Paint App

[IphoneSdk]

I have this code which creates a simple paint app

- (void)viewDidLoad {
    [super viewDidLoad];
	drawImage = [[UIImageView alloc] initWithImage:nil];
	drawImage.frame = self.view.frame;
	[self.view addSubview:drawImage];
	self.view.backgroundColor = [UIColor whiteColor];
	mouseMoved = 0;
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
	
	mouseSwiped = NO;
	UITouch *touch = [touches anyObject];
	
	if ([touch tapCount] == 2) {
		drawImage.image = nil;
		return;
	}
	
	lastPoint = [touch locationInView:self.view];
	lastPoint.y -= 20;
	
}


- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
	mouseSwiped = YES;
	
	UITouch *touch = [touches anyObject];	
	CGPoint currentPoint = [touch locationInView:self.view];
	currentPoint.y -= 20;
	
	
	UIGraphicsBeginImageContext(self.view.frame.size);
	[drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
	CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
	CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5.0);
	CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 1.0, 0.0, 0.0, 1.0);
	CGContextBeginPath(UIGraphicsGetCurrentContext());
	CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
	CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y);
	CGContextStrokePath(UIGraphicsGetCurrentContext());
	drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
	UIGraphicsEndImageContext();
	
	lastPoint = currentPoint;
	
	mouseMoved++;
	
	if (mouseMoved == 10) {
		mouseMoved = 0;
	}
	
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
	
	UITouch *touch = [touches anyObject];
	
	if ([touch tapCount] == 2) {
		drawImage.image = nil;
		return;
	}
	
	
	if(!mouseSwiped) {
		UIGraphicsBeginImageContext(self.view.frame.size);
		[drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
		CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
		CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5.0);
		CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 1.0, 0.0, 0.0, 1.0);
		CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
		CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
		CGContextStrokePath(UIGraphicsGetCurrentContext());
		CGContextFlush(UIGraphicsGetCurrentContext());
		drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
		UIGraphicsEndImageContext();
	}
}

It works perfectly however how can I change the colour of the paint from a different view?

Thanks

[MarkC]

If you're thinking about passing variables between views, look no further than the example in this link: Singleton Classes Matt Galloway's iPhone Apps

Bloody great it is - much better than global delegate variables!

[IphoneSdk]

Cool link, thanks.

How could I do it from the same view?

Thanks

[ranjit]

Not sure what u mean, but if u want to change the color of the pen, then

CGContextSetRGBStrokeColor(UIGraphicsGetCurrentCon text(), 1.0, 0.0, 0.0, 1.0);

1.0, 0.0, 0.0, 1.0 = Red, Green, Blue, Alpha.

Now it is painting red yeah? So u just need to give user option to select a color from a pallete image, (or easier way use 3 sliders with min val of 0 and max of 1). then put the variables in that function.

[IphoneSdk]

sorry to be a pain but do you have any code for that?
I'm currently on my phone so can't search for anything!

[IphoneSdk]

I couldn't find anything on this. Can anyone help me out?

[jdam]

Hi Guys,

Any tips for particles as image, I want to use the image to draw and drag. Any tips?


thanks,
-Jd

[rrichar]

Originally Posted by IphoneSdk

I have this code which creates a simple paint app

- (void)viewDidLoad {
    [super viewDidLoad];
	drawImage = [[UIImageView alloc] initWithImage:nil];
	drawImage.frame = self.view.frame;
	[self.view addSubview:drawImage];
	self.view.backgroundColor = [UIColor whiteColor];
	mouseMoved = 0;
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
	
	mouseSwiped = NO;
	UITouch *touch = [touches anyObject];
	
	if ([touch tapCount] == 2) {
		drawImage.image = nil;
		return;
	}
	
	lastPoint = [touch locationInView:self.view];
	lastPoint.y -= 20;
	
}


- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
	mouseSwiped = YES;
	
	UITouch *touch = [touches anyObject];	
	CGPoint currentPoint = [touch locationInView:self.view];
	currentPoint.y -= 20;
	
	
	UIGraphicsBeginImageContext(self.view.frame.size);
	[drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
	CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
	CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5.0);
	CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 1.0, 0.0, 0.0, 1.0);
	CGContextBeginPath(UIGraphicsGetCurrentContext());
	CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
	CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y);
	CGContextStrokePath(UIGraphicsGetCurrentContext());
	drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
	UIGraphicsEndImageContext();
	
	lastPoint = currentPoint;
	
	mouseMoved++;
	
	if (mouseMoved == 10) {
		mouseMoved = 0;
	}
	
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
	
	UITouch *touch = [touches anyObject];
	
	if ([touch tapCount] == 2) {
		drawImage.image = nil;
		return;
	}
	
	
	if(!mouseSwiped) {
		UIGraphicsBeginImageContext(self.view.frame.size);
		[drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
		CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
		CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5.0);
		CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 1.0, 0.0, 0.0, 1.0);
		CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
		CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
		CGContextStrokePath(UIGraphicsGetCurrentContext());
		CGContextFlush(UIGraphicsGetCurrentContext());
		drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
		UIGraphicsEndImageContext();
	}
}

It works perfectly however how can I change the colour of the paint from a different view?

Thanks

Code works like a charm. Just one favor. Do you have a clear screen button on your app. If so can you share the code ? Apple has a paint program that is so complex it is hard to follow. Look for MSPaint. It has a paint selector.

[rrichar]

I know begers can't be choosers but I was wondering if you cant limit the paint area to a certain percentage of the screen.

[rrichar]

any help.