Restructure wxNotificationMessage.

wxNotificationMessage has been refactored to always use wxNotificationMessageImpl (this was previously already done in the MSW implementation)

This adds various features and fixes to wxNotificationMessage:
- OS X Notification Center implementation
- Generic "toast" notifications
- SetIcon() to specify a custom icon
- AddAction() to add actions to notifications
- Events to get notify of notification clicks, dismiss or actions

src/common/notifmsgcmn.cpp

@@ -0,0 +1,103 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        src/common/notifmsgcmn.cpp
+// Purpose:     wxNotificationMessageBase implementation
+// Author:      Tobias Taschner
+// Created:     2015-08-04
+// Copyright:   (c) 2015 wxWidgets development team
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
+// For compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"
+
+#ifdef __BORLANDC__
+#pragma hdrstop
+#endif
+
+#if wxUSE_NOTIFICATION_MESSAGE
+
+#include "wx/notifmsg.h"
+
+#include "wx/private/notifmsg.h"
+
+#ifndef wxHAS_NATIVE_NOTIFICATION_MESSAGE
+#include "wx/generic/private/notifmsg.h"
+#endif
+
+wxDEFINE_EVENT( wxEVT_NOTIFICATION_MESSAGE_CLICK, wxCommandEvent );
+wxDEFINE_EVENT( wxEVT_NOTIFICATION_MESSAGE_DISMISSED, wxCommandEvent );
+wxDEFINE_EVENT( wxEVT_NOTIFICATION_MESSAGE_ACTION, wxCommandEvent );
+
+// ----------------------------------------------------------------------------
+// wxNotificationMessageBase
+// ----------------------------------------------------------------------------
+
+wxNotificationMessageBase::~wxNotificationMessageBase()
+{
+    m_impl->Detach();
+}
+
+bool wxNotificationMessageBase::Show(int timeout)
+{
+    return m_impl->Show(timeout);
+}
+
+bool wxNotificationMessageBase::Close()
+{
+    return m_impl->Close();
+}
+
+void wxNotificationMessageBase::SetTitle(const wxString& title)
+{
+    m_impl->SetTitle(title);
+}
+
+void wxNotificationMessageBase::SetMessage(const wxString& message)
+{
+    m_impl->SetMessage(message);
+}
+
+void wxNotificationMessageBase::SetParent(wxWindow *parent)
+{
+    m_impl->SetParent(parent);
+}
+
+void wxNotificationMessageBase::SetFlags(int flags)
+{
+    wxASSERT_MSG(flags == wxICON_INFORMATION ||
+        flags == wxICON_WARNING || flags == wxICON_ERROR || 
+        flags == 0,
+        "Invalid icon flags specified");
+
+    m_impl->SetFlags(flags);
+}
+
+void wxNotificationMessageBase::SetIcon(const wxIcon& icon)
+{
+    m_impl->SetIcon(icon);
+}
+
+bool wxNotificationMessageBase::AddAction(wxWindowID actionid, const wxString &label)
+{
+    return m_impl->AddAction(actionid, label);
+}
+
+//
+// wxNotificationMessage
+//
+
+#ifndef wxHAS_NATIVE_NOTIFICATION_MESSAGE
+
+void wxNotificationMessage::Init()
+{
+    m_impl = new wxGenericNotificationMessageImpl(this);
+}
+
+#endif
+
+#endif // wxUSE_NOTIFICATION_MESSAGE