/*

     File: ASCSquiggleView.m

 Abstract: ASCSquiggleView is a subclass of NSView that supports custom drawing and event handling.

  Version: 1.2

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 */

#import "ASCSquiggleView.h"

#import "ASCSquiggle.h"

@interface ASCSquiggleView()

@property NSMutableArray *squiggles;

@end

@implementation ASCSquiggleView

static CGFloat randomComponent(void) {

    return (CGFloat)(random() / (CGFloat)INT_MAX);

}

#pragma mark - Init Methods

// The designated initializer for NSView.

- (id)initWithFrame:(NSRect)frame {

    self = [super initWithFrame:frame];

    if (self) {

        // Default view has one rotation.

        _rotations = 1;

        // Default view has no squiggles.

        _squiggles = [NSMutableArray array];

    }

    return self;

}

#pragma mark - Public Methods

// Removes all squiggles from the view.

- (void)removeAllSquiggles {

    [self.squiggles removeAllObjects];

    [self setNeedsDisplay:YES];

}

- (void)setRotations:(NSUInteger)rotations {

    /*

     Updates the number of rotations and redisplay if "rotations" is different than the current number of rotations.

     */    

    if (_rotations != rotations) {

        _rotations = rotations;

        [self setNeedsDisplay:YES];

    }

}

#pragma mark - Drawing Methods

// The method invoked when it is time for an NSView to draw itself.

- (void)drawRect:(NSRect)rect {

    // Clear our current background and make it white.

    [[NSColor whiteColor] set];

    NSRectFill(rect);

    /*

      Create a coordinate transformation based on the value of the rotation slider (to be repeatedly applied below).

     */

    CGFloat widthOverTwo = self.bounds.size.width / 2.0;

    CGFloat heightOverTwo = self.bounds.size.height / 2.0;

    NSAffineTransform *transform = [NSAffineTransform transform];

    [transform translateXBy:widthOverTwo yBy:heightOverTwo];

    [transform rotateByDegrees:360.f / self.rotations];

    [transform translateXBy:-widthOverTwo yBy:-heightOverTwo];

    // For each rotation, draw the the full list of squiggles.

    for (NSUInteger idx = 0; idx < self.rotations; idx++) {

        [self.squiggles enumerateObjectsUsingBlock:^(ASCSquiggle *squiggle, NSUInteger squiggleIndex, BOOL *stop) {

            [squiggle draw];

        }];

        // Apply the transform to rotate in preparation for the next pass.

        [transform concat];

    }

}

#pragma mark - Mouse Event Methods

/*

 Override two of NSResponder's mouse handling methods to respond to the events we want.

 */

// Start drawing a new squiggle on mouse down.

- (void)mouseDown:(NSEvent *)event {

    // Convert from the window's coordinate system to this view's coordinates.

    NSPoint locationInView = [self convertPoint:event.locationInWindow fromView:nil];

    ASCSquiggle *newSquiggle = [[ASCSquiggle alloc] initWithInitialPoint:locationInView];

    CGFloat red     = randomComponent(),

            green   = randomComponent(),

            blue    = randomComponent(),

            alpha   = randomComponent() / 2.f + .5f;

    newSquiggle.color = [NSColor colorWithCalibratedRed:red green:green blue:blue alpha:alpha];

    newSquiggle.thickness = 1 + 3.f * randomComponent();

    [self.squiggles addObject:newSquiggle];

    [self setNeedsDisplay:YES];

}

// Draw points on existing squiggle on mouse drag.

- (void)mouseDragged:(NSEvent *)event {

    // Convert from the window's coordinate system to this view's coordinates.

    NSPoint locationInView = [self convertPoint:event.locationInWindow

                                       fromView:nil];

    ASCSquiggle *currentSquiggle = [self.squiggles lastObject];

    [currentSquiggle addPoint:locationInView];

    [self setNeedsDisplay:YES];

}

#pragma mark - NSView display optimization

/*

 Opaque content drawing can allow some optimizations to happen. The default value is NO.

 */

- (BOOL)isOpaque {

    return YES;

}

@end