Feed Statistics View

- Bugfix: group unread count fetch & undo / redo operations
- ModalSheet refactored

baRSS.xcodeproj/project.pbxproj

@@ -13,6 +13,7 @@
 		54195886218E1BDB00581B79 /* NSMenu+Ext.m in Sources */ = {isa = PBXBuildFile; fileRef = 54195885218E1BDB00581B79 /* NSMenu+Ext.m */; };
 		54209E942117325100F3B5EF /* DrawImage.m in Sources */ = {isa = PBXBuildFile; fileRef = 54209E932117325100F3B5EF /* DrawImage.m */; };
 		543695D8214F1F2700DA979D /* NSMenuItem+Ext.m in Sources */ = {isa = PBXBuildFile; fileRef = 543695D7214F1F2700DA979D /* NSMenuItem+Ext.m */; };
+		544936FB21F1E66100DEE9AA /* Statistics.m in Sources */ = {isa = PBXBuildFile; fileRef = 544936FA21F1E66100DEE9AA /* Statistics.m */; };
 		544B011A2114B41200386E5C /* ModalSheet.m in Sources */ = {isa = PBXBuildFile; fileRef = 544B01192114B41200386E5C /* ModalSheet.m */; };
 		544B011D2114EE9100386E5C /* AppHook.m in Sources */ = {isa = PBXBuildFile; fileRef = 544B011C2114EE9100386E5C /* AppHook.m */; };
 		544DCCB9212A2B4D002DBC46 /* RSXML.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 544DCCB8212A2B4D002DBC46 /* RSXML.framework */; };
@@ -87,6 +88,8 @@
 		54209E932117325100F3B5EF /* DrawImage.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = DrawImage.m; sourceTree = "<group>"; };
 		543695D6214F1F2700DA979D /* NSMenuItem+Ext.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "NSMenuItem+Ext.h"; sourceTree = "<group>"; };
 		543695D7214F1F2700DA979D /* NSMenuItem+Ext.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = "NSMenuItem+Ext.m"; sourceTree = "<group>"; };
+		544936F921F1E66100DEE9AA /* Statistics.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = Statistics.h; sourceTree = "<group>"; };
+		544936FA21F1E66100DEE9AA /* Statistics.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = Statistics.m; sourceTree = "<group>"; };
 		544B01182114B41200386E5C /* ModalSheet.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ModalSheet.h; sourceTree = "<group>"; };
 		544B01192114B41200386E5C /* ModalSheet.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ModalSheet.m; sourceTree = "<group>"; };
 		544B011B2114EE9100386E5C /* AppHook.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = AppHook.h; sourceTree = "<group>"; };
@@ -174,6 +177,17 @@
 			path = "Status Bar Menu";
 			sourceTree = "<group>";
 		};
+		544936F721F1E51E00DEE9AA /* Helper */ = {
+			isa = PBXGroup;
+			children = (
+				54209E922117325100F3B5EF /* DrawImage.h */,
+				54209E932117325100F3B5EF /* DrawImage.m */,
+				544936F921F1E66100DEE9AA /* Statistics.h */,
+				544936FA21F1E66100DEE9AA /* Statistics.m */,
+			);
+			path = Helper;
+			sourceTree = "<group>";
+		};
 		544FBD4321064AEB008A260C /* Frameworks */ = {
 			isa = PBXGroup;
 			children = (
@@ -241,8 +255,7 @@
 				54FE73CF21220DEC003EAC65 /* StoreCoordinator.m */,
 				54ACC29321061E270020715F /* FeedDownload.h */,
 				54ACC29421061E270020715F /* FeedDownload.m */,
-				54209E922117325100F3B5EF /* DrawImage.h */,
+				544936F721F1E51E00DEE9AA /* Helper */,
-				54209E932117325100F3B5EF /* DrawImage.m */,
 				54195880218A05E700581B79 /* Categories */,
 				546FC44D2118B357007CC3A3 /* Preferences */,
 				54ACC28521061B3C0020715F /* Assets.xcassets */,
@@ -401,6 +414,7 @@
 				546FC44321189975007CC3A3 /* SettingsGeneral.m in Sources */,
 				54ACC29521061E270020715F /* FeedDownload.m in Sources */,
 				5477D34E21233C62002BA27F /* FeedGroup+Ext.m in Sources */,
+				544936FB21F1E66100DEE9AA /* Statistics.m in Sources */,
 				540F704521B6C16C0022E69D /* FeedMeta+Ext.m in Sources */,
 				54ACC28C21061B3C0020715F /* main.m in Sources */,
 				54FE73D3212316CD003EAC65 /* BarMenu.m in Sources */,

baRSS/Categories/Feed+Ext.h

@@ -29,6 +29,7 @@
 + (instancetype)newFeedAndMetaInContext:(NSManagedObjectContext*)context;
 + (instancetype)appendToRootWithDefaultIntervalInContext:(NSManagedObjectContext*)moc;
 - (void)calculateAndSetIndexPathString;
+- (void)resetArticleCountAndIndexPathString;
 - (void)updateWithRSS:(RSParsedFeed*)obj postUnreadCountChange:(BOOL)flag;
 // Article properties
 - (NSArray<FeedArticle*>*)sortedArticles;

baRSS/Categories/Feed+Ext.m

@@ -57,6 +57,17 @@
 		self.indexPath = pthStr;
 }
 
+/// Reset attributes @c articleCount, @c unreadCount, and @c indexPath.
+- (void)resetArticleCountAndIndexPathString {
+	int16_t totalCount = (int16_t)self.articles.count;
+	int16_t unreadCount = (int16_t)[[self.articles valueForKeyPath:@"@sum.unread"] integerValue];
+	if (self.articleCount != totalCount)
+		self.articleCount = totalCount;
+	if (self.unreadCount != unreadCount)
+		self.unreadCount = unreadCount; // remember to update global total unread count
+	[self calculateAndSetIndexPathString];
+}
+
 
