Who's Up for a Challenge? (or who needs a good Color Picker?)

Question

Greetings,
I got lost in the muck trying to figure out how to make this color-picker code initialize with the last chosen color.... This is an open source project, and I posted my predicament on the blog for it, but it's been a few weeks and no one has responded. I've been able to integrate the code with my project no problem, it's just figuring out how to change this one behavior... the startup color seems to be hardcoded in several different places...
Seems like there's some folks here who enjoy a good challenge, so I thought I'd see if anyone might want to give it a shot.... I'm probably making it much more complicated than it is by starting from the wrong vantage point....
The Blog: http://www.v-vent.com/blog/?p=27
The Code: http://www.v-vent.com/source/hue/veventhuesource.zip
Any clues you have to offer would be greatly appreciated.... the idea seems simple enough....currently starts on yellow every time you load the view... would like it to start on the last color chosen, which is getting stored in user defaults....

Answer 1

Ok John, here are each of the three files I touched:
// ColorPickerViewController.m
#import "ColorPickerViewController.h"
#import "ColorPickerView.h"
#import "AboutScreenViewController.h"
@implementation ColorPickerViewController
@synthesize aboutScreenViewController;
// --> added const decl
NSString *const keyForHue = @"hue";
NSString *const keyForSat = @"sat";
NSString *const keyForBright = @"bright";
// --> register default settings
- (void)registerDefaults {
NSMutableDictionary *defaultValues = [NSMutableDictionary dictionary];
[defaultValues setObject:[NSNumber numberWithFloat:0.5] forKey:keyForHue];
[defaultValues setObject:[NSNumber numberWithFloat:0.5] forKey:keyForSat];
[defaultValues setObject:[NSNumber numberWithFloat:0.5] forKey:keyForBright];
[[NSUserDefaults standardUserDefaults] registerDefaults:defaultValues];
- (void)viewDidLoad {
[super viewDidLoad];
NSLog(@"CALL ME ! " );
[self registerDefaults]; // <-- register default settings
NSUserDefaults *saveColors = [NSUserDefaults standardUserDefaults];
ColorPickerView *theView = (ColorPickerView*) [self view];
// --> removed key existance test and explicit defaults from this block
// since defaults are now registered
[theView setCurrentHue:[saveColors floatForKey:keyForHue]];
[theView setCurrentSaturation:[saveColors floatForKey:keyForSat]];
[theView setCurrentBrightness:[saveColors floatForKey:keyForBright]];
AboutScreenViewController *abouter = [[AboutScreenViewController alloc]
initWithNibName:@"AboutScreenView" bundle:nil];
self.aboutScreenViewController = abouter;
[abouter release];
[theView onViewDidLoad]; // <-- added
- (void) viewWillDisappear :(BOOL)animated {
NSUserDefaults *saveColors = [NSUserDefaults standardUserDefaults];
ColorPickerView *theView = (ColorPickerView*) [self view];
[saveColors setFloat:[theView currentHue] forKey:keyForHue];
[saveColors setFloat:[theView currentSaturation] forKey:keyForSat];
[saveColors setFloat:[theView currentBrightness] forKey:keyForBright];
- (UIColor *) getSelectedColor {
return [(ColorPickerView *) [self view] getColorShown];
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning]; // Releases the view if it doesn't have a superview
// Release anything that's not essential, such as cached data
- (IBAction) pressedAboutButton {
[self.view addSubview:self.aboutScreenViewController.view];
[self.view bringSubviewToFront:self.aboutScreenViewController.view];
- (void)dealloc {
[super dealloc];
[aboutScreenViewController release];
@end
// ColorPickerView.h
#import <UIKit/UIKit.h>
@class GradientView;
@interface ColorPickerView : UIView {
GradientView *gradientView;
UIImageView *matrixView; // <-- added
