When flipping views, if the doc is already open on the other view, show it without closing the original pane

src/view/Pane.js

@@ -211,6 +211,23 @@ define(function (require, exports, module) {
         return {indexRequested: requestIndex, index: index};
     }
 
+    /**
+     * Ensures that the given pane is focused after other focus related events occur
+     * @params {string} paneId - paneId of the pane to focus
+     * @private
+     */
+    function _ensurePaneIsFocused(paneId) {
+        var pane = MainViewManager._getPane(paneId);
+
+        // Defer the focusing until other focus events have occurred.
+        setTimeout(function () {
+            // Focus has most likely changed: give it back to the given pane.
+            pane.focus();
+            this._lastFocusedElement = pane.$el[0];
+            MainViewManager.setActivePaneId(paneId);
+        }, 1);
+    }
+
     /**
      * @typedef {!$el: jQuery, getFile:function():!File, updateLayout:function(forceRefresh:boolean), destroy:function(),  getScrollPos:function():?,  adjustScrollPos:function(state:Object=, heightDelta:number)=, getViewState:function():?*=, restoreViewState:function(viewState:!*)=, notifyContainerChange:function()=, notifyVisibilityChange:function(boolean)=} View
      */
@@ -245,40 +262,29 @@ define(function (require, exports, module) {
             var currentFile = self.getCurrentlyViewedFile();
             var otherPaneId = self.id === FIRST_PANE ? SECOND_PANE : FIRST_PANE;
             var otherPane = MainViewManager._getPane(otherPaneId);
+            var sameDocInOtherView = otherPane.getViewForPath(currentFile.fullPath);
 
-            // If the same doc view is present in the destination pane prevent flip
-            if (otherPane.getViewForPath(currentFile.fullPath)) {
+            // If the same doc view is present in the destination, show the file instead of flipping it
+            if (sameDocInOtherView) {
+                CommandManager.execute(Commands.FILE_OPEN, {fullPath: currentFile.fullPath,
+                                                            paneId: otherPaneId}).always(function () {
+                    _ensurePaneIsFocused(otherPaneId);
+                });
                 return;
             }
 
             // Currently active pane is not necessarily self.id as just clicking the button does not
             // give focus to the pane. This way it is possible to flip multiple panes to the active one
             // without losing focus.
             var activePaneIdBeforeFlip = MainViewManager.getActivePaneId();
-            var currentFileOnOtherPaneIndex = otherPane.findInViewList(currentFile.fullPath);
 
-            // if the currentFile is already on other pane just close the current pane
-            if (currentFileOnOtherPaneIndex  !== -1) {
-                CommandManager.execute(Commands.FILE_CLOSE, {File: currentFile, paneId: self.id});
-            }
-
             MainViewManager._moveView(self.id, otherPaneId, currentFile).always(function () {
                 CommandManager.execute(Commands.FILE_OPEN, {fullPath: currentFile.fullPath,
                                                             paneId: otherPaneId}).always(function () {
-
-                    var activePaneBeforeFlip = MainViewManager._getPane(activePaneIdBeforeFlip);
-
                     // Trigger view list changes for both panes
                     self.trigger("viewListChange");
                     otherPane.trigger("viewListChange");
-
-                    // Defer the focusing until other focus events have occurred.
-                    setTimeout(function () {
-                        // Focus has most likely changed: give it back to the original pane.
-                        activePaneBeforeFlip.focus();
-                        self._lastFocusedElement = activePaneBeforeFlip.$el[0];
-                        MainViewManager.setActivePaneId(activePaneIdBeforeFlip);
-                    }, 1);
+                    _ensurePaneIsFocused(activePaneIdBeforeFlip);
                 });
             });
         });

test/spec/MainViewManager-test.js

@@ -449,6 +449,37 @@ define(function (require, exports, module) {
                     expect(MainViewManager.getCurrentlyViewedFile(MainViewManager.ACTIVE_PANE)).toEqual(null);
                 });
             });
+            it("should show the file instead of flipping if file is already open", function () {
+                runs(function () {
+                    MainViewManager.setLayoutScheme(1, 2);
+                });
+                runs(function () {
+                    promise = CommandManager.execute(Commands.CMD_ADD_TO_WORKINGSET_AND_OPEN,  { fullPath: testPath + "/test.js",
+                                                                            paneId: "first-pane" });
+                    waitsForDone(promise, Commands.CMD_ADD_TO_WORKINGSET_AND_OPEN);
+                });
+                runs(function () {
+                    promise = CommandManager.execute(Commands.CMD_ADD_TO_WORKINGSET_AND_OPEN,  { fullPath: testPath + "/test.js",
+                                                                            paneId: "second-pane" });
+                    waitsForDone(promise, Commands.CMD_ADD_TO_WORKINGSET_AND_OPEN);
+                });
+                runs(function () {
+                    promise = CommandManager.execute(Commands.CMD_ADD_TO_WORKINGSET_AND_OPEN,  { fullPath: testPath + "/test.css",
+                                                                            paneId: "second-pane" });
+                    waitsForDone(promise, Commands.CMD_ADD_TO_WORKINGSET_AND_OPEN);
+                });
+                runs(function () {
+                    MainViewManager._getPane("first-pane").$headerFlipViewBtn.trigger("click");
+                });
+                runs(function () {
+                    MainViewManager.setActivePaneId("first-pane");
+                    expect(MainViewManager.getCurrentlyViewedFile(MainViewManager.ACTIVE_PANE).name).toEqual("test.js");
+                    expect(EditorManager.getCurrentFullEditor().document.file.name).toEqual("test.js");
+                    MainViewManager.setActivePaneId("second-pane");
+                    expect(MainViewManager.getCurrentlyViewedFile(MainViewManager.ACTIVE_PANE).name).toEqual("test.js");
+                    expect(EditorManager.getCurrentFullEditor().document.file.name).toEqual("test.js");
+                });
+            });
             it("should merge two panes to the right", function () {
                 runs(function () {
                     MainViewManager.setLayoutScheme(1, 2);