antlr4ide-eclipse

Antlr4 Eclipse based editor

The editor use a the antlr v4 grammar from the antlr.org examples site: github.com/antlr/grammars-v4/tree/master/antlrv4

The translated grammar is used to provide the tokens for the eclipse editor.

Implementation notices

This editor implements a number of features.

Use the ANTLR parse tree visitor and listeners to extract details from the parsed antlr grammar.

To capture changes to the document a document listener is added in AntlrDocument

The scanner and parser is invoked from LexerHelper and the visitor ANTLRv4Visitor produces

1. Map of all parser rules
2. Map of all lexer rules
3. Map of all lexer modes
4. List of all error messages

Antlr error messages

The error messages are added to the file as resource markers.

Syntax highlighting

The text attributes are provided in ANTLRv4Scanner and IANTLRv4ColorConstants.

For example, for the Lexer keyword FRAGMENT:

Color STMTrgb        = new Color(Display.getCurrent(),153, 0, 153);
TextAttribute STMT   = new TextAttribute(STMTrgb, null, SWT.ITALIC);
IToken stmtTextToken = new org.eclipse.jface.text.rules.Token(IANTLRv4ColorConstants.STMT);
hilite.put(ANTLRv4Lexer.FRAGMENT, stmtTextToken);

Outline view

The Outline view uses the lexer rules and parser rules maps that the scanner produced. The outline content provider AntlrDocOutlineContentProvider takes the content of the maps and add to the outline content.

Supported content in the outline view

• Lexer Modes
• Lexer Rules
• Parser Rules

Building and Launching

The project nature and build will eventually request the plugin to build the antlr g4 file.

package org.github.antlr4ide.builder;
public class AntlrBuilder extends IncrementalProjectBuilder { ... }

Working on

Folding

Folding is implemented using the projection framework based on the article Folding

The scanner creates the maps for Lexer modes, Lexer rules and Parser rules. The maps has the relevant name as key and a position as value. A position org.eclipse.jface.text.Position is start offset and length. The positions can be used directly by the projection framework.

For now only initial folding of Parser Rules and Lexer Modes is implemented.

Preference Pages

Tool preference page has an option to cache the internal antlr parse tree. This require a version of the antlr tool that supports Serialization. If the parse tree is still valid and if enabled the editor will read the parse tree from the cache instead of regenerating the parse tree. Currently this fork of Antlr supports caching parse trees for Java target.

If there is interest to support this for other targets please raise an issue antlride-eclipse-issue

TODO: Add preferences multiple targets

TODO: Preference Pages for hilights

TODOs

Semantic validation

Code generation (Using eclipse Builders)

Code generation for multiple target languages

Refactoring

Code completion

Incremental Scanning/Parsing

Hovering, Quick fixes

Code definition lookup (ctrl+Mouse)

Use proper logging infrastructure

Eclipse Help

Eclipse Tutorial

TIPS and TRICKS from

This section is for various snippets collected while searching for answers

getting content of active editor

Currently the editor and document providers are cached. There might be a better way

Content of Editor

public String getCurrentEditorContent() {
    final IEditorPart editor = PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage()
        .getActiveEditor();
    if (!(editor instanceof ITextEditor)) return null;
    ITextEditor ite = (ITextEditor)editor;
    IDocument doc = ite.getDocumentProvider().getDocument(ite.getEditorInput());
    return doc.get();
}

// get all open editors
PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage().getEditorReferences()

Right-Click context menu

Searching for adding "folding" to editor context menu.

1. right-click menu
2. add right-click menu
3. Custumize popup

Parallel builder, Log listner

https://github.com/mickaelistria/eclipse-ide-parallel-builds-demo https://stackoverflow.com/questions/33718708/is-it-possible-to-generate-builder-code-automatically-in-eclipse-according-to-bu https://www.eclipse.org/articles/Article-Builders/builders.html

SWT Widgets samples etc

https://www.eclipse.org/swt/ https://www.eclipse.org/swt/snippets/ https://www.eclipse.org/swt/javadoc.php SWT: A Native Widget Toolkit for Java - Part 1 of 2 SWT: A Native Widget Toolkit for Java - Part 2 of 2