---
title: Eclipse RCP Plugin Development
---

<h1 style="font-size: 4rem">Eclipse RCP Plugin Dev</h1>

[TOC]

# Useful Links

- (Tutorial on vogella.com) https://www.vogella.com/tutorials/EclipseRCP/article.html
- (How to add toolbar menu & menubar menu & popup menu item) https://www.vogella.com/tutorials/EclipseCommands/article.html#menu-extension-points
- (Books) http://libgen.is/search.php?req=Eclipse+Rich+Client+Platform&lg_topic=libgen&open=0&view=simple&res=25&phrase=1&column=def
- (CDT code) https://github.com/eclipse-cdt/cdt
- E4AP = [Eclipse 4 Application Platform](https://wiki.eclipse.org/Eclipse4/RCP/FAQ#Adopting_the_Eclipse_4_Application_Platform)

# Eclipse RCP Lifecycle

https://wiki.eclipse.org/Eclipse4/RCP/Lifecycle

1. Component Lifecycle
- `@PostConstruct private void init()`
- `@PreDestroy private void dispose()`
2. Application Lifecycle
- A "Product" can provide a "lifecycle manager object"

# Misc Tasks

## Conditionally Visible Popup Menu Item

**NOTE: When the handler is already disabled (see next section), there's no need to disable menu item anymore**

- Add a `<visibleWhen>` tag for the condition, under the `<command>` tag
- The "Extensions" tab doesn't provide way to write this; edit `plugin.xml` directly
- Hint taken from [Name filter for eclipse.ui.menus (SO)](https://stackoverflow.com/questions/19776876/name-filter-for-eclipse-ui-menus)
- Detailed info on [ Platform Expression Framework - Eclipse Wiki](https://wiki.eclipse.org/Platform_Expression_Framework)
- `popup:org.eclipse.ui.navigator.ProjectExplorer#PopupMenu` is the locationURI for project explorer

<menuContribution
      allPopups="false"
      locationURI="popup:org.eclipse.ui.navigator.ProjectExplorer#PopupMenu?before=group.edit">
    <command
        commandId="com.example.rcpproject.commands.flashCommand"
        label="Flash hex"
        style="push">
        <visibleWhen checkEnabled="false">
            <iterate ifEmpty="false" operator="or">
                <test property="org.eclipse.core.resources.name" value="*hex"></test>
            </iterate>
        </visibleWhen>
    </command>
</menuContribution>

## Conditionally Enable Command Handler

- Add a `<enabledWhen>` tag for the condition, under the `<handler>` tag
- See links in previous section for docs
- Example: We want to enable the handler only when **both** (i.e. `<and>`) conditions meet
1. There's exactly one file selected (we don't want to handle multi-selection)
- Solved using `<count>`
2. All selected items (there's only one) are .hex files
- Solved using `<iterate>`, `<adapt>` (kinda like a type cast?), and `<test>`

<handler
      class="com.example.rcpproject.handlers.FlashHandler"
      commandId="com.example.rcpproject.commands.flashCommand">
    <enabledWhen>
        <with variable="selection">
            <and>
                <count value="1"/>
                <iterate ifEmpty="false" operator="or">
                    <adapt type="org.eclipse.core.resources.IResource">
                        <test property="org.eclipse.core.resources.name" value="*hex"></test>
                    </adapt>
                </iterate>
            </and>
        </with>
    </enabledWhen>
</handler>

## Run Code on Plugin Startup

- https://stackoverflow.com/questions/21377071/how-to-make-an-eclipse-plugin-load-on-startup
- Use `org.eclipse.ui.startup` extension point
- The relevant part of `plugin.xml`

  <extension
       point="org.eclipse.ui.startup">
    <startup
      class="com.example.rcpproject.handlers.Startup">
    </startup>
  </extension>

- The handler class

  public class Startup implements IStartup {
      @Override
      public void earlyStartup() {
          System.out.println("Plugin early startup");
      }
  }

## Get Notified on Window Open and Close

- Use `PlatformUI.getWorkbench().addWindowListener(listener)` in `Startup::earlyStartup`
- Known Problem: First (the initial one) window is not detected if put in `earlyStartup`
- Example code

  PlatformUI.getWorkbench().addWindowListener(new IWindowListener() {
      @Override
      public void windowActivated(IWorkbenchWindow window) {
          System.out.println("Window activated");
      }

      @Override
      public void windowDeactivated(IWorkbenchWindow window) {
          System.out.println("Window de-activated");
      }

      @Override
      public void windowClosed(IWorkbenchWindow window) {
          System.out.println("Window closed");				
      }

      @Override
      public void windowOpened(IWorkbenchWindow window) {
          System.out.println("Window opened");
      }
  });

- `IWindowListener` build issue:
Maybe follow https://stackoverflow.com/questions/3086859/importing-org-eclipse-core-packages-for-eclipse-plug-in
1. Window - Show View - Others - (type "Plug-ins") - On `org.eclipse.core.runtime`, "Add to Java Workspace Scope"
2. Add it on `plugin.xml` - Dependencies tab - Required plug-ins

## Get File Selected in Project Explorer

https://stackoverflow.com/questions/27954738/how-can-i-get-the-path-of-a-file-in-the-project-explorer-of-exlipse

ISelectionService service =
    PlatformUI
        .getWorkbench()
        .getActiveWorkbenchWindow()
        .getSelectionService();

ISelection selection = service.getSelection();

if (selection instanceof IStructuredSelection) {
   Object selected = ((IStructuredSelection)selection).getFirstElement();

   IFile file =
       (IFile) Platform.getAdapterManager().getAdapter(selected, IFile.class);
}

## Build Eclipse Plugin without Eclipse

- Use *Tycho* (https://github.com/eclipse-tycho/tycho)
- Not tested yet
- See eclipse markdown editor plugin (https://github.com/winterstein/Eclipse-Markdown-Editor-Plugin/blob/master/pom.xml) for example, it uses tycho to build