save dialogs don't automatically add extensions

[wxl]

Save dialogs in don't provide an option to automatically add extensions, so even where some application understands one particular extension, saving a file in it doesn't result in an extension being added.

Expected Behavior

Save dialogs should at least have a checkbox providing an option to automatically add an extension.

Current Behavior

Save dialogs have no options regarding extensions and files get saved without them unless manually added.

Possible Solution

To be fair, I'm not sure. I know it's not reasonable to imagine that LXQt is going to provide every single app-specific option known to man (e.g. LibreOffice's encrypt with a password), but I would imagine that having the option to automatically add a file extension seems pretty universally applicable.

Steps to Reproduce (for bugs)

I originally noticed this in k3b, so:

1. Open k3b
2. Click "Create a New Data Project"
3. Click "Save"
4. Note that the file name does not have the ".k3b" extension
5. Click ok to use the default file name
6. Open the file manager to the save location and note the file does not have the extension

Context

@agaida suggested I file this here.

System Information

• Distribution & Version: Lubuntu 19.10
• Kernel: 5.0.0-13-generic
• Qt Version: 5.12.2
• libqtxdg Version: 3.3.1-0ubuntu2
• lxqt-build-tools Version: 0.6.0-2ubuntu1
• Package version: 0.14.1-0ubuntu2

Downstream bug

[tsujan]

@wxl That's the app's job.

Our dialog supports everything that a file dialog needs -- including QFileDialog::setDefaultSuffix(), which can be used by codes -- plus functionalities that aren't found in Qt file dialog.

For example, ScreenGrab, lximage-qt, Falkon and many other Qt apps add a default extension with "Save As" when no extension is given.

I think what you see with K3b is K3b's fault but I'll look into it.

[tsujan]

OK, I investigated it.

Unlike other apps, K3b doesn't set a default suffix — and so, we have no responsibility — but the KDE file dialog adds it when the current name filter starts with a usable extension. That isn't a Qt standard.

However, I patched libfm-qt to do the same thing, i.e if (1) there is no default suffix, (2) the dialog is in the save mode, and (3) the file name doesn't end with an extension, LXQt file dialog could extract the first extension in the current name filter and add it to the file name.

It worked with K3b and I don't think it could have any side effect. But I should try it for a while before making a PR.

[tsujan]

This needs some discussion. I tell my opinion to see who dares to disagree ;)

When there isn't a default suffix (bad code like K3b's?) but there is a name filter (like Image Files (*.png *.jpg)), LXQt save-dialog adds the first extension when the name typed by the user doesn't have one.

If the user doesn't want an extension for whatever reason (?), he/she could choose All Files(*) in the File Type combo. If the app doesn't provide All Files(*), it means that an extension is important to it and so, the file will be always saved with an extension.

Now, this looks logical to me and, I think, it's better than cluttering the GUI with a checkbox that says, "Save with extension" (saying nothing about the extra codes the latter would need). KDE GUI's are all cluttered but I don't think we want that for LXQt when we can avoid it reasonably.

Any objection?

[wxl]

Thanks for the further investigation. I didn't think this was an LXQt problem, per se, but I think this will be a nice feature that will provide a consistent experience for users despite the fallibility of other software.

Totally agree that KDE is cluttered. I mean they like to pitch how configurable their software is and while I agree, my common retort is: if you can find where to change the setting you want 😉

That said, I think what you're saying makes sense. The idea of not having an extension seems, as you implied, like a pretty strange edge case. That person will get annoyed by the behavior, I'm sure, but in the effort of serving the vast majority of users in the best possible way (KISS), I think what you suggest is a good idea.

Oh, and this is totally tangential, but I also note that Featherpad doesn't seem to have a default extension. I guess it shouldn't necessarily have one, but there should be a whole variety of different text file types, no? I mean, Kate behaves similar, so maybe not.

[tsujan]

The idea of not having an extension seems, as you implied, like a pretty strange edge case.

Yes, but it's still possible if the filter is All Files(*).

The more I use it, the more reasonable it seems to me. Why should we save a file without extension when the File Type combo has one? IMO, KDE's way makes sense.

Featherpad doesn't seem to have a default extension.

That's intentional. Text documents aren't just simple texts. They can be C/C++/Python/Bash... codes or markdown, config, etc. There's a huge number of them and apps may add to them. So, adding a filter doesn't make sense — multiple screens would be needed for showing it ;) FeatherPad only adds a proper extension when a suffixed file is opened and the save-as dialog is called. I made it so for security reasons (it has a story) before the first version of FeatherPad.

[wxl]

Sounds good to me!

[tsujan]

Thanks for the feedback!

[wxl]

Actually I noticed Falkon defaults to saving pages as MIME HTML archives, but provides options for HTML pages, both single and complete. The default filename ends in .mhtml. If you toggle the file type, the extension does not change. That said, would you be adding anything to allow one to change different extensions?

[tsujan]

The default filename ends in .mhtml

I use it a lot with Falkon. With the patch, it'll be the default extension when the user doesn't type it.

Apart from that, no file dialog can change which extensions an app provides or prefers.

[wxl]

That's not exactly what I mean. Consider: 1. Right click on page in Falkon 2. Click Save As 3. Note File Type is MIME Type Archive (*.mhtml) and extension of file name is .mhtml 4. Change File Type to HTML page, single (*.html) 5. Note extension of file name is still .mhtml So what I'm suggesting is not that somehow we overwrite or modify the defaults or the options available in the File Types, but that where an application provides more than one option, selecting a different File Type will result in a change to the file name extension. The result would be: 1. Right click on page in Falkon 2. Click Save As 3. Note File Type is MIME Type Archive (*.mhtml) and extension of file name is .mhtml 4. Change File Type to HTML page, single (*.html) 5. Note extension of file name is now .html

[tsujan]

Please open another issue for that! I agree that it should be as you said. I may make the patch more complete to cover it too because both issues/features are about extensions and I'm lazy. But opening a separate issue for it would show its importance.

[tsujan]

The patch is here: #425

It doesn't need recompilation of pcmanfm-qt but a previous patch (1baee3e) does. So, recompilation of pcmanfm-qt (and other libfm-qt based apps) is really recommended.