Adapt font and icon sizes to High Definition screen resolutions in Ubuntu-Studio XFCE

Solution 1:

There is no global setting like the zoom scale factor in Unity, but you can follow these steps to achieve most of it:

1. Set a Custom DPI setting

Open a terminal with CTRL+ALT+t and enter

    LANG=c xfce4-settings-manager

In "Appearence"->Fonts-> "Custom DPI Setting:" set this to 192 (instead of the default 96).

Log off and on again to accept the new settings in all windows.

2. Adapt Theme and settings

Set your panel size to a height of 48
In xfce4-settings-manager->"Settings Editor" (xfce4-settings-editor)
- in section xfce4-desktop (create an entry if it doesn't exist)
  desktop-icons/icon-size Type Integer and set it to 128
- in section xsettings set CursorThemeSize to 48
- in section xsettings set Gtk/IconSizes to
```
gtk-large-toolbar=32,32:gtk-small-toolbar=24,24:gtk-menu=32,32:gtk-dialog=88,88:gtk-button=32,32:gtk-dnd=32,32
```
  Or use the commandline:
```
xfconf-query -c xsettings -p /Gtk/IconSizes -s "gtk-large-toolbar=32,32:gtk-small-toolbar=24,24:gtk-menu=32,32:gtk-dialog=88,88:gtk-button=32,32:gtk-dnd=32,32"
```
  - gtk-large-toolbar are main toolbars
  - gtk-small-toolbar are secondary toolbars
  - gtk-menu are menus
  - gtk-dialog are dialog icons
  - gtk-button are buttons (eg the xfce panel uses buttons)
  - gtk-dnd are the icons displayed if you drag and drop a file or a folder
    
    you can change them to any size as long your icon theme supports it
In xfce4-settings-manager->"Window Manager"
- select the theme Default-xhdpi (since Xfce 4.12 - upgrade instructions for 14.04)
- Set the Title Font to 12
Download the Widepanel Appearance ** in xfce4-settings-manager->"Appearance" select Widepanel
In the File Manager thunar adapt the preferences:
- Set Iconsize in the sidepanel to "small" or "normal"

3. Adapt Firefox

see: Adjust Firefox and Thunderbird to a High DPI touchscreen display (retina)

(or use Chrome, which works fine since Version 41.0.2272.76 Ubuntu 14.10)

4. Increase font in Pidgin

There is a plugin you can install

sudo apt-get install pidgin-extprefs

Then you can increase the font in Plugins->Extended Prefs

5. Create starter for applications that still don't scale

Some applications still don't obey the global scaling (mainly java) for those few applications you can create a starter to only Fix scaling of java-based applications for a high DPI screen

source: https://askubuntu.com/a/472266/34298