/*

 Copyright (C) 2016 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 An example demonstrating adding accessibility to an NSView subclass that behaves like a checkbox by implementing the NSAccessibilityCheckBox protocol.

 */

#import "AAPLTicTacToeCheckboxView.h"

static NSString * const AAPLCheckboxSelected = @"CustomCheckboxSelected";

static NSString * const AAPLCheckboxUnselected = @"CustomCheckboxUnselected";

static const CGFloat AAPLCheckboxWidth = 12.0;

static const CGFloat AAPLCheckboxHeight = AAPLCheckboxWidth;

static const CGFloat AAPLCheckboxTextSpacing = 8.0; // spacing between box and text

@interface AAPLTicTacToeCheckboxView ()

@property (nonatomic, strong) IBInspectable NSString *checkboxText;

@property (nonatomic) BOOL checked;

@end

@implementation AAPLTicTacToeCheckboxView

- (BOOL)acceptsFirstResponder

{

    return YES;

}

- (BOOL)becomeFirstResponder

{

    BOOL didBecomeFirstResponder = [super becomeFirstResponder];

    [self setNeedsDisplay:YES];

    return didBecomeFirstResponder;

}

- (BOOL)resignFirstResponder

{

    BOOL didResignFirstResponder = [super resignFirstResponder];

    [self setNeedsDisplay:YES];

    return didResignFirstResponder;

}

- (void)mouseUp:(NSEvent *)mouseEvent

{

    [self toggleCheckedState];

}

- (void)toggleCheckedState

{

    self.checked = !self.checked;

    [self.delegate checkboxCheckedStateChanged:self];

    // Whenever the value of the checkbox changes, let accessibility clients know

    NSAccessibilityPostNotification(self, NSAccessibilityValueChangedNotification);

    [self setNeedsDisplay:YES];

}

- (void)keyDown:(NSEvent *)keyEvent

{

    int spacebarKeyCode = 49;

    if ( [keyEvent keyCode] == spacebarKeyCode )

    {

        [self toggleCheckedState];

    }

    else

    {

        [super keyDown:keyEvent];

    }

}

- (void)drawRect:(NSRect)dirtyRect

{

    NSRect bounds = self.bounds;

    NSRect boxRect = NSMakeRect(bounds.origin.x,

                                bounds.origin.y + 5,

                                AAPLCheckboxWidth,

                                AAPLCheckboxHeight);

    NSRect textRect = NSMakeRect(bounds.origin.x + AAPLCheckboxWidth + AAPLCheckboxTextSpacing,

                                 bounds.origin.y,

                                 bounds.size.width,

                                 bounds.size.height);

    // Draw the checkbox box

    // Obtain the bundle based on our class in order to support `IB_DESIGNABLE`.

    NSBundle *bundle = [NSBundle bundleForClass:[self class]];

    NSImage *boxImage = nil;

    if ( self.checked )

    {

        boxImage = [bundle imageForResource:AAPLCheckboxSelected];

    }

    else

    {

        boxImage = [bundle imageForResource:AAPLCheckboxUnselected];

    }

    [boxImage drawInRect:boxRect fromRect:NSZeroRect operation:NSCompositeSourceOver fraction:1.0];

    // Draw the checkbox text

    NSDictionary *textAttributes = @{ NSFontAttributeName : [NSFont fontWithName:@"Andale Mono" size:16.0f],

                                      NSForegroundColorAttributeName : [NSColor blackColor] };

    [self.checkboxText drawInRect:textRect withAttributes:textAttributes];

    // Draw the focus ring

    BOOL isFirstResponder = [[[NSApp mainWindow] firstResponder] isEqual:self];

    if ( isFirstResponder )

    {

        [NSGraphicsContext saveGraphicsState];

        NSSetFocusRingStyle(NSFocusRingOnly);

        [[NSBezierPath bezierPathWithRect:boxRect] fill];

        [NSGraphicsContext restoreGraphicsState];

    }

}

#pragma mark Accessibility

- (NSString *)accessibilityLabel

{

    return self.checkboxText;

}

- (NSNumber *)accessibilityValue

{

    return self.checked ? @YES : @NO;

}

- (BOOL)accessibilityPerformPress

{

    [self toggleCheckedState];

    return YES;

}

@end