The QuickNotepadPlugin Class
Prev | Chapter 18. Implementing a Simple Plugin | Next

## The QuickNotepadPlugin Class

The major issues encountered when writing a plugin core class arise from the developer's decisions on what features the plugin will make available. These issues have implications for other plugin elements as well.

- Will the plugin provide for actions that the user can trigger using jEdit's menu items, toolbar buttons and keyboard shortcuts?

- Will the plugin have its own visible interface?

- Will the plugin have settings that the user can configure?

- Will the plugin respond to any messages reflecting changes in the host application's state?

- Should the plugin do something special when it gets focus?

Recall that the plugin core class must extend `EditPlugin`. In QuickNotepad's plugin core class, there are no special initialization or shutdown chores to perform, so we will not need a `start()` or `stop()` method.

The resulting plugin core class is lightweight and straightforward to implement:

-     public class QuickNotepadPlugin extends EditPlugin {
        public static final String NAME = "quicknotepad";
        public static final String OPTION_PREFIX = "options.quicknotepad.";
      }

  The class has been simplified since 4.1, and all we defined here were a couple of `String` data members to enforce consistent syntax for the name of properties we will use throughout the plugin.

- These names are used in `actions.xml` for each of the menu choices. This file is discussed in more detail in the section called “The Actions.xml Catalog”. Each action is a beanshell script.

      <!DOCTYPE ACTIONS SYSTEM "actions.dtd">
      <ACTIONS>
        <ACTION NAME="quicknotepad.choose-file">
          <CODE>
            wm.addDockableWindow(QuickNotepadPlugin.NAME);
            wm.getDockableWindow(QuickNotepadPlugin.NAME).chooseFile();
          </CODE>
        </ACTION>

        <ACTION NAME="quicknotepad.save-file">
          <CODE>
            wm.addDockableWindow(QuickNotepadPlugin.NAME);
            wm.getDockableWindow(QuickNotepadPlugin.NAME).saveFile();
          </CODE>
        </ACTION>

        <ACTION NAME="quicknotepad.copy-to-buffer">
          <CODE>
            wm.addDockableWindow(QuickNotepadPlugin.NAME);
            wm.getDockableWindow(QuickNotepadPlugin.NAME).copyToBuffer();
          </CODE>
        </ACTION>
      </ACTIONS>

- The names also come up in the properties file, `QuickNotePad.props` file. The properties define option panes and strings used by the plugin. It is explained in more detail in the section called “The Property Files” and the `EditPlugin` API docs.

      # jEdit only needs to load the plugin the first time the user accesses it
      # the presence of this property also tells jEdit the plugin is using the new API
      plugin.QuickNotepadPlugin.activate=defer

      # Even if you don't store additional files, this is a good idea to set:
      plugin.QuickNotepadPlugin.usePluginHome=true

      # Required for all plugins:
      plugin.QuickNotepadPlugin.name=QuickNotepad
      plugin.QuickNotepadPlugin.author=John Gellene

      # version number == jEdit version number
      plugin.QuickNotepadPlugin.version=4.5

      # online help
      plugin.QuickNotepadPlugin.docs=index.html

      # we only have one dependency, jEdit 4.5
      # See jEdit.getBuild() to understand version numbering scheme.
      plugin.QuickNotepadPlugin.depend.0=jedit 4.05.99.00

      # quicknotepad's plugin menu - a list of actions or separators
      plugin.QuickNotepadPlugin.menu=quicknotepad \
        - \
        quicknotepad.choose-file \
        quicknotepad.save-file \
        quicknotepad.copy-to-buffer

      # action labels for actions supplied by dockables.xml
      quicknotepad.label=QuickNotepad

      # action labels for actions supplied by actions.xml
      quicknotepad.choose-file.label=Choose notepad file
      quicknotepad.save-file.label=Save notepad file
      quicknotepad.copy-to-buffer.label=Copy notepad to buffer

      # plugin option pane
      plugin.QuickNotepadPlugin.option-pane=quicknotepad

      # Option pane activation BeanShell snippet
      options.quicknotepad.code=new QuickNotepadOptionPane();

      # Option pane labels
      options.quicknotepad.label=QuickNotepad
      options.quicknotepad.file=File:
      options.quicknotepad.choose-file=Choose
      options.quicknotepad.choose-file.title=Choose a notepad file
      options.quicknotepad.choose-font=Font:
      options.quicknotepad.show-filepath.title=Display notepad file path

      # window title
      quicknotepad.title=QuickNotepad

      # window toolbar buttons
      quicknotepad.choose-file.icon=Open.png
      quicknotepad.save-file.icon=Save.png
      quicknotepad.copy-to-buffer.icon=CopyToBuffer.png

      # default settings
      options.quicknotepad.show-filepath=true
      options.quicknotepad.font=Monospaced
      options.quicknotepad.fontstyle=0
      options.quicknotepad.fontsize=14

      # Setting not defined but supplied for completeness
      options.quicknotepad.filepath=

Prev | Up | Next
How Plugins are Loaded | Home | The Property Files