Keep window open after closing last tab. Fixes #24.

When the last tab is closed the window will be kept open if the
file browser is shown. It will close the existing document and
replace it with a scratch document.

Frameworks/DocumentWindow/src/DocumentController.mm

@@ -943,6 +943,23 @@ - (void)performCloseTab:(id)sender
 {
 	D(DBF_DocumentController, bug("\n"););
 	ASSERT([sender isKindOfClass:[OakTabBarView class]]);
+
+	if(documentTabs.size() == 1 && !fileBrowserHidden)
+	{
+		document::document_ptr document = *documentTabs[0];
+		if(!document->is_modified())
+		{
+			if(document->path() == NULL_STR)
+			{
+				return [[self window] performClose:self];
+			}
+			else
+			{
+				[self newDocumentInTab:nil];
+				scratchDocument = [self selectedDocument]->identifier();
+			}
+		}
+	}
 	[self closeTabsAtIndexes:[NSIndexSet indexSetWithIndex:[sender tag]] quiet:NO];
 }
 

Frameworks/OakAppKit/src/OakTabBarView.mm

@@ -545,9 +545,7 @@ - (void)performClose:(id)sender
 {
 	D(DBF_TabBarView, bug("\n"););
 	tag = selectedTab; // performCloseTab: asks for [sender tag]
-	if([tabTitles count] > 1)
-			[NSApp sendAction:@selector(performCloseTab:) to:nil from:self];
-	else	[[self nextResponder] tryToPerform:_cmd with:sender];
+	[NSApp sendAction:@selector(performCloseTab:) to:nil from:self];
 }
 
 - (void)setSelectedTab:(NSUInteger)anIndex