 #pragma mark - Update Feed Items -
 
@@ -144,6 +155,8 @@
 	fa.author = entry.author;
 	fa.link = entry.link;
 	fa.published = entry.datePublished;
+	if (!fa.published)
+		fa.published = entry.dateModified;
 	[self addArticlesObject:fa];
 	return fa;
 }

baRSS/FeedDownload.m

@@ -133,6 +133,13 @@ static BOOL _nextUpdateIsForced = NO;
 	[FeedDownload batchUpdateFeeds:list showErrorAlert:NO finally:^(NSArray<Feed*> *successful, NSArray<Feed*> *failed) {
 		[self saveContext:moc andPostChanges:successful];
 		[moc reset];
+		if (updateAll) { // forced update will also download missing feed icons
+			NSArray<Feed*> *missingIcons = [StoreCoordinator listOfFeedsMissingIconsInContext:moc];
+			[self batchDownloadFavicons:missingIcons replaceExisting:NO finally:^{
+				[self saveContext:moc andPostChanges:successful];
+				[moc reset];
+			}];
+		}
 		[self resumeUpdates]; // always reset the timer
 	}];
 }
@@ -285,14 +292,20 @@ static BOOL _nextUpdateIsForced = NO;
 	}
 	dispatch_group_enter(group);
 	[self parseFeedRequest:[self newRequest:feed.meta] xmlBlock:nil feedBlock:^(RSParsedFeed *rss, NSError *error, NSHTTPURLResponse *response) {
-		if (error) {
+		if (!feed.isDeleted) {
-			if (alert) [NSApp presentError:error];
+			if (error) {
-			[feed.meta setErrorAndPostponeSchedule];
+				if (alert) {
-			[failed addObject:feed];
+					NSAlert *alertPopup = [NSAlert alertWithError:error];
-		} else {
+					alertPopup.informativeText = [NSString stringWithFormat:@"Error loading source: %@", response.URL.absoluteString];
-			[feed.meta setSucessfulWithResponse:response];
+					[alertPopup runModal];
-			if (rss) [feed updateWithRSS:rss postUnreadCountChange:YES];
+				}
-			[successful addObject:feed]; // will be added even if statusCode == 304 (rss == nil)
+				[feed.meta setErrorAndPostponeSchedule];
+				[failed addObject:feed];
+			} else {
+				[feed.meta setSucessfulWithResponse:response];
+				if (rss) [feed updateWithRSS:rss postUnreadCountChange:YES];
+				[successful addObject:feed]; // will be added even if statusCode == 304 (rss == nil)
+			}
 		}
 		dispatch_group_leave(group);
 	}];
@@ -421,6 +434,8 @@ static BOOL _nextUpdateIsForced = NO;
 	dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
 		NSURL *favURL = [[self hostURL:urlStr] URLByAppendingPathComponent:@"favicon.ico"];
 		// TODO: fix anonymous session. initWithContentsOfURL: will set cookie in ~/Library/Cookies/
+		// TODO: check ~/Library/Caches/de.relikd.baRSS/fsCachedData/
+		// TODO: fix missing favicon by parsing html
 		NSImage *img = [[NSImage alloc] initWithContentsOfURL:favURL];
 		if (!img || ![img isValid])
 			img = nil;

baRSS/Helper/Statistics.h

@@ -0,0 +1,38 @@
+//
+//  The MIT License (MIT)
+//  Copyright (c) 2019 Oleg Geier
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy of
+//  this software and associated documentation files (the "Software"), to deal in
+//  the Software without restriction, including without limitation the rights to
+//  use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+//  of the Software, and to permit persons to whom the Software is furnished to do
+//  so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+
+#import <Cocoa/Cocoa.h>
+
+@protocol RefreshIntervalButtonDelegate <NSObject>
+@required
+/**
+ The interval-unit combination is stored as follows:
+ :: @c sender.tag @c >> @c 3 (Refresh Interval)
+ :: @c sender.tag @c & @c 0x7 (Refresh Unit, where 0: seconds and 4: weeks)
+ */
+- (void)refreshIntervalButtonClicked:(NSButton*)sender;
+@end
+
+@interface Statistics : NSObject
++ (NSDictionary*)refreshInterval:(NSArray<NSDate*> *)list;
++ (NSView*)viewForRefreshInterval:(NSDictionary*)info articleCount:(NSUInteger)count callback:(nullable id<RefreshIntervalButtonDelegate>)callback;
+@end

