[md] syntax highlighting

tutorials/action_system/action_system.md

@@ -24,19 +24,23 @@ To create a new we need to extend
 [AnAction] (https://github.com/JetBrains/intellij-community/blob/master/platform/editor-ui-api/src/com/intellij/openapi/actionSystem/AnAction.java)
 class:
 
-    public class SimpleAction extends AnAction {
+```java
-    }
+public class SimpleAction extends AnAction {
+}
+```
 
 The only method of an inheritor of
 [AnAction] (https://github.com/JetBrains/intellij-community/blob/master/platform/editor-ui-api/src/com/intellij/openapi/actionSystem/AnAction.java)
 which needs to be overridden is ```public void actionPerformed(AnActionEvent anActionEvent);```
 , and it should contain a part of code to be executed after the action has been invoked. In this case the action does nothing.
 
-    public class SimpleAction extends AnAction {
+```java
+public class SimpleAction extends AnAction {
     @Override
     public void actionPerformed(AnActionEvent anActionEvent) {
     }
-    }
+}
+```
 
 -------------
 
@@ -57,19 +61,22 @@ After filling the "New Action" form and applying the changes *<actions>* section
 [plugin.xml]()
 file will look like this:
 
-    <actions>
+```xml
+<actions>
   <!-- Add your actions here -->
     <action id="org.jetbrains.tutorials.actions.SimpleAction" class="org.jetbrains.tutorials.actions.SimpleAction"
             text="Simple Action" description="IntelliJ Action System Demo">
         <add-to-group group-id="ToolsMenu" anchor="first"/>
     </action>
-    </actions>
+</actions>
+```
 
 Full list of action's attributes can also be set manually in
 [plugin.xml]()
 configuration file like the following code sample shows:
 
-      <actions>
+```xml
+<actions>
     <!-- Add your actions here -->
     <!-- The <action> element defines an action to register.
     The mandatory "id" attribute specifies an unique identifier for the action.
@@ -102,7 +109,8 @@ configuration file like the following code sample shows:
           the current action is inserted. -->
           <add-to-group group-id="ToolsMenu" anchor="first"/>
       </action>
-      </actions>
+</actions>
+```
 
 After performing the steps described above we need to compile and run the plugin to the the newly created action available as a Tools Menu item.
 !["Register action" quick fix](img/tools_menu_item_action.png)
@@ -113,13 +121,15 @@ After performing the steps described above we need to compile and run the plugin
 In order to make the action do something we need to implement it's ```public void actionPerformed(AnActionEvent anActionEvent);``` method.
 In the following example action invokes a dialog that shows information about a selected Project View Item and has no icon and any pre-selected default option:
 
-    @Override
+```java
-    public void actionPerformed(AnActionEvent anActionEvent) {
+@Override
+public void actionPerformed(AnActionEvent anActionEvent) {
     Object navigatable = anActionEvent.getData(CommonDataKeys.NAVIGATABLE);
     if (navigatable != null) {
         Messages.showDialog(navigatable.toString(), "Selected Element:", new String[]{"OK"}, -1, null);
     }
-    }
+}
+```
 
 -----------
 
@@ -131,7 +141,8 @@ Default implementation of this method does nothing.
 Override this method to provide the ability to dynamically change action's
 state and(or) presentation depending on the context.
 
-    public class SimpleAction extends AnAction {
+```java
+public class SimpleAction extends AnAction {
     @Override
     public void actionPerformed(AnActionEvent anActionEvent) {
     //...
@@ -140,12 +151,14 @@ state and(or) presentation depending on the context.
     @Override
     public void update(AnActionEvent anActionEvent) {
     }
-    }
+}
+```
 
 The following code sample illustrates how to make the action visible and available only when the following conditions are met:
 there's a project available and there's an item you can navigate to selected in the project view pane:
 
-    public class SimpleAction extends AnAction {
+```java
+public class SimpleAction extends AnAction {
     @Override
     public void actionPerformed(AnActionEvent anActionEvent) {
     //...
@@ -159,7 +172,8 @@ there's a project available and there's an item you can navigate to selected in
          Object navigatable = anActionEvent.getData(CommonDataKeys.NAVIGATABLE);
          anActionEvent.getPresentation().setEnabledAndVisible(navigatable != null);
      }
-    }
+}
+```
 
 Parameter anActionEvent carries information on the invocation place and data available.
 
@@ -188,26 +202,31 @@ Grouping can be done by extending adding *<group>* attribute to *<actions>*
 [plugin.xml]()
 file.
 
