/*

 Copyright (C) 2018 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 View controller object to host the icon collection view.

 */

#import "IconViewController.h"

#import "IconViewBox.h"

#import "BaseNode.h"

// notification for indicating file system content has been received

NSString *kReceivedContentNotification = @"ReceivedContentNotification";

@interface IconViewController ()

@property (readwrite, strong) NSMutableArray *icons;

@end

#pragma mark -

@implementation IconViewController

@synthesize baseNode = _baseNode;

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

//  awakeFromNib

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

- (void)awakeFromNib

{

    // Listen for changes in the url for this view.

    [self addObserver:self

           forKeyPath:@"url"

              options:(NSKeyValueObservingOptionNew | NSKeyValueObservingOptionOld)

              context:nil];

}

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

//  dealloc

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

- (void)dealloc

{

    [self removeObserver:self forKeyPath:@"url"];

}

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

//  setBaseNode:baseNode

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

- (void)setBaseNode:(BaseNode *)baseNode

{

    // Our base node has changed, notify ourselves to update our data source.

    _baseNode = baseNode;

    [self gatherContents:baseNode];

}

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

//  baseNode

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

- (BaseNode *)baseNode

{

    return _baseNode;

}

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

//  updateIcons:iconArray

//

//  The incoming object is the NSArray of file system objects to display.

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

- (void)updateIcons:(id)iconArray

{

    self.icons = iconArray;

    [[NSNotificationCenter defaultCenter] postNotificationName:kReceivedContentNotification object:nil];

}

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

//  gatherContents:inObject

//

//  Gathering the contents and their icons could be expensive.

//  This method is being called on a separate thread to avoid blocking the UI.

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

- (void)gatherContents:(id)inObject

{

    @autoreleasepool {

        NSMutableArray *contentArray = [[NSMutableArray alloc] init];

        if ([inObject isKindOfClass:[BaseNode class]])

        {

            // We are populating our collection view with a set of internet shortcuts from our baseNode.

            //

            NSArray *shortcuts = self.baseNode.children;

            for (BaseNode *node in shortcuts)

            {

                // the node's icon was set to a smaller size before, for this collection view we need to make it bigger

                NSImage *shortcutIcon = [node.nodeIcon copy];

                shortcutIcon.size = NSMakeSize(kIconLargeImageSize, kIconLargeImageSize);

                [contentArray addObject:[NSMutableDictionary dictionaryWithObjectsAndKeys:

                                            shortcutIcon, KEY_ICON,

                                            node.nodeTitle, KEY_NAME,

                                         nil]];

            }

        }

        else

        {

            // We are populating our collection view with a file system directory URL.

            //

            NSURL *urlToDirectory = inObject;

            NSArray *fileURLs = [[NSFileManager defaultManager] contentsOfDirectoryAtURL:urlToDirectory

                                                              includingPropertiesForKeys:@[]

                                                                                 options:0

                                                                                   error:nil];

            if (fileURLs != nil)

            {

                for (NSURL *element in fileURLs)

                {

                    NSImage *elementIcon = [[NSWorkspace sharedWorkspace] iconForFile:element.path];

                    // only allow visible objects

                    NSNumber *hiddenFlag = nil;

                    if ([element getResourceValue:&hiddenFlag forKey:NSURLIsHiddenKey error:nil])

                    {

                        if (!hiddenFlag.boolValue)

                        {

                            NSString *elementNameStr = nil;

                            if ([element getResourceValue:&elementNameStr forKey:NSURLLocalizedNameKey error:nil])

                            {

                                // file system object is visible so add to our array

                                [contentArray addObject:[NSMutableDictionary dictionaryWithObjectsAndKeys:

                                                            elementIcon, KEY_ICON,

                                                            elementNameStr, KEY_NAME,

                                                         nil]];

                            }

                        }

                    }

                }

            }

        }

        // call back on the main thread to update the icons in our view

        [self performSelectorOnMainThread:@selector(updateIcons:) withObject:contentArray waitUntilDone:YES];

    }

}

#pragma mark - KVO

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

//  observeValueForKeyPath:ofObject:change:context

//

//  Listen for changes in the file url.

//  Given a url, obtain its contents and add only the invisible items to the collection.

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

- (void)observeValueForKeyPath:(NSString *)keyPath

                                ofObject:(id)object 

                                change:(NSDictionary *)change 

                                context:(void *)context

{

    // build our directory contents on a separate thread,

    // some portions are from disk which could get expensive depending on the size

    //

    [NSThread detachNewThreadSelector:  @selector(gatherContents:)

                                        toTarget:self // we are the target

                                        withObject:self.url];

}

@end