baRSS/Helper/Statistics.m

@@ -0,0 +1,222 @@
+//
+//  The MIT License (MIT)
+//  Copyright (c) 2019 Oleg Geier
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy of
+//  this software and associated documentation files (the "Software"), to deal in
+//  the Software without restriction, including without limitation the rights to
+//  use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+//  of the Software, and to permit persons to whom the Software is furnished to do
+//  so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+
+#import "Statistics.h"
+
+@implementation Statistics
+
+#pragma mark - Generate Refresh Interval Statistics
+
+/**
+ @return @c nil if list contains less than 2 entries. Otherwise: @{min, max, avg, median, earliest, latest}
+ */
++ (NSDictionary*)refreshInterval:(NSArray<NSDate*> *)list {
+	if (!list || list.count == 0)
+		return nil;
+	
+	NSDate *earliest = [NSDate distantFuture];
+	NSDate *latest = [NSDate distantPast];
+	NSDate *prev = nil;
+	NSMutableArray<NSNumber*> *differences = [NSMutableArray array];
+	for (NSDate *d in list) {
+		if (![d isKindOfClass:[NSDate class]]) // because valueForKeyPath: can return NSNull
+			continue;
+		earliest = [d earlierDate:earliest];
+		latest = [d laterDate:latest];
+		if (prev) {
+			int dif = abs((int)[d timeIntervalSinceDate:prev]);
+			[differences addObject:[NSNumber numberWithInt:dif]];
+		}
+		prev = d;
+	}
+	if (differences.count == 0)
+		return nil;
+	
+	[differences sortUsingDescriptors:@[[NSSortDescriptor sortDescriptorWithKey:@"intValue" ascending:YES]]];
+	
+	NSUInteger i = differences.count;
+	NSUInteger mid = (i/2);
+	unsigned int med = differences[mid].unsignedIntValue;
+	if (i > 1 && (i % 1) == 0) { // even feed count, use median of two values
+		med = (med + differences[mid+1].unsignedIntValue) / 2;
+	}
+	return @{@"min" : [self stringForInterval:differences.firstObject.unsignedIntValue],
+			 @"max" : [self stringForInterval:differences.lastObject.unsignedIntValue],
+			 @"avg" : [self stringForInterval:[(NSNumber*)[differences valueForKeyPath:@"@avg.self"] unsignedIntValue]],
+			 @"median" : [self stringForInterval:med],
+			 @"earliest" : earliest,
+			 @"latest" : latest };
+}
+
+/// Print @c 1.1f float string with single char unit: e.g., 3.3m, 1.7h
++ (NSString*)stringForInterval:(unsigned int)val {
+	float i;
+	NSUInteger u = [self findAppropriateTimeUnit:val interval:&i];
+	return [NSString stringWithFormat:@"%1.1f%c", i, [@"smhdw" characterAtIndex:u]];
+}
+
+/// @return Unit as int @c (0-4) (0: seconds - 4: weeks). Sets division result @c intv.
++ (NSUInteger)findAppropriateTimeUnit:(unsigned int)val interval:(float*)intv {
+	if (val > 604800) {*intv = (val / 604800.f); return 4;} // weeks
+	if (val > 86400) {*intv = (val / 86400.f); return 3;} // days
+	if (val > 3600) {*intv = (val / 3600.f); return 2;} // hours
+	if (val > 60) {*intv = (val / 60.f); return 1;} // minutes
+	*intv = (val / 1.f);
+	return 0;
+}
+
+/// @return Single integer value that combines refresh interval and refresh unit. To be used as @c NSButton.tag
++ (NSInteger)buttonTagFromRefreshString:(NSString*)str {
+	NSInteger refresh = (NSInteger)roundf([str floatValue]) << 3;
+	switch ([str characterAtIndex:(str.length - 1)]) {
+		case 's': return 0 | refresh;
+		case 'm': return 1 | refresh;
+		case 'h': return 2 | refresh;
+		case 'd': return 3 | refresh;
+		case 'w': return 4 | refresh;
+	}
+	return 0; // error, should never happen though
+}
+
+
+#pragma mark - Feed Statistics UI
+
+
+/**
+ Generate UI with buttons for min, max, avg and median. Also show number of articles and latest article date.
+
+ @param info The dictionary generated with @c -refreshInterval:
+ @param count Article count.
+ @param callback If set, @c sender will be called with @c -refreshIntervalButtonClicked:.
+                 If not disable button border and display as bold inline text.
+ @return Centered view without autoresizing.
+ */
++ (NSView*)viewForRefreshInterval:(NSDictionary*)info articleCount:(NSUInteger)count callback:(nullable id<RefreshIntervalButtonDelegate>)callback {
+	NSString *lbl = [NSString stringWithFormat:NSLocalizedString(@"%lu articles.", nil), count];
+	if (!info || info.count == 0)
+		return [self grayLabel:lbl];
+	
+	// Subview with 4 button (min, max, avg, median)
+	NSView *buttonsView = [[NSView alloc] init];
+	NSPoint origin = NSZeroPoint;
+	for (NSString *str in @[@"min", @"max", @"avg", @"median"]) {
+		NSString *title = [str stringByAppendingString:@":"];
+		NSString *value = [info valueForKey:str];
+		NSView *v = [self viewWithLabel:title andRefreshButton:value callback:callback];
+		[v setFrameOrigin:origin];
+		[buttonsView addSubview:v];
+		origin.x += NSWidth(v.frame);
+	}
+	[buttonsView setFrameSize:NSMakeSize(origin.x, NSHeight(buttonsView.subviews.firstObject.frame))];
+	
+	// Subview with article count and latest article date
+	NSDate *lastUpdate = [info valueForKey:@"latest"];
+	NSString *mod = [NSDateFormatter localizedStringFromDate:lastUpdate dateStyle:NSDateFormatterMediumStyle timeStyle:NSDateFormatterShortStyle];
+	NSTextField *dateView = [self grayLabel:[lbl stringByAppendingFormat:@" (latest: %@)", mod]];
+	
+	// Feed wasn't updated in a while ...
+	if ([lastUpdate timeIntervalSinceNow] < (-360 * 24 * 60 * 60)) {
+		NSMutableAttributedString *as = dateView.attributedStringValue.mutableCopy;
+		[as addAttribute:NSForegroundColorAttributeName value:[NSColor systemRedColor] range:NSMakeRange(lbl.length, as.length - lbl.length)];
+		[dateView setAttributedStringValue:as];
+	}
+	
+	// Calculate offset and align both horizontally centered
+	CGFloat maxWidth = NSWidth(buttonsView.frame);
+	if (maxWidth < NSWidth(dateView.frame))
+		maxWidth = NSWidth(dateView.frame);
+	[buttonsView setFrameOrigin:NSMakePoint(0.5f*(maxWidth - NSWidth(buttonsView.frame)), 0)];
+	[dateView setFrameOrigin:NSMakePoint(0.5f*(maxWidth - NSWidth(dateView.frame)), NSHeight(buttonsView.frame))];
+	
+	// Dump both into single parent view and make that view centered during resize
+	NSView *parent = [[NSView alloc] initWithFrame:NSMakeRect(0, 0, maxWidth, NSMaxY(dateView.frame))];
+	parent.autoresizingMask = NSViewMinXMargin | NSViewMaxXMargin;// | NSViewMinYMargin | NSViewMaxYMargin;
+	parent.autoresizesSubviews = NO;
+//	parent.layer = [CALayer layer];
+//	parent.layer.backgroundColor = [NSColor systemYellowColor].CGColor;
+	[parent addSubview:dateView];
+	[parent addSubview:buttonsView];
+	return parent;
+}
+
+/**
+ Create view with duration button, e.g., '3.4h' and label infornt of it.
+ */
++ (NSView*)viewWithLabel:(NSString*)title andRefreshButton:(NSString*)value callback:(nullable id<RefreshIntervalButtonDelegate>)callback {
+	static const int buttonPadding = 5;
+	if (!value  || value.length == 0)
+		return nil;
+	
+	NSButton *button = [self grayInlineButton:value];
+	if (callback) {
+		button.target = callback;
+		button.action = @selector(refreshIntervalButtonClicked:);
+	} else {
+		button.bordered = NO;
+		button.enabled = NO;
+	}
+	NSTextField *label;
+	if (title && title.length > 0) {
+		label = [self grayLabel:title];
+		[label setFrameOrigin:NSMakePoint(0, button.alignmentRectInsets.bottom + 0.5f*(NSHeight(button.frame) - NSHeight(label.frame)))];
+	}
+	[button setFrameOrigin:NSMakePoint(NSWidth(label.frame), 0)];
+	
+	CGFloat maxHeight = NSHeight(button.frame);
+	if (maxHeight < NSHeight(label.frame))
+		maxHeight = NSHeight(label.frame);
+	
+	NSView *parent = [[NSView alloc] initWithFrame: NSMakeRect(0, 0, NSMaxX(button.frame) + buttonPadding, maxHeight + buttonPadding)];
+	[parent addSubview:label];
+	[parent addSubview:button];
+	return parent;
+}
+
+/**
+ @return Rounded, gray inline button with tag equal to refresh interval.
+ */
++ (NSButton*)grayInlineButton:(NSString*)text {
+	NSButton *button = [NSButton buttonWithTitle:text target:nil action:nil];
+	button.font = [NSFont monospacedDigitSystemFontOfSize: NSFont.labelFontSize weight:NSFontWeightBold];
+	button.bezelStyle = NSBezelStyleInline;
+	button.controlSize = NSControlSizeSmall;
+	button.tag = [self buttonTagFromRefreshString:text];
+	[button sizeToFit];
+	return button;
+}
+
+/**
+ @return Simple Label with smaller gray text, non-editable.
+ */
++ (NSTextField*)grayLabel:(NSString*)text {
+	NSTextField *label = [NSTextField textFieldWithString:text];
+	label.font = [NSFont monospacedDigitSystemFontOfSize: NSFont.labelFontSize weight:NSFontWeightRegular];
+	label.textColor = [NSColor systemGrayColor];
+	label.drawsBackground = NO;
+	label.selectable = NO;
+	label.editable = NO;
+	label.bezeled = NO;
+	[label sizeToFit];
+	return label;
+}
+
+@end

baRSS/Preferences/Feeds Tab/ModalFeedEdit.m

@@ -26,6 +26,8 @@
 #import "Feed+Ext.h"
 #import "FeedMeta+Ext.h"
 #import "FeedGroup+Ext.h"
+#import "Statistics.h"
+#import <QuartzCore/QuartzCore.h>
 
