[Minor Bug] Clipboard monitor is unreliable when another clipboard-monitoring application is running

[aziraphale]

Hey - me again! 😄

• TumblThree version: 1.0.8.68 (the current latest)
• OS: Windows 10 Pro x64 (10.0.17134.345 according to cmd.exe!)

As per the subject of this issue report, I consider this to be quite a minor bug. However, I fear that this might not be something that's too easy to fix! ☹️

The problem I encountered is that, when my PC has the Scatter application running, TumblThree's clipboard monitor would only intermittently notice that I'd copied blog URLs to the clipboard. Maybe 50% of the time it would notice the blog URL and add the blog to the index, but the rest of the time it just wouldn't notice it at all...

Scatter is an application that automatically synchronises clipboard content between my PCs and my Android devices - although, uh, it appears to have been annoyingly discontinued, so here's an article from 2013 that at least describes what it does! (FYI, Scatter wasn't running on the same PC as TumblThree when TumblThree crashed as mentioned in my other issue report, so it isn't relevant to that crash.)

(Scatter is still available to download for Android on the Google Play Store, and for Windows via a redirect link on the developers' website, but since the main Scatter website is now offline, you wouldn't be able to create an account in order to sign in to the app anyway, so you'll probably have trouble replicating this... That said, seeing as they've taken the Scatter website down, presumably they will also at some point be shutting off the central authentication and relay server(s), which will force me to find an alternative app, and if that causes the same issue with TumblThree then at least we can try to fix it for use with whatever app I migrate to!)

I'm not a Windows application developer, so I don't have much of a clue how your clipboard monitor works, but judging by these lines in the stack trace of my previous bug report ...

at TumblThree.Applications.Controllers.ManagerController.OnClipboardContentChanged(System.Object, System.EventArgs)
at TumblThree.Applications.ClipboardMonitor.WndProc(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)
at System.Windows.Interop.HwndSource.PublicHooksFilterMessage(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)
at MS.Win32.HwndWrapper.WndProc(IntPtr, Int32, IntPtr, IntPtr, Boolean ByRef)
at MS.Win32.HwndSubclass.DispatcherCallbackOperation(System.Object)

... I wonder if Windows just isn't calling TumblThree's event handler when there's another application that's also listening for that event? That would seem like a weird oversight on Microsoft's part, though, so that feels rather unlikely!

Alternatively, maybe TumblThree and Scatter are trying to access the clipboard at the same time (and maybe Scatter's briefly emptying and re-populating the clipboard when I copy something?!), and something in that process results in TumblThree not being given the clipboard content that it expects? Maybe just attempting to request that content a few times over the course of a few hundred milliseconds might help? No idea! 😹

Thanks again - but don't worry about this one too much! I just wanted to make a note of this bug for completeness 😺