Updated installer with custom action

installer/src/installer-lib/interaction.h

 /**
  * \file interaction.h User interaction classes. Message boxes and translations.
  */
 
 #ifndef INTERACTION_H
 #define INTERACTION_H
 
+#include <string>
+
+#include "session.h"
+
+#include <Windows.h>
+#include <Msi.h>
+#include <MsiQuery.h>
+
+/**
+ * A modal dialog box as displayable from within a custom action.
+ *
+ * The only fully user interface element that the Windows Installer supports for use within custom actions is a small set of modal dialog boxes.
+ * The Windows Installer provides the call MsiProcessMessage, overloaded by a set of message type constants.
+ * This class represents those messages with user-provided messages; these ultimately call MessageBox.
+ *
+ * \sa 
+ *    * MSDN [MsiProcessMessage function](http://msdn.microsoft.com/en-us/library/windows/desktop/aa370354%28v=vs.85%29.aspx)
+ *    * MSDN [Sending Messages to Windows Installer Using MsiProcessMessage](http://msdn.microsoft.com/en-us/library/windows/desktop/aa371614%28v=vs.85%29.aspx)
+ */
+class Installer_Message_Box
+  : public Message
+{
+public:
+  typedef enum 
+  {
+    default_box = 0,
+    error_box = INSTALLMESSAGE::INSTALLMESSAGE_ERROR,
+    warning_box = INSTALLMESSAGE::INSTALLMESSAGE_WARNING,
+    user_box = INSTALLMESSAGE::INSTALLMESSAGE_USER
+  }
+  box_type ;
+
+  typedef enum
+  {
+    default_buttonset = 0,
+    ok = MB_OK, 
+    ok_cancel = MB_OKCANCEL, 
+    abort_retry_ignore = MB_ABORTRETRYIGNORE, 
+    yes_no_cancel = MB_YESNOCANCEL, 
+    yes_no = MB_YESNO, 
+    retry_cancel = MB_RETRYCANCEL
+  }
+  buttonset_type ;
+
+  typedef enum
+  {
+    default_default_button = 0,     ///< use the default button
+    default_button_one = MB_DEFBUTTON1,
+    default_button_two = MB_DEFBUTTON2,
+    default_button_three = MB_DEFBUTTON3
+  }
+  default_button_type ;
+
+  typedef enum
+  {
+    default_icon = 0,                       ///< use the default icon associated with the box_type
+    warning_icon = MB_ICONWARNING,          ///< exclamation point
+    information_icon = MB_ICONINFORMATION,  ///< lowercase letter "i" in a circle
+    error_icon = MB_ICONERROR               ///< stop sign
+  }
+  icon_type ;
+
+  /**
+   * Ordinary constructor, wide string
+   */
+  Installer_Message_Box(
+    std::wstring message, 
+    box_type box = box_type::user_box, 
+    buttonset_type buttonset = buttonset_type::default_buttonset, 
+    default_button_type default_button = default_button_type::default_default_button,
+    icon_type icon = icon_type::default_icon
+  ) ;
+
+  /**
+   * Ordinary constructor, regular string
+   */
+  Installer_Message_Box(
+    std::string message, 
+    box_type box = box_type::user_box, 
+    buttonset_type buttonset = buttonset_type::default_buttonset, 
+    default_button_type default_button = default_button_type::default_default_button,
+    icon_type icon = icon_type::default_icon
+  ) ;
+} ;
+
+/**
+ * Error for any non-handled return value from Session.write_message().
+ */
+struct unexpected_return_value_from_message_box
+  : std::logic_error
+{
+  unexpected_return_value_from_message_box()
+    : std::logic_error( "Unexpected return value from message box." )
+  {}
+} ;
+
 #endif