Getting started code for Intellij Plugin that adds a view with two textareas and a button that calls an endpoint

Getting started code for Intellij Plugin View

Posted on by Toma Velev

Here’s a basic example of how to create an IntelliJ plugin that adds a custom view.

Step 1: Create a new IntelliJ Plugin project

First, you need to create a new IntelliJ plugin project in IntelliJ IDEA Community. To do this:

  • Open IntelliJ IDEA
  • Go to File > New Project
  • In the “New Project” dialog box, select “IDE Plugin” under the “Generators” section.
  • Fill in the required information (e.g., plugin name, description, etc.)
  • Click on “Create”

Step 2: Register the plugin

We need to register our plugin with IntelliJ IDEA. To do this:

  • Open the plugin.xml file in the src/resources/META-INF
  • Add a new <toolWindow> element to the <extensions> section:
<extensions defaultExtensionNs="com.intellij">
<toolWindow id="GPT Chat"
            factoryClass="com.programtom.intellijgpt.GptWindowFactory"
            anchor="right"/>
</extensions>

Step 2: Create a new UI component

IntelliJ has moved to kotlin programming language – so live with it. Create new Kotlin class:

class GptWindowFactory : ToolWindowFactory {

    override fun createToolWindowContent(project: Project, toolWindow: ToolWindow) {
        val myToolWindow = GPTChatWindow()
        val contentFactory = ContentFactory.getInstance()
        val content = contentFactory.createContent(myToolWindow.content, "", false)
        toolWindow.contentManager.addContent(content)
    }
}

and create a awt/swing UI for your view:

@Service(Service.Level.PROJECT)
class GPTChatWindow {
val content: JPanel
 init {
    this.content = JPanel().apply {
 //... your UI code here
}}}

Caveats

There are probably million and one items that you need to address. The IntelliJ SDK has virtual wrappers around all kinds of APIs

  • File API
  • Background Work API
  • UI Access/change API
  • etc

As minimal – I want to share how to execute some work and “push” it to the UI. You need to

  • Start a new thread like this: 
    ApplicationManager.getApplication().executeOnPooledThread { ... }
  • Publish back to the UI with 
    ApplicationManager.getApplication().runReadAction { ... } //runWriteAction

Step 3: Run the plugin

The project comes with run configuration of “gradle runIde”, that allows you to hit Run Plugin – and test your code.

Step 4: Deploy

There are some more steps in the way of trully publishing it to the world and getting it approved in the marketplace, but – they are for another article. To get an actual build – just add “gradle assemble” Run Configuration. It will create a zip in build/distribution that you could share for beta testing.

If you are interested, I’ve done some plugins for: