I encountered a problem with updating the status message on Firefox from a Plugin code.
As the documentation says calling NPN_Status works only when called from the main thread. My requirement is to update the status from any thread within the Firefox process.
Any help would be appreciated!
You can't update it from any thread because that would violate some of the threadsafety rules. You will have to proxy your update back to the main thread.
Like sdwilsh said, you are to call the NPN_*-functions only from the main thread. NPN_PluginThreadAsyncCall was only introduced in Gecko 1.9 and isn't supported in all current browsers.
Workarounds depend on the platform:
on Windows subclass the window your plugin receives, post/send messages to it and invoke the call from the handling window process
on Mac with Cocoa you can use e.g. performSelectorOnMainThread
on Mac with Carbon you can use invoke the calls on the null event
... etc.
Related
I'm in the process of writing an app to interface with a service running on another machine. When I ask this service for some information, this service adds the requested information to a separate queue, and sends a windows message to the calling application (my application) indicating there is a message waiting in this separate queue which needs to be decoded.
The windows message this service sends is a custom message, defined in the service code as having some constant int value. I've found examples of creating custom events in wxpython, and using TryBefore() and TryAfter() to react to these events in specific ways, but I haven't found any way to associate this NewEvent() with an int value so I can identify it when it comes in, much less any way to determine what an int value of an incoming event is.
Has anyone done this before or know of any functions I'm not aware of? I'm using python 3.6 and wxpython 4.0.
Thanks for your help, everyone.
I think this is what you are looking for: https://wiki.wxpython.org/HookingTheWndProc
When you get the custom message from the hooked WndProc you can either react to it there, or you can turn it into a wx event and send it so it can be caught by binding an event handler like normal. The wx.lib.newevent module has some helpers for creating a custom event class and an event binder. Its use is demonstrated in some of the demo samples and library modules.
I'm writing a plugin for an application and need to use Carbon to show a dialog. I have everything set up including the event handler, but I cannot possibly call RunApplicationEventLoop() because this would stall the host application.
How can I fix this? Will I need to create a separate thread and call RunApplicationEventLoop() from there?
-Joe
What makes you think you need to call RunApplicationEventLoop? The host app is presumably running an event loop, probably either using RunApplicationEventLoop or NSApplicationMain. By the way, would your dialog be modal? Modal is easier.
I'm trying to create an NPAPI plugin to listen to the Media Keys on a macbook and pass that to javascript to control things like pandora or soundcloud. I'm using Spotify's SPMediaKeyTap library, which just wraps CGEventTap running on a separate thread.
My problem is that I use npn_invoke to call back to javascript. This works normally, but when it's triggered from the CGEventTap callback, it crashes the plugin. I realize this needs to be run from the plugin thread, and I've tried to pass it back to the main thread both by using [NSObject performSelectorOnMainThread] and [NSObject performSelector:onThread] with the thread i've stored away in the main plugin threads create method. Both of these solutions still crash on any npn call. Is there anything else that goes on when handling a CGEventTap event that causes state to be invalid for NPN browser interaction calls?
Don't try to second guess the threading model by saving the thread like you are; just use performSelectorOnMainThread to call NPN methods. I do this all the time and it works fine, so I'm guessing that something with your method of cross-thread marshalling isn't working the way it needs to.
I have a Mac OS X application that is also a protocol handler (just as, for example, Safari is a protocol handler for the HTTP and HTTPS protocols). So when a user clicks a link of the form myscheme://some-kind-of-info in any application at all, my application launches to handle the link.
Now I need to be able to determine if the application was launched by such a link click, or if it was launched by any other method. In other words, it was launched by any method besides a link click. (In those cases, I want the app to stay open, but if it was launched by a link it should quit and ignore the link. This way it only operates when already running.)
Is there some way within the app at startup to introspect and find out that it was launched by a standard method rather than by an AppleScript GetURL event? I'd like to find out through a documented method, rather than - for example - just have my app only open these links after it's been running for a half a second.
You can register a handler for each of the possible Apple Events you'll get on launch, and make note of which one you receive first.
If the application is launched without documents, you'll get kAEOpenApplication.
If it's launched with documents, you'll get kAEOpenDocuments (or
kAEPrintDocuments).
If it's launched with a URL, then (obviously) you'll get kAEGetURL.
There's also kAEOpenContents, but I wasn't able to trigger it easily in my test app; it's probably worth supporting no matter what.
How Cocoa Applications Handle Apple Events documents all of this stuff.
There is one error in there, though; it says that AppleScript's "launch" will send kAEOpenApplication. It won't, it'll send ascr/noop (kASAppleScriptSuite/kASLaunchEvent, defined in ASRegistry.h). I couldn't get the usual Cocoa event handler mechanism to trap this event, so you may need to do some more digging there.
One way you can check if the event is sent at launch is to register the event handlers in your application delegate's applicationWillFinishLaunching: method; they should deliver by the time applicationDidFinishLaunching: is invoked. With that method, you could potentially only check for kAEGetURL.
I was wondering if there's some sort of system event that gets fired every time a user changes the time in Windows. I know there's a way to enable this in Windows' EventLog, but I was looking for a way to respond to this event programatically (like using the Windows API).
A WM_TIMECHANGE message is sent whenever there is a change in the system time
I'm not sure from your question if you're working in managed or native code. But if you're working in managed code you can use the TimeChanged event on the SystemEvents class.
Microsoft.Win32.SystemEvents.TimeChanged