/*

 Copyright (C) 2017 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 The NSView that handles the label color tracking.

 */

#import "TrackView.h"

@interface TrackView ()

@property (strong) NSMutableArray *viewTrackingAreas;

@property NSInteger whichTrackedID;   // indicates the currently tracked label

@property BOOL trackEntered;          // indicates we are currently inside a label tracking area

@end

#pragma mark -

@implementation TrackView

// key for dictionary in NSTrackingAreas's userInfo

NSString *kTrackerKey = @"whichTracker";

// key values for dictionary in NSTrackingAreas's userInfo,

// which tracking area is being tracked

typedef NS_ENUM(NSInteger, trackingAreaIDs) {

    kTrackingArea1 = 1,

    kTrackingArea2,

    kTrackingArea3,

    kTrackingArea4,

    kTrackingArea5,

    kTrackingArea6,

    kTrackingArea7,

    kTrackingArea8

};

// -------------------------------------------------------------------------------

//  awakeFromNib:

//

//  Setup the tracking areas for each colored dot.  Each colored dot is a separate

//  NSView for easy management/tracking purposes.

// -------------------------------------------------------------------------------

- (void)awakeFromNib

{

    [super awakeFromNib];

    [self setupTrackingAreas];

}

// -------------------------------------------------------------------------------

//  setupTrackingAreas:

// -------------------------------------------------------------------------------

- (void)setupTrackingAreas

{

    if (self.viewTrackingAreas == nil)

    {

        // load all the suviews and add tracking areas to them

        NSArray *viewsToFrame = self.subviews;

        _viewTrackingAreas = [NSMutableArray array];    // keep all tracking areas in an array

        // determine the tracking options

        NSTrackingAreaOptions trackingOptions = NSTrackingEnabledDuringMouseDrag |

                                                NSTrackingMouseEnteredAndExited |

                                                NSTrackingActiveInActiveApp |

                                                NSTrackingActiveAlways;

        for (NSUInteger index = 1; index < self.subviews.count; index++)

        {

            // make tracking data (to be stored in NSTrackingArea's userInfo)

            // so we can later determine which tracking area is focused on

            //

            NSDictionary *trackerData = @{kTrackerKey: @(index)};

            NSTrackingArea *trackingArea = [[NSTrackingArea alloc]

                                                initWithRect:[viewsToFrame[index-1] frame]

                                                // note: since we are working with this view's coordinate system,

                                                // we need to  use the 'frame' for each subview instead of its bounds

                                                options:trackingOptions

                                                owner:self

                                                userInfo:trackerData];

            [self.viewTrackingAreas addObject:trackingArea];    // keep track of this tracking area for later disposal

            [self addTrackingArea:trackingArea];    // add the tracking area to the view/window

        }

    }

}

// -------------------------------------------------------------------------------

//  drawRect:rect

//

//  Returns the NSColor corresponding to the sub-view index.

// -------------------------------------------------------------------------------

- (NSColor *)colorForViewIndex:(NSInteger)viewIndex

{

    NSColor *returnColor = nil;

    switch (viewIndex)

    {

        case kTrackingArea1:    // grey

            returnColor = [NSColor grayColor];

            break;

        case kTrackingArea2:    // purple

            returnColor = [NSColor purpleColor];

            break;

        case kTrackingArea3:    // blue

            returnColor = [NSColor blueColor];

            break;

        case kTrackingArea4:    // green

            returnColor = [NSColor greenColor];

            break;

        case kTrackingArea5:    // yellow

            returnColor = [NSColor yellowColor];

            break;

        case kTrackingArea6:    // orange

            returnColor = [NSColor orangeColor];

            break;

        case kTrackingArea7:    // red

            returnColor = [NSColor redColor];

            break;

        case kTrackingArea8:    // none (black)

            returnColor = [NSColor blackColor];

            break;

    }

    return returnColor;

}

// -------------------------------------------------------------------------------

//  drawRect:rect

//

//  Examine all the sub-view colored dots and color them with their appropriate colors.

