/*

     File: TrackingView.m 

 Abstract: The NSView that handles various NSTrackingArea objects, draws menu-like highlighting,

 and exposes its containing views as a suggestion for accessibility.

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 */

#import "TrackingView.h"

@interface TrackingView ()

@property (retain) NSMutableArray *trackingAreas;

@end

@implementation TrackingView

@synthesize trackingAreas;

// key for dictionary in NSTrackingAreas's userInfo

NSString *kTrackerKey = @"whichTracker";

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

// which tracking area is being tracked

enum trackingAreaIDs

{

    kTrackingArea1 = 1,

    kTrackingArea2,

    kTrackingArea3,

    kTrackingArea4,

    kTrackingArea5,

    kTrackingArea6,

    kTrackingArea7,

    kTrackingArea8

};

#pragma mark -

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

//  dealloc:

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

- (void)dealloc

{

    [trackingAreas release];

    [super dealloc];

}

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

//  setupTrackingAreas

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

- (void)setupTrackingAreas

{

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

    //

    self.trackingAreas = [NSMutableArray array];    // keep all tracking areas in an array

    // determine the tracking options

    NSTrackingAreaOptions trackingOptions = NSTrackingEnabledDuringMouseDrag |

                                            NSTrackingMouseEnteredAndExited |

                                            NSTrackingActiveInActiveApp |

                                            NSTrackingActiveAlways;

    NSView *subView;

    NSInteger tag = 1;

    for (subView in self.subviews)

    {

        // make tracking data (to be stored in NSTrackingArea's userInfo) so we can later

        // determine which tracking area is focused on

        //

        NSDictionary *trackerData = [NSDictionary dictionaryWithObjectsAndKeys:

                                     [NSNumber numberWithInteger:tag++], kTrackerKey,

                                     nil];

        NSTrackingArea *trackingArea = [[NSTrackingArea alloc]

                                        initWithRect:[subView 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.trackingAreas addObject:trackingArea];    // keep track of this tracking area for later disposal

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

        [trackingArea release];

    }

}

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

//  removeTrackingAreas

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

- (void)removeTrackingAreas

{

    NSTrackingArea *trackingArea;

    for (trackingArea in self.trackingAreas)

    {

        [self removeTrackingArea:trackingArea];

    }

}

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

//  viewDidMoveToWindow

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

- (void)viewDidMoveToWindow

{

    [super viewDidMoveToWindow];

    if ([self window] != nil)

    {

        // Setup the tracking areas for each colored box; each colored box is a separate NSTrackingArea

        [self setupTrackingAreas];

    }

    else

    {

        // we are being removed from our window

        [self removeTrackingAreas];

    }

}

#pragma mark - Drawing

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

//  colorForViewIndex:viewIndex

//

//  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;

        default:

            break;

    }

    return returnColor;

}

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

//  drawRect:rect

//

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

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

- (void)drawRect:(NSRect)rect

{

#pragma unused(rect)

    NSView *subView;

    NSInteger idx = 1;

    for (subView in self.subviews)

    {

        if (whichTrackedID == idx)

        {

            // draw the square highlighted (brighter/darker depending on the color)

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

            NSBezierPath* theFill = [NSBezierPath bezierPathWithRect:subView.frame];

            NSColor* theColor = [self colorForViewIndex:whichTrackedID];

            if (trackEntered)

            {

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

                if (whichTrackedID == kTrackingArea1)

                {

                    theColor = [NSColor lightGrayColor];    // use a light gray to draw for the black square

                }

                else if (whichTrackedID == kTrackingArea8)

                {

                    theColor = [NSColor darkGrayColor];     // use a dark gray to draw for the black square

                }

                else

                {

                    // 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-.60f

                                                brightness:brightness + 40.0f

                                                     alpha:alpha];

                }

            }

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

            [self lockFocus];

            [theColor set];

            [theFill fill];

            [self unlockFocus];

        }

        else

        {

            // just draw the square

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

            NSBezierPath *theFill = [NSBezierPath bezierPathWithRect:subView.frame];

            // fill the area with the appropriate color

            [[self colorForViewIndex:idx] set];

            [theFill fill];

        }

        idx++;

    }

}

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

//  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 objectForKey: kTrackerKey];

    return [whichTracker intValue];

}

#pragma mark - Events

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

//  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 *colorViews = [self subviews];

    NSInteger numViews = [colorViews count];

    NSInteger idx;

    for (idx = 1; idx <= numViews; idx++)

    {

        NSRect labelRect = [[colorViews objectAtIndex:idx-1] frame];

        if (NSPointInRect(mousePoint, labelRect))

        {

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

            //

            NSLog(@"%@", [NSString stringWithFormat:@"Color %ld selected", (long)idx]);

        }

    }

    // 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];

}

#pragma mark - Accessibility

// This view groups the contents of one suggestion.

// It should be exposed to accessibility, and should report itself with the role 'AXGroup'.

// Because this is an NSView subclass, most of the basic accessibility behavior

//      (accessibility parent, children, size, position, window, and more) is inherited from NSView.

// Note that even the role description attribute will update accordingly and its behavior does not need to be overridden.

//

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

//  accessibilityIsIgnored

//  Make sure we are reported by accessibility.  NSView's default return value is YES.

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

- (BOOL)accessibilityIsIgnored

{

    return NO;

}

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

//  accessibilityAttributeValue:attribute

//

//  When asked for the value of our role attribute, return the group role.

//  For other attributes, use the inherited behavior of NSView.

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

- (id)accessibilityAttributeValue:(NSString *)attribute

{

    id attributeValue;

    if ([attribute isEqualToString:NSAccessibilityRoleAttribute])

    {

        attributeValue = NSAccessibilityGroupRole;

    }

    else

    {

        attributeValue = [super accessibilityAttributeValue:attribute];

    }

    return attributeValue;

}

@end