-    <actions>
+```xml
+<actions>
     <group id="SimpleGroup" text="Custom Action Group" popup="true">
     </group>
-    </actions>
+</actions>
+```
 
 ##Binding action groups to UI component.
 The following sample shows how to place a custom action group on top of the editor popup menu:
 
-    <actions>
+```xml
+<actions>
     <group id="SimpleGroup" text="Custom Action Group" popup="true">
         <add-to-group group-id="EditorPopupMenu" anchor="first"/>
     </group>
-    </actions>
+</actions>
+```
 
 ##Adding actions to the group.
 To create an action we need to extend
 [AnAction.java]()
 class:
 
-    public class GroupedAction extends AnAction {
+```java
+public class GroupedAction extends AnAction {
     @Override
     public void update(AnActionEvent event) {
         event.getPresentation().setEnabledAndVisible(true);
@@ -217,18 +236,21 @@ class:
     public void actionPerformed(AnActionEvent event) {
         //Does nothing
     }
-    }
+}
+```
 
 And then the actions needs to be registered in the newly created group:
 
-    <action>
+```xml
+<action>
     <group id="SimpleGroup" text="Custom Action Group" popup="true">
         <add-to-group group-id="EditorPopupMenu" anchor="first"/>
             <action class="org.jetbrains.tutorials.actions.GroupedAction" id="org.jetbrains.tutorials.actions.GroupedAction"
                       text="Grouped Action" description="Grouped Action Demo">
             </action>
     </group>
-    </actions>
+</actions>
+```
 
 After performing the steps described above the action group nad it's content will be available in the editor popup menu:
 
@@ -248,11 +270,13 @@ This class is used if a set of actions belonging to the group is fixed, which is
 
 Firstly, [DefaultActionGroup.java] should be derived:
 
-    public class CustomDefaultActionGroup extends DefaultActionGroup {
+```java
+public class CustomDefaultActionGroup extends DefaultActionGroup {
     @Override
     public void update(AnActionEvent event) {
     }
-    }
+}
+```
 
 ###Registering action group.
 As in case with the simple action group, the inheritor of
@@ -261,41 +285,50 @@ should be declared in
 [plugin.xml]()
 file:
 
-    <actions>
+```xml
+<actions>
     <group id="CustomDefaultActionGroup" class="org.jetbrains.tutorials.actions.CustomDefaultActionGroup" popup="true"
            text="DefaultActionGroup Inheritor" description="Default Action Group Demo">
         <add-to-group group-id="ToolsMenu" anchor="last"/>
   </group>
-    </actions>
+</actions>
+```
 
 ###Creating an action.
 [AnAction.java]()
 needs to be extended:
-    public class CustomGroupedAction extends AnAction {
+
+```java
+public class CustomGroupedAction extends AnAction {
     @Override
     public void actionPerformed(AnActionEvent anActionEvent) {
         //Does nothing
     }
-    }
+}
+```
 
 ###Adding actions to the group.
 Action's class should be registered in
 [plugin.xml]()
 :
 
+```xml
+<actions>
     <group id="CustomDefaultActionGroup" class="org.jetbrains.tutorials.actions.CustomDefaultActionGroup" popup="true"
          text="DefaultActionGroup Inheritor" description="Default Action Group Demo">
         <add-to-group group-id="ToolsMenu" anchor="last"/>
         <action class="org.jetbrains.tutorials.actions.CustomGroupedAction" id="CustomGroupedAction"
                   text="Custom Grouped Action" description="Custom Grouped Action Demo"/>
     </group>
-     </actions>
+</actions>
+```
 
 ###Providing specific behaviour for the group.
 In this case we override ```public void update(AnActionEvent event);``` method to make the group visible as a *Tools* menu item,
 however, it will be enabled only if there's an instance of the editor available. Also a custom icon is set up:
 
-    public class CustomDefaultActionGroup extends DefaultActionGroup {
+```java
+public class CustomDefaultActionGroup extends DefaultActionGroup {
     @Override
     public void update(AnActionEvent event) {
         Editor editor = event.getData(CommonDataKeys.EDITOR);
@@ -303,7 +336,8 @@ however, it will be enabled only if there's an instance of the editor available.
         event.getPresentation().setEnabled(editor != null);
         event.getPresentation().setIcon(AllIcons.General.Error);
     }
-    }
+}
+```
 
 After compiling and running the code sample above, *Tools* menu item should contain an extra group of action with a user-defined icon: