PBWebController: Add asynchronous functions

This allows us to keep the UI responsive while
running expensive commands

Documentation/CallingFromWebKit.txt

@@ -0,0 +1,81 @@
+Introduction
+============
+
+A lot of the display code in GitX is based on the HTML views that are rendered
+by WebKit. As such, it's necessary to access a lot of information from WebKit
+that is only available in the Objective-C environment.
+
+Because of this, some convenience methods have been added. Most notably, some
+objects can be accessed completely from WebKit, including:
+
+	* All webcontrollers
+	* All PBGitRefs and PBGitCommits
+
+All WebKit views should be controlled by a subclass of PBWebController.
+
+
+Subclassing PBWebController
+===========================
+
+PBWebController does some magic to make using it easier. First of all, it
+automatically loads in the view specified by "startFile". This means that
+your views have to conform to a specific structure. For example, if you set
+startFile (in your awakeFromNib) to "commit", there should be a file named
+html/views/commit/index.html that will get loaded.
+
+Furthermore, the controller keeps a finishedLoading member that indicates
+whether or not the webview is ready to be used. If it is ready, and your
+subclass has implemented the didLoad method, that method will be called.
+
+After the document has succesfully loaded, the controller inserts itself into
+the Javascript environment under the "Controller" variable.
+
+Useful PBWebController functions
+================================
+
+There are some functions that might be useful in any context. These are put in
+the PBWebController class for easy access. To access these, replace the colons
+with underscores in the JS call. for example,
+
+	- (void) log:(NSString) logMessage
+
+would be called in JS by:
+
+	Controller.log_("Hello from javascript!");
+
+## - (void) log:(NSString) logMessage
+
+This method simply relays a JS message to the program, which outputs it using
+NSLog. Handy for debugging.
+
+## - (BOOL) isReachable:(NSString *)hostname
+
+Will return true if the hostname is reachable from Javascript without creating
+an internet connection (for example, dialup). This is useful for optional
+features that depend on a working internet connection.
+
+** NOTE ** The GitX JS environment is _NOT_ secure, which means that external
+HTTP calls should only be made to trusted sites. For example, DON'T open any
+link in a commit message, as this could potentially allow any site to run any
+command on your mac.
+
+## - (void) runCommand:(WebScriptObject *)arguments
+          inRepository:(PBGitRepository *)repository
+              callBack:(WebScriptObject *)callBack
+
+This somewhat specific function allows you to call any git command and have
+its output returned to a callback function. For example, the following:
+
+Controller.runCommand_inRepository_callBack_(["--version"], obj.repository, 
+             function(v) { notify("Git Version: " + v, 1); });
+
+will show a notification displaying the current git version. This method is
+async, which means that it doesn't matter if it takes a long time to run.
+
+## - (void) callSelector:(NSString *)selectorString
+                onObject:(id)object
+                callBack:(WebScriptObject *)callBack
+
+While you can have direct access to most objects, sometimes it is useful to
+have an async task, for example if the operation can take a long time. Use
+this function to keep the UI responsive.

GitX.xcodeproj/project.pbxproj

@@ -381,8 +381,8 @@
 				911111F60E594F3F00BF76B4 /* PBRepositoryDocumentController.h */,
 				911111F70E594F3F00BF76B4 /* PBRepositoryDocumentController.m */,
 				F5E926040E8827D300056E75 /* PBViewController.h */,
-				F5EF8C8C0E9D4A5D0050906B /* PBWebController.h */,
 				F5E926050E8827D300056E75 /* PBViewController.m */,
+				F5EF8C8C0E9D4A5D0050906B /* PBWebController.h */,
 				F5EF8C8D0E9D4A5D0050906B /* PBWebController.m */,
 				F5FE6C010EB13BC900F30D12 /* PBServicesController.h */,
 				F5FE6C020EB13BC900F30D12 /* PBServicesController.m */,

PBWebController.h

@@ -13,6 +13,9 @@
 	IBOutlet WebView* view;
 	NSString *startFile;
 	BOOL finishedLoading;
+
+	// For async git reading
+	NSMapTable *callbacks;
 }
 
 @property (retain) NSString *startFile;

