Allow double-click to open scenes in File Browser and Browser Room.

For #2941.

toonz/sources/toonz/filebrowser.cpp

@@ -2303,6 +2303,22 @@ void FileBrowser::enableGlobalSelection(bool enabled) {
 
 void FileBrowser::selectNone() { m_itemViewer->selectNone(); }
 
+//-----------------------------------------------------------------------------
+
+void FileBrowser::enableDoubleClickToOpenScenes() {
+  // perhaps this should disconnect existing signal handlers first
+  connect(this, SIGNAL(filePathDoubleClicked(const TFilePath &)),
+  this, SLOT(tryToOpenScene(const TFilePath &)));
+}
+
+//-----------------------------------------------------------------------------
+
+void FileBrowser::tryToOpenScene(const TFilePath &filePath) {
+  if (filePath.getType() == "tnz") {
+    IoCmd::loadScene(filePath);
+  }
+}
+
 //=============================================================================
 // FCData methods
 //-----------------------------------------------------------------------------

toonz/sources/toonz/filebrowser.h

@@ -124,6 +124,12 @@ types to be displayed in the file browser.
 
   QSplitter *getMainSplitter() const { return m_mainSplitter; }
 
+  // Enable double-click to open a scene.
+  // This is not always desirable (e.g. if a user double-clicks on a file in
+  // a "Save As" dialog, they expect the file will be saved to, not opened).
+  // So it is disabled by default.
+  void enableDoubleClickToOpenScenes();
+
 protected:
   int findIndexWithPath(TFilePath path);
   void getExpandedFolders(DvDirModelNode *node,
@@ -198,6 +204,9 @@ protected slots:
 
   void onFileSystemChanged(const QString &folderPath);
 
+  // If filePath is a valid scene file, open it. Otherwise do nothing.
+  void tryToOpenScene(const TFilePath &filePath);
+
 signals:
 
   void filePathClicked(const TFilePath &);

toonz/sources/toonz/tpanels.cpp

@@ -1089,6 +1089,7 @@ public:
     TFilePath currentProjectFolder =
         TProjectManager::instance()->getCurrentProjectPath().getParentDir();
     browser->setFolder(currentProjectFolder, true);
+    browser->enableDoubleClickToOpenScenes();
   }
 } browserFactory;