From 083de5031e872af8df34d82bc5cbc3e9d272c503 Mon Sep 17 00:00:00 2001
From: Daniel Langbein <daniel@systemli.org>
Date: Sun, 26 Jan 2025 13:24:07 +0100
Subject: [PATCH] intellij and java

---
 modules/java.nix                  | 43 +++++++++++++++++++++++++++++++
 modules/jetbrains-ide.nix         | 15 +++++------
 shell-intellij-gradle-openjdk.nix | 28 +++++++++++---------
 3 files changed, 65 insertions(+), 21 deletions(-)
 create mode 100644 modules/java.nix

diff --git a/modules/java.nix b/modules/java.nix
new file mode 100644
index 0000000..cdb5f6e
--- /dev/null
+++ b/modules/java.nix
@@ -0,0 +1,43 @@
+{ config, pkgs, lib, ... }:
+let
+  # Select a JDK version
+  #
+  jdk = pkgs.jdk23;
+  #
+  # If a more recent OpenJDK version than the bundled JDK is needed.
+  #jdk = pkgs.unstable.jdk;
+  #jdk = pkgs.unstable.jdk23;
+  #
+  # If JavaFX with WebKit is required.
+  # https://github.com/NixOS/nixpkgs/blob/4b218e54ae22c8b3ad642ff0dec842363c3abd0f/pkgs/top-level/all-packages.nix#L14583-L14588
+  #jdk = pkgs.jdk23.override {
+  #  enableJavaFX = true;
+  #  openjfx_jdk = pkgs.openjfx23.override { withWebKit = true; };
+  #};
+
+  # https://github.com/NixOS/nixpkgs/blob/23e89b7da85c3640bbc2173fe04f4bd114342367/pkgs/development/tools/build-managers/gradle/default.nix#L46
+  gradle = pkgs.gradle.override {
+    java = jdk;
+    javaToolchains = [ jdk ];
+  };
+in
+{
+  # System-wide installation makes pkgs available at:
+  #   /run/current-system/sw/bin/
+  # This makes it easier to configure them in Jetbrain's IDE.
+  environment.systemPackages = with pkgs; [
+    # To use Gradle in IntelliJ:
+    # - Project settings > Add and select JDK
+    # - `type java` gives `/run/current-system/sw/bin/java`.
+    #   - Somehow IntelliJ can't select it
+    #   - Thus we use the symlinks destination instead ...
+    jdk
+    # To use Gradle in IntelliJ:
+    # - Settings > Build tools > Gradle > Local installation
+    # - `type gradle` gives `/run/current-system/sw/bin/gradle`.
+    #   - Somehow IntelliJ can't select it
+    #   - Thus we use the symlinks destination instead ...
+    gradle
+    maven
+  ];
+}
diff --git a/modules/jetbrains-ide.nix b/modules/jetbrains-ide.nix
index 2b4975a..9c165e7 100644
--- a/modules/jetbrains-ide.nix
+++ b/modules/jetbrains-ide.nix
@@ -18,6 +18,12 @@ in
     [
       # Rust programming lang
       ./rust.nix
+
+      # Java programming lang (with Gradle and Maven)
+      #
+      # For IntelliJ to use Gradles toolchain,
+      # see `shell-intellij-gradle-openjdk.nix`.
+      ./java.nix
     ];
 
   allowUnfree = [
@@ -30,15 +36,6 @@ in
     # This makes it easier to configure it as interpreter in Jetbrain's IDE.
     python3
 
-    maven
-
-    # To use Gradle within InelliJ (or to use a specific OpenJDK version with Gradle), see
-    # shell-intellij-grade-openjd.nix
-
-    # If a more recent OpenJDK version than the bundled JDK is needed
-    #unstable.jdk
-    #unstable.jdk23
-
     # Markdown preview
     #pandoc
     # TODO: Currently markdown previews are broken anyways because of issues with the sandboxed webbrowser on NixOS
diff --git a/shell-intellij-gradle-openjdk.nix b/shell-intellij-gradle-openjdk.nix
index 3d4b6a2..d170c20 100644
--- a/shell-intellij-gradle-openjdk.nix
+++ b/shell-intellij-gradle-openjdk.nix
@@ -1,24 +1,28 @@
 # Example from my (non public) Software Quality course homework.
 # That (private) repo might contain a more up to date version.
 
-{
-  pkgs ? import <nixpkgs> {
-     # https://github.com/NixOS/nixpkgs/issues/166220#issuecomment-1745803058
-     config.allowUnfree = true;
-  }
-}:
-
+{ }:
 let
-  unstable = import (fetchTarball https://github.com/NixOS/nixpkgs/archive/nixos-unstable.tar.gz) { };
+  ### Import nixpkgs with Niv ###
+  #
+  sources = import ./nix/sources.nix;
+  # nixpkgs stable
+  pkgs = import sources.nixpkgs {
+    # Required for IntelliJ Ultimate
+    config.allowUnfree = true;
+  };
 
-  # https://github.com/NixOS/nixpkgs/blob/4b218e54ae22c8b3ad642ff0dec842363c3abd0f/pkgs/top-level/all-packages.nix#L14583-L14588
-  jdk = unstable.jdk23.override {
+  # https://github.com/NixOS/nixpkgs/blob/d9e98537533e7d978556bd58739813a47db5d591/pkgs/top-level/all-packages.nix#L14078-L14083
+  jdk = pkgs.jdk23.override {
     enableJavaFX = true;
-    openjfx_jdk = unstable.openjfx23.override { withWebKit = true; };
+    openjfx_jdk = pkgs.openjfx23.override { withWebKit = true; };
   };
 
   # https://github.com/NixOS/nixpkgs/blob/23e89b7da85c3640bbc2173fe04f4bd114342367/pkgs/development/tools/build-managers/gradle/default.nix#L46
-  gradle = unstable.gradle.override { java = jdk; };
+  gradle = pkgs.gradle.override {
+    java = jdk;
+    javaToolchains = [ jdk ];
+  };
 in
 
 (