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org.eclipse.jdt.astview - AST View

Purpose

A view to visualize the AST (abstract syntax tree) of a Java file open in the editor. Navigate from text selection to AST nodes and from nodes to selections. Show bindings and compare them.

Install


Update Site:

Since Eclipse Release 2023-03, the view is shipped with the Eclipse SDK package and can be installed in other packages via the eclipse release update site:

  • https://download.eclipse.org/eclipse/updates/latest/

Source:

  • Source is included in the plugin archives or available on GitHub or via Project: org.eclipse.jdt.astview

Manual Install:

Usage

  1. Open the AST view
    • from the view menu: Window > Show View > Other..., Java > AST View
    • via shortcut: Alt+Shift+Q, A
  2. Open a Java file in the editor
  3. Click on 'Show AST of active editor' () to populate the view: The view shows the AST of the file opened in the editor and will also reveal the element corresponding to the current text selection.
  4. Enable 'Link with editor' () to automatically track the active editor and the selection in the active editor.
  5. Double click on AST nodes to get the corresponding element revealed in the editor.
  6. Double click again to see the 'extended range' of a node, that means the range including all comments associated with it (comment mapper heuristic).
  7. Open the context menu on a binding to add it to the comparison tray
  8. When the AST's underlying document has been changed use 'Refresh' ()  to update the AST.

AST View Elements

The AST view shows the following nodes:

AST View

  • AST nodes are shown in gray color and with source range information. Children of AST nodes are the node properties.
  • node properties have names that are all all capitalized. Node properties represent lists of child nodes, a child node or a primitive node attribute (String, int, or boolean).
  • bindings are shown in blue. Only selected bindings are shown initially. The rest can be toggled via view menu > Hide Non-Relevant Attributes

Advanced Features

  • You can toggle between the AST Level 2 and AST level 3 in the view menu (triangle). AST level 3 is the extended and modified AST that includes the new 1.5 language constructs. Note that the AST level 3 is only available in 3.1 and later builds
  • You can choose to show or hide bindings in the view menu
  • You can choose the method to generate an AST in the view menu
  • You can choose 'Add to Comparison Tray' in the context menu of a binding. This moves the binding to a special area in the view. When you select another binding in the tree, the comparison tray shows various relationships between the selection and the chosen binding

Comments and Requests

  • Comments to markus_keller[at]ch.ibm.com
  • Bugs / enhancement requests go to the JDT/UI component (preferably with patches;-)
  • Thanks and credits go to Christian Hauser: The current AST view plug-in is based his AST view implementation from the Zuerich Code Camp. Thanks a lot!
    Martin Aeschlimann productized and maintained the plug-in in the first few years.

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