TextEdit Beans

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Last Updated 9/29/97

JavaBean support

TextEdit may be extended by JavaBean plug-ins. These beans appear in the editor's "Options" menu. The standard distribution includes samples of these beans (source code for these beans may be found in the "src" folder).

JavaBeans, as specified by JavaSoft, may vary considerably in complexity. The beans used in this editor are on the very simple end of the scale. Two Java class interfaces are provided. Edit beans which implement these interfaces are dynamiclly loaded by the edtior at start-up. The member functions required by the editor are defined by these interfaces, so no further class introspection is needed.

The interfaces are very simple, containing just two methods:

• getMenuString - returns a string which is added to the Options menu.
• filterText - processes text from the editor.

The way it works

1. The editor searches its "jars" folder and loads all beans on start-up.
2. The editor calls the bean's getMenuString method and inserts the result in the "Options" menu.
3. When the user selects a bean from the "Options" menu, the editor calls that bean's filterText method. The filterText method is passed a String containing any currenly selected text from the editor. If no text is selected an empty String is passed. The filterText method returns a new String containing updated text. (A null pointer may be returned to cancel the operation.)
4. The editor then deletes any selected text and inserts the String provided by the bean.

More Information:

• SimpleFilterInterface - The standard interface.
• Test01FilterInterface - An alternate inferface which passes the editor's main frame.

• Building an example bean
- We build a "Hello World" bean.

Please drop me a line if you have any questions.