 
 #pragma mark - ModalEditDialog -
@@ -46,7 +48,7 @@
 /// @return New @c ModalSheet with its subclass @c .view property as dialog content.
 - (ModalSheet *)getModalSheet {
 	if (!self.modalSheet)
-		self.modalSheet = [ModalSheet modalWithView:self.view];
+		self.modalSheet = [[ModalSheet alloc] initWithView:self.view];
 	return self.modalSheet;
 }
 /// This method should be overridden by subclasses. Used to save changes to persistent store.
@@ -60,7 +62,7 @@
 #pragma mark - ModalFeedEdit -
 
 
-@interface ModalFeedEdit()
+@interface ModalFeedEdit() <RefreshIntervalButtonDelegate>
 @property (weak) IBOutlet NSTextField *url;
 @property (weak) IBOutlet NSTextField *name;
 @property (weak) IBOutlet NSTextField *refreshNum;
@@ -69,6 +71,7 @@
 @property (weak) IBOutlet NSProgressIndicator *spinnerName;
 @property (weak) IBOutlet NSButton *warningIndicator;
 @property (weak) IBOutlet NSPopover *warningPopover;
+@property (strong) NSView *statisticsView;
 
 @property (copy) NSString *previousURL; // check if changed and avoid multiple download
 @property (copy) NSString *httpDate;
@@ -105,6 +108,7 @@
 		unit = self.refreshUnit.numberOfItems - 1;
 	[self.refreshUnit selectItemAtIndex:unit];
 	self.warningIndicator.image = [fg.feed iconImage16];
+	[self statsForCoreDataObject];
 }
 
 #pragma mark - Edit Feed Data
@@ -189,6 +193,7 @@
 	NSPoint belowURL = NSMakePoint(0,self.url.frame.size.height);
 	if ([menu popUpMenuPositioningItem:nil atLocation:belowURL inView:self.url]) {
 		NSInteger idx = [menu indexOfItem:menu.highlightedItem];
+		if (idx < 0) idx = 0; // User hit enter without selection. Assume first item, because PopUpMenu did return YES!
 		return [list objectAtIndex:(NSUInteger)idx].link;
 	}
 	return nil; // user selection canceled
@@ -214,6 +219,8 @@
 	if (parsedTitle.length > 0 && [self.name.stringValue isEqualToString:@""]) {
 		self.name.stringValue = parsedTitle; // no damage to replace an empty string
 	}
+	// TODO: user preference to automatically select refresh interval (selection: None,min,max,avg,median)
+	[self statsForDownloadObject];
 	// 4. Continue with favicon download (or finish with error)
 	if (self.feedError) {
 		[self finishDownloadWithFavicon:[NSImage imageNamed:NSImageNameCaution]];
@@ -243,6 +250,70 @@
 	[self.modalSheet setDoneEnabled:YES];
 }
 
+#pragma mark - Feed Statistics
+
+/// Perform statistics on newly downloaded feed item
+- (void)statsForDownloadObject {
+	NSMutableArray<NSDate*> *arr = [NSMutableArray arrayWithCapacity:self.feedResult.articles.count];
+	for (RSParsedArticle *a in self.feedResult.articles) {
+		NSDate *d = a.datePublished;
+		if (!d) d = a.dateModified;
+		if (!d) continue;
+		[arr addObject:d];
+	}
+	[self appendViewWithFeedStatistics:arr count:self.feedResult.articles.count];
+}
+
+/// Perform statistics on stored core data object
+- (void)statsForCoreDataObject {
+	NSArray<FeedArticle*> *articles = [self.feedGroup.feed sortedArticles];
+	[self appendViewWithFeedStatistics:[articles valueForKeyPath:@"published"] count:articles.count];
+}
+
+/// Generate statistics UI with buttons to quickly select refresh unit and duration.
+- (void)appendViewWithFeedStatistics:(NSArray*)dates count:(NSUInteger)count {
+	static const CGFloat statsPadding = 15.f;
+	CGFloat prevHeight = 0.f;
+	if (self.statisticsView != nil) {
+		prevHeight = self.statisticsView.frame.size.height + statsPadding;
+		[self.statisticsView removeFromSuperview];
+		self.statisticsView = nil;
+	}
+	NSDictionary *stats = [Statistics refreshInterval:dates];
+	NSView *v = [Statistics viewForRefreshInterval:stats articleCount:count callback:self];
+	[[self getModalSheet] extendContentViewBy:v.frame.size.height + statsPadding - prevHeight];
+	[v setFrameOrigin:NSMakePoint(0.5f*(NSWidth(self.view.frame) - NSWidth(v.frame)), 0)];
+	[self.view addSubview:v];
+	self.statisticsView = v;
+}
+
+/// Callback method for @c Statistics @c +viewForRefreshInterval:articleCount:callback:
+- (void)refreshIntervalButtonClicked:(NSButton *)sender {
+	NSInteger num = (sender.tag >> 3);
+	NSInteger unit = (sender.tag & 0x7);
+	if (self.refreshNum.integerValue != num) {
+		[self animateControlAttention:self.refreshNum];
+		self.refreshNum.integerValue = num;
+	}
+	if (self.refreshUnit.indexOfSelectedItem != unit) {
+		[self animateControlAttention:self.refreshUnit];
+		[self.refreshUnit selectItemAtIndex:unit];
+	}
+}
+
+/// Helper method to animate @c NSControl to draw user attention. View will be scalled up in a fraction of a second.
+- (void)animateControlAttention:(NSView*)control {
+	CABasicAnimation *scale = [CABasicAnimation animationWithKeyPath:@"transform"];
+	CATransform3D tr = CATransform3DIdentity;
+	tr = CATransform3DTranslate(tr, NSMidX(control.bounds), NSMidY(control.bounds), 0);
+	tr = CATransform3DScale(tr, 1.1, 1.1, 1);
+	tr = CATransform3DTranslate(tr, -NSMidX(control.bounds), -NSMidY(control.bounds), 0);
+	scale.toValue = [NSValue valueWithCATransform3D:tr];
+	scale.duration = 0.15f;
+	scale.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
+	[control.layer addAnimation:scale forKey:scale.keyPath];
+}
+
 
