Editor handing in IntelliJ can be confusing at times. There are several different types of editors and several layers of abstraction to handle the content of files. An editor is one of them.
A plugin might want to enhance an editor's UI and needs to attach to newly created editors. Resources are usually released when an editor is closed and a plugin needs a way to track this, as well.
This post introduces the basic editor concepts and lists the different ways to track open and close events of the different types of editors.
Concepts & classes
com.intellij.openapi.fileEditor.FileEditor(Link to github.com)
- The fundamental interface which is implemented to provide an editor for a VirtualFile.
com.intellij.openapi.fileEditor.FileEditorManager(Link to github.com)
- The class to work with editors . Use it to retrieve, open, close, track and modify editors. It mostly uses
FileEditorbut also offers access to text editors of type
Editor. This class should be sufficient for most tasks.
FileEditorManagerand provides ways to work with splitted editors and editor tabs, among other things.
com.intellij.openapi.editor.Editor(Link to github.com)
- An interface which specializes for text files. The interface
FileEditorinterface above and links it to the corresponding
Editordoes not extend the
com.intellij.openapi.editor.Document(Link to github.com)
- A document provides high-level access to the content of a VirtualFile. An
Editordisplays and modifies a document and provides
There are several types of editors and several ways to track them. More basic handling could be done by tracking FileEditors, more advanced features can be added to instances of Editor after tracking them.
Tracking file editors of type
Open and close events are tracked using the message bus, the corresponding topic is
The used listener class is
com.intellij.openapi.fileEditor.FileEditorManagerListener. If you just want to track newly opened and closed editors then just implement the methods
More advanced tracking is available by implementing the method
selectionChanged(...). It allows you to react to newly created editors, closed editors and changes of the currently active editor. If you use it then you don't have to implement
fileClosed(...) because both are called in addition to
A sample component which tracks editors using the message bus is available as EditorStatusComponent on github.com.
Tracking text editors of type
Document editors, i.e. instances of
Editor, are created by
com.intellij.openapi.editor.EditorFactory. This factory offers a listener to be notified when a new editor was created or an existing editor was released. Use
addEditorFactoryListener() to register your listener.
com.intellij.openapi.editor.event.EditorFactoryListener. If you need to track properties of an editor, e.g. the caret position of the current selection, then add your editor listeners in
The generic editor event multicaster
com.intellij.openapi.editor.event.EditorEventMulticaster is a central place to track the variours kinds of Editor events. An instance is returned by
Accessing an editor's
Please remember that a document is only available for text files. Instances of
PsiFile are not available for binary files like images.
com.intellij.openapi.fileEditor.FileDocumentManager to retrieve the document which belongs to a
VirtualFile which is shown in the currently visible
PsiFile are managed by
com.intellij.psi.PsiDocumentManager, use it to the
PsiFile for a given
Accessing an editor's
VirtualFile of a
FileEditor can be retrieved by calling
Editor is returned by
FileDocumentManager#getFile(Document), the document is available as a property of the editor.