// --> unused ivars
// UIImage *backgroundImage; //Image that will sit in back on the view
// UIImage *closeButtonImage; //Image for close button
// UIImage *nextButtonImage; //Image for next button
IBOutlet UIImageView *backgroundImageView;
IBOutlet UIView *showColor;
IBOutlet UIImageView *crossHairs;
IBOutlet UIImageView *brightnessBar;
IBOutlet UILabel *colorInHex;
IBOutlet UILabel *Hcoords;
IBOutlet UILabel *Scoords;
IBOutlet UILabel *Lcoords;
IBOutlet UILabel *Rcoords;
IBOutlet UILabel *Gcoords;
IBOutlet UILabel *Bcoords;
//Private vars
// --> ok, private.. but atm, the controller still needs to call getters
// and setters for currentBrightness, currentHue, and currentSaturation
@private
// CGRect colorMatrixFrame; // <-- removed - using matrixView ivar instead
CGFloat currentBrightness;
CGFloat currentHue;
CGFloat currentSaturation;
UIColor *currentColor;
// unused properties
// @property (nonatomic,retain) UIImage *backgroundImage;
// @property (nonatomic,retain) UIImage *closeButtonImage;
// @property (nonatomic,retain) UIImage *nextButtonImage;
@property (nonatomic,retain) GradientView *gradientView;// <-- added
@property (nonatomic,retain) UIImageView *matrixView; // <-- added
@property (readwrite) CGFloat currentBrightness;
@property (readwrite) CGFloat currentHue;
@property (readwrite) CGFloat currentSaturation;
- (UIColor *) getColorShown;
- (void) onViewDidLoad; // <-- added
@end
// ColorPickerView.m
#import "ColorPickerView.h"
#import "GradientView.h"
#import "Constants.h"
// --> declare private properties, methods and functions
@interface ColorPickerView ()
@property (nonatomic,retain) UIColor *currentColor;
- (void) getStringForHSL : (CGFloat) hue : (CGFloat) sat : (CGFloat) bright;
- (void) getStringForRGB :(CGColorRef) theColor;
- (NSString *) hexStringFromColor : (CGColorRef) theColor;
static int myRoundOff(CGFloat value);
@end
@implementation ColorPickerView
// --> unused properties
// @synthesize backgroundImage;
// @synthesize closeButtonImage;
// @synthesize nextButtonImage;
@synthesize gradientView; // <-- added
@synthesize matrixView; // <-- added
@synthesize currentHue;
@synthesize currentSaturation;
@synthesize currentBrightness;
@synthesize currentColor; // <-- added
- (id)initWithCoder:(NSCoder*)coder {
if (self = [super initWithCoder:coder]) {
// --> changes to support gradientView, which is now a retaining property
GradientView *gradView = [[GradientView alloc] initWithFrame:kBrightnessGradientPlacent];
self.gradientView = gradView;
[gradView release];
// [gradientView setTheColor:
// [UIColor yellowColor].CGColor]; // <-- fixed and moved to onViewDidLoad
[self addSubview:gradientView];
[self sendSubviewToBack:gradientView];
// --> changes to support retaining property 'matrixView'
// colorMatrixFrame = kHueSatFrame; // <-- removed colorMatrixFrame ivar
UIImageView *hueSatImageView = [[UIImageView alloc] initWithFrame:kHueSatFrame];
[hueSatImageView setImage:[UIImage imageNamed:kHueSatImage]];
self.matrixView = hueSatImageView;
[hueSatImageView release];
[self addSubview:matrixView];
[self sendSubviewToBack:matrixView];
[self setMultipleTouchEnabled:YES]; // <-- moved to keep similar blocks together
// currentBrightness = kInitialBrightness; // <-- removed
// currentColor = [[UIColor alloc]init]; // <-- fixed and moved to onViewDidLoad
return self;
// --> several of the ivars in this class should be moved to the controller -
// for now this method should be called at the end of the controller's viewDidLoad method
- (void)onViewDidLoad {
self.currentColor = [UIColor colorWithHue:currentHue
saturation:currentSaturation
brightness:currentBrightness
alpha:1.0];
[showColor setBackgroundColor:currentColor];
[self getStringForRGB:currentColor.CGColor];
[self getStringForHSL:currentHue :currentSaturation :currentBrightness];
