Feature: Registry Preview -- Show current values for entries that .reg file would add/edit

[gaiking-uk]

Description of the new feature / enhancement

Please would it be possible to:

1. Add a column to the preview panel showing the current value next to the values from the .reg file
2. Highlight (e.g. with bold / colour-coding) where the .reg file would change | add | delete values

[NB: colours purely indicative]

Scenario when this would be used?

• The ability to preview (and so check before applying) is great, but context and current information is key to understanding the impact of applying a .reg file
• This would help users better understand the changes that a given .reg file would make the registry and so better decide whether to execute it or not
• This would help tasks like troubleshooting whereby users would be able to see (know) "I've already applied this .reg file", or "This .reg file I've been told to run probably won't make any difference as it looks like all the values it sets are already set that way"... Rather than the current, more "apply this .reg file blindly and see what it does" approach we are essentially forced to follow today

To clarify, I am not criticising PowerToys for this in any way, simply acknowledging the limitations of the current situation whereby we all have to double-click and .reg file and see then test that it had the desired effect, etc

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EDIT: This request was modified after posting to roll-in the suggestion of highlighting and colour-coding values that were added, changed and deleted, previously raised separately as #25722

[crutkas]

@randyrants this is a neat idea

[randyrants]

Very neat idea but also a very expensive one, as near as I can tell. The process would go, where new items are in italic:

• Load in a REG file
• Parse the REG file into the preview
• Query the Registry for the existing state every Key and Value in the file.
• On initial line and for each additional keystroke:
  -  Add that data to the preview
  -  Add visual cue to call out the new/different values (in my mind there's no way we do 25748 without 25722)

I would worry that there'd be a lot of processing involved in this one. Especially with the current large file limit at 10MB - maybe we drop that down and see what happens?

We'd also need to elevate the Previewer on open as well. I get that it wouldn't have to if a REG file only looks at HKCU, but with the REG file open to editing, as soon as someone hits the last ] in HKLM, they'd have to be prompted to elevate then, and that feels... well, almost like phishing, since it's so unexpected.

[htcfreek]

I think this also requires #25118. (I did some private investigation about decoding the values in the past.)

[randyrants]

I could benefit from it, but I don't think it's required: the compare between old/new would be done on the binary values either way and continued to be represented in the same way it is today.

[gaiking-uk]

Hi all, just to clarify that I have merged the colour-coding / highlighting element from #25722 into this request (as requested).

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@randyrants -- I agree that it is not "required", although, arguably this probably depends on the definition, as in PowerToys isn't "required" for Windows to work for example, but it definitely makes it better and easy to do certain things, and this request would definitely make it easier to preview .reg files. (in terms of "understanding what this file will do" / "knowing BEFORE applying what the impact will be".

I appreciate that there are loads of requests for PowerToys and only a finite amount of time to implement them, but do hope this one makes it in (eventually). If you need anything else from me, please don't hesitate to reach out, otherwise I will leave this to work it's way through the queue/process. 👍🏼

[randyrants]

@gaiking-uk Sure, that's a great practice for bugs, especially for issues that may or may not be related to each other, but for feature requests, that pull together many a topic, especially if the collection bring greater value as a whole. I guess, for me, that I see the pulling in of the data as such a large effort that I would want to justify it by having as many things tied to it as possible. And since the compare or the highlight can't exist without it, it's all together in my mind. Something about, if you're going to put in the effort, get the full value of it that effort.