Forward/Backward navigation with the mouse thumb buttons for Visual Studio 2008 (C++)

• Download source code and plug-in - 14.3 KB

Introduction

For most programs, users can use the "thumb-buttons" of the mouse to navigate forwards or backwards. This add-in will implement this feature in Visual Studio 2008 C++. (C# has this feature built-in).

Example usage

1. Jump to a function definition (right click on the function name, "Go to definition").
2. Jump back using the "backward button" of your mouse.

A look inside the code

The API for Visual Studio add-ins do not provide the possibility to get informed if a mouse button is pressed inside the Visual Studio window. It is necessary to use a Hook to achieve this:

private void InitHook()
{
  this.MouseProcDelegate = new HookProc(this.MouseProc);
  uint id = GetCurrentThreadId();
  hhook=SetWindowsHookEx(WH_MOUSE, 
        this.MouseProcDelegate, IntPtr.Zero, id);
}

The InitHook() function is called if Visual Studio is loading an add-in (on VS start). The hook is only attached to the thread whose the thread-ID is returned by GetCurrentThreadId(). The hook will receive the mouse events before Visual Studio does. Another possibility could be a ShellHook (WH_SHELL) (HSHELL_APPCOMMAND with the APPCOMMAND_BROWSER_BACKWARD and APPCOMMAND_BROWSER_FORWARD events). But, this does not work well (the event is not triggered under all circumstances).

The Hook will call the MouseProc function:

 private int MouseProc(int code, IntPtr wParam, ref MOUSEHOOKSTRUCTEX lParam)
    {
      try
      {
        if (code != HC_ACTION)
        {
          return CallNextHookEx(hhook, code, wParam, ref lParam);
        }

        if (wParam.ToInt32() == WM_XBUTTONUP)
        {
          switch (HiWord(lParam.mouseData))
          {
            case XBUTTON1:
              Debug.Write("mouse back button\n");
              _applicationObject.ExecuteCommand("View.NavigateBackward", "");
            return 1;

            case XBUTTON2:
              Debug.Write("mouse forward button\n");
              _applicationObject.ExecuteCommand("View.NavigateForward", "");
            return 1;
           }

        }

      }
      catch
      {

      }

      return CallNextHookEx(hhook, code, wParam, ref lParam);
    }

MOUSEHOOKSTRUCTEX is an updated version of MOUSEHOOKSTRUCT which supports the extra mouse buttons. If the wParam is WM_XBUTTONUP, one of the mouse thumb-buttons was released. You can find out which one was released using the hi-word of lParam.mouseData:

• XBUTTON1: backward button
• XBUTTON2: forward button

Finally, ExecuteCommand() is used to call the navigation functionality of Visual Studio:

_applicationObject.ExecuteCommand("View.NavigateBackward", "");
_applicationObject.ExecuteCommand("View.NavigateForward", "");

History

• 0.2: Checks if the mouse button is pressed inside a C++ editor window.
• 0.1: Initial version.