Present a warning to the user when attempting to print the current table's content view which exceeds a set number of rows. This number is currently set to 1000 which can be changed via the hidden preference key 'PrintWarningRowLimit'. The approach to cancelling the print HTML generation thread may also need to be re-implemented to ensure that it is killed straight away, something that is currently not possible using NSThread. Rowan suggested using pthreads instead, but this should be discussed in terms of potential memory leaks and stability.

1 files changed, 55 insertions, 4 deletions

diff --git a/Source/SPPrintController.m b/Source/SPPrintController.m
index f83f3625..d12f764f 100644
--- a/Source/SPPrintController.m
+++ b/Source/SPPrintController.m
@@ -102,10 +102,61 @@
  */
 - (IBAction)printDocument:(id)sender
 {		
+	// Only display warning for the 'Table Content' view
+	if ([tableTabView indexOfTabViewItem:[tableTabView selectedTabViewItem]] == 1) {
+				
+		NSInteger rowLimit = [prefs integerForKey:SPPrintWarningRowLimit];
+		
+		// Result count minus one because the first element is the column names
+		NSUInteger resultRows = ([[tableContentInstance currentResult] count] - 1);
+		
+		if (resultRows > rowLimit) {
+			
+			NSNumberFormatter *numberFormatter = [[[NSNumberFormatter alloc] init] autorelease];
+			
+			[numberFormatter setNumberStyle:NSNumberFormatterDecimalStyle];
+									
+			NSAlert *alert = [NSAlert alertWithMessageText:NSLocalizedString(@"Continue to print?", @"continue to print message")
+											 defaultButton:NSLocalizedString(@"Print", @"print button")
+										   alternateButton:NSLocalizedString(@"Cancel", @"cancel button") 
+											   otherButton:nil 
+								 informativeTextWithFormat:[NSString stringWithFormat:NSLocalizedString(@"Are you sure you want to print the current content view of the table '%@'?\n\nIt currently contains %@ rows, which may take a significant amount of time to print.", @"continue to print informative message"), [self table], [numberFormatter stringFromNumber:[NSNumber numberWithLongLong:resultRows]]]];
+			
+			NSArray *buttons = [alert buttons];
+			
+			// Change the alert's cancel button to have the key equivalent of return
+			[[buttons objectAtIndex:0] setKeyEquivalent:@"p"];
+			[[buttons objectAtIndex:0] setKeyEquivalentModifierMask:NSCommandKeyMask];
+			[[buttons objectAtIndex:1] setKeyEquivalent:@"\r"];
+			
+			[alert beginSheetModalForWindow:tableWindow modalDelegate:self didEndSelector:@selector(printWarningDidEnd:returnCode:contextInfo:) contextInfo:NULL];
+		
+			return;
+		}
+	}
+	
+	[self startPrintDocumentOperation];
+}
+
+/**
+ * Called when the print warning dialog is dismissed.
+ */
+- (void)printWarningDidEnd:(id)sheet returnCode:(NSInteger)returnCode contextInfo:(NSString *)contextInfo
+{
+	if (returnCode == NSAlertDefaultReturn) {
+		[self startPrintDocumentOperation];
+	}
+}
+
+/**
+ * Starts tge print document operation by spawning a new thread if required.
+ */
+- (void)startPrintDocumentOperation
+{
 	[self startTaskWithDescription:NSLocalizedString(@"Generating print document...", @"generating print document status message")];
 	
 	BOOL isTableInformation = ([tableTabView indexOfTabViewItem:[tableTabView selectedTabViewItem]] == 3);
-
+	
 	if ([NSThread isMainThread]) {
 		printThread = [[NSThread alloc] initWithTarget:self selector:(isTableInformation) ? @selector(generateTableInfoHTMLForPrinting) : @selector(generateHTMLForPrinting) object:nil];
 		
@@ -263,7 +314,7 @@
 	NSString *HTMLString = [engine processTemplateInFileAtPath:[[NSBundle mainBundle] pathForResource:SPHTMLPrintTemplate ofType:@"html"] withVariables:printData];
 	
 	// Check if the operation has been cancelled
-	if ((printThread != nil) && (![NSThread isMainThread]) && ([printThread isCancelled])) {		
+	if ((printThread != nil) && (![NSThread isMainThread]) && ([printThread isCancelled])) {				
 		[pool drain];
 		[self endTask];
 		
@@ -300,6 +351,8 @@
 	[printData setObject:heading forKey:@"heading"];
 	[printData setObject:[[NSUnarchiver unarchiveObjectWithData:[prefs objectForKey:SPCustomQueryEditorFont]] fontName] forKey:@"font"];
 	
+	NSString *HTMLString = [engine processTemplateInFileAtPath:[[NSBundle mainBundle] pathForResource:SPHTMLTableInfoPrintTemplate ofType:@"html"] withVariables:printData];
+	
 	// Check if the operation has been cancelled
 	if ((printThread != nil) && (![NSThread isMainThread]) && ([printThread isCancelled])) {	
 		[pool drain];
@@ -310,8 +363,6 @@
 		return;
 	}
 	
-	NSString *HTMLString = [engine processTemplateInFileAtPath:[[NSBundle mainBundle] pathForResource:SPHTMLTableInfoPrintTemplate ofType:@"html"] withVariables:printData];
-	
 	[self performSelectorOnMainThread:@selector(loadPrintWebViewWithHTMLString:) withObject:HTMLString waitUntilDone:NO];
 							   
 	[pool drain];