Tirth Tirth - 4 months ago 31
iOS Question

How can i change the color of pagination dots of UIPageControl?

I am developing an application in which I want to change either color or image of

UIPageControl
pagination dots. How can I change it? Is it possible to customize
UIpageControl
on above scenario?

Answer

UPDATE:

This answer is 6 years old and very outdated, but it's still attracting votes and comments. Ever since iOS 6.0 you should be using the pageIndicatorTintColor and currentPageIndicatorTintColor properties on UIPageControl.

ORIGINAL ANSWER:

I ran into this problem today and decided to write my own simple replacement class.

It's a sublassed UIView that uses Core Graphics to render the dots in the colors you specify.

You use the exposed properties to customize and control it.

If you want to you can register a delegate object to get notifications when the user taps on one of the little page dots. If no delegate is registered then the view will not react to touch input.

It's completely fresh from the oven, but seems to work. Let me know if you run into any problems with it.

Future improvements:

  • Resize the dots to fit the current bounds if there are too many.
  • Don't redraw the entire view in drawRect:

Example use:

CGRect f = CGRectMake(0, 0, 320, 20); 
PageControl *pageControl = [[[PageControl alloc] initWithFrame:f] autorelease];
pageControl.numberOfPages = 10;
pageControl.currentPage = 5;
pageControl.delegate = self;
[self addSubview:pageControl];

Header file:

//
//  PageControl.h
//
//  Replacement for UIPageControl because that one only supports white dots.
//
//  Created by Morten Heiberg <morten@heiberg.net> on November 1, 2010.
//

#import <UIKit/UIKit.h>

@protocol PageControlDelegate;

@interface PageControl : UIView 
{
@private
    NSInteger _currentPage;
    NSInteger _numberOfPages;
    UIColor *dotColorCurrentPage;
    UIColor *dotColorOtherPage;
    NSObject<PageControlDelegate> *delegate;
    //If ARC use __unsafe_unretained id delegate;
}

// Set these to control the PageControl.
@property (nonatomic) NSInteger currentPage;
@property (nonatomic) NSInteger numberOfPages;

// Customize these as well as the backgroundColor property.
@property (nonatomic, retain) UIColor *dotColorCurrentPage;
@property (nonatomic, retain) UIColor *dotColorOtherPage;

// Optional delegate for callbacks when user taps a page dot.
@property (nonatomic, retain) NSObject<PageControlDelegate> *delegate;

@end

@protocol PageControlDelegate<NSObject>
@optional
- (void)pageControlPageDidChange:(PageControl *)pageControl;
@end

Implementation file:

//
//  PageControl.m
//
//  Replacement for UIPageControl because that one only supports white dots.
//
//  Created by Morten Heiberg <morten@heiberg.net> on November 1, 2010.
//

#import "PageControl.h"

// Tweak these or make them dynamic.
#define kDotDiameter 7.0
#define kDotSpacer 7.0

@implementation PageControl

@synthesize dotColorCurrentPage;
@synthesize dotColorOtherPage;
@synthesize delegate;

- (NSInteger)currentPage
{
    return _currentPage;
}

- (void)setCurrentPage:(NSInteger)page
{
    _currentPage = MIN(MAX(0, page), _numberOfPages-1);
    [self setNeedsDisplay];
}

- (NSInteger)numberOfPages
{
    return _numberOfPages;
}

- (void)setNumberOfPages:(NSInteger)pages
{
    _numberOfPages = MAX(0, pages);
    _currentPage = MIN(MAX(0, _currentPage), _numberOfPages-1);
    [self setNeedsDisplay];
}

    - (id)initWithFrame:(CGRect)frame
{
    if ((self = [super initWithFrame:frame]))
    {
        // Default colors.
        self.backgroundColor = [UIColor clearColor];
        self.dotColorCurrentPage = [UIColor blackColor];
        self.dotColorOtherPage = [UIColor lightGrayColor];

        UISwipeGestureRecognizer *swipeRight = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipedRight:)];
        [swipeRight setDirection:UISwipeGestureRecognizerDirectionRight];
        [self addGestureRecognizer:swipeRight];




        UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipedLeft:)];
        [swipe setDirection:UISwipeGestureRecognizerDirectionLeft];
        [self addGestureRecognizer:swipe];

    }
    return self;
}
-(void) swipedLeft:(UISwipeGestureRecognizer *) recognizer
{
    self.currentPage++;
}
-(void) swipedRight:(UISwipeGestureRecognizer *) recognizer
{
    self.currentPage--;
}

- (void)drawRect:(CGRect)rect 
{
    CGContextRef context = UIGraphicsGetCurrentContext();   
    CGContextSetAllowsAntialiasing(context, true);

    CGRect currentBounds = self.bounds;
    CGFloat dotsWidth = self.numberOfPages*kDotDiameter + MAX(0, self.numberOfPages-1)*kDotSpacer;
    CGFloat x = CGRectGetMidX(currentBounds)-dotsWidth/2;
    CGFloat y = CGRectGetMidY(currentBounds)-kDotDiameter/2;
    for (int i=0; i<_numberOfPages; i++)
    {
        CGRect circleRect = CGRectMake(x, y, kDotDiameter, kDotDiameter);
        if (i == _currentPage)
        {
            CGContextSetFillColorWithColor(context, self.dotColorCurrentPage.CGColor);
        }
        else
        {
            CGContextSetFillColorWithColor(context, self.dotColorOtherPage.CGColor);
        }
        CGContextFillEllipseInRect(context, circleRect);
        x += kDotDiameter + kDotSpacer;
    }
}

- (void)dealloc 
{
    [dotColorCurrentPage release];
    [dotColorOtherPage release];
    [delegate release];
    [super dealloc];
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    if (!self.delegate) return;

    CGPoint touchPoint = [[[event touchesForView:self] anyObject] locationInView:self];

    CGFloat dotSpanX = self.numberOfPages*(kDotDiameter + kDotSpacer);
    CGFloat dotSpanY = kDotDiameter + kDotSpacer;

    CGRect currentBounds = self.bounds;
    CGFloat x = touchPoint.x + dotSpanX/2 - CGRectGetMidX(currentBounds);
    CGFloat y = touchPoint.y + dotSpanY/2 - CGRectGetMidY(currentBounds);

    if ((x<0) || (x>dotSpanX) || (y<0) || (y>dotSpanY)) return;

    self.currentPage = floor(x/(kDotDiameter+kDotSpacer));
    if ([self.delegate respondsToSelector:@selector(pageControlPageDidChange:)])
    {
        [self.delegate pageControlPageDidChange:self];
    }
}

@end
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