LINK

Definition

LINK [id]
{
  [Common flags]
  [ACCEPT idlist;]
  [REFUSE idlist;]
}

Description

Represents BaseLink objects in a container. Rendered as a link box (LinkBoxGui) to which the user can drag objects.
Provides a smart link to node objects. Specify what kinds of nodes are accepted and/or refused for this field with ACCEPT and/or REFUSE.

Further specify what objects are accepted by listening for MSG_DESCRIPTION_CHECKDRAGANDDROP in NodeData::Message() and returning true of false depending on the DescriptionCheckDragAndDrop data:

SplineRailObject::Message(GeListNode *node, Int32 type, void *data)
{
  ...
  if (type==MSG_DESCRIPTION_CHECKDRAGANDDROP)
  {
    DescriptionCheckDragAndDrop *dcu = static_cast<DescriptionCheckDragAndDrop*>(data);
    switch (dcu->id[0].id)
    {
      case SPLINERAILOBJECT_SPLINE1:
      case SPLINERAILOBJECT_SPLINE2:
      case SPLINERAILOBJECT_SPLINE3:
      case SPLINERAILOBJECT_SPLINE4:
      dcu->result = dcu->element->GetInfo() & OBJECT_SPLINE;
        return true;
      }
  }
}

In a dialog listen for MSG_DESCRIPTION_CHECKDRAGANDDROP instead in GeDialog::Message() with the following message container IDs:

Container ID	Type	Description
LINKBOX_ACCEPT_MESSAGE_TYPE	Int32	The type of the item dragged in the link box.
LINKBOX_ACCEPT_MESSAGE_ELEMENT	void*	A pointer (BaseList2D*) to the dragged object.
LINKBOX_ACCEPT_MESSAGE_ACCEPT	void*	A pointer to a boolean value. Set this value to true to accept the object.
LINKBOX_ACCEPT_MESSAGE_CONTROL_ID	Int32	The ID of the control that sent the message.

Flags

ACCEPT idlist;	The node types to accept, separated with semi-colons.
REFUSE idlist;	The node types to refuse, separated with semi-colons.

Example

LINK NO_SKY_OR_FOREGROUND_LINK
{
  ACCEPT { Obase; }
  REFUSE { Osky; Oforeground; }
}

Further Reading

• GUI & User Interaction
• Resource Files Manual
• Description Resource