Vincent Gable’s Blog

January 20, 2009

Control Screen Saver Security With Automator

Filed under: Announcement,Security | , , ,
― Vincent Gable on January 20, 2009

Set Screen Saver Security sets the time until the screen saver activates, and whether a password is required to unlock the screen saver.

Preview.png

Every company I’ve worked for that had an office also had a rule that any computer in the office had to be password-protected with a screensaver that kicked in pretty quickly. But at home it’s annoying to have to unlock your own laptop when you get up to make a sandwich.

If you use the same computer at home and in the office, IMLocation can use this action to lock down your computer at work, but leave it easy-to-use at home.

I recommend trying IMLocation (which includes the Set Screen Saver Security action) for best results.

January 19, 2009

Setting iChat Status With Automator

Filed under: Announcement,MacOSX | , ,
― Vincent Gable on January 19, 2009

Set iChat Status is an Automator action that sets your status message, and availability in iChat. Amazingly, this action did not ship with Mac OS X.

Preview.png

I wrote it, because I wanted a user-friendly way for people to control iChat in IMLocation workflows.

I Need Your Help, Tiger

This action should run on Mac OS X 10.4. But since I don’t have a second computer running Tiger, I’m not sure. If someone would let me know if this works on Tiger I would really appreciate it! It should work just fine, but you know what they say about “should”…

Download.

January 13, 2009

Automatically Closing NSFW Content (Beta)

Filed under: Announcement,MacOSX | , , ,
― Vincent Gable on January 13, 2009

I’ve finally implemented a neat feature for IMLocation that I’ve wanted to do for a while now, when you arrive at work, it can automagically close NSFW webpages. NSFW content is detected using the same technology behind Mac OS X’s Parental Controls.

I recommend downloading IMLocation to get the full effect, but you can also get just the automator action. Leopard is required, and it only works with Safari right now.

As you guessed, there is a trade-off between accidentally closing important webpages and letting questionable content slip through. I’m not yet sure what the best way to expose tweaking this tradeoff is. In the mean time I’ve chosen the more-confusing-but-powerful road, because I think it’s best to start with something that can do the job, and then refine and simplify it.

Firefox?

I want this to work with Firefox, but I am hamstrung by Firefox’s poor-to-nonexistant AppleScript support. (In the meantime you can try the worksafer Firefox plugin, but it’s not a true substitute).

Firefox is geared towards extension through plugins, while Safari has a less-rich plugin architecture, but good scripting support. Arguably, the Firefox way is better for a web-browser. I’ve seen some really cool Firefox plugins that extend the web-browsing experience in ways a script just can’t. Unfortunately, what I’m trying to do — have NSFW content automatically closed for you when you get to work — is the sort of thing a script does well, and a plugin does cumbersomely, if at all.

If anyone has some advice on how to hack around Firefox’s limitations please drop me a line. Right now my prognosis is “a lot of work for a clunky payoff”, so right now I’m focusing on more pressing concerns.

January 12, 2009

Stopping an AMWorkflow Workaround

Filed under: Cocoa,MacOSX,Objective-C,Programming,Sample Code | , , ,
― Vincent Gable on January 12, 2009

-[AMWorkflowController stop:] does not stop a workflow from executing (more info). Here is a workaround that will stop all workflows your application is be running.

When you execute a worklfow using Automator.framework, the workflow is run in its own process, which insulates it from the invoking application, and vica verca 1

. At least on Leopard, the program that runs the workflow is /System/Library/CoreServices/Automator Runner.app/Contents/MacOS/Automator Runner . It has the bundle-identifier com.apple.AutomatorRunner , and it will be a sub-process of your application, since your application kicked it off.

That gives us enough information to kill just the instances of Automator Runner that are running your worklfows. This will stop workflow execution dead in it’s tracks.


- (void) killAutomatorRunnerSubprocesses; {
   ProcessSerialNumber   PSN = {kNoProcess};
   while(GetNextProcess(&PSN) == noErr) {
      NSDictionary *info = (NSDictionary*)ProcessInformationCopyDictionary(&PSN,kProcessDictionaryIncludeAllInformationMask);
      if(info) {
         NSString *theirBundleID = [info objectForKey:@"CFBundleIdentifier"];
         if([theirBundleID isEqualTo:@"com.apple.AutomatorRunner"] && [self processWasLaunchedByUs:PSN]){
            NSLog(@"Killing AutomatorRunner sub-process: PSN={high=%u low=%u}", PSN.highLongOfPSN, PSN.lowLongOfPSN);
            KillProcess(&PSN);
         }
         CFRelease((CFDictionaryRef)info);
      }
   }
}

- (BOOL) processWasLaunchedByUs:(ProcessSerialNumber)PSN; {
   ProcessInfoRec processInfo = {0};
   //we use GetProcessInformation(), and not the more modern ProcessInformationCopyDictionary()
   //because ProcessInformationCopyDictionary stores the "ParentPSN" as a 32 or 64-bit number,
   //and it is not clear to me what the endian-safe way to transform it into a ProcessSerialNumber
   //structure is, see http://lists.apple.com/archives/carbon-dev/2007/Mar/msg00283.html
   if(GetProcessInformation(&PSN,&processInfo) != noErr)
      return NO;
   Boolean   theyAreOurChild = FALSE;
   ProcessSerialNumber ourPSN = {0,kCurrentProcess};
   OSStatus err = SameProcess(&processInfo.processLauncher, &ourPSN, &theyAreOurChild);
   return !err && theyAreOurChild;
}
   

Please let me know if this works for you, of if you have a better solution.

