Cleanups to status bar language-switcher:

* Make LanguageManager the official public API that is used to set per-file
overrides, rather than proxying through Document objects - remove Document.setLanguageOverride()
* Clear path overrides when switching projects, so it's more obvious that
it's not something that gets persisted across sessions
* Simplify how JS Code Hints listen for language updates: remove dependency
on "currentDocumentLanguageChanged" event; remove unneeded extra 'if' tests

Author: peterflynn

src/document/Document.js

@@ -672,19 +672,7 @@ define(function (require, exports, module) {
     };
 
     /**
-     * Overrides the default language of this document and sets it to the given
-     * language. This change is not persisted if the document is closed.
-     * @param {?Language} language The language to be set for this document; if
-     * null, the language will be set back to the default.
-     */
-    Document.prototype.setLanguageOverride = function (language) {
-        LanguageManager._setLanguageOverrideForPath(this.file.fullPath, language);
-        this._updateLanguage();
-    };
-
-    /**
-     * Updates the language according to the file extension. If the current
-     * language was forced (set manually by user), don't change it.
+     * Updates the language to match the current mapping given by LanguageManager
      */
     Document.prototype._updateLanguage = function () {
         var oldLanguage = this.language;

src/editor/EditorStatusBar.js

@@ -365,9 +365,9 @@ define(function (require, exports, module) {
             var document = EditorManager.getActiveEditor().document,
                 fullPath = document.file.fullPath,
                 defaultLang = LanguageManager.getLanguageForPath(fullPath, true);
-            // if default language selected, don't "force" it
-            // (passing in null will reset the force flag)
-            document.setLanguageOverride(lang === defaultLang ? null : lang);
+            
+            // if default language selected, pass null to clear the override
+            LanguageManager.setLanguageOverrideForPath(fullPath, lang === defaultLang ? null : lang);
         });
 
         $statusOverwrite.on("click", _updateEditorOverwriteMode);

src/extensions/default/JavaScriptCodeHints/ScopeManager.js

@@ -1037,8 +1037,8 @@ define(function (require, exports, module) {
          *  Do the work to initialize a code hinting session.
          *
          * @param {Session} session - the active hinting session
-         * @param {Document} document - the document the editor has changed to
-         * @param {Document} previousDocument - the document the editor has changed from
+         * @param {!Document} document - the document the editor has changed to
+         * @param {?Document} previousDocument - the document the editor has changed from
          */
         function doEditorChange(session, document, previousDocument) {
             var file        = document.file,
@@ -1138,7 +1138,7 @@ define(function (require, exports, module) {
          *
          * @param {Session} session - the active hinting session
          * @param {Document} document - the document of the editor that has changed
-         * @param {Document} previousDocument - the document of the editor is changing from
+         * @param {?Document} previousDocument - the document of the editor is changing from
          */
         function handleEditorChange(session, document, previousDocument) {
             if (addFilesPromise === null) {
@@ -1376,7 +1376,7 @@ define(function (require, exports, module) {
      *
      * @param {Session} session - the active hinting session
      * @param {Document} document - the document of the editor that has changed
-     * @param {Document} previousDocument - the document of the editor is changing from
+     * @param {?Document} previousDocument - the document of the editor is changing from
      */
     function handleEditorChange(session, document, previousDocument) {
 

src/extensions/default/JavaScriptCodeHints/main.js

@@ -564,7 +564,7 @@ define(function (require, exports, module) {
          * information, and reject any pending deferred requests.
          * 
          * @param {Editor} editor - editor context to be initialized.
-         * @param {Editor} previousEditor - the previous editor.
+         * @param {?Editor} previousEditor - the previous editor.
          */
         function initializeSession(editor, previousEditor) {
             session = new Session(editor);
@@ -579,7 +579,7 @@ define(function (require, exports, module) {
          * 
          * @param {Editor} editor - editor context on which to listen for
          *      changes
-         * @param {Editor} previousEditor - the previous editor
+         * @param {?Editor} previousEditor - the previous editor
          */
         function installEditorListeners(editor, previousEditor) {
             // always clean up cached scope and hint info
@@ -624,18 +624,21 @@ define(function (require, exports, module) {
          * @param {Editor} previous - the previous editor context
          */
         function handleActiveEditorChange(event, current, previous) {
-            // Uninstall "languageChanged" event listeners on the previous editor's document
-            if (previous && previous !== current) {
+            // Uninstall "languageChanged" event listeners on previous editor's document & put them on current editor's doc
+            if (previous) {
                 $(previous.document)
                     .off(HintUtils.eventName("languageChanged"));
             }
-            if (current && current.document !== DocumentManager.getCurrentDocument()) {
+            if (current) {
                 $(current.document)
                     .on(HintUtils.eventName("languageChanged"), function () {
+                        // If current doc's language changed, reset our state by treating it as if the user switched to a
+                        // different document altogether
                         uninstallEditorListeners(current);
                         installEditorListeners(current);
                     });
             }
+            
             uninstallEditorListeners(previous);
             installEditorListeners(current, previous);
         }
@@ -803,13 +806,6 @@ define(function (require, exports, module) {
             .on(HintUtils.eventName("activeEditorChange"),
                 handleActiveEditorChange);
 
