diff --git a/.idea/gradle.xml b/.idea/gradle.xml
index f64616079..b488bc0ba 100644
--- a/.idea/gradle.xml
+++ b/.idea/gradle.xml
@@ -122,6 +122,17 @@
+
+
+
+
+
+
+
diff --git a/.idea/intellij-sdk-docs.iml b/.idea/intellij-sdk-docs.iml
index 6715cee37..ab54d4229 100644
--- a/.idea/intellij-sdk-docs.iml
+++ b/.idea/intellij-sdk-docs.iml
@@ -4,10 +4,11 @@
+
-
\ No newline at end of file
+
diff --git a/.idea/modules.xml b/.idea/modules.xml
index d254b3342..baaf09cf6 100644
--- a/.idea/modules.xml
+++ b/.idea/modules.xml
@@ -10,7 +10,6 @@
-
diff --git a/code_samples/psi_demo/build.gradle b/code_samples/psi_demo/build.gradle
new file mode 100644
index 000000000..eb233a417
--- /dev/null
+++ b/code_samples/psi_demo/build.gradle
@@ -0,0 +1,31 @@
+plugins {
+ id 'java'
+ id 'org.jetbrains.intellij' version '0.4.16'
+}
+
+group 'org.intellij.sdk'
+version '2.0.0'
+
+sourceCompatibility = 1.8
+
+repositories {
+ mavenCentral()
+}
+
+dependencies {
+ testCompile group: 'junit', name: 'junit', version: '4.12'
+}
+
+// See https://github.com/JetBrains/gradle-intellij-plugin/
+intellij {
+ version '2019.3.3'
+ plugins 'java'
+ updateSinceUntilBuild = false
+}
+
+patchPluginXml {
+ version = project.version
+}
+
+// Force javadoc rebuild before jar is built
+jar.dependsOn javadoc
diff --git a/code_samples/psi_demo/gradle/wrapper/gradle-wrapper.jar b/code_samples/psi_demo/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 000000000..f3d88b1c2
Binary files /dev/null and b/code_samples/psi_demo/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/code_samples/psi_demo/gradle/wrapper/gradle-wrapper.properties b/code_samples/psi_demo/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 000000000..ec3470148
--- /dev/null
+++ b/code_samples/psi_demo/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Fri Feb 14 11:47:16 CET 2020
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-all.zip
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStorePath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
diff --git a/code_samples/psi_demo/gradlew b/code_samples/psi_demo/gradlew
new file mode 100755
index 000000000..2fe81a7d9
--- /dev/null
+++ b/code_samples/psi_demo/gradlew
@@ -0,0 +1,183 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+##
+## Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+ ls=`ls -ld "$PRG"`
+ link=`expr "$ls" : '.*-> \(.*\)$'`
+ if expr "$link" : '/.*' > /dev/null; then
+ PRG="$link"
+ else
+ PRG=`dirname "$PRG"`"/$link"
+ fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+ echo "$*"
+}
+
+die () {
+ echo
+ echo "$*"
+ echo
+ exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+ CYGWIN* )
+ cygwin=true
+ ;;
+ Darwin* )
+ darwin=true
+ ;;
+ MINGW* )
+ msys=true
+ ;;
+ NONSTOP* )
+ nonstop=true
+ ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+ if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+ # IBM's JDK on AIX uses strange locations for the executables
+ JAVACMD="$JAVA_HOME/jre/sh/java"
+ else
+ JAVACMD="$JAVA_HOME/bin/java"
+ fi
+ if [ ! -x "$JAVACMD" ] ; then
+ die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+ fi
+else
+ JAVACMD="java"
+ which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+ MAX_FD_LIMIT=`ulimit -H -n`
+ if [ $? -eq 0 ] ; then
+ if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+ MAX_FD="$MAX_FD_LIMIT"
+ fi
+ ulimit -n $MAX_FD
+ if [ $? -ne 0 ] ; then
+ warn "Could not set maximum file descriptor limit: $MAX_FD"
+ fi
+ else
+ warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+ fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+ GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+ APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+ CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+ JAVACMD=`cygpath --unix "$JAVACMD"`
+
+ # We build the pattern for arguments to be converted via cygpath
+ ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+ SEP=""
+ for dir in $ROOTDIRSRAW ; do
+ ROOTDIRS="$ROOTDIRS$SEP$dir"
+ SEP="|"
+ done
+ OURCYGPATTERN="(^($ROOTDIRS))"
+ # Add a user-defined pattern to the cygpath arguments