 #pragma mark - NSTextField Delegate
 

baRSS/Preferences/Feeds Tab/ModalFeedEdit.xib

@@ -23,7 +23,7 @@
         <customObject id="-3" userLabel="Application" customClass="NSObject"/>
         <customView id="i0K-k8-GMU" userLabel="View">
             <rect key="frame" x="0.0" y="0.0" width="320" height="79"/>
-            <autoresizingMask key="autoresizingMask" widthSizable="YES" flexibleMinY="YES"/>
+            <autoresizingMask key="autoresizingMask" widthSizable="YES" heightSizable="YES"/>
             <subviews>
                 <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" fixedFrame="YES" translatesAutoresizingMaskIntoConstraints="NO" id="MOX-a1-Yda" userLabel="URL Label">
                     <rect key="frame" x="-2" y="60" width="103" height="17"/>

baRSS/Preferences/Feeds Tab/OpmlExport.m

@@ -45,7 +45,7 @@
 /// Display Save File Panel to select export destination. All feeds from core data will be exported.
 + (void)showExportDialog:(NSWindow*)window withContext:(NSManagedObjectContext*)moc {
 	NSSavePanel *sp = [NSSavePanel savePanel];
-	sp.nameFieldStringValue = [NSString stringWithFormat:@"baRSS feeds %@", [self currentDayAsString]];
+	sp.nameFieldStringValue = [NSString stringWithFormat:@"baRSS feeds %@", [self currentDayAsStringISO8601:NO]];
 	sp.allowedFileTypes = @[@"opml"];
 	sp.allowsOtherFileTypes = YES;
 	NSView *radioView = [self radioGroupCreate:@[NSLocalizedString(@"Hierarchical", nil),
@@ -68,6 +68,7 @@
 /// Handle import dialog and perform web requests (feed data & icon). Creates a single undo group.
 + (void)showImportDialog:(NSWindow*)window withTreeController:(NSTreeController*)tree {
 	NSManagedObjectContext *moc = tree.managedObjectContext;
+	//[moc refreshAllObjects];
 	[moc.undoManager beginUndoGrouping];
 	[self showImportDialog:window withContext:moc success:^(NSArray<Feed *> *added) {
 		[StoreCoordinator saveContext:moc andParent:YES];
@@ -204,7 +205,9 @@
  @return Save this string to file.
  */
 + (NSString*)exportFeedsHierarchical:(BOOL)flag inContext:(NSManagedObjectContext*)moc {
-	NSDictionary *info = @{@"dateCreated" : [NSDate date], @"ownerName" : @"baRSS", OPMLTitleKey : @"baRSS feeds"};
+	NSDictionary *info = @{OPMLTitleKey : @"baRSS feeds",
+						   @"ownerName" : @"baRSS",
+						   @"dateCreated" : [self currentDayAsStringISO8601:YES]};
 	RSOPMLItem *doc = [RSOPMLItem itemWithAttributes:info];
 	@autoreleasepool {
 		NSArray<FeedGroup*> *arr = [StoreCoordinator sortedListOfRootObjectsInContext:moc];
@@ -246,10 +249,13 @@
 #pragma mark - Helper
 
 
-/// @return Date formatted as @c yyyy-MM-dd
+/// @param flag If @c YES use long internet format for opml file. If @c NO use short format as filename.
-+ (NSString*)currentDayAsString {
++ (NSString*)currentDayAsStringISO8601:(BOOL)flag {
-	NSDateComponents *now = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:[NSDate date]];
+	if (flag)
-	return  [NSString stringWithFormat:@"%04ld-%02ld-%02ld", now.year, now.month, now.day];
+		return [[[NSISO8601DateFormatter alloc] init] stringFromDate:[NSDate date]];
+//	NSDateComponents *now = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:[NSDate date]];
+//	return [NSString stringWithFormat:@"%04ld-%02ld-%02ld", now.year, now.month, now.day];
+	return [NSDateFormatter localizedStringFromDate:[NSDate date] dateStyle:NSDateFormatterShortStyle timeStyle:NSDateFormatterNoStyle];
 }
 
 /// Count items where @c xmlURL key is set.

baRSS/Preferences/Feeds Tab/SettingsFeeds.m

@@ -38,6 +38,7 @@
 
 @implementation SettingsFeeds
 
+// TODO: drag-n-drop feeds to opml file?
 // Declare a string constant for the drag type - to be used when writing and retrieving pasteboard data...
 static NSString *dragNodeType = @"baRSS-feed-drag";
 
@@ -52,37 +53,80 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 	
 	self.dataStore.managedObjectContext = [StoreCoordinator createChildContext];
 	self.dataStore.managedObjectContext.undoManager = self.undoManager;
+	self.dataStore.managedObjectContext.automaticallyMergesChangesFromParent = NO;
+}
+
+/**
+ Refresh current context from parent context and start new undo grouping.
+ @note Should be balanced with @c endCoreDataChangeUndoChanges:
+ */
+- (void)beginCoreDataChange {
+	// Does seem to create problems with undo stack if refreshing from parent context
+	//[self.dataStore.managedObjectContext refreshAllObjects];
+	[self.undoManager beginUndoGrouping];
+}
+
+/**
+ End undo grouping and save changes to persistent store. Or undo group if no changes occured.
+ @note Should be balanced with @c beginCoreDataChange
+
+ @param flag If @c YES force @c NSUndoManager to undo the changes immediatelly.
+ @return Returns @c YES if context was saved.
+ */
+- (BOOL)endCoreDataChangeShouldUndo:(BOOL)flag {
+	[self.undoManager endUndoGrouping];
+	if (!flag && self.dataStore.managedObjectContext.hasChanges) {
+		[StoreCoordinator saveContext:self.dataStore.managedObjectContext andParent:YES];
+		return YES;
+	}
+	[self.undoManager disableUndoRegistration];
+	[self.undoManager undoNestedGroup];
+	[self.undoManager enableUndoRegistration];
+	return NO;
+}
+
+/**
+ After the user did undo or redo we can't ensure integrity without doing some additional work.
+ */
+- (void)saveWithUnpredictableChange {
+	NSSet<Feed*> *arr = [self.dataStore.managedObjectContext.insertedObjects
+						 filteredSetUsingPredicate:[NSPredicate predicateWithFormat:@"class == %@", [Feed class]]];
+	[StoreCoordinator saveContext:self.dataStore.managedObjectContext andParent:YES];
+	[StoreCoordinator restoreFeedCountsAndIndexPaths:[arr valueForKeyPath:@"objectID"]]; // main context will not create undo group
+	[[NSNotificationCenter defaultCenter] postNotificationName:kNotificationTotalUnreadCountReset object:nil];
+	[self.dataStore rearrangeObjects]; // update ordering
 }
 
