how to scroll text on label like marquee - iphone

Question

I have text on label which is not appearing completely so i want text to scroll on label from left to right. Please don't suggest numberoflines property as a solution.

Answer 1

FWIW, I did something similar using 2 labels in a scroll view...
#import <UIKit/UIKit.h>
#interface ScrolledTextView : UIScrollView
{
UILabel *label1;
UILabel *label2;
NSString *_text;
NSString *newText;
CGFloat textWidth;
BOOL animating;
BOOL needToUpdateText;
}
#property (nonatomic, copy, setter = setText:) NSString *text;
#property (nonatomic, assign) NSTimeInterval scrollInterval;
#property (nonatomic, assign) NSTimeInterval scrollDuration;
- (id) initWithFrame:(CGRect)frame andText : (NSString*) text;
- (void) setText:(NSString *)text;
- (BOOL) textFitsInFrame;
#implementation ScrolledTextView
#synthesize text = _text;
#synthesize scrollDuration;
#synthesize scrollInterval;
- (void) adjustLabelsForNewText : (NSString*) text andParentFrame : (CGRect) frame
{
_text = [NSString stringWithFormat:#"%# ", text];
CGSize textSize = [[self text] sizeWithFont:[label1 font] constrainedToSize:CGSizeMake(CGFLOAT_MAX, CGFLOAT_MAX) lineBreakMode:UILineBreakModeClip];
[self setContentSize:CGSizeMake(textSize.width * 2, textSize.height)];
textWidth = textSize.width;
[label1 setFrame:CGRectMake(0.0, 0.0, textWidth, frame.size.height)];
[label1 setText:[self text]];
if([self textFitsInFrame])
{
[label2 removeFromSuperview];
}
else
{
[label2 setFrame:CGRectMake([label1 frame].size.width, 0.0, textWidth, frame.size.height)];
[label2 setText:[self text]];
if( ! [[self subviews] containsObject:label2])
{
[self addSubview:label2];
}
[self beginScrolling];
}
}
- (id) initWithFrame:(CGRect)frame andText : (NSString*) text
{
self = [super initWithFrame:frame];
if (self) {
[self setClipsToBounds:YES];
animating = NO;
needToUpdateText = NO;
[self setScrollDuration:10.0];
[self setScrollInterval:2.0];
label1 = [UILabel new];
label2 = [UILabel new];
[label1 setBackgroundColor:[UIColor clearColor]];
[label2 setBackgroundColor:[UIColor clearColor]];
[self addSubview:label1];
[self adjustLabelsForNewText:text andParentFrame:frame];
}
return self;
}
- (void)animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context
{
if(needToUpdateText)
{
animating = NO;
needToUpdateText = NO;
[self adjustLabelsForNewText:#"" andParentFrame:[self frame]];
[self adjustLabelsForNewText:newText andParentFrame:[self frame]];
newText = nil;
return;
}
[self setContentOffset:CGPointMake(0.0, 0.0)];
[self beginScrolling];
}
- (void) beginScrolling
{
animating = YES;
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:[self scrollDuration]];
[UIView setAnimationDelay:[self scrollInterval]];
[UIView setAnimationDelegate:self];
[UIView setAnimationDidStopSelector:#selector(animationDidStop:finished:context:)];
[UIView setAnimationCurve:UIViewAnimationCurveLinear];
[self setContentOffset:CGPointMake(textWidth, 0.0)];
[UIView commitAnimations];
}
- (BOOL) textFitsInFrame
{
return textWidth <= [self frame].size.width;
}
- (void) setText:(NSString *)text
{
if(animating)
{
newText = text;
needToUpdateText = YES;
}
else
{
[self adjustLabelsForNewText:text andParentFrame:[self frame]];
}
}

Answer 2

if u appear a complete string in label using this line
CGSize labelsize = [label.text sizeWithFont:label.font];
then in CGRectMark(10,10, label.width,100 );
marquee are based on scroll content-size,if u set content-size(200,300),mean take that value to compare with x and y value to set a marquee.
regard
CNSivakumar