Fix Issue #574 (foreign key links not working after first use):

 - Move foreign key reference loading into it's own task and set state modification markers to allow it to override the table state history
 - Rename modifyingHistoryState to modifyingState now the usge has broadened slightly

5 files changed, 43 insertions, 18 deletions

diff --git a/Source/SPHistoryController.h b/Source/SPHistoryController.h
index 0b2d50d9..dd5c7133 100644
--- a/Source/SPHistoryController.h
+++ b/Source/SPHistoryController.h
@@ -45,12 +45,12 @@ enum sphistory_view_types
 	NSMutableArray *history;
 	NSMutableDictionary *tableContentStates;
 	NSUInteger historyPosition;
-	BOOL modifyingHistoryState;
+	BOOL modifyingState;
 }
 
 @property (readonly) NSUInteger historyPosition;
 @property (readonly) NSMutableArray *history;
-@property (readwrite, assign) BOOL modifyingHistoryState;
+@property (readwrite, assign) BOOL modifyingState;
 
 // Interface interaction
 - (void) updateToolbarItem;
diff --git a/Source/SPHistoryController.m b/Source/SPHistoryController.m
index 2c1a657f..04d8a765 100644
--- a/Source/SPHistoryController.m
+++ b/Source/SPHistoryController.m
@@ -32,7 +32,7 @@
 
 @synthesize history;
 @synthesize historyPosition;
-@synthesize modifyingHistoryState;
+@synthesize modifyingState;
 
 #pragma mark Setup and teardown
 
@@ -45,7 +45,7 @@
 		history = [[NSMutableArray alloc] init];
 		tableContentStates = [[NSMutableDictionary alloc] init];
 		historyPosition = NSNotFound;
-		modifyingHistoryState = NO;
+		modifyingState = NO;
 	}
 	return self;	
 }
@@ -183,7 +183,7 @@
 {
 
 	// Don't modify anything if we're in the process of restoring an old history state
-	if (modifyingHistoryState) return;
+	if (modifyingState) return;
 
 	// Work out the current document details
 	NSString *theDatabase = [theDocument database];
@@ -298,7 +298,7 @@
 	NSAutoreleasePool *loadPool = [[NSAutoreleasePool alloc] init];
 	NSUInteger position = [positionNumber unsignedIntegerValue];
 
-	modifyingHistoryState = YES;
+	modifyingState = YES;
 
 	// Update the position and extract the history entry
 	historyPosition = position;
@@ -317,7 +317,7 @@
 		&& [[historyEntry objectForKey:@"view"] integerValue] == [self currentlySelectedView] == SP_VIEW_CONTENT)
 	{
 		[tableContentInstance loadTable:[historyEntry objectForKey:@"table"]];
-		modifyingHistoryState = NO;
+		modifyingState = NO;
 		[self updateToolbarItem];
 		[theDocument endTask];
 		[loadPool drain];
@@ -379,7 +379,7 @@
 		}
 	}
 
-	modifyingHistoryState = NO;
+	modifyingState = NO;
 	[self updateToolbarItem];
 
 	// End the task
@@ -394,7 +394,7 @@
 - (void) abortEntryLoadWithPool:(NSAutoreleasePool *)pool
 {
 	NSBeep();
-	modifyingHistoryState = NO;
+	modifyingState = NO;
 	[theDocument endTask];
 	if (pool) [pool drain];
 }
@@ -421,7 +421,7 @@
 	NSDictionary *contentState;
 
 	// Return if the history state is currently being modified
-	if (modifyingHistoryState) return;
+	if (modifyingState) return;
 
