Use Breeze style in Flatpak

[ilya-fedin]

Before

After

[KitsuneRal]

Many thanks for the contribution!

To be honest, it looks quite hardcodey (and ugliness is a matter of taste - call me old-fashioned but I don't find Fusion too ugly - especially after Windows :-/). I'm fine to override the default theme to be Breeze but what if someone actually uses Fusion on his, say, LXQt-based desktop? And what if Quaternion is packed with Snap another day? Your code seems to narrow the target case unnecessarily.

[ilya-fedin]

I'm fine to override the default theme to be Breeze but what if someone actually uses Fusion on his, say, LXQt-based desktop?

I also thought about that, but Qt doesn't have any API to get the current style name nor to check if it is was by the user or is default fallback. All I can do is check the values of the variables QT_QPA_PLATFORMTHEME and QT_STYLE_OVERRIDE, but, probably, that would be even more ugly (that's why I didn't do it first).

And what if Quaternion is packed with Snap another day?

Currently, the recommended way for snapping is kde-neon extension. Their wrapper already sets a theme.

[KitsuneRal]

Qt doesn't have any API to get the current style name nor to check if it is was by the user or is default fallback. All I can do is check the values of the variables QT_QPA_PLATFORMTHEME and QT_STYLE_OVERRIDE, but, probably, that would be even more ugly (that's why I didn't do it first).

Right, relying on environment variables for hints is even more fragile. However, for now this looks like we impose another default over the Qt's default with no means to revert to the Qt's default - and if I got it right then sorry it's not an option :) If we can't give users the flexibility to bring the theme back to Fusion, we can merely provide an easy and unobtrusive way to switch to Breeze from inside Quaternion (via a setting, or a button somewhere in the settings dialog (to be merged)). Or, given that Quaternion is for technical audience anyway, just document how to override the theme with generic means (-style and QT_STYLE_OVERRIDE).

And what if Quaternion is packed with Snap another day?

Currently, the recommended way for snapping is kde-neon extension. Their wrapper already sets a theme.

Good to know, thanks.

[ilya-fedin]

with no means to revert to the Qt's default

There are a check if additional themes is installed (e.g. org.kde.KStyle.Adwaita). And if some theme is installed, then theme won't be set.

we can merely provide an easy and unobtrusive way to switch to Breeze from inside Quaternion

Hmm, just like Kdenlive:

[KitsuneRal]

with no means to revert to the Qt's default

There are a check if additional themes is installed (e.g. org.kde.KStyle.Adwaita). And if some theme is installed, then theme won't be set.

What if there are no additional themes but the user just wants to use Fusion? This can be a case at Windows, e.g.

we can merely provide an easy and unobtrusive way to switch to Breeze from inside Quaternion

Hmm, just like Kdenlive:

Yeah, looks good to me.

[ilya-fedin]

This can be a case at Windows, e.g.

Windows doesn't have Breeze anyway...

[KitsuneRal]

This can be a case at Windows, e.g.

Windows doesn't have Breeze anyway...

Ok, this is actually irrelevant if we talk about Flatpak. But Adwaita (any extra theme actually) may easily be missing exactly in cases you mentioned above - LXQt, WM, ion etc.

[ilya-fedin]

Created a setting, didn't relocate inFlatpak since it is in #682 and I think it is better to rebase this PR when #682 will be merged

[KitsuneRal]

One nitpick, and yes let's put your other PR in first.

[KitsuneRal]

Suggested change

	using Quotient::SettingsGroup;
	const auto useBreezeStyle = SettingsGroup("UI").value("use_breeze_style", inFlatpak()).toBool();
	const auto useBreezeStyle = Quotient::Settings().get("UI/use_breeze_style", inFlatpak());

SettingsGroup is fine too but is only worth it when the same group is used multiple times (FWIW, it's been made as a generic base for AccountSettings). For one-off uses Settings comes slightly more concise and optimal.

[ilya-fedin]

Fixed

[ilya-fedin]

Rebased on the current master