1
Automator.app does not appear to spawn an Automator Runner when it runs a workflow. I’m not sure why. But since the stop button works in Automator.app, understanding why might lead to a better work around. Or not.

December 19, 2008

Undocumented Automator.framework Goodness: Actions Library

Filed under: Cocoa,Interface Builder,MacOSX,Objective-C,Programming,Reverse Engineering | , , , , ,
― Vincent Gable on December 19, 2008

In Leopard, Apple introduced AMWorkflowView and AMWorkflowController, which let you easily add automator-editing capabilities to your application (modulo bugs!)

Obviously, for editing a workflow to be useful, you need to be able to add actions to it. And to do that, you need to be able to browse and search actions. But the current Automator.framework has no official support for doing this.

But there are undocumented private APIs, which Automator.app (link launches it) uses…

How to Find Them

class-dump is an amazingly useful command-line tool that lets you generate headers from a compiled Objective-C binary. Download it, and point it at /System/Library/Frameworks/Automator.framework/Automator, to see everything Automator.framework really lets you do.

Instant Library Panel

The most useful definition I found was,
@interface NSApplication (AMLibraryPanel)
- (void)orderFrontAutomatorLibraryPanel:(id)sender;
@end

Calling [NSApp orderFrontAutomatorLibraryPanel:nil]; will show a panel with the same action-library view Automator has.

This is what I’m using right now in IMLocation to let people find actions for workflows. I don’t like the idea of using private APIs. But I like the idea of implementing my own AMLibraryView replacement even less. It would be a lot of work to make it as good as the real thing. Any differences give users a fractured experience — one way to do something in Automator, another in my program. And I would get dismal ROI, because I expect Apple to expose this functionality in the (near) future.

(I also wouldn’t be so bullish on using private APIs if I didn’t have workarounds in place right now. The only way orderFrontAutomatorLibraryPanel: gets called is if a user presses a “Show Actions” button on the toolbar. That same toolbar has an “Open in Automator” button that opens the worklfow in Automator, where they can edit it without bugs. So even if orderFrontAutomatorLibraryPanel: stopped working tomorrow, users could still do everything they could before — albeit less elegantly).

Looking Just Like Automator

I don’t recommend doing this, but I’ve been able to embed an AMLibraryView in an NSSplitView next to an AMWorkflowView, to get a more Automator.app-like appearance.

Here’s how I did it, given the IBOutlets workflowViewAndLibrarySplitView which is an NSSplit view with an AMWorkflowView in one side, and the other side’s view connected to the outlet workflowLibraryView,

[workflowViewAndLibrarySplitView replaceSubview:workflowLibraryView with:[[AMLibraryPanel sharedLibraryPanel] _libraryView]];

Will put the library view inside your split view.

Of course this screws up orderFrontAutomatorLibraryPanel:. And I would not expect it to work in two windows. And it’s using an underscore-private method of an already private and undocumented API. That’s just to too risky for me; so I stick with the panel. It gets the job done with one line of code, and that’s good enough for me.

December 18, 2008

Automator Bugs

Filed under: Announcement,Bug Bite,Cocoa,MacOSX,Objective-C,Programming,Sample Code | , , , ,
― Vincent Gable on December 18, 2008

I’ve started using Automator in IMLocation to let people build a set of actions that are executed when they arrive somewhere (for example, muting their laptop’s speakers in a classroom).

Unfortunately, my impression of Automator.framework so far is: buggy.

Here are some issues I’ve run into so far.

-[AMWorkflowController stop:] does not stop the workflow! I do not yet have a workaround.

AMWorkflowController sends its delegate a -document message whenever an action is removed from the workflowView, by clicking the (x) button. If the delegate does not implement it, the action will not be removed!

The (x) button is enabled , but does nothing, in workflows that are not editable.

-[AMWorkflow initWithContentsOfURL:error:] throws an exception when the URL is nil.

This project demonstrates the first two issues.

July 5, 2008

Missing Frameworks

Filed under: Bug Bite,Cocoa,MacOSX,Objective-C,Programming | , ,
― Vincent Gable on July 5, 2008

I tried using an AMWorkflowView in a project, but when I ran it, I would crash with the following printed to the console:


*** Terminating app due to uncaught exception ‘NSInvalidUnarchiveOperationException’, reason: ‘*** -[NSKeyedUnarchiver decodeObjectForKey:]: cannot decode object of class (AMWorkflowView)’

It turns out I just forgot to include Automator.framework in my project!

It turns out that you also have to include Automator.framework to use any OSAScriptView objects.

I hope this helps someone who googles the error message :-).

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