Switched to a Gradle build

.gitignore

@@ -1,15 +1,44 @@
-*.class
-
-# Mobile Tools for Java (J2ME)
-.mtj.tmp/
-
-# Package Files #
-*.jar
-*.war
-*.ear
-
 # virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
 hs_err_pid*
 
 # ANTLR4
-*.tokens
+*.tokens
+
+target/
+/build/
+/.gradle/
+
+# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
+
+# User-specific stuff
+.idea/**/workspace.xml
+.idea/**/tasks.xml
+.idea/**/usage.statistics.xml
+.idea/**/dictionaries
+.idea/**/shelf
+
+# Generated files
+.idea/**/contentModel.xml
+
+# Sensitive or high-churn files
+.idea/**/dataSources/
+.idea/**/dataSources.ids
+.idea/**/dataSources.local.xml
+.idea/**/sqlDataSources.xml
+.idea/**/dynamic.xml
+.idea/**/uiDesigner.xml
+.idea/**/dbnavigator.xml
+
+# Gradle
+.idea/**/gradle.xml
+.idea/**/libraries
+
+# Gradle and Maven with auto-import
+# When using Gradle or Maven with auto-import, you should exclude module files,
+# since they will be recreated, and may cause churn.  Uncomment if using
+# auto-import.
+.idea/modules.xml
+.idea/*.iml
+.idea/modules
+
+.idea/misc.xml

README.md

@@ -1,20 +1,55 @@
-# Sample Jetbrains plugin using ANTLR grammar
+# Sample IntelliJ plugin using ANTLR grammar
 
-This is a demonstration of [ANTLR-jetbrains supported library](https://github.com/antlr/jetbrains).
+This is a demonstration of [ANTLRv4 library for IntelliJ plugins](https://github.com/antlr/antlr4-intellij-adaptor/), 
+which makes it easy to create plugins for IntelliJ-based IDEs based on an ANTLRv4 grammar.
 
 <img src=screenshot.png>
 
-**WARNING**. Turn on Dragon speech recognition for Mac and do a rename.
-GUI deadlocks.  Every time. Turn off dragon. No problem ever.
-See [jetbrains forum](https://devnet.jetbrains.com/message/5566967#5566967).
-
 ## Running the plugin for the first time
 
-You need to fetch the antlr dependencies from the maven pom file with `mvn dependency:resolve`. To process the 
-grammar files, call `mvn process-resources`.
+Make sure the Gradle plugin is installed in your IDE, go to `File -> Open`, select the `build.gradle` file
+and choose `Open as Project`. 
+
+If you already imported the project when it was not based on Gradle, then choose the option to delete the existing 
+project and reimport it.
+
+Once the IDE is done downloading dependencies and refreshing the project, you can use the `Gradle` tool window
+and use the following `Tasks`:
+* `build > assemble` to build the project
+* `intellij > runIde` to run the plugin in a sandboxed instance
+
+## Noteworthy things
+
+### Gradle build
+The build is based on Gradle, and uses the [gradle-intellij-plugin](https://github.com/JetBrains/gradle-intellij-plugin),
+which makes it easy to:
+
+* pull dependencies, especially the IntelliJ SDK and `antlr4-intellij-adaptor`
+* build and run tests in a CI environment on different versions of the SDK
+* generate lexers & parsers from your grammars, thanks to the [ANTLR plugin for Gradle](https://docs.gradle.org/current/userguide/antlr_plugin.html)
+* publish plugins to the [JetBrains Plugins Repository](https://plugins.jetbrains.com/)
+* configure the project for occasional contributors 🙂
 
-Go to `File -> Project Structure -> Project` and add a new `IntelliJ Platform Plugin SDK` or use a valid existing one.
+### ANTLRPsiNode
 
-You also need the jetbrains antlr adapter. It may be added with `git submodule init` and `git submodule update`.
+PSI nodes defined in the plugin extend `ANTLRPsiNode` and `IdentifierDefSubtree`, which automatically
+makes them `PsiNameIdentifierOwner`s.
 
-Now create a new `Run Configuration` of the type `Plugin`. 
+### Error highlighting
+
+Errors are shown by `SampleExternalAnnotator`, which makes use of `org.antlr.intellij.adaptor.xpath.XPath` to
+detect references to unknown functions.
+
+### ParserDefinition
+
+`SampleParserDefinition` uses several handy classes from the adaptor library:
+
+* `PSIElementTypeFactory` to generate `IElementType`s from tokens and rules defined in your ANTLRv4 grammar
+* `ANTLRLexerAdaptor` to bind generated lexers to a `com.intellij.lexer.Lexer`
+* `ANTLRParserAdaptor` to bind generated parsers to a `com.intellij.lang.PsiParser`
+
+## Misc
+
+**WARNING**. Turn on Dragon speech recognition for Mac and do a rename.
+GUI deadlocks.  Every time. Turn off dragon. No problem ever.
+See [JetBrains forum](https://devnet.jetbrains.com/message/5566967#5566967).

build.gradle

@@ -0,0 +1,49 @@
+buildscript {
+    repositories {
+        mavenCentral()
+    }
+}
+
+plugins {
+    id "org.jetbrains.intellij" version "0.4.2"
+}
+
+wrapper {
+    gradleVersion = '5.2.1'
+}
+
+group 'antlr'
+version pluginVersion
+
+apply plugin: 'java'
+apply plugin: 'org.jetbrains.intellij'
+apply plugin: 'antlr'
+
+compileJava {
+    sourceCompatibility = '1.8'
+    targetCompatibility = '1.8'
+}
+
+intellij {
+    version = ideaVersion
+
+    pluginName 'antlr4-intellij-plugin-sample'
+    downloadSources true
+    updateSinceUntilBuild false
+}
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    antlr("org.antlr:antlr4:$antlr4Version") { // use ANTLR version 4
+        exclude group:'com.ibm.icu', module:'icu4j'
+    }
+    implementation 'org.antlr:antlr4-intellij-adaptor:0.1'
+    testCompile group: 'junit', name: 'junit', version: '4.11'
+}
+
+generateGrammarSource {
+    arguments += ["-package", "org.antlr.jetbrains.sample.parser", "-Xexact-output-dir"]
+}

contributors.txt

@@ -52,4 +52,5 @@ CONTRIBUTORS:
 
 YYYY/MM/DD, github id, Full name, email
 2015/11/09, parrt, Terence Parr, [email protected]
-2019/02/13, Kisioj, Krzysztof Jura, [email protected]
+2019/02/13, Kisioj, Krzysztof Jura, [email protected]
+2019/02/13, bjansen, Bastien Jansen, [email protected]

gradle.properties

@@ -0,0 +1,8 @@
+pluginVersion=0.1
+
+# e.g. IC-2016.3.3, IU-2018.2.5 etc
+# For a list of possible values, refer to the section 'com.jetbrains.intellij.idea' at https://www.jetbrains.com/intellij-repository/releases
+ideaVersion=2018.3.2
+
+# The version of ANTLR v4 that will be used to generate the parser
+antlr4Version=4.7.2

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.2.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists