Switch using common directory names

Switch/SwitchCore/SwitchTargets/ExtensionSwitchTarget.cs

@@ -1,4 +1,8 @@
-using EnvDTE;
+using System;
+using System.Text;
+using System.IO;
+using System.Windows.Forms;
+using EnvDTE;
 using EnvDTE80;
 
 namespace SwitchCore.SwitchTargets
@@ -44,7 +48,108 @@ public bool DoSwitch(DTE2 application, Document activeDocument)
             var mappedPath = path.Substring(0, path.Length - From.Length) + To;
 
             //  Try and open the mapped path.
-            return SwitchHelper.TryOpenDocument(application, mappedPath);
+            bool success = SwitchHelper.TryOpenDocument(application, mappedPath);
+
+            if (success) {
+                return success;
+            }
+
+            // Try using common path names.
+            //
+            // In C++, header files are usually in 'include' directories
+            // and implementation files are in 'source' directories. These
+            // directories usually share a common root path.
+            //
+            // <root>\include\...
+            // <root>\source\...
+            //
+            // There is also the possibility that C++ project components are
+            // placed in their own sub-directory with corresponding 'include'
+            // and 'source' directories.
+            //
+            // <root>\component_1\include\...
+            // <root>\component_1\source\...
+            // <root>\component_2\include\...
+            // <root>\component_2\source\...
+            //
+            // What it does not yet do is scan for other directory layouts.
+            // An example is when 'include' files are placed into deeper
+            // subdirectories:
+            //
+            // <root>\component_1\include\sub1\*.h
+            // <root>\component_1\include\sub2\*.h
+            // <root>\component_1\source\*.cpp
+            //
+            // ----
+            // TODO: Create separate SwitchTarget for this scenario
+
+            string filenameOnly = Path.GetFileNameWithoutExtension(path);
+            // Get the path without the leading path separator.
+            string pathOnly = path.Substring(0, path.Length - Path.GetFileName(path).Length - 1);
+            string[] directories = pathOnly.Split(Path.DirectorySeparatorChar);
+
+            // Be safe
+            if (directories.Length == 0) return false;
+
+            // Make sure the first directory path have a directory separator
+            // since Path.Combine does not seem to append one.
+            if (!directories[0].EndsWith(Path.DirectorySeparatorChar.ToString()))
+            {
+                directories[0] += Path.DirectorySeparatorChar;
+            }
+
+            // Possible directories names; add more if necessary.
+            // Used to find possible directory names and substitute.
+            //
+            // TODO: Make configurable
+
+            // TODO: Must be class members and initialized once only.
+            string[] includeFolder = new string[] { "includes", "include", "inc" };
+            string[] sourceFolder = new string[] { "sources", "source", "src" };
+
+            // If the current document is a header file then we search in
+            // the source directory and vice versa.
+            string[] fromFolder = new string[3];
+            string[] toFolder = new string[3];
+            if (From.StartsWith("h")) {
+                fromFolder = includeFolder;
+                toFolder = sourceFolder;
+            } else {
+                fromFolder = sourceFolder;
+                toFolder = includeFolder;
+            }
+
+            string newPath;
+            string newFilename;
+            // Temporary buffer
+            string originalDirectory;
+
+            // Scan directories backwards.
+            for (int i = directories.Length - 1; i >= 0; i--)
+            {
+                if (Array.Exists(fromFolder, s => { return String.Compare(s, directories[i]) == 0; }))
+                {
+                    // Save directory name so we can restore it later.
+                    originalDirectory = directories[i];
+
+                    foreach (string t in toFolder)
+                    {
+                        // Build the new path using the current possible directory name
+                        directories[i] = t;
+                        newPath = Path.Combine(directories) + Path.DirectorySeparatorChar;
+                        newFilename = String.Concat(newPath, filenameOnly + "." + To);
+                        MessageBox.Show("File to open: " + newFilename);
+
+                        success = SwitchHelper.TryOpenDocument(application, newFilename);
+                        if (success) return success;
+                    }
+
+                    // Restore original directory name.
+                    directories[i] = originalDirectory;
+                }
+            }
+
+            return success;
         }
 
         /// <summary>