Intellij Idea 13 UI Designer and automatic Gradle building

I've used the Intellij UI Designer to create forms for a project. Everything works fine when I'm building with idea as it handles compiling the forms for me, but as we recently switched to using Gradle for building it hasn't been possible to produce an executable jar file yet.

My google-fu has led me to several posts that explains that an ant script is needed to compile (eg link, link2, link3 ,and the one i ended on following: link4)

My project is a multi-module setup.

root build.gradle

subprojects {
    apply plugin: 'java'
    apply plugin: 'idea'

    repositories {
        mavenCentral()
    }
}

supproject build.gradle

apply plugin:'application'
mainClassName = "dk.OfferFileEditor.OfferFileEditorProgram"

configurations {
    antTask
}

dependencies {
    compile 'org.json:json:20140107'
    compile project(":Shared:HasOffers Api")

    //dependencies for java2c
    antTask files('../../lib/javac2-13.1.1.jar', '../../lib/asm4-all-13.1.1-idea.jar', '../../lib/forms_rt-13.1.1.jar')
    antTask group: 'org.jdom', name: 'jdom', version: '1.1'
}

task compileJava(overwrite: true, dependsOn: configurations.compile.getTaskDependencyFromProjectDependency(true, 'jar')) {
    doLast {
        println 'using java2c to compile'
        project.sourceSets.main.output.classesDir.mkdirs()
        ant.taskdef name: 'javac2', classname: 'com.intellij.ant.Javac2', classpath: configurations.antTask.asPath
        ant.javac2 srcdir: project.sourceSets.main.java.srcDirs.join(':'),
                classpath: project.sourceSets.main.compileClasspath.asPath,
                destdir: project.sourceSets.main.output.classesDir,
                source: sourceCompatibility,
                target: targetCompatibility,
                includeAntRuntime: false
    }
}

But even though the compilation is successfull, a Nullpointer exception is thrown the first time I try to access one of the fields the UI Designer created. So something is not being compiled correctly.

I'm probably missing some setting, but after unsuccesfully pouring several hours into forums and google I still haven't found any solution.

So I made this a lot more complicated than needs be.

To make it work you need to change two things in your project.

A setting in IDEA 13.1.5

Settings -> GUI Designer -> Generate GUI into: Java source code

This makes IntelliJ IDEA add 3 methods into the bottom of your forms:

• $$$setupUI$$$()
• $$$setupUI$$$()
• $$$getRootComponent$$$()

If they are missing try recompiling your project after you change the setting.

Add the missing classes

Intellij has a jar called forms_rt.jar, and I found mine in {IntelliJ IDEA Root}\lib. And renamed it to "forms_rt-13.1.1.jar"

This needs to be included during compile time to your project. If you are using Gradle as I did you could copy it to {project root}/lib and add a flatfile repository like so:

repositories {
    mavenCentral()
    flatDir dirs: "${rootDir}/lib"
}

After that you need to include it in your project gradle file:

dependencies {
    compile name: 'forms_rt', version: '13.1.1'
}

After that it should be possible to build it both in IntelliJ IDEA and Gradle.

IntelliJ IDEA 2019.1

I found this issue still exists. It's at least somehow documented now:

If your build actions are delegated to Gradle, GUI Designer will not generate Java source code.

So by disabling the according setting

Build, Execution, Deployment | Build Tools | Gradle | Runner | Delegate IDE build/run actions to gradle

I was able to build and run the project successfully. Note that I didn't need any other settings or additional libraries from the answers above. I let Generate GUI into be set to Binary class files.

The forms_rt library is in mavenCentral. http://search.maven.org/#search%7Cga%7C1%7Ca%3A%22forms_rt%22

Once you have configured IntelliJ to update the SourceCode it is sufficient to just add the library to the dependencies in your build.gradle.

dependencies {
    compile 'com.intellij:forms_rt:7.0.3'
}