Module configuration UI: hide tab header if one tab is shown

java/idea-ui/src/com/intellij/openapi/roots/ui/configuration/HeaderHidingTabbedModuleEditor.java

@@ -0,0 +1,95 @@
+package com.intellij.openapi.roots.ui.configuration;
+
+import com.intellij.openapi.module.Module;
+import com.intellij.openapi.module.ModuleConfigurationEditor;
+import com.intellij.openapi.project.Project;
+import com.intellij.ui.navigation.Place;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import javax.swing.*;
+
+/**
+ * @author ksafonov
+ */
+public abstract class HeaderHidingTabbedModuleEditor extends TabbedModuleEditor {
+
+  public HeaderHidingTabbedModuleEditor(Project project, ModulesProvider modulesProvider, @NotNull Module module) {
+    super(project, modulesProvider, module);
+  }
+
+  @Override
+  protected JComponent createCenterPanel() {
+    ModuleConfigurationEditor singleEditor = getSingleEditor();
+    if (singleEditor != null) {
+      final JComponent component = singleEditor.createComponent();
+      singleEditor.reset();
+      return component;
+    }
+    else {
+      return super.createCenterPanel();
+    }
+  }
+
+  @Nullable
+  private ModuleConfigurationEditor getSingleEditor() {
+    return myEditors.size() == 1 ? myEditors.get(0) : null;
+  }
+
+  @Override
+  public ModuleConfigurationEditor getSelectedEditor() {
+    ModuleConfigurationEditor singleEditor = getSingleEditor();
+    return singleEditor != null ? singleEditor : super.getSelectedEditor();
+  }
+
+  @Override
+  public void selectEditor(String displayName) {
+    if (displayName != null) {
+      ModuleConfigurationEditor singleEditor = getSingleEditor();
+      if (singleEditor != null) {
+        assert singleEditor.getDisplayName().equals(displayName);
+      }
+      else {
+        super.selectEditor(displayName);
+      }
+    }
+  }
+
+  @Override
+  protected void restoreSelectedEditor() {
+    ModuleConfigurationEditor singleEditor = getSingleEditor();
+    if (singleEditor == null) {
+      super.restoreSelectedEditor();
+    }
+  }
+
+  @Override
+  public ModuleConfigurationEditor getEditor(@NotNull String displayName) {
+    ModuleConfigurationEditor singleEditor = getSingleEditor();
+    if (singleEditor != null) {
+      assert singleEditor.getDisplayName().equals(displayName);
+      return singleEditor;
+    }
+    else {
+      return super.getEditor(displayName);
+    }
+  }
+
+  @Override
+  protected void disposeCenterPanel() {
+    if (getSingleEditor() == null) {
+      super.disposeCenterPanel();
+    }
+  }
+
+  @Override
+  public void queryPlace(@NotNull Place place) {
+    ModuleConfigurationEditor singleEditor = getSingleEditor();
+    if (singleEditor != null) {
+      place.putPath(SELECTED_EDITOR_NAME, singleEditor.getDisplayName());
+    }
+    else {
+      super.queryPlace(place);
+    }
+  }
+}

java/idea-ui/src/com/intellij/openapi/roots/ui/configuration/ModuleEditor.java

@@ -62,6 +62,7 @@ import java.util.List;
 @SuppressWarnings({"AssignmentToStaticFieldFromInstanceMethod"})
 public abstract class ModuleEditor implements Place.Navigator, Disposable {
   private static final ExtensionPointName<ModuleConfigurableEP> MODULE_CONFIGURABLES = ExtensionPointName.create("com.intellij.moduleConfigurable");
+  public static final String SELECTED_EDITOR_NAME = "selectedEditor";
 
   private final Project myProject;
   private JPanel myGenericSettingsPanel;

java/idea-ui/src/com/intellij/openapi/roots/ui/configuration/ModulesConfigurator.java

@@ -162,7 +162,7 @@ public class ModulesConfigurator implements ModulesProvider, ModuleEditor.Change
   }
 
   private ModuleEditor doCreateModuleEditor(final Module module) {
-    final ModuleEditor moduleEditor = new TabbedModuleEditor(myProject, this, module) {
+    final ModuleEditor moduleEditor = new HeaderHidingTabbedModuleEditor(myProject, this, module) {
       @Override
       public ProjectFacetsConfigurator getFacetsConfigurator() {
         return myFacetsConfigurator;

java/idea-ui/src/com/intellij/openapi/roots/ui/configuration/ProjectStructureConfigurable.java

@@ -375,7 +375,7 @@ public class ProjectStructureConfigurable extends BaseConfigurable implements Se
     if (moduleToSelect != null) {
       final Module module = ModuleManager.getInstance(myProject).findModuleByName(moduleToSelect);
       assert module != null;
-      place = place.putPath(ModuleStructureConfigurable.TREE_OBJECT, module).putPath(TabbedModuleEditor.EDITOR_NAME, editorNameToSelect);
+      place = place.putPath(ModuleStructureConfigurable.TREE_OBJECT, module).putPath(ModuleEditor.SELECTED_EDITOR_NAME, editorNameToSelect);
     }
     return navigateTo(place, requestFocus);
   }

java/idea-ui/src/com/intellij/openapi/roots/ui/configuration/TabbedModuleEditor.java

@@ -18,7 +18,6 @@ import javax.swing.event.ChangeEvent;
  */
 public abstract class TabbedModuleEditor extends ModuleEditor {
 
-  public static final String EDITOR_NAME = "selectedEditor";
   private static final String SELECTED_EDITOR_KEY = TabbedModuleEditor.class.getName() + ".selectedEditor";
 
   private TabbedPaneWrapper myTabbedPane;
@@ -66,13 +65,13 @@ public abstract class TabbedModuleEditor extends ModuleEditor {
 
   public ActionCallback navigateTo(@Nullable final Place place, final boolean requestFocus) {
     if (place != null) {
-      myTabbedPane.setSelectedTitle((String)place.getPath(EDITOR_NAME));
+      selectEditor((String)place.getPath(SELECTED_EDITOR_NAME));
     }
     return new ActionCallback.Done();
   }
 
   public void queryPlace(@NotNull final Place place) {
-    place.putPath(EDITOR_NAME, getSavedSelectedEditor());
+    place.putPath(SELECTED_EDITOR_NAME, getSavedSelectedEditor());
   }
 
   @Nullable