Partly solving issue 1490: "Comparator Tab / Light Table / Inspector" with the addition of an "Inspect" tab to the File Browser panel.

rtgui/filebrowser.h

@@ -45,6 +45,7 @@ class FileBrowserListener {
         virtual void copyMoveRequested      (std::vector<FileBrowserEntry*> tbe, bool moveRequested) {}
         virtual void selectionChanged       (std::vector<Thumbnail*> tbe) {}
         virtual void clearFromCacheRequested(std::vector<FileBrowserEntry*> tbe, bool leavenotrace) {}
+        virtual bool isInTabMode            () { return false; }
 };
 
 struct FileBrowserIdleHelper {
@@ -166,6 +167,8 @@ class FileBrowser  : public ThumbBrowserBase,
     void saveThumbnailHeight (int height);
     int  getThumbnailHeight ();
 
+    bool isInTabMode() { return tbl ? tbl->isInTabMode() : false; }
+
     void openNextImage ();
     void openPrevImage ();
     void copyProfile ();