 
 #pragma mark - UI Button Interaction
 
 
+/// Add feed button.
 - (IBAction)addFeed:(id)sender {
 	[self showModalForFeedGroup:nil isGroupEdit:NO];
 }
 
+/// Add group button.
 - (IBAction)addGroup:(id)sender {
 	[self showModalForFeedGroup:nil isGroupEdit:YES];
 }
 
+/// Add separator button.
 - (IBAction)addSeparator:(id)sender {
-	[self.undoManager beginUndoGrouping];
+	[self beginCoreDataChange];
 	[self insertFeedGroupAtSelection:SEPARATOR].name = @"---";
-	[self.undoManager endUndoGrouping];
+	[self endCoreDataChangeShouldUndo:NO];
-	[self saveChanges];
 }
 
-/// Remove user selected item from persistent store.
+/// Remove feed button. User has selected one or more item in outline view.
 - (IBAction)remove:(id)sender {
-	[self.undoManager beginUndoGrouping];
+	[self beginCoreDataChange];
 	NSArray<NSTreeNode*> *parentNodes = [self.dataStore.selectedNodes valueForKeyPath:@"parentNode"];
 	[self.dataStore remove:sender];
 	for (NSTreeNode *parent in parentNodes) {
 		[self restoreOrderingAndIndexPathStr:parent];
 	}
-	[self.undoManager endUndoGrouping];
+	[self endCoreDataChangeShouldUndo:NO];
-	[self saveChanges];
 	[[NSNotificationCenter defaultCenter] postNotificationName:kNotificationTotalUnreadCountReset object:nil];
 }
 
@@ -94,6 +138,7 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 	[self showModalForFeedGroup:fg isGroupEdit:YES]; // yes will be overwritten anyway
 }
 
+/// Share menu button. Currently only import & export feeds as OPML.
 - (IBAction)shareMenu:(NSButton*)sender {
 	if (!sender.menu) {
 		sender.menu = [[NSMenu alloc] initWithTitle:NSLocalizedString(@"Import / Export menu", nil)];
@@ -116,11 +161,6 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 #pragma mark - Insert & Edit Feed Items / Modal Dialog
 
 
-/// Save core data changes of current object context to persistent store
-- (void)saveChanges {
-	[StoreCoordinator saveContext:self.dataStore.managedObjectContext andParent:YES];
-}
-
 /**
  Open a new modal window to edit the selected @c FeedGroup.
  @note isGroupEdit @c flag will be overwritten if @c FeedGroup parameter is not @c nil.
@@ -130,7 +170,7 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
  */
 - (void)showModalForFeedGroup:(FeedGroup*)fg isGroupEdit:(BOOL)flag {
 	if (fg.type == SEPARATOR) return;
-	[self.undoManager beginUndoGrouping];
+	[self beginCoreDataChange];
 	if (!fg || ![fg isKindOfClass:[FeedGroup class]]) {
 		fg = [self insertFeedGroupAtSelection:(flag ? GROUP : FEED)];
 	}
@@ -140,19 +180,9 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 	[self.view.window beginSheet:[editDialog getModalSheet] completionHandler:^(NSModalResponse returnCode) {
 		if (returnCode == NSModalResponseOK) {
 			[editDialog applyChangesToCoreDataObject];
-			[self.undoManager endUndoGrouping];
-		} else {
-			[self.undoManager endUndoGrouping];
-			[self.dataStore.managedObjectContext rollback];
 		}
-		BOOL hasChanges = [self.dataStore.managedObjectContext hasChanges];
+		if ([self endCoreDataChangeShouldUndo:(returnCode != NSModalResponseOK)]) {
-		if (hasChanges) {
-			[self saveChanges];
 			[self.dataStore rearrangeObjects];
-		} else {
-			[self.undoManager disableUndoRegistration];
-			[self.undoManager undoNestedGroup];
-			[self.undoManager enableUndoRegistration];
 		}
 	}];
 }
@@ -213,7 +243,7 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 
 /// Begin drag-n-drop operation by copying selected nodes to memory
 - (BOOL)outlineView:(NSOutlineView *)outlineView writeItems:(NSArray *)items toPasteboard:(NSPasteboard *)pboard {
-	[self.undoManager beginUndoGrouping];
+	[self beginCoreDataChange];
 	[pboard declareTypes:[NSArray arrayWithObject:dragNodeType] owner:self];
 	[pboard setString:@"dragging" forType:dragNodeType];
 	self.currentlyDraggedNodes = items;
@@ -222,14 +252,7 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 
 /// Finish drag-n-drop operation by saving changes to persistent store
 - (void)outlineView:(NSOutlineView *)outlineView draggingSession:(NSDraggingSession *)session endedAtPoint:(NSPoint)screenPoint operation:(NSDragOperation)operation {
-	[self.undoManager endUndoGrouping];
+	[self endCoreDataChangeShouldUndo:NO];
-	if (self.dataStore.managedObjectContext.hasChanges) {
-		[self saveChanges];
-	} else {
-		[self.undoManager disableUndoRegistration];
-		[self.undoManager undoNestedGroup];
-		[self.undoManager enableUndoRegistration];
-	}
 	self.currentlyDraggedNodes = nil;
 }
 
@@ -318,17 +341,13 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 /// Perform undo operation and redraw UI & menu bar unread count
 - (void)undo:(id)sender {
 	[self.undoManager undo];
-	[self saveChanges];
+	[self saveWithUnpredictableChange];
-	[[NSNotificationCenter defaultCenter] postNotificationName:kNotificationTotalUnreadCountReset object:nil];
-	[self.dataStore rearrangeObjects]; // update ordering
 }
 
 /// Perform redo operation and redraw UI & menu bar unread count
 - (void)redo:(id)sender {
 	[self.undoManager redo];
-	[self saveChanges];
+	[self saveWithUnpredictableChange];
-	[[NSNotificationCenter defaultCenter] postNotificationName:kNotificationTotalUnreadCountReset object:nil];
-	[self.dataStore rearrangeObjects]; // update ordering
 }
 
 /// User pressed enter; open edit dialog for selected item.
@@ -362,7 +381,6 @@ static NSString *dragNodeType = @"baRSS-feed-drag";
 	}
 	[[NSPasteboard generalPasteboard] clearContents];
 	[[NSPasteboard generalPasteboard] setString:str forType:NSPasteboardTypeString];
-	NSLog(@"%@", str); // TODO: drag-n-drop feed to opml?
 }
 