// -------------------------------------------------------------------------------

- (void)drawRect:(NSRect)rect

{

    NSArray *viewsToFrame = self.subviews;

    NSInteger viewCount = viewsToFrame.count - 1;

    for (NSInteger index = 1; index <= viewCount; index++)

    {

        if (self.whichTrackedID == index)

        {

            // obtain the bezier path (a filled circle) to draw in

            NSBezierPath *theFill = [NSBezierPath bezierPathWithOvalInRect:[viewsToFrame[self.whichTrackedID - 1] frame]];

            NSColor *theColor = [self colorForViewIndex:self.whichTrackedID];

            if (self.trackEntered)

            {

                // if we are tracking inside any label, we want to brighten the color to show selection feedback

                // take the current label color and brighten it

                CGFloat hue, saturation, brightness, alpha;

                [[theColor

                    colorUsingColorSpaceName:NSDeviceRGBColorSpace] getHue:&hue

                    saturation:&saturation brightness:&brightness alpha:&alpha];

                theColor = [NSColor colorWithDeviceHue:hue saturation:saturation-.60 brightness:brightness + 40.0 alpha:alpha];

            }

            // finally, render the color change (light or dark)

            [self lockFocus];

            [theColor set];

            [theFill fill];

            [self unlockFocus];

        }

        else

        {

            // obtain the bezier path (a filled circle) to draw in

            NSBezierPath *theFill = [NSBezierPath bezierPathWithOvalInRect:[viewsToFrame[index-1] frame]];

            // fill the area with the appropriate color

            [[self colorForViewIndex:index] set];

            [theFill fill];

        }

    }

}

// -------------------------------------------------------------------------------

//  getTrackerIDFromDict:dict

//

//  Used in obtaining dictionary entry info from the 'userData', used by each

//  mouse event method.  It helps determine which tracking area is being tracked.

// -------------------------------------------------------------------------------

- (int)getTrackerIDFromDict:(NSDictionary *)dict

{

    id whichTracker = dict[kTrackerKey];

    return [whichTracker intValue];

}

// -------------------------------------------------------------------------------

//  mouseEntered:event

//

//  Because we installed NSTrackingArea to our NSImageView, this method will be called.

// -------------------------------------------------------------------------------

- (void)mouseEntered:(NSEvent *)event

{

    // which tracking area is being tracked?

    _whichTrackedID = [self getTrackerIDFromDict:event.userData];

    _trackEntered = YES;

    [self setNeedsDisplay:YES]; // force update the currently tracked label back to its original color

}

// -------------------------------------------------------------------------------

//  mouseExited:event

//

//  Because we installed NSTrackingArea to our NSImageView, this method will be called.

// -------------------------------------------------------------------------------

- (void)mouseExited:(NSEvent *)event

{

    // which tracking area is being tracked?

    _whichTrackedID = [self getTrackerIDFromDict:event.userData];

    _trackEntered = NO;

    [self setNeedsDisplay:YES]; // force update the currently tracked label to a lighter color

}

// -------------------------------------------------------------------------------

//  mouseDown:event

// -------------------------------------------------------------------------------

- (void)mouseUp:(NSEvent*)event

{

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

    // figure out which label color was clicked on at mouseUp time

    NSArray *labelViews = self.subviews;

    for (NSUInteger index = 1; index < labelViews.count; index++)

    {

        NSRect labelRect = [labelViews[index-1] frame];

        if (NSPointInRect(mousePoint, labelRect))

        {

            // here you would respond to the particular label selection...

            NSLog(@"label %ld was selected", index);

        }

    }

    // on mouse up, we want to dismiss the menu being tracked

    NSMenu *menu = self.enclosingMenuItem.menu;

    [menu cancelTracking];

    // we are no longer tracking, reset the tracked label color (if any)

    _whichTrackedID = NSNotFound;

    [self setNeedsDisplay:YES];

}

@end