This article describes the themeing functionality of RWT, the RAP Widget Toolkit. This themeing defines the default look and feel of the basic RWT controls like Shell, Button, Text etc. It must not be mixed up with the themeing of the Eclipse workbench. Instead, it can be compared to the themeing functionality of a desktop system that allows the user to set custom colors for title bars, text background and the like.
State of Development
The RWT themeing mechanism, as introduced with the M4 milestone, is still in an early state of development. Some details are still likely to change, as our experience with this approach grows. Your comments and suggestions are welcome.
Currently, the RWT themeing only allows to define colors and icons. Themeing of fonts, borders, margins etc. will follow shortly.
How to define a custom RWT Theme
Create a custom theme file
RWT theme files are simple Java Property files.
A template named
theme-template.properties can be found in the
src/ directory of the RWT plugin (
You only have to specify those properties that are relevant for your customization, as undefined properties will stay at their default value.
Note that some property names are likely to be changed in the future, other properties will emerge and a few properties will even be dropped.
Please refer to the template file shipped with your current version.
See below for the syntax of the property values.
Register the new theme with the extension point
plugin.xml of your application project, add an extension like this:
<extension id="my.application.themes" point="org.eclipse.rap.swt.themes"> <theme id="my.application.aquablue" name="Aqua Blue Test Theme" file="aqua-blue.properties" default="true"/> </extension>
Activate the theme
The extension parameter
default specifies whether the theme should be active by default.
Another method of activating a custom theme is by specifying the theme id with URL parameter
Support for programmatic activation of custom themes is planned for future versions.
Syntax for Property Values
Property values specified in a theme file must conform to the following syntactical rules:
Colors can be specified in one of these ways:
- A color keyword.
Only the 16 basic HTML 4.0 colors (aqua, black, blue, fuchsia, gray, green, lime, maroon, navy, olive, purple, red, silver, teal, white, and yellow) are supported. The keywords are case-insensitive.
- A comma separated list of three decimal integer numbers in the range
0 .. 255that denote the red, green, and blue portion of the color, respectively.
- A hexadecimal color notation in the format
#rrggbb, that is commonly used for HTML pages.
Custom images must be referred to using a '/'-separated path name that identifies the location of an image resource within the bundle.
SWT System Colors
The SWT system colors, as returned by
Display#getSystemColor(), are also themeable.
The following list indicates which theme parameters manipulate these colors:
SWT.COLOR_WIDGET_DARK_SHADOW: widget.darkshadow SWT.COLOR_WIDGET_NORMAL_SHADOW: widget.shadow SWT.COLOR_WIDGET_LIGHT_SHADOW: widget.lightshadow SWT.COLOR_WIDGET_HIGHLIGHT_SHADOW: widget.highlight SWT.COLOR_WIDGET_BACKGROUND: widget.background SWT.COLOR_WIDGET_BORDER: widget.thinborder SWT.COLOR_WIDGET_FOREGROUND: widget.foreground SWT.COLOR_LIST_FOREGROUND: list.foreground SWT.COLOR_LIST_BACKGROUND: list.background SWT.COLOR_LIST_SELECTION: list.selection.background SWT.COLOR_LIST_SELECTION_TEXT: list.selection.foreground SWT.COLOR_INFO_FOREGROUND: widget.info.foreground SWT.COLOR_INFO_BACKGROUND: widget.info.background SWT.COLOR_TITLE_FOREGROUND: shell.title.foreground SWT.COLOR_TITLE_BACKGROUND: shell.title.background SWT.COLOR_TITLE_BACKGROUND_GRADIENT: shell.title.background.gradient SWT.COLOR_TITLE_INACTIVE_FOREGROUND: shell.title.inactive.foreground SWT.COLOR_TITLE_INACTIVE_BACKGROUND: shell.title.inactive.background SWT.COLOR_TITLE_INACTIVE_BACKGROUND_GRADIENT: shell.title.inactive.background.gradient