Implementing a Tree Representation Model

Graphic Classes

Our tree representation is implemented by two graphic classes, TreeGadget and TreeGadgetItem.

TreeGadget

The class TreeGadget defines a gadget that displays the label of the tree root. This class provides the following methods:

• a constructor that takes the root label as its parameter;

• the function setLabel, which modifies the root label;

• the function addItem, which takes a label as its argument and creates a new item with this label in the tree;

• the function removeItem, which suppresses the item passed as its argument;

• the function setCallback, which allows a callback and data to be associated with a specific graphic event occurring on the tree gadget.

Below is the synopsis of the class TreeGadget:

class TreeGadget

{

public:

TreeGadget(const char* label);

void setLabel(IlsString label);

TreeGadgetItem* addItem(const char* itemLabel);

void removeItem(TreeGadgetItem&);

void setCallback(GraphicEvent&,Callback,CallbackData);

};

TreeGadgetItem

The class TreeGadgetItem implements an item in the tree. It can also be attached to other sub-items. Its API is similar to the TreeGadget API.

Note that the classes TreeGadget and TreeGadgetItem are implemented independently from any server classes.