-        $(DocumentManager)
-            .on("currentDocumentLanguageChanged", function (e) {
-                var activeEditor = EditorManager.getActiveEditor();
-                uninstallEditorListeners(activeEditor);
-                installEditorListeners(activeEditor);
-            });
-        
         $(ProjectManager).on("beforeProjectClose", function () {
             ScopeManager.handleProjectClose();
         });

src/language/LanguageManager.js

@@ -227,28 +227,6 @@ define(function (require, exports, module) {
         _modeToLanguageMap[mode] = language;
     }
 
-    /**
-     * Adds a language mapping for the specified fullPath. If language is falsy (null or undefined), the mapping
-     * is removed.
-     *
-     * @param {!fullPath} fullPath absolute path of the file
-     * @param {?object} language language to associate the file with or falsy value to remove the existing mapping
-     */
-    function _setLanguageOverrideForPath(fullPath, language) {
-        if (!language) {
-            delete _filePathToLanguageMap[fullPath];
-        } else {
-            _filePathToLanguageMap[fullPath] = language;
-        }
-    }
-    
-    /**
-     * Resets all the language overrides for file paths. Used by unit tests only.
-     */
-    function _resetLanguageOverrides() {
-        _filePathToLanguageMap = {};
-    }
-
     /**
      * Resolves a language ID to a Language object.
      * File names have a higher priority than file extensions. 
@@ -260,7 +238,9 @@ define(function (require, exports, module) {
     }
 
     /**
-     * Resolves a language to a file extension
+     * Resolves a file extension to a Language object.
+     * *Warning:* it is almost always better to use getLanguageForPath(), since Language can depend
+     * on file name and even full path. Use this API only if no relevant file/path exists.
      * @param {!string} extension Extension that language should be resolved for
      * @return {?Language} The language for the provided extension or null if none exists
      */
@@ -383,6 +363,37 @@ define(function (require, exports, module) {
         $(exports).triggerHandler("languageModified", [language]);
     }
 
+    /**
+     * Adds a language mapping for the specified fullPath. If language is falsy (null or undefined), the mapping
+     * is removed. The override is NOT persisted across Brackets sessions.
+     *
+     * @param {!fullPath} fullPath absolute path of the file
+     * @param {?object} language language to associate the file with or falsy value to remove any existing override
+     */
+    function setLanguageOverrideForPath(fullPath, language) {
+        var oldLang = getLanguageForPath(fullPath);
+        if (!language) {
+            delete _filePathToLanguageMap[fullPath];
+        } else {
+            _filePathToLanguageMap[fullPath] = language;
+        }
+        var newLang = getLanguageForPath(fullPath);
+        
+        // Old language changed since this path is no longer mapped to it
+        _triggerLanguageModified(oldLang);
+        // New language changed since a path is now mapped to it that wasn't before
+        _triggerLanguageModified(newLang);
+    }
+    
+    /**
+     * Resets all the language overrides for file paths. Used by unit tests only.
+     */
+    function _resetPathLanguageOverrides() {
+        _filePathToLanguageMap = {};
+    }
+
+
+    
 
     /**
      * Model for a language.
@@ -1100,11 +1111,7 @@ define(function (require, exports, module) {
     // Private for unit tests
     exports._EXTENSION_MAP_PREF         = _EXTENSION_MAP_PREF;
     exports._NAME_MAP_PREF              = _NAME_MAP_PREF;
-    exports._resetLanguageOverrides     = _resetLanguageOverrides;
-    // Internal use only
-    // _setLanguageOverrideForPath is used by Document to help LanguageManager keeping track of
-    // in-document language overrides
-    exports._setLanguageOverrideForPath  = _setLanguageOverrideForPath;
+    exports._resetPathLanguageOverrides = _resetPathLanguageOverrides;
 
