P: Completely broken Hand tool (PS24.5) Hand Tool Sticking, sticky, not seeing mouse-up

@CJButlerThank you for the detailed explanation on the problem.

In my case, I have not encountered the problem anymore since the 25.6 update (so for the past 3 days).

I have to untrain myself again to just double-clicking always when using any tool XD

So at least for myself, I think the bug is finally fixed. Thank you and the Adobe team 🙂

> I'd love to see a technical write-up of exactly what was causing this

I posted something earlier with details (March 8).

Our inability to reliably reproduce was what prevented us from making progress on the bug.

My assessment is that the dominant element that was preventing us from reproducing the bug and making progress was that Photoshop was not calling the Windows OS function EnableMouseInPointer(false) on startup. Photoshop is an old application, and this function was added when Microsft rolled out Pen/Stylus support. Because of how Microsoft implemented the behavior of this function, if it is not set at application launch, the application property bit can be set to 'true' ANY time by ANY subprocess. For most of us at Adobe, we theorize it was not being set and so stayed 'false' for the session. For users consistently experiencing the problem, we theorize that something, some code somewhere, was consistently setting EnableMouseInPointer(true) for them when they ran Photoshop. We still do not know what that was, but it literally could be anything, including Chrome libraries, or any third-party technology we embed in Photoshop. It's also possible that Microsoft was setting this property to 'false' earlier for us as a legacy application, but that we fell off their "special cases list" (yes - they do that sort of thing. So does Apple.) and things started breaking as soon as the Photoshop version advanced enough to not longer be considered a special case. Or perhaps a Windows update somehow lost track of treating Photoshop as a special case. We don't know.

EnableMouseInPointer(true) tells Windows that Photoshop is "pointer-aware", and that it is ok to send us just Pointer messages, and not synthesize mouse messages. But Photoshop is a legacy application and it is only partially pointer aware:  for example, Painting is largely pointer aware with things like pen pressure, but much of the other Tracker code (like the Hand Tool or Marquee Tool) is not. The older code assumes just mouse behavior and we expect to get mouse-button events. No WM_LBUTTONUP event for those trackers means that we never see the mouse-up. And that's the observed bug.

Once we figured out that we needed to explicitly call this function and declare ourselves a legacy application, this allowed us to make progress. Windows was not consistent when it would decide to not synthesize WM_LBUTTONUP, leading to further unpredictability. In our explorations and debugging, we also found a few other problems with our usage of the Windows OS function PeekMessage when it was called with PM_REMOVE, especially when the Windows Message queue was very busy with a lot of queued messages (e.g. fast mouse or pen work). We're still reviewing and fixing those bits of code up to make them more reliable.

Personally, I think this method of requiring an application to declare itself as a legacy application via EnableMouseInPointer(false) was a terrible approach by Microsoft when it implemented Pen/Stylus event handling years ago. It is a very obscure OS function call with poor default behaviors.

> Now GPU acceleration turns off randomly as I'm trying to work. 

Please start a new thread with this problem, along with your system information and anything you can think of that might help Adobe reproduce this problem. GPU issues are handled by a different team, and we'll need to let them investigate. This thread is too large; any information posted here runs a high risk of being lost. Thanks.

(This is something that would normally be done by a Community Manager. Alas, I am not such a person.)

I reported this issue with 25.5 and feared that it would still be broken in 26.X.  GPU acceleration breaks immediately upon opening a new document.  26.X is doing exactly the same thing.  I'm really, really frustrated with trying to upgrade, only to downgrade 5 minutes later, then fear the next update.

I've been using it for about a day now without any issues (mouse only).  I still have some other unrelated issues from other topics, but this one in particular appears to be cured for me now.

I've updated to 25.6 and as of today, I don't see the issue anymore with the mouse.

However.

Now GPU acceleration turns off randomly as I'm trying to work. I work with shapes constantly and I have my lines colored green. In the middle of work my image will blink, became lanky and the green lines turn gray. It won't go away unless I restart the app only for it to happen again minutes after restarting, This has to be the worst version to date. I wish for once instead of adding new features Adobe would dedicate to fix known bugs. I can assure you, users prefer that.

I used it for about an hour yesterday,  mostly with a Wacom tablet and pen. Had no problems, even when I tried to get it to stick by holding the space bar down and quickly panning the image around.  Before I had to move it rather slowly,  and release the space bar before relocating the pen. So, looks good. I'll be doing much more work next week.  I'll let you know if I have any problems. 

We deployed several underlying changes in 25.6 that were designed to help address this issue, specifically for mouse, so there may still be some cases where stylus fails but we're working on those as well. 
If you aren't seeing this anymore with 25.6, please confirm. 
It has not been easy or straight forward to fix this and know how frustrating this has been.  
We REALLY appreciate your patience on this. 

This has been an issue for many users for the last few updates of Photoshop. It's unfortuantely nothing new. But holy hell I need this fixed because it's making the program borderline unusable.

And also unfortunately, it's only one of far too many bugs needing fixing.
Adobe, you need some healthy competition because the way these programs are handled is inexcusable.

As someone who's had this issue for a long time myself, I got the update to 25.6.0 yesterday.

For one I reinstalled a plugin and then the PS update happened the same day. It might be connected, but PS decided to reset it's whole preferences.

For what it's worth though, I can't specifically say it's the reset or the update (I've had reset tries before though without effect). But I didn't encounter this error throughout the rest of the day! So fingers crossed it's finally fixed for good with 25.6? 🙂