PBWebController.m

@@ -7,7 +7,8 @@
 //
 
 #import "PBWebController.h"
-
+#import "PBGitRepository.h"
+#include <SystemConfiguration/SCNetworkReachability.h>
 
 @implementation PBWebController
 
@@ -19,6 +20,7 @@
 	NSString* file = [[NSBundle mainBundle] pathForResource:@"index" ofType:@"html" inDirectory:path];
 	NSLog(@"path: %@, file: %@", path, file);
 	NSURLRequest * request = [NSURLRequest requestWithURL:[NSURL fileURLWithPath:file]];
+	callbacks = [NSMapTable mapTableWithKeyOptions:(NSPointerFunctionsObjectPointerPersonality|NSPointerFunctionsStrongMemory) valueOptions:(NSPointerFunctionsObjectPointerPersonality|NSPointerFunctionsStrongMemory)];
 
 	finishedLoading = NO;
 	[view setUIDelegate:self];
@@ -51,13 +53,12 @@
 }
 
 #pragma mark Functions to be used from JavaScript
+
 - (void) log: (NSString*) logMessage
 {
 	NSLog(@"%@", logMessage);
 }
 
-#include <SystemConfiguration/SCNetworkReachability.h>
-
 - (BOOL) isReachable:(NSString *)hostname
 {
 	SCNetworkConnectionFlags flags;
@@ -71,4 +72,62 @@
 	return flags > 0;
 }
 
+#pragma mark Using async function from JS
+
+- (void) runCommand:(WebScriptObject *)arguments inRepository:(PBGitRepository *)repository callBack:(WebScriptObject *)callBack
+{
+	// The JS bridge does not handle JS Arrays, even though the docs say it does. So, we convert it ourselves.
+	int length = [[arguments valueForKey:@"length"] intValue];
+	NSMutableArray *realArguments = [NSMutableArray arrayWithCapacity:length];
+	int i = 0;
+	for (i = 0; i < length; i++)
+		[realArguments addObject:[arguments webScriptValueAtIndex:i]];
+
+	NSFileHandle *handle = [repository handleInWorkDirForArguments:realArguments];
+	[callbacks setObject:callBack forKey:handle];
+	[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(JSRunCommandDone:) name:NSFileHandleReadToEndOfFileCompletionNotification object:handle]; 
+	[handle readToEndOfFileInBackgroundAndNotify];
+}
+
+- (void) callSelector:(NSString *)selectorString onObject:(id)object callBack:(WebScriptObject *)callBack
+{
+	NSArray *arguments = [NSArray arrayWithObjects:selectorString, object, nil];
+	NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(runInThread:) object:arguments];
+	[callbacks setObject:callBack forKey:thread];
+	[thread start];
+}
+
+- (void) runInThread:(NSArray *)arguments
+{
+	SEL selector = NSSelectorFromString([arguments objectAtIndex:0]);
+	id object = [arguments objectAtIndex:1];
+	id ret = [object performSelector:selector];
+	NSArray *returnArray = [NSArray arrayWithObjects:[NSThread currentThread], ret, nil];
+	[self performSelectorOnMainThread:@selector(threadFinished:) withObject:returnArray waitUntilDone:NO];
+}
+
+
+- (void) returnCallBackForObject:(id)object withData:(id)data
+{
+	WebScriptObject *a = [callbacks objectForKey: object];
+	if (!a) {
+		NSLog(@"Could not find a callback for object: %@", object);
+		return;
+	}
+
+	[callbacks removeObjectForKey:object];
+	[a callWebScriptMethod:@"call" withArguments:[NSArray arrayWithObjects:@"", data, nil]];
+}
+
+- (void) threadFinished:(NSArray *)arguments
+{
+	[self returnCallBackForObject:[arguments objectAtIndex:0] withData:[arguments objectAtIndex:1]];
+}
+
+- (void) JSRunCommandDone:(NSNotification *)notification
+{
+	NSString *data = [[NSString alloc] initWithData:[[notification userInfo] valueForKey:NSFileHandleNotificationDataItem] encoding:NSUTF8StringEncoding];
+	[self returnCallBackForObject:[notification object] withData:data];
+}
+
 @end