     // Public methods
     exports.ready                       = _ready;
@@ -1113,4 +1120,5 @@ define(function (require, exports, module) {
     exports.getLanguageForExtension     = getLanguageForExtension;
     exports.getLanguageForPath          = getLanguageForPath;
     exports.getLanguages                = getLanguages;
+    exports.setLanguageOverrideForPath  = setLanguageOverrideForPath;
 });

src/project/ProjectManager.js

@@ -1117,8 +1117,8 @@ define(function (require, exports, module) {
     }
 
     /**
-     * Loads the given folder as a project. Normally, you would call openProject() instead to let the
-     * user choose a folder.
+     * Loads the given folder as a project. Does NOT prompt about any unsaved changes - use openProject()
+     * instead to check for unsaved changes and (optionally) let the user choose the folder to open.
      *
      * @param {!string} rootPath  Absolute path to the root folder of the project.
      *  A trailing "/" on the path is optional (unlike many Brackets APIs that assume a trailing "/").
@@ -1155,8 +1155,9 @@ define(function (require, exports, module) {
             DocumentManager.closeAll();
 
             _unwatchProjectRoot().always(function () {
-                // Done closing old project (if any)
+                // Finish closing old project (if any)
                 if (_projectRoot) {
+                    LanguageManager._resetPathLanguageOverrides();
                     PreferencesManager._reloadUserPrefs(_projectRoot);
                     $(exports).triggerHandler("projectClose", _projectRoot);
                 }

test/spec/LanguageManager-test.js

@@ -47,7 +47,7 @@ define(function (require, exports, module) {
         });
 
         afterEach(function () {
-            LanguageManager._resetLanguageOverrides();
+            LanguageManager._resetPathLanguageOverrides();
         });
 
         function defineLanguage(definition) {
@@ -544,7 +544,7 @@ define(function (require, exports, module) {
 
                 var renameDeferred = $.Deferred();
                 runs(function () {
-                    DocumentManager.setCurrentDocument(doc);                    
+                    DocumentManager.setCurrentDocument(doc);
                     javascript = LanguageManager.getLanguage("javascript");
 
                     // sanity check language
@@ -705,7 +705,7 @@ define(function (require, exports, module) {
                 // make active
                 doc.addRef();
 
-                doc.setLanguageOverride(phpLang);
+                LanguageManager.setLanguageOverrideForPath(doc.file.fullPath, phpLang);
 
                 // language should change
                 expect(doc.getLanguage()).toBe(phpLang);
@@ -747,7 +747,7 @@ define(function (require, exports, module) {
                 // make active
                 doc.addRef();
 
-                doc.setLanguageOverride(phpLang);
+                LanguageManager.setLanguageOverrideForPath(doc.file.fullPath, phpLang);
 
                 // language should change
                 expect(doc.getLanguage()).toBe(phpLang);
@@ -756,7 +756,7 @@ define(function (require, exports, module) {
                 expect(spy.mostRecentCall.args[2]).toBe(phpLang);
                 expect(LanguageManager.getLanguageForPath(doc.file.fullPath)).toBe(phpLang);
 
-                doc.setLanguageOverride(null);
+                LanguageManager.setLanguageOverrideForPath(doc.file.fullPath, null);
 
                 // language should revert
                 expect(doc.getLanguage()).toBe(unknownLang);
@@ -777,7 +777,7 @@ define(function (require, exports, module) {
                 expect(LanguageManager.getLanguageForPath(doc.file.fullPath)).toBe(modifiedLanguage);
 
                 // override again
-                doc.setLanguageOverride(phpLang);
+                LanguageManager.setLanguageOverrideForPath(doc.file.fullPath, phpLang);
 
                 expect(doc.getLanguage()).toBe(phpLang);
                 expect(spy.callCount).toBe(4);
@@ -786,7 +786,7 @@ define(function (require, exports, module) {
                 expect(LanguageManager.getLanguageForPath(doc.file.fullPath)).toBe(phpLang);
 
                 // remove override, should restore to modifiedLanguage
-                doc.setLanguageOverride(null);
+                LanguageManager.setLanguageOverrideForPath(doc.file.fullPath, null);
 
                 expect(doc.getLanguage()).toBe(modifiedLanguage);
                 expect(spy.callCount).toBe(5);