viewController

#import VerticallyAlignedLabel.h

....

VerticallyAlignedLabel *myLabel = [[VerticallyAlignedLabel alloc] initWithFrame:CGRectMake(x,y,w,h)];
[myLabel setVerticalAlignment:VerticalAlignmentMiddle]; //change VerticalAlignmentMiddle if you need someother

[self.view addSubview:myLabel];

[ScottishPirate]

So I create a brand new class for the VerticallyAlignedLabel.h and .m, and then call upon that class by importing it into my viewcontroller class?

[iSDK]

I have just successfully done what you wanted in my application.

Here is my code:

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {

            if (indexPath.row == 3){
                NSString *text = [self getItemForKey:kRights];
                CGSize constraintSize = CGSizeMake(310.0f, MAXFLOAT);
                CGSize labelSize = [text sizeWithFont:[UIFont systemFontOfSize:15]
                                    constrainedToSize:constraintSize 
                                        lineBreakMode:UILineBreakModeWordWrap];
                return labelSize.height+(labelSize.height/2)+([@"Rights" sizeWithFont:[UIFont systemFontOfSize:15]].height);
            }
            else
                return 30;

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

if (row == 3) {
			cell.textLabel.text = @"Rights";
            cell.backgroundColor = [UIColor clearColor];
            cell.detailTextLabel.lineBreakMode = UILineBreakModeWordWrap;
            cell.detailTextLabel.numberOfLines = 0;
            cell.detailTextLabel.text = [self getItemForKey:kRights];
            cell.textLabel.font = [UIFont systemFontOfSize:15];
            cell.detailTextLabel.font = cell.textLabel.font;
            cell.textLabel.textColor = [UIColor whiteColor];
            CGSize constraintSize = CGSizeMake(310.0f, MAXFLOAT);
            CGSize labelSize = [[cell.detailTextLabel text] sizeWithFont:[cell.detailTextLabel font] constrainedToSize:constraintSize lineBreakMode:UILineBreakModeWordWrap];
            cell.detailTextLabel.frame = CGRectMake( 0, 0, 310, labelSize.height);
            cell.userInteractionEnabled = YES;
            cell.selectionStyle = UITableViewCellSelectionStyleNone;
            cell.accessoryType = UITableViewCellAccessoryNone;

		}

Hope it helps

[ScottishPirate]

So I created a new class for the verticallyalignedlabel, ran it and everything worked well.

Then, I added that last piece of code to my view controller class, in the viewdidload section, and I had a number of errors. First, I had an error with the import, which I corrected by adding "" to your code.

I also have an error saying that x, y, w, and h are undeclared, which makes me think that it isn't importing the verticallyalignedlabel.h properly.

Any thoughts?

[ScottishPirate]

Originally Posted by iSDK

I have just successfully done what you wanted in my application.

Here is my code:

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {

            if (indexPath.row == 3){
                NSString *text = [self getItemForKey:kRights];
                CGSize constraintSize = CGSizeMake(310.0f, MAXFLOAT);
                CGSize labelSize = [text sizeWithFont:[UIFont systemFontOfSize:15]
                                    constrainedToSize:constraintSize 
                                        lineBreakMode:UILineBreakModeWordWrap];
                return labelSize.height+(labelSize.height/2)+([@"Rights" sizeWithFont:[UIFont systemFontOfSize:15]].height);
            }
            else
                return 30;

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

if (row == 3) {
			cell.textLabel.text = @"Rights";
            cell.backgroundColor = [UIColor clearColor];
            cell.detailTextLabel.lineBreakMode = UILineBreakModeWordWrap;
            cell.detailTextLabel.numberOfLines = 0;
            cell.detailTextLabel.text = [self getItemForKey:kRights];
            cell.textLabel.font = [UIFont systemFontOfSize:15];
            cell.detailTextLabel.font = cell.textLabel.font;
            cell.textLabel.textColor = [UIColor whiteColor];
            CGSize constraintSize = CGSizeMake(310.0f, MAXFLOAT);
            CGSize labelSize = [[cell.detailTextLabel text] sizeWithFont:[cell.detailTextLabel font] constrainedToSize:constraintSize lineBreakMode:UILineBreakModeWordWrap];
            cell.detailTextLabel.frame = CGRectMake( 0, 0, 310, labelSize.height);
            cell.userInteractionEnabled = YES;
            cell.selectionStyle = UITableViewCellSelectionStyleNone;
            cell.accessoryType = UITableViewCellAccessoryNone;

		}

Hope it helps

Thanks for this! Will this still work with my app though? I have the label embedded in a scroll view, on a tab bar view controlled window. Like I said earlier, I'm very new to xcode. What is a table view?

[iSDK]

Sorry, didn't read the OP properly... I assumed you were using a tableView as well.

Originally Posted by ScottishPirate

Thanks for this! Will this still work with my app though? I have the label embedded in a scroll view, on a tab bar view controlled window. Like I said earlier, I'm very new to xcode. What is a table view?