+ if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+ OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+ fi
+ # Now convert the arguments - kludge to limit ourselves to /bin/sh
+ i=0
+ for arg in "$@" ; do
+ CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+ CHECK2=`echo "$arg"|egrep -c "^-"` ### Determine if an option
+
+ if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then ### Added a condition
+ eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+ else
+ eval `echo args$i`="\"$arg\""
+ fi
+ i=`expr $i + 1`
+ done
+ case $i in
+ 0) set -- ;;
+ 1) set -- "$args0" ;;
+ 2) set -- "$args0" "$args1" ;;
+ 3) set -- "$args0" "$args1" "$args2" ;;
+ 4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+ 5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+ 6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+ 7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+ 8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+ 9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+ esac
+fi
+
+# Escape application args
+save () {
+ for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+ echo " "
+}
+APP_ARGS=`save "$@"`
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"
diff --git a/code_samples/psi_demo/gradlew.bat b/code_samples/psi_demo/gradlew.bat
new file mode 100644
index 000000000..9618d8d96
--- /dev/null
+++ b/code_samples/psi_demo/gradlew.bat
@@ -0,0 +1,100 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/code_samples/psi_demo/psi_demo.iml b/code_samples/psi_demo/psi_demo.iml
deleted file mode 100644
index e025b203c..000000000
--- a/code_samples/psi_demo/psi_demo.iml
+++ /dev/null
@@ -1,13 +0,0 @@
-
-
-
-
-
-
-
-
-
-
-
-
-
\ No newline at end of file
diff --git a/code_samples/psi_demo/settings.gradle b/code_samples/psi_demo/settings.gradle
new file mode 100644
index 000000000..aeff22385
--- /dev/null
+++ b/code_samples/psi_demo/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = 'psi'
diff --git a/code_samples/psi_demo/src/com/intellij/tutorials/psi/PsiNavigationDemoAction.java b/code_samples/psi_demo/src/main/java/com/intellij/sdk/psi/PsiNavigationDemoAction.java
similarity index 98%
rename from code_samples/psi_demo/src/com/intellij/tutorials/psi/PsiNavigationDemoAction.java
rename to code_samples/psi_demo/src/main/java/com/intellij/sdk/psi/PsiNavigationDemoAction.java
index 9eedf9be6..e9e2ad825 100644
--- a/code_samples/psi_demo/src/com/intellij/tutorials/psi/PsiNavigationDemoAction.java
+++ b/code_samples/psi_demo/src/main/java/com/intellij/sdk/psi/PsiNavigationDemoAction.java
@@ -1,4 +1,4 @@
-package com.intellij.tutorials.psi;
+package com.intellij.sdk.psi;
import com.intellij.openapi.actionSystem.AnAction;
import com.intellij.openapi.actionSystem.AnActionEvent;
diff --git a/code_samples/psi_demo/resources/META-INF/plugin.xml b/code_samples/psi_demo/src/main/resources/META-INF/plugin.xml
similarity index 72%
rename from code_samples/psi_demo/resources/META-INF/plugin.xml
rename to code_samples/psi_demo/src/main/resources/META-INF/plugin.xml
index 399e57ee6..f06c88b72 100644
--- a/code_samples/psi_demo/resources/META-INF/plugin.xml
+++ b/code_samples/psi_demo/src/main/resources/META-INF/plugin.xml
@@ -10,9 +10,9 @@
com.intellij.modules.java
-
+
-
\ No newline at end of file
+
diff --git a/code_samples/psi_demo/src/main/resources/META-INF/pluginIcon.svg b/code_samples/psi_demo/src/main/resources/META-INF/pluginIcon.svg
new file mode 100644
index 000000000..613290897
--- /dev/null
+++ b/code_samples/psi_demo/src/main/resources/META-INF/pluginIcon.svg
@@ -0,0 +1,58 @@
+
diff --git a/code_samples/tree_structure_provider/gradle/wrapper/gradle-wrapper.properties b/code_samples/tree_structure_provider/gradle/wrapper/gradle-wrapper.properties
index 3f7da722c..72118044d 100644
--- a/code_samples/tree_structure_provider/gradle/wrapper/gradle-wrapper.properties
+++ b/code_samples/tree_structure_provider/gradle/wrapper/gradle-wrapper.properties
@@ -1,4 +1,4 @@
-#Fri Feb 14 11:33:16 CET 2020
+#Fri Feb 14 11:47:37 CET 2020
distributionUrl=https\://services.gradle.org/distributions/gradle-6.1.1-all.zip
distributionBase=GRADLE_USER_HOME
distributionPath=wrapper/dists