improving devel doc

Development.md

@@ -2,23 +2,45 @@
 
 ## Build system
 
-The project uses gradle. 
-The gradle wrapper is included in the source code so just a java vm is required. However since it is a Java 8 + Java 11 multi release build both versions are needed.
-
+The project uses gradle to build the native and the java code. 
 
-## General Requirements
+### Environment
 
+#### Java
+You need Java 8 with fx and Java 11 without fx.   
+You can for example use the zulu packages:
+ * jdk8fx: https://www.azul.com/downloads/zulu-community/?version=java-8-lts&architecture=x86-64-bit&package=jdk-fx
+ * jdk11: https://www.azul.com/downloads/zulu-community/?version=java-11-lts&architecture=x86-64-bit&package=jdk
 
+The following environment variables need to be set:
+ * `JAVA_HOME_8` needs to point to a jdk8fx
+ * `JAVA_HOME_11` needs to point to a jdk11
+ * `JAVA_HOME` needs to point to the jdk11 for gradle to work
 
-## My setup
+#### native code toolchains
 
-## Native
+### Project structure
+The java code is split in 3 projects. This is needed since IDEs like eclipse only support one jdk per project.
 
- * visual studio
+ * `org.eclipse.fx.drift` the base project with most of the code
+ * `org.eclipse.fx.drift.java8` the java8 only overlay
+ * `org.eclipse.fx.drift.java11` the java11 only overlay
 
-## Java
+`./gradle buildMultireleaseJar` assembles the jar from those 3 projects.
+
+ * `org.eclipse.fx.drift.native` contains the native code of driftfx
+ * `native-driftcpp` contains the cpp binding
+
+### IDEs
+
+Gradle can generate the project files for many IDEs. 
+
+examples:
+```
+  ./gradlew eclipse
+
+  ./gradlew :org.eclipse.fx.drift.native:visualStudio
+  ./gradlew :org.eclipse.fx.drift.native:xcode
+
+```
 
- * Java 8 JDK + JavaFX
- * Java 11 JDK (without JavaFX)
-
- I use the zulu fx packages (https://www.azul.com/downloads/zulu-community/?architecture=x86-64-bit&package=jdk-fx)