baRSS/baRSS/Core Data/FeedGroup+Ext.m

#import "FeedGroup+Ext.h"
#import "Feed+Ext.h"
#import "StoreCoordinator.h"

@implementation FeedGroup (Ext)

#pragma mark - Properties

/// Try return @c self.name or @c self.feed.title ; If both fail return "(no title)"
- (nonnull NSString*)anyName {
	if (self.name.length > 0)
		return self.name;
	if (self.type == FEED && self.feed.title.length > 0)
		return self.feed.title;
	return NSLocalizedString(@"(no title)", nil);
}

/// @return Return @c 16x16px NSImageNameFolder image.
- (nonnull NSImage*)groupIconImage16 {
	NSImage *groupIcon = [NSImage imageNamed:NSImageNameFolder];
	groupIcon.size = NSMakeSize(16, 16);
	return groupIcon;
}

/**
 @return Return @c 16x16px image.
 Either feed icon ( @c type @c == @c FEED ) or @c NSImageNameFolder ( @c type @c == @c GROUP ).
 */
- (nonnull NSImage*)iconImage16 {
	if (self.type == FEED)
		return self.feed.iconImage16;
	return self.groupIconImage16;
}


#pragma mark - Generator

/// Create new instance and set @c Feed and @c FeedMeta if group type is @c FEED
+ (instancetype)newGroup:(FeedGroupType)type inContext:(NSManagedObjectContext*)moc {
	FeedGroup *fg = [[FeedGroup alloc] initWithEntity: FeedGroup.entity insertIntoManagedObjectContext:moc];
	fg.type = type;
	switch (type) {
		case GROUP:     break;
		case FEED:      fg.feed = [Feed newFeedAndMetaInContext:moc]; break;
		case SEPARATOR: fg.name = @"---"; break;
	}
	return fg;
}

/// Instantiates new @c FeedGroup at root level and append at end.
+ (instancetype)appendToRoot:(FeedGroupType)type inContext:(NSManagedObjectContext*)moc {
	NSUInteger lastIndex = [StoreCoordinator countRootItemsInContext:moc];
	FeedGroup *fg = [FeedGroup newGroup:type inContext:moc];
	[fg setParent:nil andSortIndex:(int32_t)lastIndex];
	return fg;
}

/// Set @c parent and @c sortIndex. Also if type is @c FEED calculate and set @c indexPath string.
- (void)setParent:(nullable FeedGroup *)parent andSortIndex:(int32_t)sortIndex {
	self.parent = parent;
	self.sortIndex = sortIndex;
	if (self.type == FEED)
		[self.feed calculateAndSetIndexPathString];
}

/// Set @c sortIndex of @c FeedGroup. Iterate over all @c Feed child items and update @c indexPath string.
- (void)setSortIndexIfChanged:(int32_t)sortIndex {
	if (self.sortIndex != sortIndex) {
		self.sortIndex = sortIndex;
	}
	// Otherwise move from 0.0 -> 0 will not trigger index path update
	[self iterateSorted:NO overDescendantFeeds:^(Feed *feed, BOOL *cancel) {
		[feed calculateAndSetIndexPathString];
	}];
}

/// Set @c name attribute but only if value differs.
- (void)setNameIfChanged:(nullable NSString*)name {
	if (name.length == 0) {
		if (self.name.length > 0)
			self.name = nil; // nullify empty strings
	} else if (![self.name isEqualToString: name]) {
		self.name = name;
	}
}

/// @return Fully initialized @c NSMenuItem with @c title and @c image.
- (NSMenuItem*)newMenuItem {
	NSMenuItem *item = [NSMenuItem new];
	item.title = self.anyName;
	item.enabled = (self.children.count > 0);
	item.image = self.groupIconImage16;
	item.representedObject = self.objectID;
	return item;
}


#pragma mark - Handle Children And Parents -


/// @return IndexPath as semicolon separated string for sorted children starting with root index.
- (NSString*)indexPathString {
	if (self.parent == nil)
		return [NSString stringWithFormat:@"%d", self.sortIndex];
	return [[self.parent indexPathString] stringByAppendingFormat:@".%d", self.sortIndex];
}

/// @return Children sorted by attribute @c sortIndex (same order as in preferences).
- (nullable NSArray<FeedGroup*>*)sortedChildren {
	if (self.children.count == 0)
		return nil;
	return [self.children sortedArrayUsingDescriptors:@[[NSSortDescriptor sortDescriptorWithKey:@"sortIndex" ascending:YES]]];
}

/// @return @c NSArray of all ancestors: First object is root. Last object is the @c FeedGroup that executed the command.
- (NSMutableArray<FeedGroup*>*)allParents {
	if (self.parent == nil)
		return [NSMutableArray arrayWithObject:self];
	NSMutableArray *arr = [self.parent allParents];
	[arr addObject:self];
	return arr;
}

/**
 Iterate over all descenden feeds.

 @param ordered If @c YES items are executed in the same order they are listed in the menu. Pass @n NO for a speed-up.
 @param block Set @c cancel to @c YES to stop execution of further descendants.
 @return @c NO if execution was stopped with @c cancel @c = @c YES in @c block.
 */
- (BOOL)iterateSorted:(BOOL)ordered overDescendantFeeds:(void(^)(Feed*,BOOL*))block  {
	if (self.feed) {
		BOOL stopEarly = NO;
		block(self.feed, &stopEarly);
		if (stopEarly) return NO;
	} else {
		for (FeedGroup *fg in (ordered ? [self sortedChildren] : self.children)) {
			if (![fg iterateSorted:ordered overDescendantFeeds:block])
				return NO;
		}
	}
	return YES;
}


#pragma mark - Printing -


/// @return Simplified description of the feed object.
- (NSString*)readableDescription {
	switch (self.type) {
		case GROUP:     return [NSString stringWithFormat:@"%@:", self.anyName];
		case FEED:      return [NSString stringWithFormat:@"%@ (%@)", self.anyName, self.feed.meta.url];
		case SEPARATOR: return @"-------------";
	}
}

@end