Theme selector and dark theme

[rurigk]

I only added a theme selector and a dark theme

Themes are loaded from a resource file

I forgot to put it as draft

[rurigk]

It is necessary to correct some flaws in the themes

[kanryu]

@rurigk It's an interesting feature.
In order to actually introduce it, a new setting that switches on / off in the main menu or setting dialog is required. How did you implement it?

[rurigk]

Take the other configurations as an example
It cost me a bit to know how that system worked since there are no comments

[rurigk]

The only problem I saw when implementing it is that when you put an empty theme (Default) you lose styles of some elements

The dark theme is based on the subject of obs-studio with some small modifications
Do you have individually defined styles in the components?

[kanryu]

@rurigk In each ui file, some widgets customize their style sheets. If you change the overall display in the theme feature, you will need to be careful not to contradict it.

By the way, when I tried to build your repository, it seems that the symbol defined by Qt-5.12 called QPalette::PlaceholderText is used. I want to guarantee that I can build with Qt-5.9 for the time being, is it possible to fix your patch?

[rurigk]

I will try to compile it in that version of qt
It will take me a while, my internet is not very fast

And for the styles, I think we can migrate the styles that are in the ui files to the themes

[rurigk]

I could not make it work in my version of Qt Creator 4.8.2 with Qt 5.9

https://bugreports.qt.io/browse/QTBUG-72555

Could you try replacing optionsdialog.ui with the version of your branch and adding a combobox called comboBoxThemeSelector with "Default" and "Dark" items?

[kanryu]

I confirmed that I can build at least qt-5.11 except where I pointed out, so I accept it once. I will fix it myself later.

Thanks!