Supporting bidirectional text
A bidirectional language is one that can write either right to left or left to
right based on context. Bidirectional text is supported throughout the platform.
Eclipse will recognize Hebrew, Arabic, Farsi and Urdu as bidirectional by default.
Enabling Bidirectional Support
The orientation of the workbench is determined in one of the following ways
(in order of priority):
-dir command line parameter. If the -dir command line option
is used this will be the default orientation. Valid values are -dir rtl or -dir ltr.
system properties. If the system property eclipse.orientation
is set this will be used. The recognized values of this property are the same as
the -dir command line argument.
-nl command line parameter. If the -nl option is used and
the language is Hebrew, Arabic, Farsi or Urdu the orientation will be right
- Failing all of the above, the platform defaults to a left to right orientation.
In JFace, the orientation can be determined by calling
org.eclipse.jface.Window#getDefaultOrientation(). Standalone JFace
applications must set the default orientation by calling
org.eclipse.jface.Window#setDefaultOrientation(), otherwise it
will assume a default value of SWT.NONE. The default orientation is
set automatically when running the Workbench. All subclasses of org.eclipse.jface.Window
inherit this default orientation.
Views and editors inherit the window orientation from their
parent. Dialogs should inherit orientation by using the shell style of their
superclass by calling super.getShellStyle() when creating or configuring their shell.
Figure 1 - Screen shot of right to left orientation of the resource
perspective in English
Enabling Text Processing
The orientation of the workbench is independant of the special case processing
for bidirectional languages. If the language of the current Locale is Hebrew,
Arabic, Farsi or Urdu text processing will be enabled. Text processing is used
to handle special case characters that should not be processed as birdirectional
text such as path seperators. See
for more details.
Enabling your plug-in for looking up alternate icons
In many cases your icons will not make any sense in right to left mode. In
particular any icon to do with editing will have this issue.To enable lookup
of images in a fragment, use $nl$ in your icon path and use
the org.eclipse.core.runtime.FileLocator class to find icons at runtime.
String iconPath = "$nl$/icons/myicon.gif";
URL url = FileLocator.find( Platform.getBundle(MyPluginId), new Path(iconPath), null);
Image Descriptor descriptor = ImageDescriptor.createFromURL(url);
If the icon reference is in your plugin.xml file, make sure you have the $nl$
prefix on your path and the lookup will be handled for you. If you define your
own extension points that involve icons, be sure to load images in the same way.
How to choose icons to override
There are no hard and fast rules for determining what icons need to be overridden
in a right to left language. In general, focus on icons that imply a textual direction with a