Add: AI functions to set/get vehicle group parent.

src/script/api/ai/ai_group.hpp.sq

@@ -31,6 +31,8 @@ void SQAIGroup_Register(Squirrel *engine)
 	SQAIGroup.DefSQStaticMethod(engine, &ScriptGroup::GetVehicleType,              "GetVehicleType",              2, ".i");
 	SQAIGroup.DefSQStaticMethod(engine, &ScriptGroup::SetName,                     "SetName",                     3, ".i.");
 	SQAIGroup.DefSQStaticMethod(engine, &ScriptGroup::GetName,                     "GetName",                     2, ".i");
+	SQAIGroup.DefSQStaticMethod(engine, &ScriptGroup::SetParent,                   "SetParent",                   3, ".ii");
+	SQAIGroup.DefSQStaticMethod(engine, &ScriptGroup::GetParent,                   "GetParent",                   2, ".i");
 	SQAIGroup.DefSQStaticMethod(engine, &ScriptGroup::EnableAutoReplaceProtection, "EnableAutoReplaceProtection", 3, ".ib");
 	SQAIGroup.DefSQStaticMethod(engine, &ScriptGroup::GetAutoReplaceProtection,    "GetAutoReplaceProtection",    2, ".i");
 	SQAIGroup.DefSQStaticMethod(engine, &ScriptGroup::GetNumEngines,               "GetNumEngines",               3, ".ii");

src/script/api/ai_changelog.hpp

@@ -20,6 +20,8 @@
  * 1.9.0 is not yet released. The following changes are not set in stone yet.
  * API additions:
  * \li AIAirport::GetMonthlyMaintenanceCost
+ * \li AIGroup::SetParent
+ * \li AIGroup::GetParent
  *
  * Other changes:
  * \li AIBridge::GetName takes one extra parameter to refer the vehicle type

src/script/api/script_group.cpp

@@ -70,6 +70,22 @@
 	return GetString(STR_GROUP_NAME);
 }
 
+/* static */ bool ScriptGroup::SetParent(GroupID group_id, GroupID parent_group_id)
+{
+	EnforcePrecondition(false, IsValidGroup(group_id));
+	EnforcePrecondition(false, IsValidGroup(parent_group_id));
+
+	return ScriptObject::DoCommand(0, group_id | 1 << 16, parent_group_id, CMD_ALTER_GROUP);
+}
+
+/* static */ ScriptGroup::GroupID ScriptGroup::GetParent(GroupID group_id)
+{
+	EnforcePrecondition((ScriptGroup::GroupID)INVALID_GROUP, IsValidGroup(group_id));
+
+	const Group *g = ::Group::GetIfValid(group_id);
+	return (ScriptGroup::GroupID)g->parent;
+}
+
 /* static */ bool ScriptGroup::EnableAutoReplaceProtection(GroupID group_id, bool enable)
 {
 	EnforcePrecondition(false, IsValidGroup(group_id));

src/script/api/script_group.hpp

@@ -84,6 +84,24 @@ public:
 	 */
 	static char *GetName(GroupID group_id);
 
+	/**
+	 * Set parent group of a group.
+	 * @param group_id The group to set the parent for.
+	 * @param parent_group_id The parent group to set.
+	 * @pre IsValidGroup(group_id).
+	 * @pre IsValidGroup(parent_group_id).
+	 * @return True if and only if the parent group was changed.
+	 */
+	static bool SetParent(GroupID group_id, GroupID parent_group_id);
+
+	/**
+	 * Get parent group of a group.
+	 * @param group_id The group to get the parent of.
+	 * @pre IsValidGroup(group_id).
+	 * @return The group id of the parent group.
+	 */
+	static GroupID GetParent(GroupID group_id);
+
 	/**
 	 * Enable or disable autoreplace protected. If the protection is
 	 *  enabled, global autoreplace won't affect vehicles in this group.