[colorInHex setText:[self hexStringFromColor:currentColor.CGColor]];
NSLog(@"%s: hue=%1.2f sat=%1.2f bright=%1.2f",
_func_, currentHue, currentSaturation, currentBrightness);
- (NSString *) hexStringFromColor : (CGColorRef) theColor {
const CGFloat *c = CGColorGetComponents(theColor);
CGFloat r, g, b;
r = c[0];
g = c[1];
b = c[2];
// Fix range if needed
if (r < 0.0f) r = 0.0f;
if (g < 0.0f) g = 0.0f;
if (b < 0.0f) b = 0.0f;
if (r > 1.0f) r = 1.0f;
if (g > 1.0f) g = 1.0f;
if (b > 1.0f) b = 1.0f;
// Convert to hex string between 0x00 and 0xFF
return [NSString stringWithFormat:@"#%02X%02X%02X",
// --> using myRoundOff instead of int typecast
myRoundOff(r * 255), myRoundOff(g * 255), myRoundOff(b * 255)];
// --> use this if needed to fudge extrema
static int myRoundOff(CGFloat value) {
return lround(value);
- (void) getStringForHSL : (CGFloat) hue : (CGFloat) sat : (CGFloat) bright { // <-- CGFloat params
// NSLog(@"%s: hue=%1.4lf sat=%1.4lf bright=%1.4lf", _func_, hue, sat, bright);
// --> using myRoundOff instead of int typecast
[Hcoords setText:[NSString stringWithFormat:@"%d",myRoundOff(hue*255)]];
[Scoords setText:[NSString stringWithFormat:@"%d",myRoundOff(sat*255)]];
[Lcoords setText:[NSString stringWithFormat:@"%d",myRoundOff(bright*255)]];
- (void) getStringForRGB :(CGColorRef) theColor {
const CGFloat *c = CGColorGetComponents(theColor);
CGFloat r, g, b;
r = c[0];
g = c[1];
b = c[2];
// --> using myRoundOff instead of int typecast
[Rcoords setText:[NSString stringWithFormat:@"%d",myRoundOff(r*255)]];
[Gcoords setText:[NSString stringWithFormat:@"%d",myRoundOff(g*255)]];
[Bcoords setText:[NSString stringWithFormat:@"%d",myRoundOff(b*255)]];
- (void) updateHueSatWithMovement : (CGPoint) position {
// --> correcting currentHue and currentSaturation calculations
// currentHue = (position.x-kXAxisOffset)/kMatrixWidth;
// currentSaturation = 1.0 - (position.y-kYAxisOffset)/kMatrixHeight;
CGPoint ptInMatrix = [self convertPoint:position toView:matrixView];
currentHue = ptInMatrix.x/(matrixView.frame.size.width-1);
currentSaturation = 1.0 - ptInMatrix.y/(matrixView.frame.size.height-1);
// printf("hue Of the touch is : %f
",currentHue);
// printf("sat Of the touch is : %f
",currentSaturation);
UIColor *forGradient = [UIColor colorWithHue:currentHue
saturation:currentSaturation
brightness: kInitialBrightness
alpha:1.0];
[gradientView setTheColor:forGradient.CGColor];
[gradientView setupGradient];
[gradientView setNeedsDisplay];
self.currentColor = [UIColor colorWithHue:currentHue // --> using setter to retain color
saturation:currentSaturation
brightness:currentBrightness
alpha:1.0];
[showColor setBackgroundColor:currentColor];
[colorInHex setText:[self hexStringFromColor:currentColor.CGColor]];
[self getStringForRGB:currentColor.CGColor];
[self getStringForHSL:currentHue :currentSaturation :currentBrightness];
- (void) updateBrightnessWithMovement : (CGPoint) position {
// --> correcting currentBrightness calculation
// currentBrightness = 1.0-(position.x/gradientView.frame.size.width) + kBrightnessEpsilon;
CGPoint ptInGradient = [self convertPoint:position toView:gradientView];
currentBrightness = 1.0 - ptInGradient.x/(gradientView.frame.size.width-1);
// printf("Brightness Of the touch is : %f
",currentBrightness);
// --> setting and using currentColor ivar instead of local var
self.currentColor = [UIColor colorWithHue:currentHue
saturation:currentSaturation
brightness:currentBrightness
alpha:1.0];
[showColor setBackgroundColor:currentColor];
[colorInHex setText:[self hexStringFromColor:currentColor.CGColor]];
[self getStringForRGB:currentColor.CGColor];
[self getStringForHSL:currentHue :currentSaturation :currentBrightness];
//Touch parts :
// Scales down the view and moves it to the new position.
