From 37e321044a1c32873980fc6d75c45011639ca2f3 Mon Sep 17 00:00:00 2001
From: michi_cc <michi_cc@openttd.org>
Date: Tue, 17 Apr 2012 19:44:16 +0000
Subject: [PATCH] (svn r24139) -Add: Creating a new vehicle group by drag and
 drop. (Based on patch by Juanjo)

---
 src/command_func.h              |  1 +
 src/group_cmd.cpp               | 10 +++++++++-
 src/group_gui.cpp               | 19 +++++++++++++++++--
 src/group_type.h                |  1 +
 src/network/network_command.cpp |  1 +
 5 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/src/command_func.h b/src/command_func.h
index df5f099a7b..c4cc51e3da 100644
--- a/src/command_func.h
+++ b/src/command_func.h
@@ -91,6 +91,7 @@ CommandCallback CcGame;
 
 /* group_gui.cpp */
 CommandCallback CcCreateGroup;
+CommandCallback CcAddVehicleNewGroup;
 
 /* industry_gui.cpp */
 CommandCallback CcBuildIndustry;
diff --git a/src/group_cmd.cpp b/src/group_cmd.cpp
index a3587abbfe..ca671e6800 100644
--- a/src/group_cmd.cpp
+++ b/src/group_cmd.cpp
@@ -429,7 +429,7 @@ CommandCost CmdAddVehicleGroup(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 	Vehicle *v = Vehicle::GetIfValid(GB(p2, 0, 20));
 	GroupID new_g = p1;
 
-	if (v == NULL || (!Group::IsValidID(new_g) && !IsDefaultGroupID(new_g))) return CMD_ERROR;
+	if (v == NULL || (!Group::IsValidID(new_g) && !IsDefaultGroupID(new_g) && new_g != NEW_GROUP)) return CMD_ERROR;
 
 	if (Group::IsValidID(new_g)) {
 		Group *g = Group::Get(new_g);
@@ -438,6 +438,14 @@ CommandCost CmdAddVehicleGroup(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 
 	if (v->owner != _current_company || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
+	if (new_g == NEW_GROUP) {
+		/* Create new group. */
+		CommandCost ret = CmdCreateGroup(0, flags, v->type, 0, NULL);
+		if (ret.Failed()) return ret;
+
+		new_g = _new_group_id;
+	}
+
 	if (flags & DC_EXEC) {
 		AddVehicleToGroup(v, new_g);
 
diff --git a/src/group_gui.cpp b/src/group_gui.cpp
index 0c7a412c7d..c68d4405ff 100644
--- a/src/group_gui.cpp
+++ b/src/group_gui.cpp
@@ -646,9 +646,9 @@ public:
 				this->SetDirty();
 
 				uint id_g = this->group_sb->GetScrolledRowFromWidget(pt.y, this, WID_GL_LIST_GROUP, 0, this->tiny_step_height);
-				if (id_g >= this->groups.Length()) return;
+				GroupID new_g = id_g >= this->groups.Length() ? NEW_GROUP : this->groups[id_g]->index;
 
-				DoCommandP(0, this->groups[id_g]->index, vindex | (_ctrl_pressed ? 1 << 31 : 0), CMD_ADD_VEHICLE_GROUP | CMD_MSG(STR_ERROR_GROUP_CAN_T_ADD_VEHICLE));
+				DoCommandP(0, new_g, vindex | (_ctrl_pressed ? 1 << 31 : 0), CMD_ADD_VEHICLE_GROUP | CMD_MSG(STR_ERROR_GROUP_CAN_T_ADD_VEHICLE), new_g == NEW_GROUP ? CcAddVehicleNewGroup : NULL);
 				break;
 			}
 
@@ -864,6 +864,21 @@ void CcCreateGroup(const CommandCost &result, TileIndex tile, uint32 p1, uint32
 	if (w != NULL) w->ShowRenameGroupWindow(_new_group_id, true);
 }
 
+/**
+ * Open rename window after adding a vehicle to a new group via drag and drop.
+ * @param success Did command succeed?
+ * @param tile Unused.
+ * @param p1 Unused.
+ * @param p2 Bit 0-19: Vehicle ID.
+ */
+void CcAddVehicleNewGroup(const CommandCost &result, TileIndex tile, uint32 p1, uint32 p2)
+{
+	if (result.Failed()) return;
+	assert(Vehicle::IsValidID(GB(p2, 0, 20)));
+
+	CcCreateGroup(result, 0, Vehicle::Get(GB(p2, 0, 20))->type, 0);
+}
+
 /**
  * Removes the highlight of a vehicle in a group window
  * @param *v Vehicle to remove all highlights from
diff --git a/src/group_type.h b/src/group_type.h
index ef93e91d99..530f31f1ea 100644
--- a/src/group_type.h
+++ b/src/group_type.h
@@ -14,6 +14,7 @@
 
 typedef uint16 GroupID; ///< Type for all group identifiers.
 
+static const GroupID NEW_GROUP     = 0xFFFC; ///< Sentinel for a to-be-created group.
 static const GroupID ALL_GROUP     = 0xFFFD; ///< All vehicles are in this group.
 static const GroupID DEFAULT_GROUP = 0xFFFE; ///< Ungrouped vehicles are in this group.
 static const GroupID INVALID_GROUP = 0xFFFF; ///< Sentinel for invalid groups.
diff --git a/src/network/network_command.cpp b/src/network/network_command.cpp
index 41f853f15d..6cf96c9f58 100644
--- a/src/network/network_command.cpp
+++ b/src/network/network_command.cpp
@@ -48,6 +48,7 @@ static CommandCallback * const _callback_table[] = {
 	/* 0x18 */ CcBuildIndustry,
 	/* 0x19 */ CcStartStopVehicle,
 	/* 0x1A */ CcGame,
+	/* 0x1B */ CcAddVehicleNewGroup,
 };
 
 /**