Merge pull request #9024

spec/text-editor-spec.coffee

@@ -168,6 +168,37 @@ describe "TextEditor", ->
         buffer.setPath(undefined)
         expect(editor.getLongTitle()).toBe 'untitled'
 
+    describe ".getUniqueTitle()", ->
+      it "returns file name when there is no opened file with identical name", ->
+        expect(editor.getUniqueTitle()).toBe 'sample.js'
+        buffer.setPath(undefined)
+        expect(editor.getLongTitle()).toBe 'untitled'
+
+      it "returns <parent-directory>/<filename> when opened files has identical file names", ->
+        editor1 = null
+        editor2 = null
+        waitsForPromise ->
+          atom.workspace.open(path.join('sample-theme-1', 'readme')).then (o) ->
+            editor1 = o
+            atom.workspace.open(path.join('sample-theme-2', 'readme')).then (o) ->
+              editor2 = o
+        runs ->
+          expect(editor1.getUniqueTitle()).toBe 'sample-theme-1/readme'
+          expect(editor2.getUniqueTitle()).toBe 'sample-theme-2/readme'
+
+      it "or returns <parent-directory>/.../<filename> when opened files has identical file names", ->
+        editor1 = null
+        editor2 = null
+        waitsForPromise ->
+          atom.workspace.open(path.join('sample-theme-1', 'src', 'js', 'main.js')).then (o) ->
+            editor1 = o
+            atom.workspace.open(path.join('sample-theme-2', 'src', 'js', 'main.js')).then (o) ->
+              editor2 = o
+        runs ->
+          expect(editor1.getUniqueTitle()).toBe 'sample-theme-1/.../main.js'
+          expect(editor2.getUniqueTitle()).toBe 'sample-theme-2/.../main.js'
+
+
     it "notifies ::onDidChangeTitle observers when the underlying buffer path changes", ->
       observed = []
       editor.onDidChangeTitle (title) -> observed.push(title)

src/text-editor.coffee

@@ -573,6 +573,45 @@ class TextEditor extends Model
     else
       'untitled'
 
+  # Essential: Get unique title for display in other parts of the UI
+  # such as the window title.
+  #
+  # If the editor's buffer is unsaved, its title is "untitled"
+  # If the editor's buffer is saved, its unique title is formatted as one
+  # of the following,
+  # * "<filename>" when it is the only editing buffer with this file name.
+  # * "<unique-dir-prefix>/.../<filename>", where the "..." may be omitted
+  # if the the direct parent directory is already different.
+  #
+  # Returns a {String}
+  getUniqueTitle: ->
+    if sessionPath = @getPath()
+      title = @getTitle()
+
+      # find text editors with identical file name.
+      paths = []
+      for textEditor in atom.workspace.getTextEditors() when textEditor isnt this
+        if textEditor.getTitle() is title
+          paths.push(textEditor.getPath())
+      if paths.length is 0
+        return title
+      fileName = path.basename(sessionPath)
+
+      # find the first directory in all these paths that is unique
+      nLevel = 0
+      while (_.some(paths, (apath) -> path.basename(apath) is path.basename(sessionPath)))
+        sessionPath = path.dirname(sessionPath)
+        paths = _.map(paths, (apath) -> path.dirname(apath))
+        nLevel += 1
+
+      directory = path.basename sessionPath
+      if nLevel > 1
+        path.join(directory, "...", fileName)
+      else
+        path.join(directory, fileName)
+    else
+      'untitled'
+
   # Essential: Get the editor's long title for display in other parts of the UI
   # such as the window title.
   #