/*

     File: TargetGallery.m 

 Abstract: A basic view that animates the movement of "targets". A target is simply an object that associates a view with a velocity. This class adds each target's view as a subview and moves the view according to its associated veloicty.

  Version: 1.1 

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 */

#import "TargetGallery.h"

#import "TargetView.h"

#import "TargetObject.h"

static const NSTimeInterval kAnimationDelay = 0.03333333;

@interface TargetGallery ()

- (void)moveTargets:(id)ignored;

@end

@implementation TargetGallery

@synthesize isEditing = _isEditing;

@synthesize targets = _targets;

- (id)initWithFrame:(NSRect)frame {

    self = [super initWithFrame:frame];

    if (self) {

        _targets = [[NSMutableArray alloc] initWithCapacity:1];

    }

    return self;

}

- (void)dealloc {

    [self stopAnimating];

    [_targets release];

    [super dealloc];

}

#pragma mark NSResponder

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

    // In edit mode, let super route the event as normal 

    if (self.isEditing) return [super mouseDown:event];

    // Otherwise, a click hitting this view means the user missed. Beep to let them know.

    NSBeep();

}

#pragma mark NSView

// By overriding -hitTest: we can control where Cocoa routes mouse events. In this case, when the TargetGallery is in editing mode, we stop Cocoa from sending mouse events to our subviews (targets) by returning self.

- (NSView *)hitTest:(NSPoint)aPoint {

    if (self.isEditing) {

        return self;

    }

    // Not in editing mode, let super (NSView) do its normal hit testing.

    return [super hitTest:aPoint];

}

#pragma mark API

- (void)addTarget:(TargetObject *)target {

    [_targets addObject:target];

    [self addSubview:target.view];

}

- (TargetObject *)targetForView:(NSView *)view {

    for (TargetObject *target in _targets) {

        if (target.view == view) return target;

    }

    return nil;

}

- (TargetObject *)targetAtPoint:(NSPoint)point {

    return [self targetForView:[super hitTest:point]];

}

- (void)startAnimating {

    // cancel any outstanding animation request before requesting a new one.

    [self stopAnimating];

    [self performSelector:@selector(moveTargets:) withObject:nil afterDelay:kAnimationDelay];

}

- (void)stopAnimating {

    [[self class] cancelPreviousPerformRequestsWithTarget:self];

}

- (void)moveTargets:(id)ignored {

    // Adjust each target by its velocity

    for (TargetObject *target in _targets) {

        if (!NSEqualPoints(NSZeroPoint, target.velocity)) {

            NSRect frame = [target.view frame];

            frame.origin.x += target.velocity.x * kAnimationDelay;

            frame.origin.y += target.velocity.y * kAnimationDelay;

            if (!NSIntersectsRect(frame, self.bounds)) {

                // Take horizontal wrap around into consideration.

                if (target.velocity.x < 0) {

                    if (NSMaxX(frame) < NSMinX(self.bounds)) {

                        frame.origin.x = NSMaxX(self.bounds) - 1;

                    }

                } else if (target.velocity.x > 0) {

                    if (NSMinX(frame) > NSMaxX(self.bounds)) {

                        frame.origin.x = NSMinX(self.bounds) - NSWidth(frame) + 1;

                    }

                }

                // Take vertical wrap around into consideration.

                if (target.velocity.y < 0) {

                    if (NSMaxY(frame) < NSMinY(self.bounds)) {

                        frame.origin.y = NSMaxY(self.bounds) - 1;

                    }

                } else if (target.velocity.y > 0) {

                    if (NSMinY(frame) > NSMaxY(self.bounds)) {

                        frame.origin.y = NSMinY(self.bounds) - NSHeight(frame) + 1;

                    }

                }

            }

            [target.view setFrameOrigin:frame.origin];

        }

    }

    // Set up calling next frame of the animation.

    [self performSelector:@selector(moveTargets:) withObject:nil afterDelay:kAnimationDelay];

}

@end