- (void)animateView:(UIImageView *)theView toPosition:(CGPoint) thePosition
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:kAnimationDuration];
// Set the center to the final postion
theView.center = thePosition;
// Set the transform back to the identity, thus undoing the previous scaling effect.
theView.transform = CGAffineTransformIdentity;
[UIView commitAnimations];
-(void) dispatchTouchEvent:(CGPoint)position
if (CGRectContainsPoint(matrixView.frame,position)) // <-- colorMatrixFrame ivar was removed
// NSLog(@"Color!");
// printf("X Of the touch in grad view is : %f
",position.x);
// printf("Y Of the touch in grad view is : %f
",position.y);
[self animateView:crossHairs toPosition: position];
[self updateHueSatWithMovement:position];
else if (CGRectContainsPoint(gradientView.frame, position))
// NSLog(@"Bright!");
CGPoint newPos = CGPointMake(position.x,kBrightBarYCenter);
[self animateView:brightnessBar toPosition: newPos];
[self updateBrightnessWithMovement:position];
else
// printf("X Of the touch in grad view is : %f
",position.x);
// printf("Y Of the touch in grad view is : %f
",position.y);
// Handles the start of a touch
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
for (UITouch *touch in touches) {
[self dispatchTouchEvent:[touch locationInView:self]];
// printf("X IS %f
",[touch locationInView:self].x);
// printf("Y IS %f
",[touch locationInView:self].y);
// Handles the continuation of a touch.
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
for (UITouch *touch in touches){
[self dispatchTouchEvent:[touch locationInView:self]];
- (void)drawRect:(CGRect)rect {
// --> corrected calculation of crosshairs.center
CGFloat x = currentHue * matrixView.frame.size.width;
CGFloat y = (1 - currentSaturation) * matrixView.frame.size.height;
CGPoint ptInMatrix = CGPointMake(x, y);
crossHairs.center = [matrixView convertPoint:ptInMatrix toView:self];
// --> corrected calculation of brightnessBar.center
x = (1 - currentBrightness) * gradientView.frame.size.width;
y = gradientView.frame.size.height/2 - 3;
CGPoint ptInGradient = CGPointMake(x, y);
brightnessBar.center = [gradientView convertPoint:ptInGradient toView:self];
// NSLog(@"%s: gradientView.frame=%@", _func_, NSStringFromCGRect(gradientView.frame));
// NSLog(@" brightnessBar.center=%@", NSStringFromCGPoint(brightnessBar.center));
UIColor *forGradient = [UIColor colorWithHue:currentHue // added
saturation:currentSaturation
brightness: kInitialBrightness
alpha:1.0];
[gradientView setTheColor:forGradient.CGColor]; // added
[gradientView setupGradient];
[gradientView setNeedsDisplay];
[colorInHex setFont:[UIFont fontWithName:@"helvetica" size:16]];
[self sendSubviewToBack:showColor];
- (UIColor *) getColorShown {
// NSLog(@"Are we here ? ");
return [UIColor colorWithHue:currentHue saturation:currentSaturation
brightness:currentBrightness alpha:1.0];
- (void)dealloc {
[currentColor release]; // <-- added
[gradientView release]; // <-- added
[matrixView release]; // <-- added
[super dealloc];
@end
Disclaimer: While the above is working, tested code, the files are not meant to be examples of good practice. The objective was to hose out most of the functional bugs while changing the old files as little as possible. This is usually the best first step in cleaning up a project, since it allows the original programmers to see the changes in the context of the existing structure. Those changes can be much more difficult to see after a complete overhaul. Improving the structure will also change the nib files, and describing those changes in the forum can be tedious.
Thus I perpetuated the structural weaknesses instead of moving most of the ivars, along with the code that administers them, into the ColorPickerViewController class. A number of useless but harmless artifacts were also left in the files.
Most of my tests were only for functionality on the simulator. Though I tried to take care of memory management in the code I added or changed, there's lots of memory management clean up to do. I did some brief tests on a first gen iPod Touch with iOS 3.12, and at first glance I was surprised how well things seemed to be working. I was even able to position the crosshairs in a couple corners after a few tries (e.g. at full brightness, the upper-right corner should be HSL: 255, 255, 255; RGB: 255, 0, 0). All four of these extrema are reachable on the simulator, and if you have steady hands and/or small fingers, they're probably all reachable on an iPhone as well.
Enjoy!
- Ray