 /**

baRSS/Preferences/General Tab/SettingsGeneral.m

@@ -61,7 +61,7 @@
 
 - (IBAction)fixCache:(NSButton *)sender {
 	[StoreCoordinator deleteUnreferencedFeeds];
-	[StoreCoordinator restoreFeedCountsAndIndexPaths];
+	[StoreCoordinator restoreFeedCountsAndIndexPaths:nil];
 }
 
 - (IBAction)changeMenuBarIconSetting:(NSButton*)sender {

baRSS/Preferences/ModalSheet.h

@@ -26,6 +26,9 @@
 @property (readonly) BOOL didCloseAndSave;
 @property (readonly) BOOL didCloseAndCancel;
 
-+ (instancetype)modalWithView:(NSView*)content;
+- (instancetype)initWithContentRect:(NSRect)contentRect styleMask:(NSWindowStyleMask)style backing:(NSBackingStoreType)backingStoreType defer:(BOOL)flag NS_UNAVAILABLE;
+- (instancetype)initWithView:(NSView*)content NS_DESIGNATED_INITIALIZER;
+
 - (void)setDoneEnabled:(BOOL)accept;
+- (void)extendContentViewBy:(CGFloat)dy;
 @end

baRSS/Preferences/ModalSheet.m

@@ -23,7 +23,7 @@
 #import "ModalSheet.h"
 
 @interface ModalSheet()
-@property (strong) NSButton *btnDone;
+@property (weak) NSButton *btnDone;
 @end
 
 @implementation ModalSheet
@@ -52,15 +52,13 @@
 	[self.sheetParent endSheet:self returnCode:response];
 }
 
-
 /**
- Designated initializer for @c ModalSheet.
+ Designated initializer for @c ModalSheet. 'Done' and 'Cancel' button will be added automatically.
 
- @param content @c NSView will be displayed in dialog box. 'Done' and 'Cancel' button will be added automatically.
+ @param content @c NSView will be displayed in dialog box.
  */
-+ (instancetype)modalWithView:(NSView*)content {
+- (instancetype)initWithView:(NSView*)content {
 	static const int padWindow = 20;
-	static const int padButtons = 12;
 	static const int minWidth = 320;
 	static const int maxWidth = 1200;
 	
@@ -68,48 +66,67 @@
 	if      (prevWidth < minWidth)  prevWidth = minWidth;
 	else if (prevWidth > maxWidth)  prevWidth = maxWidth;
 	
-	NSRect cFrame = NSMakeRect(padWindow, padWindow, prevWidth, content.frame.size.height);
+	NSSize contentSize = NSMakeSize(prevWidth, content.frame.size.height);
-	NSRect wFrame = CGRectInset(cFrame, -padWindow, -padWindow);
+	[content setFrameSize:contentSize];
+	
+	NSSize wSize = NSMakeSize(contentSize.width + 2 * padWindow, contentSize.height + 2 * padWindow);
 	
 	NSWindowStyleMask style = NSWindowStyleMaskTitled | NSWindowStyleMaskResizable | NSWindowStyleMaskFullSizeContentView;
-	ModalSheet *sheet = [[super alloc] initWithContentRect:wFrame styleMask:style backing:NSBackingStoreBuffered defer:NO];
+	self = [super initWithContentRect:NSMakeRect(0, 0, wSize.width, wSize.height) styleMask:style backing:NSBackingStoreBuffered defer:NO];
+	if (self) {
+		NSButton *btnDone = [NSButton buttonWithTitle:NSLocalizedString(@"Done", nil) target:self action:@selector(didTapDoneButton:)];
+		NSButton *btnCancel = [NSButton buttonWithTitle:NSLocalizedString(@"Cancel", nil) target:self action:@selector(didTapCancelButton:)];
+		btnDone.keyEquivalent = @"\r"; // Enter / Return
+		btnCancel.keyEquivalent = [NSString stringWithFormat:@"%c", 0x1b]; // ESC
 		
-	// Respond buttons
+		// Make room for buttons
-	sheet.btnDone = [NSButton buttonWithTitle:NSLocalizedString(@"Done", nil) target:sheet action:@selector(didTapDoneButton:)];
+		wSize.height += btnDone.frame.size.height;
-	sheet.btnDone.keyEquivalent = @"\r"; // Enter / Return
+		[self setContentSize:wSize];
-	sheet.btnDone.autoresizingMask = NSViewMinXMargin | NSViewMaxYMargin;
 		
-	NSButton *btnCancel = [NSButton buttonWithTitle:NSLocalizedString(@"Cancel", nil) target:sheet action:@selector(didTapCancelButton:)];
+		// Restrict resizing to width only (after setContentSize:)
-	btnCancel.keyEquivalent = [NSString stringWithFormat:@"%c", 0x1b]; // ESC
+		self.minSize = NSMakeSize(minWidth + 2 * padWindow, wSize.height);
-	btnCancel.autoresizingMask = NSViewMinXMargin | NSViewMaxYMargin;
+		self.maxSize = NSMakeSize(maxWidth + 2 * padWindow, wSize.height);
 		
-	NSRect align = [sheet.btnDone alignmentRectForFrame:sheet.btnDone.frame];
+		// Content view (set origin after setContentSize:)
-	align.origin.x = wFrame.size.width - align.size.width - padWindow;
+		[content setFrameOrigin:NSMakePoint(padWindow, wSize.height - padWindow - contentSize.height)];
-	align.origin.y = padWindow;
+		[self.contentView addSubview:content];
-	[sheet.btnDone setFrameOrigin:[sheet.btnDone frameForAlignmentRect:align].origin];
 		
