// MyViewController.h // 010-NSView // #import <Cocoa/Cocoa.h> #import "MyPoint.h" @interface MyViewController : NSView { NSMutableArray * myMutaryOfBrushStrokes; NSMutableArray * myMutaryOfPoints; } - (float)randVar; @end // MyViewController.m // 010-NSView // #import "MyViewController.h" @implementation MyViewController - (id)initWithFrame:(NSRect)pNsrectFrameRect { if ((self = [super initWithFrame:pNsrectFrameRect]) == nil) { return self; } // end if myMutaryOfBrushStrokes = [[NSMutableArray alloc]init]; // initialise random numebr generator used in drawRect for creating colours etc. srand(time(NULL)); return self; } // end initWithFrame

-(void)mouseDown:(NSEvent *)pTheEvent { myMutaryOfPoints = [[NSMutableArray alloc]init]; [myMutaryOfBrushStrokes addObject:myMutaryOfPoints]; NSPoint tvarMousePointInWindow = [pTheEvent locationInWindow]; NSPoint tvarMousePointInView = [self convertPoint:tvarMousePointInWindow fromView:nil]; MyPoint * tvarMyPointObj = [[MyPoint alloc]initWithNSPoint:tvarMousePointInView]; [myMutaryOfPoints addObject:tvarMyPointObj]; } // end mouseDown

-(void)mouseDragged:(NSEvent *)pTheEvent { NSPoint tvarMousePointInWindow = [pTheEvent locationInWindow]; NSPoint tvarMousePointInView = [self convertPoint:tvarMousePointInWindow fromView:nil]; MyPoint * tvarMyPointObj = [[MyPoint alloc]initWithNSPoint:tvarMousePointInView]; [myMutaryOfPoints addObject:tvarMyPointObj]; [self setNeedsDisplay:YES]; } // end mouseDragged

-(void)mouseUp:(NSEvent *)pTheEvent { NSPoint tvarMousePointInWindow = [pTheEvent locationInWindow]; NSPoint tvarMousePointInView = [self convertPoint:tvarMousePointInWindow fromView:nil]; MyPoint * tvarMyPointObj = [[MyPoint alloc]initWithNSPoint:tvarMousePointInView]; [myMutaryOfPoints addObject:tvarMyPointObj]; [self setNeedsDisplay:YES]; } // end mouseUp - (float)randVar; { return ( (float)(rand() % 10000 ) / 10000.0); } // end randVar

- (void)drawRect:(NSRect)pNSRect { // colour the background white [[NSColor whiteColor] set]; // this is Cocoa NSRectFill( pNSRect ); if ([myMutaryOfBrushStrokes count] == 0) { return; } // end if // This is Quartz NSGraphicsContext * tvarNSGraphicsContext = [NSGraphicsContext currentContext]; CGContextRef tvarCGContextRef = (CGContextRef) [tvarNSGraphicsContext graphicsPort]; NSUInteger tvarIntNumberOfStrokes = [myMutaryOfBrushStrokes count]; NSUInteger i; for (i = 0; i < tvarIntNumberOfStrokes; i++) { CGContextSetRGBStrokeColor(tvarCGContextRef,[self randVar],[self randVar],[self randVar],[self randVar]); CGContextSetLineWidth(tvarCGContextRef, (1.0 + ([self randVar] * 10.0)) ); myMutaryOfPoints = [myMutaryOfBrushStrokes objectAtIndex:i]; NSUInteger tvarIntNumberOfPoints = [myMutaryOfPoints count]; // always >= 2 MyPoint * tvarLastPointObj = [myMutaryOfPoints objectAtIndex:0]; CGContextBeginPath(tvarCGContextRef); CGContextMoveToPoint(tvarCGContextRef,[tvarLastPointObj x],[tvarLastPointObj y]); NSUInteger j; for (j = 1; j < tvarIntNumberOfPoints; j++) { // note the index starts at 1 MyPoint * tvarCurPointObj = [myMutaryOfPoints objectAtIndex:j]; CGContextAddLineToPoint(tvarCGContextRef,[tvarCurPointObj x],[tvarCurPointObj y]); } // end for CGContextDrawPath(tvarCGContextRef,kCGPathStroke); } // end for } // end drawRect @end

// MyPoint.h // 010-NSView // // wrapper for NSPoint #import <Cocoa/Cocoa.h> @interface MyPoint : NSObject { NSPoint myNSPoint; } - (id) initWithNSPoint:(NSPoint)pNSPoint; - (NSPoint) myNSPoint; - (float)x; - (float)y; @end // MyPoint.m // 010-NSView // #import "MyPoint.h" @implementation MyPoint - (id) initWithNSPoint:(NSPoint)pNSPoint; { if ((self = [super init]) == nil) { return self; } // end if myNSPoint.x = pNSPoint.x; myNSPoint.y = pNSPoint.y; return self; } // end initWithNSPoint - (NSPoint) myNSPoint; { return myNSPoint; } // end myNSPoint - (float)x; { return myNSPoint.x; } // end x - (float)y; { return myNSPoint.y; } // end y @end