Update gtk-3.0 theme thumbnail.

[Initu-Castilhos]

Sorry to bother you again but I figured out how to generate thumbnail for gtk-3.0 themes, there is a text file explaining how to generate thumbnail for themes located at:/usr/share/cinnamon/gtk-3.0.

Here are the images.

The tutorial is this:

HOW TO MAKE A GTK THEME THUMBNAIL?

• Install ImageMagick ("apt install imagemagick")

• Open a terminal and run "cinnamon-preview-gtk-theme mytheme" (where mytheme is the name of the Theme you want to thumbnail)

• Press Alt+Print-Screen to take a screenshot of the window

• Go to your Pictures directory and move the screenshot to ~/screenshot.png

• Open a terminal and type:

  cd
  convert screenshot.png -gravity north-west -extent 120x35 thumbnail.png

WHICH THUMBNAIL IS USED BY CINNAMON TO REPRESENT A THEME?

• Cinnamon first tries to find a gtk-3.0/thumbnail.png file in the theme directory
• If it doesn't find any, it looks in /usr/share/cinnamon/thumbnails/gtk-3.0/

Again I apologize but I thought it was important to pass this information on to future compilations.

[Jupi007]

Thanks a lot for this @Initu-Castilhos 👍
I will be useful for future updates.

[Initu-Castilhos]

I've made an update to the image cropping if you're interested in creating a P.R. just download the images.

[Jupi007]

I could do it, but what about doing this by yourself.
So you being attributed for your work :)

[Initu-Castilhos]

I can't create a PR.

[Jupi007]

No problem, I'll do it so :)

[Initu-Castilhos]

Thanks!