/*

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

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 NSButton subclass for supporting drop down menus.

 */

#import "DropDownButton.h"

@implementation DropDownButton

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

//  awakeFromNib

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

- (void)awakeFromNib

{

    [super awakeFromNib];

    if (self.menu != nil)

    {

        [self setUsesMenu:YES];

    }

}

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

//  setUsesMenu:flag

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

- (void)setUsesMenu:(BOOL)flag

{

    if (popUpCell == nil && flag)

    {

        popUpCell = [[NSPopUpButtonCell alloc] initTextCell:@""];

        [popUpCell setPullsDown:YES];

        popUpCell.preferredEdge = NSMaxYEdge;

    }

    else if (popUpCell != nil && !flag)

    {

        popUpCell = nil;

    }

}

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

//  usesMenu

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

- (BOOL)usesMenu

{

    return (popUpCell != nil);

}

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

//  runPopUp:theEvent

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

- (void)runPopUp:(NSEvent *)theEvent

{

    // create the menu the popup will use

    NSMenu *popUpMenu = [self.menu copy];

    [popUpMenu insertItemWithTitle:@"" action:NULL keyEquivalent:@"" atIndex:0];    // blank item at top

    popUpCell.menu = popUpMenu;

    // and show it

    [popUpCell performClickWithFrame:self.bounds inView:self];

    [self setNeedsDisplay: YES];

}

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

//  mouseDown:theEvent

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

- (void)mouseDown:(NSEvent *)theEvent

{

    if (self.usesMenu)

    {

        [self runPopUp:theEvent];

    }

    else

    {

        [super mouseDown:theEvent];

    }

}

@end