-	align.origin.x -= [btnCancel alignmentRectForFrame:btnCancel.frame].size.width + padButtons;
+		// Respond buttons
-	[btnCancel setFrameOrigin:[btnCancel frameForAlignmentRect:align].origin];
+		[self placeButtons:@[btnDone, btnCancel] inBottomRightCornerWithPadding:padWindow];
-	
+		[self.contentView addSubview:btnCancel];
-	// this is equivalent, however I'm not sure if these values will change in a future OS
+		[self.contentView addSubview:btnDone];
-//	[btnDone setFrameOrigin:NSMakePoint(wFrame.size.width - btnDone.frame.size.width - 12, 13)]; // =20 with alignment
+		self.btnDone = btnDone;
-//	[btnCancel setFrameOrigin:NSMakePoint(btnDone.frame.origin.x - btnCancel.frame.size.width, 13)];
+	}
-	
+	return self;
-	// add all UI elements to the window view
-	content.frame = cFrame;
-	[sheet.contentView addSubview:content];
-	[sheet.contentView addSubview:sheet.btnDone];
-	[sheet.contentView addSubview:btnCancel];
-	
-	// add respond buttons to the window height
-	wFrame.size.height += align.size.height + padButtons;
-	[sheet setContentSize:wFrame.size];
-	
-	// constraints on resizing
-	sheet.minSize = NSMakeSize(minWidth + 2 * padWindow, wFrame.size.height);
-	sheet.maxSize = NSMakeSize(maxWidth, wFrame.size.height);
-	return sheet;
 }
+
+/**
+ Buttons will stick to the right margin and bottom margin when resizing. Also sets autoresizingMask.
+
+ @param buttons First item is rightmost button. Next buttons will be appended left of that button and so on.
+ @param padding Distance between button and right / bottom edge.
+ */
+- (void)placeButtons:(NSArray<NSButton*> *)buttons inBottomRightCornerWithPadding:(int)padding {
+	NSEdgeInsets edge = buttons.firstObject.alignmentRectInsets;
+	NSPoint p = NSMakePoint(self.contentView.frame.size.width - padding + edge.right, padding - edge.bottom);
+	for (NSButton *btn in buttons) {
+		p.x -= btn.frame.size.width;
+		[btn setFrameOrigin:p];
+		btn.autoresizingMask = NSViewMinXMargin | NSViewMaxYMargin;
+	}
+}
+
+/**
+ Resize modal window by @c dy. Makes room for additional content. Use negative values to shrink window.
+ */
+- (void)extendContentViewBy:(CGFloat)dy {
+	self.minSize = NSMakeSize(self.minSize.width, self.minSize.height + dy);
+	self.maxSize = NSMakeSize(self.maxSize.width, self.maxSize.height + dy);
+	NSRect r = self.frame;
+	r.size.height += dy;
+	[self setFrame:r display:YES animate:YES];
+}
+
 @end
 
 

baRSS/StoreCoordinator.h

@@ -38,6 +38,7 @@
 + (NSArray<FeedGroup*>*)sortedListOfRootObjectsInContext:(NSManagedObjectContext*)moc;
 // Restore sound state
 + (void)deleteUnreferencedFeeds;
-+ (void)restoreFeedCountsAndIndexPaths;
++ (void)restoreFeedCountsAndIndexPaths:(NSArray<NSManagedObjectID*>*)list;
-+ (NSArray<Feed*>*)listOfMissingFeedsInContext:(NSManagedObjectContext*)moc;
++ (NSArray<Feed*>*)listOfFeedsMissingArticlesInContext:(NSManagedObjectContext*)moc;
++ (NSArray<Feed*>*)listOfFeedsMissingIconsInContext:(NSManagedObjectContext*)moc;
 @end

baRSS/StoreCoordinator.m

@@ -40,7 +40,7 @@
 	NSManagedObjectContext *context = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
 	[context setParentContext:[self getMainContext]];
 	context.undoManager = nil;
-	//context.automaticallyMergesChangesFromParent = YES;
+	context.automaticallyMergesChangesFromParent = YES;
 	return context;
 }
 
@@ -137,7 +137,7 @@
 	NSExpression *exp = [NSExpression expressionForFunction:@"sum:" arguments:@[[NSExpression expressionForKeyPath:@"unreadCount"]]];
 	NSFetchRequest *fr = [NSFetchRequest fetchRequestWithEntityName: Feed.entity.name];
 	if (str && str.length > 0)
-		fr.predicate = [NSPredicate predicateWithFormat:@"indexPath BEGINSWITH %@", str];
+		fr.predicate = [NSPredicate predicateWithFormat:@"indexPath BEGINSWITH %@", [str stringByAppendingString:@"."]];
 	return [self fetchInteger:moc request:fr expression:exp];
 }
 
@@ -192,29 +192,40 @@
 
 /**
  Iterate over all @c Feed and re-calculate @c unreadCount, @c articleCount and @c indexPath.
+ Restore will happend on the main context.
+ 
+ @param list A list of @c Feed objectIDs. Acts like a filter, if @c nil performs a fetch on all feed items.
  */
-+ (void)restoreFeedCountsAndIndexPaths {
++ (void)restoreFeedCountsAndIndexPaths:(NSArray<NSManagedObjectID*>*)list {
 	NSManagedObjectContext *moc = [self getMainContext];
-	NSArray *result = [self fetchAllRows:[NSFetchRequest fetchRequestWithEntityName: Feed.entity.name] inContext:moc];
+	if (!list) {
+		NSFetchRequest *fr = [NSFetchRequest fetchRequestWithEntityName: Feed.entity.name];
+		[fr setResultType:NSManagedObjectIDResultType];
+		list = [self fetchAllRows:fr inContext:moc];
+	}
 	[moc performBlock:^{
-		for (Feed *feed in result) {
+		for (NSManagedObjectID *moi in list) {
-			int16_t totalCount = (int16_t)feed.articles.count;
+			Feed *f = [moc objectWithID:moi];
-			int16_t unreadCount = (int16_t)[[feed.articles valueForKeyPath:@"@sum.unread"] integerValue];
+			if ([f isKindOfClass:[Feed class]])
-			if (feed.articleCount != totalCount)
+				[f resetArticleCountAndIndexPathString];
-				feed.articleCount = totalCount;
-			if (feed.unreadCount != unreadCount)
-				feed.unreadCount = unreadCount; // remember to update global total unread count
-			[feed calculateAndSetIndexPathString];
 		}
+		[self saveContext:moc andParent:YES];
 	}];
 }
 
 /// @return All @c Feed items where @c articles.count @c == @c 0
-+ (NSArray<Feed*>*)listOfMissingFeedsInContext:(NSManagedObjectContext*)moc {
++ (NSArray<Feed*>*)listOfFeedsMissingArticlesInContext:(NSManagedObjectContext*)moc {
 	NSFetchRequest *fr = [NSFetchRequest fetchRequestWithEntityName: Feed.entity.name];
 	// More accurate but with subquery on FeedArticle: "count(articles) == 0"
 	fr.predicate = [NSPredicate predicateWithFormat:@"articleCount == 0"];
 	return [self fetchAllRows:fr inContext:moc];
 }
 
+/// @return All @c Feed items where @c icon is @c nil.
++ (NSArray<Feed*>*)listOfFeedsMissingIconsInContext:(NSManagedObjectContext*)moc {
+	NSFetchRequest *fr = [NSFetchRequest fetchRequestWithEntityName: Feed.entity.name];
+	fr.predicate = [NSPredicate predicateWithFormat:@"icon = NULL"];
+	return [self fetchAllRows:fr inContext:moc];
+}
+
 @end