How to get native windows decorations on GTK3 on Windows 7+ and MSYS2

Question

I am trying to port my application from linux to windows and I have a problem with theming. In linux this works out of a box, just compile it and application is using good theme

Answer 1

For people like me who use (activestate) perl, the /share and /etc need to be placed one directory above the perl.exe (say in C:\Perl64 if perl.exe is in C:\Perl64\bin).

Answer 2

Thera are two sub-problems: missing icons and setting right theme.

Missing icons

For missing icons it was enough to copy these icons

• window-close-symbolic.symbolic.png
• window-maximize-symbolic.symbolic.png
• window-minimize-symbolic.symbolic.png

from: C:\msys64\mingw32\share\icons\Adwaita\22x22\actions

to: "your executable folder"\share\icons\Adwaita\22x22\actions

Theme

Using win32 native theme

There is actually a built-in native-like theme in GTK3. For using native-like theme just create file "your executable folder"\etc\gtk-3.0\settings.ini with this in it

[Settings]
gtk-theme-name=win32

win32 theme is built in into GTK3 and only three icons from previous step seems to be needed.

On windows 7 this looks as following:

The problem is, that the decorations looks the same even on Windows 10 (including window decorations).

From comment from @andlabs : GTK+ 3 uses the uxtheme.dll APIs to get its Windows look and feel, and unfortunately Microsoft has kept those Windows 7-like for window borders. (more in comments)

You can see Windows 10 Gtk3 application with win32 theme here:

Using non default theme

And if you are not happy with default or win32 theme, you can use custom themes (like this Flat-Pat) from the internet. :) In order to do it you need to create config file:

"your executable folder"\etc\gtk-3.0\settings.ini with this in it

[Settings]
gtk-theme-name=Flat-Plat

and you need to copy the theme files to directory in path of your executable

"your executable folder"\share\themes\Flat-Plat

in that folder, the index.theme file and gtk-x.x folders should be present. Obviously gtk-theme-name and folder name should match.

After you run the executable you should be able to get different theme.

EDIT: So there is a win32 theme built-in, thank you @andlabs

EDIT2: Added screenshots

EDIT3: Added Windows 10 screenshot and corrected facts.

Answer 3

Actually, Gtk+3 been compatible with Windows 10 and you can use the native windows theme by making this your default theme.

gtk-theme-name = MS-Windows

Answer 4

You can set GTK_CSD=0 environment variable to disable client-side window decorations and enable Windows native decorations, which gets rid of the ugly win7-like titlebar, as well as Adwaita-like one.

Answer 5

While GTK_CSD=0 is doing a fine job for windows frame icons, it seams that default Drag-And-Drop (DND) icons are missing too.

Dragging GtkEntry or GtkTreeView contents shows a drag-icon.

I've prepared a button as drag source under Gtk+-3.24.4. When dragging the button, the mouse cursor disappears and no drag icon is shown.

When using gtk_drag_source_set_icon_pixbuf(bt, pixbuf), the pixbuf appears as drag icon. But doing it this way is only half the job done, because move/copy indicators are missing on the icon.