Add a diff window

This allows you to do something like

	gitx --diff

to display a diff similar to 'git diff', but with GitX prettification.

It accepts all git diff parameters, so you can do something like

	gitx --diff HEAD~10

to show the diff compared to the last 10 commits. Or, you can something like

	git diff | gitx

to pipe anything that produces a diff to GitX

PBWebDiffController.m

@@ -0,0 +1,41 @@
+//
+//  PBWebDiffController.m
+//  GitX
+//
+//  Created by Pieter de Bie on 13-10-08.
+//  Copyright 2008 Pieter de Bie. All rights reserved.
+//
+
+#import "PBWebDiffController.h"
+
+
+@implementation PBWebDiffController
+
+- (void) awakeFromNib
+{
+	startFile = @"simpleDiff";
+	[super awakeFromNib];
+	[diffController addObserver:self forKeyPath:@"diff" options:0 context:@"ChangedDiff"];
+}
+
+- (void) didLoad
+{
+	[self showDiff:diffController.diff];
+}
+
+- (void) observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(NSString *)context
+{
+    if ([context isEqualToString: @"ChangedDiff"])
+		[self showDiff:diffController.diff];
+}
+
+- (void) showDiff: (NSString *) diff
+{
+	if (diff == nil || !finishedLoading)
+		return;
+
+	id script = [view windowScriptObject];
+	[script callWebScriptMethod:@"showDiff" withArguments: [NSArray arrayWithObject:diff]];
+}
+
+@end