iphone slider with constum steps - iphone

Question

i am not really familiar with objC and looking for a solution to build a slider that slides with "steps". on moving the slider the value increases like value+=10 or maybe value+=100. how do i do that?

Answer 1

I modified the code above for a custom Cocos2D slider http://yannickloriot.com/library/ios/cccontrolextension/Classes/CCControlSlider.html
It has properties:
#property (nonatomic, readwrite) float value;
#property (nonatomic, readwrite) minimumValue;
#property (nonatomic, readwrite) maximumValue;
#property (nonatomic, readwrite) int steps;
the recalculation:
- (void)recalcuateValue
{
float stepValues[self.steps];
stepValues[0] = self.minimumValue;
stepValues[self.steps - 1] = self.maximumValue;
for(int i = 1; i < self.steps; i++){
stepValues[i] = i * (self.maximumValue - self.minimumValue) / (self.steps - 1);
if (self.value < stepValues[i] && self.value > stepValues[i-1]){
self.value = (self.value > (stepValues[i] - stepValues[i-1]) / 2 + stepValues[i-1])?stepValues[i]:stepValues[i-1];
}
}
}
And the ccTouchesEnded: I added if(self.steps != 0), for the case steps is set to 0, the slider could work in usual mode
- (void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event
{
if ([self isSelected]){
self.value = [self valueForLocation:_thumbSprite.position];
if(self.steps != 0) {
[self recalcuateValue];
[_thumbSprite setPosition:[self locationFromValue:self.value]];
}
}
self.thumbSprite.color = ccWHITE;
self.selected = NO;
}
It calls valueForLocation and locationFromValue methods:
- (float)valueForLocation:(CGPoint)location
{
float percent = location.x / _backgroundSprite.contentSize.width;
return _minimumValue + percent * (_maximumValue - _minimumValue);
}
- (CGPoint)locationFromValue:(float)value{
float percent = self.value / self.maximumValue;
return ccp(percent * _backgroundSprite.contentSize.width, _backgroundSprite.position.y);
}
So an example of usage. I needed a slider with 3 steps and values 0, 1 and 2 on each step:
self.Slider = [CCControlSlider sliderWithBackgroundFile:#"sliderTrack.png"
progressFile:#"sliderProgress.png"
thumbFile:#"sliderThumb-hd.png"]; progressFile:#"sliderProgress.png" thumbFile:#"sliderThumb-hd.png"];
self.Slider.minimumValue = 0.0f;
self.Slider.maximumValue = 2.0f;
self.Slider.steps = 3;
self.Slider.value = [[GameSettings sharedSettings] defaultAILevel];
[self.Slider addTarget:self action:#selector(onSliderValueChanged:) forControlEvents:CCControlEventValueChanged];
Hope it may be useful

Answer 2

I created my discrete slider this way:
#import <UIKit/UIKit.h>
#interface DiscreteSlider : UISlider {
int step;
}
#property (nonatomic) int step;
#end
which that implementation:
#import "DiscreteSlider.h"
#implementation DiscreteSlider
#synthesize step;
- (void) recalcuateStep
{
float lValue = self.value;
int lLowerValue = (int) ( lValue / self.step );
float lDifference = lValue - ( lLowerValue * step );
float lHalfStep = ((float) step) / 2;
if( lDifference < lHalfStep ) {
} else {
self.value = (float) ( lLowerValue + step );
[self sendActionsForControlEvents:UIControlEventValueChanged];
}
}
- (void) touchesMoved:(NSSet *) touches
withEvent:(UIEvent *) event
{
[super touchesMoved:touches withEvent:event];
NSLog( #"DS.touchesMoved(), event: %#", event );
[self recalcuateStep];
}
- (void) endTrackingWithTouch:(UITouch *) touch
withEvent:(UIEvent *) event
{
[super endTrackingWithTouch:touch withEvent:event];
NSLog( #"DS.endTrackingWithTouch(), event: %#", event );
[self recalcuateStep];
}
- (int) step {
return ( step ? step : 1 );
}
#end