CR-IC-1738 IDEA-88210 "Remember" the global code style selection for each project

platform/lang-api/src/com/intellij/psi/codeStyle/CodeStyleSchemes.java

@@ -16,6 +16,7 @@
 package com.intellij.psi.codeStyle;
 
 import com.intellij.openapi.components.ServiceManager;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * @author MYakovlev
@@ -43,6 +44,27 @@ public abstract class CodeStyleSchemes {
 
   public abstract CodeStyleScheme findSchemeByName(String name);
 
+  /**
+   * Attempts to find a scheme with a given name or an alternative suitable scheme.
+   * 
+   * @param preferredSchemeName The scheme name to find or null for the currently selected scheme.
+   * @return A found scheme or a default scheme if the scheme name was not found or, if neither exists or the scheme name is null, the
+   *         currently selected scheme.
+   */
+  public CodeStyleScheme findPreferredScheme(@Nullable String preferredSchemeName) {
+    CodeStyleScheme scheme = null;
+    if (preferredSchemeName != null) {
+      scheme = findSchemeByName(preferredSchemeName);
+      if (scheme == null) {
+        scheme = getDefaultScheme();
+      }
+    }
+    if (scheme == null) {
+      scheme = getCurrentScheme();
+    }
+    return scheme;
+  }
+
   public abstract CodeStyleScheme getDefaultScheme();
 
   public abstract void addScheme(CodeStyleScheme currentScheme);

platform/lang-api/src/com/intellij/psi/codeStyle/CodeStyleSettingsManager.java

@@ -32,6 +32,7 @@ public class CodeStyleSettingsManager implements PersistentStateComponent<Elemen
 
   public volatile CodeStyleSettings PER_PROJECT_SETTINGS = null;
   public volatile boolean USE_PER_PROJECT_SETTINGS = false;
+  public volatile String PREFERRED_PROJECT_CODE_STYLE = null;
   private volatile CodeStyleSettings myTemporarySettings;
   private volatile boolean myIsLoaded = false;
 
@@ -72,7 +73,7 @@ public class CodeStyleSettingsManager implements PersistentStateComponent<Elemen
     if (temporarySettings != null) return temporarySettings;
     CodeStyleSettings projectSettings = PER_PROJECT_SETTINGS;
     if (USE_PER_PROJECT_SETTINGS && projectSettings != null) return projectSettings;
-    return CodeStyleSchemes.getInstance().getCurrentScheme().getCodeStyleSettings();
+    return CodeStyleSchemes.getInstance().findPreferredScheme(PREFERRED_PROJECT_CODE_STYLE).getCodeStyleSettings();
   }
 
   private void readExternal(Element element) throws InvalidDataException {

platform/lang-impl/src/com/intellij/application/options/codeStyle/CodeStyleSchemesModel.java

@@ -104,7 +104,7 @@ public class CodeStyleSchemesModel {
     mySettingsToClone.clear();
     mySchemes.clear();
     ContainerUtil.addAll(mySchemes, allSchemes);
-    myGlobalSelected = CodeStyleSchemes.getInstance().getCurrentScheme();
+    myGlobalSelected = CodeStyleSchemes.getInstance().findPreferredScheme(getProjectSettings().PREFERRED_PROJECT_CODE_STYLE);
 
     CodeStyleSettings perProjectSettings = getProjectSettings().PER_PROJECT_SETTINGS;
     if (perProjectSettings != null) {
@@ -150,17 +150,24 @@ public class CodeStyleSchemesModel {
   }
 
   public boolean isSchemeListModified() {
+    CodeStyleSchemes schemes = CodeStyleSchemes.getInstance();
     if (getProjectSettings().USE_PER_PROJECT_SETTINGS != myUsePerProjectSettings) return true;
-    if (!myUsePerProjectSettings && (getSelectedScheme() != CodeStyleSchemes.getInstance().getCurrentScheme())) return true;
+    if (!myUsePerProjectSettings &&
+        (getSelectedScheme() != schemes.findPreferredScheme(getProjectSettings().PREFERRED_PROJECT_CODE_STYLE))) {
+      return true;
+    }
     Set<CodeStyleScheme> configuredSchemesSet = new HashSet<CodeStyleScheme>(getSchemes());
-    Set<CodeStyleScheme> savedSchemesSet = new HashSet<CodeStyleScheme>(Arrays.asList(CodeStyleSchemes.getInstance().getSchemes()));
+    Set<CodeStyleScheme> savedSchemesSet = new HashSet<CodeStyleScheme>(Arrays.asList(schemes.getSchemes()));
     if (!configuredSchemesSet.equals(savedSchemesSet)) return true;
     return false;
   }
-
+  
   public void apply() {
-    getProjectSettings().USE_PER_PROJECT_SETTINGS = myUsePerProjectSettings;
-    getProjectSettings().PER_PROJECT_SETTINGS = myProjectScheme.getCodeStyleSettings();
+    CodeStyleSettingsManager projectSettingsManager = getProjectSettings();
+    projectSettingsManager.USE_PER_PROJECT_SETTINGS = myUsePerProjectSettings;
+    projectSettingsManager.PREFERRED_PROJECT_CODE_STYLE =
+      myUsePerProjectSettings || myGlobalSelected == null ? null : myGlobalSelected.getName();
+    projectSettingsManager.PER_PROJECT_SETTINGS = myProjectScheme.getCodeStyleSettings();
 
     final CodeStyleScheme[] savedSchemes = CodeStyleSchemes.getInstance().getSchemes();
     final Set<CodeStyleScheme> savedSchemesSet = new HashSet<CodeStyleScheme>(Arrays.asList(savedSchemes));
@@ -261,6 +268,7 @@ public class CodeStyleSchemesModel {
     return new CodeStyleSchemeImpl(name, false, parentScheme);
   }
 
+  @Nullable
   private CodeStyleScheme findSchemeByName(final String name) {
     for (CodeStyleScheme scheme : mySchemes) {
       if (name.equals(scheme.getName())) return scheme;