Before going to this, please follow these steps:
1) AutoScrollLabel.h
#import <UIKit/UIKit.h>
#define NUM_LABELS 2
enum AutoScrollDirection {
AUTOSCROLL_SCROLL_RIGHT,
AUTOSCROLL_SCROLL_LEFT,
};
@interface AutoScrollLabel : UIScrollView <UIScrollViewDelegate>{
UILabel *label[NUM_LABELS];
enum AutoScrollDirection scrollDirection;
float scrollSpeed;
NSTimeInterval pauseInterval;
int bufferSpaceBetweenLabels;
bool isScrolling;
}
@property(nonatomic) enum AutoScrollDirection scrollDirection;
@property(nonatomic) float scrollSpeed;
@property(nonatomic) NSTimeInterval pauseInterval;
@property(nonatomic) int bufferSpaceBetweenLabels;
// normal UILabel properties
@property(nonatomic,retain) UIColor *textColor;
@property(nonatomic, retain) UIFont *font;
- (void) readjustLabels;
- (void) setText: (NSString *) text;
- (NSString *) text;
- (void) scroll;
@end
2) AutoScrollLabel.m
#import "AutoScrollLabel.h"
#define LABEL_BUFFER_SPACE 20 // pixel buffer space between scrolling label
#define DEFAULT_PIXELS_PER_SECOND 30
#define DEFAULT_PAUSE_TIME 0.5f
@implementation AutoScrollLabel
@synthesize pauseInterval;
@synthesize bufferSpaceBetweenLabels;
- (void) commonInit
{
for (int i=0; i< NUM_LABELS; ++i){
label[i] = [[UILabel alloc] init];
label[i].textColor = [UIColor whiteColor];
label[i].backgroundColor = [UIColor clearColor];
[self addSubview:label[i]];
}
scrollDirection = AUTOSCROLL_SCROLL_LEFT;
scrollSpeed = DEFAULT_PIXELS_PER_SECOND;
pauseInterval = DEFAULT_PAUSE_TIME;
bufferSpaceBetweenLabels = LABEL_BUFFER_SPACE;
self.showsVerticalScrollIndicator = NO;
self.showsHorizontalScrollIndicator = NO;
self.userInteractionEnabled = NO;
}
-(id) init
{
if (self = [super init]){
// Initialization code
[self commonInit];
}
return self;
}
- (id)initWithCoder:(NSCoder *)aDecoder
{
if (self = [super initWithCoder:aDecoder]) {
// Initialization code
[self commonInit];
}
return self;
}
- (id)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
// Initialization code
[self commonInit];
}
return self;
}
#if 0
- (void)animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context
{
[NSThread sleepForTimeInterval:pauseInterval];
isScrolling = NO;
if ([finished intValue] == 1 && label[0].frame.size.width > self.frame.size.width){
[self scroll];
}
}
#else
- (void)animationDidStop:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context
{
isScrolling = NO;
if ([finished intValue] == 1 && label[0].frame.size.width > self.frame.size.width){
[NSTimer scheduledTimerWithTimeInterval:pauseInterval target:self selector:@selector(scroll) userInfo:nil repeats:NO];
}
}
#endif
- (void) scroll
{
// Prevent multiple calls
if (isScrolling){
// return;
}
isScrolling = YES;
if (scrollDirection == AUTOSCROLL_SCROLL_LEFT){
self.contentOffset = CGPointMake(0,0);
}else{
self.contentOffset = CGPointMake(label[0].frame.size.width+LABEL_BUFFER_SPACE,0);
}
[UIView beginAnimations:@"scroll" context:nil];
[UIView setAnimationDelegate:self];
[UIView setAnimationCurve:UIViewAnimationCurveLinear];
[UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)];
[UIView setAnimationDuration:label[0].frame.size.width/(float)scrollSpeed];
if (scrollDirection == AUTOSCROLL_SCROLL_LEFT){
self.contentOffset = CGPointMake(label[0].frame.size.width+LABEL_BUFFER_SPACE,0);
}else{
self.contentOffset = CGPointMake(0,0);
}
[UIView commitAnimations];
}
- (void) readjustLabels
{
float offset = 0.0f;
for (int i = 0; i < NUM_LABELS; ++i){
[label[i] sizeToFit];
// Recenter label vertically within the scroll view
CGPoint center;
center = label[i].center;
center.y = self.center.y - self.frame.origin.y;
label[i].center = center;
CGRect frame;
frame = label[i].frame;
frame.origin.x = offset;
label[i].frame = frame;
offset += label[i].frame.size.width + LABEL_BUFFER_SPACE;
}
CGSize size;
size.width = label[0].frame.size.width + self.frame.size.width + LABEL_BUFFER_SPACE;
size.height = self.frame.size.height;
self.contentSize = size;
[self setContentOffset:CGPointMake(0,0) animated:NO];
// If the label is bigger than the space allocated, then it should scroll
if (label[0].frame.size.width > self.frame.size.width){
for (int i = 1; i < NUM_LABELS; ++i){
label[i].hidden = NO;
}
[self scroll];
}else{
// Hide the other labels out of view
for (int i = 1; i < NUM_LABELS; ++i){
label[i].hidden = YES;
}
// Center this label
CGPoint center;
center = label[0].center;
center.x = self.center.x - self.frame.origin.x;
label[0].center = center;
}
}
- (void) setText: (NSString *) text
{
// If the text is identical, don't reset it, otherwise it causes scrolling jitter
if ([text isEqualToString:label[0].text]){
// But if it isn't scrolling, make it scroll
// If the label is bigger than the space allocated, then it should scroll
if (label[0].frame.size.width > self.frame.size.width){
[self scroll];
}
return;
}
for (int i=0; i<NUM_LABELS; ++i){
label[i].text = text;
}
[self readjustLabels];
}
- (NSString *) text
{
return label[0].text;
}
- (void) setTextColor:(UIColor *)color
{
for (int i=0; i<NUM_LABELS; ++i){
label[i].textColor = color;
}
}
- (UIColor *) textColor
{
return label[0].textColor;
}
- (void) setFont:(UIFont *)font
{
for (int i=0; i<NUM_LABELS; ++i){
label[i].font = font;
}
[self readjustLabels];
}
- (UIFont *) font
{
return label[0].font;
}
- (void) setScrollSpeed: (float)speed
{
scrollSpeed = speed;
[self readjustLabels];
}
- (float) scrollSpeed
{
return scrollSpeed;
}
- (void) setScrollDirection: (enum AutoScrollDirection)direction
{
scrollDirection = direction;
[self readjustLabels];
}
- (enum AutoScrollDirection) scrollDirection
{
return scrollDirection;
}
- (void)dealloc {
for (int i=0; i<NUM_LABELS; ++i){
[label[i] release];
}
[super dealloc];
}
@end
Now, time is for use this library files
In your viewController where you want autoscroll text on UINavigation bar
1) In .h file
Forward declaration of class and make an object of this.
@class AutoScrollLabel;
AutoScrollLabel *autoScrollLabel;
2)In .m file
In viewDidLoad (){
//AutoScrolling Text
autoScrollLabel = [[AutoScrollLabel alloc] initWithFrame:CGRectMake(0, 0 , 220, 14)];
autoScrollLabel.text=@"Apan Munde bhi desi haan pinde bhi desi haan (Song is uncensored by Count3rB@bA)";
autoScrollLabel.textColor = [UIColor whiteColor];
autoScrollLabel.font=[UIFont systemFontOfSize:12.0];
[self.navigationController.navigationBar addSubview:autoScrollLabel];
}
