Index: ps/trunk/source/tools/atlas/AtlasUI/ScenarioEditor/ScenarioEditor.cpp
===================================================================
--- ps/trunk/source/tools/atlas/AtlasUI/ScenarioEditor/ScenarioEditor.cpp
+++ ps/trunk/source/tools/atlas/AtlasUI/ScenarioEditor/ScenarioEditor.cpp
@@ -51,6 +51,11 @@
 
 static HighResTimer g_Timer;
 
+/**
+ * wxWidgets only registers the double click on mousedown.
+ */
+static int g_Clicks = 1;
+
 using namespace AtlasMessage;
 
 //////////////////////////////////////////////////////////////////////////
@@ -272,9 +277,12 @@
 		// Button down and double click appear to be mutually exclusive events,
 		//   meaning a second button down event is not sent before a double click
 		if (evt.ButtonDown() || evt.ButtonDClick())
-			POST_MESSAGE(GuiMouseButtonEvent, (evt.GetButton(), true, evt.GetPosition()));
+		{
+			g_Clicks = evt.ButtonDClick() ? 2 : 1;
+			POST_MESSAGE(GuiMouseButtonEvent, (evt.GetButton(), true, evt.GetPosition(), g_Clicks));
+		}
 		else if (evt.ButtonUp())
-			POST_MESSAGE(GuiMouseButtonEvent, (evt.GetButton(), false, evt.GetPosition()));
+			POST_MESSAGE(GuiMouseButtonEvent, (evt.GetButton(), false, evt.GetPosition(), g_Clicks));
 		else if (evt.GetEventType() == wxEVT_MOTION)
 			POST_MESSAGE(GuiMouseMotionEvent, (evt.GetPosition()));
 	}
Index: ps/trunk/source/tools/atlas/GameInterface/Handlers/MiscHandlers.cpp
===================================================================
--- ps/trunk/source/tools/atlas/GameInterface/Handlers/MiscHandlers.cpp
+++ ps/trunk/source/tools/atlas/GameInterface/Handlers/MiscHandlers.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2014 Wildfire Games.
+/* Copyright (C) 2017 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -170,6 +170,7 @@
 	ev.ev.type = msg->pressed ? SDL_MOUSEBUTTONDOWN : SDL_MOUSEBUTTONUP;
 	ev.ev.button.button = msg->button;
 	ev.ev.button.state = msg->pressed ? SDL_PRESSED : SDL_RELEASED;
+	ev.ev.button.clicks = msg->clicks;
 	float x, y;
 	msg->pos->GetScreenSpace(x, y);
 	ev.ev.button.x = (u16)clamp((int)x, 0, g_xres);
Index: ps/trunk/source/tools/atlas/GameInterface/Messages.h
===================================================================
--- ps/trunk/source/tools/atlas/GameInterface/Messages.h
+++ ps/trunk/source/tools/atlas/GameInterface/Messages.h
@@ -90,6 +90,7 @@
 		((int, button))
 		((bool, pressed))
 		((Position, pos))
+		((int, clicks))
 		);
 
 MESSAGE(GuiMouseMotionEvent,