 	// Return if no database or table are selected
 	if (!theDatabase || !theTable) return;
diff --git a/Source/TableContent.h b/Source/TableContent.h
index 1b9e4af6..2e45ac59 100644
--- a/Source/TableContent.h
+++ b/Source/TableContent.h
@@ -137,6 +137,7 @@
 // Additional methods
 - (void)setConnection:(MCPConnection *)theConnection;
 - (void)clickLinkArrow:(SPTextAndLinkCell *)theArrowCell;
+- (void)clickLinkArrowTask:(SPTextAndLinkCell *)theArrowCell;
 - (IBAction)setCompareTypes:(id)sender;
 - (void)processResultIntoDataStorage:(MCPStreamingResult *)theResult approximateRowCount:(NSUInteger)targetRowCount;
 - (BOOL)addRowToDB;
diff --git a/Source/TableContent.m b/Source/TableContent.m
index a0e2d610..3a736a90 100644
--- a/Source/TableContent.m
+++ b/Source/TableContent.m
@@ -1528,17 +1528,33 @@
 	if ([tableDocumentInstance isWorking]) return;
 
 	if ([theArrowCell getClickedColumn] == NSNotFound || [theArrowCell getClickedRow] == NSNotFound) return;
+
+	// Check whether a save of the current row is required.
+	if ( ![self saveRowOnDeselect] ) return;
+
+	// If on the main thread, fire up a thread to perform the load while keeping the modification flag
+	[tableDocumentInstance startTaskWithDescription:NSLocalizedString(@"Loading reference...", @"Loading referece task string")];
+	if ([NSThread isMainThread]) {
+		[NSThread detachNewThreadSelector:@selector(clickLinkArrowTask:) toTarget:self withObject:theArrowCell];
+	} else {
+		[self clickLinkArrowTask:theArrowCell];
+	}
+}
+- (void)clickLinkArrowTask:(SPTextAndLinkCell *)theArrowCell
+{
+	NSAutoreleasePool *linkPool = [[NSAutoreleasePool alloc] init];
 	NSUInteger dataColumnIndex = [[[[tableContentView tableColumns] objectAtIndex:[theArrowCell getClickedColumn]] identifier] integerValue];
 
 	// Ensure the clicked cell has foreign key details available
 	NSDictionary *refDictionary = [[dataColumns objectAtIndex:dataColumnIndex] objectForKey:@"foreignkeyreference"];
-	if (!refDictionary) return;
-
-	// Check whether a save of the current row is required.
-	if ( ![self saveRowOnDeselect] ) return;
+	if (!refDictionary) {
+		[linkPool release];
+		return;
+	}
 
-	// Save existing scroll position and details
+	// Save existing scroll position and details and mark that state is being modified
 	[spHistoryControllerInstance updateHistoryEntries];
+	[spHistoryControllerInstance setModifyingState:YES];
 
 	NSString *targetFilterValue = [tableValues cellDataAtRow:[theArrowCell getClickedRow] column:dataColumnIndex];
 
@@ -1569,6 +1585,14 @@
 			[self setFiltersToRestore:nil];
 		}
 	}
+
+	// End state and ensure a new history entry
+	[spHistoryControllerInstance setModifyingState:NO];
+	[spHistoryControllerInstance updateHistoryEntries];
+
+	// Empty the loading pool and exit the thread
+	[tableDocumentInstance endTask];
+	[linkPool drain];
 }
 
 /**
diff --git a/Source/TableDocument.m b/Source/TableDocument.m
index 67d30f71..25fa50a0 100644
--- a/Source/TableDocument.m
+++ b/Source/TableDocument.m
@@ -991,10 +991,10 @@
 	NSAutoreleasePool *taskPool = [[NSAutoreleasePool alloc] init];
 
 	// Save existing scroll position and details, and ensure no duplicate entries are created as table list changes
-	BOOL historyStateChanging = [spHistoryControllerInstance modifyingHistoryState];
+	BOOL historyStateChanging = [spHistoryControllerInstance modifyingState];
 	if (!historyStateChanging) {
 		[spHistoryControllerInstance updateHistoryEntries];
-		[spHistoryControllerInstance setModifyingHistoryState:YES];
+		[spHistoryControllerInstance setModifyingState:YES];
 	}
 
 	// show error on connection failed
@@ -1018,7 +1018,7 @@
 
 	// Add a history entry
 	if (!historyStateChanging) {
-		[spHistoryControllerInstance setModifyingHistoryState:NO];
+		[spHistoryControllerInstance setModifyingState:NO];
 		[spHistoryControllerInstance updateHistoryEntries];
 	}