CODEWITHSUNDEEP
c#design-patternsadapter
Rohan West
Rohan West

Reputation: 9298

Design pattern for abstracting existing objects

i want to create an abstract representation of an existing object. For this example i want to wrap the functionality of a System.Windows.Forms.TreeNode. I started by creating an adapter as follows...

Edit : The purpose of the abstraction will allow me to use the ITreeNodeAdapter in my application without knowing about the TreeNode, at a later stage I could implement a different ITreeNodeAdapter and the application would still work. I basically want to remove dependency on the TreeNode.

public interface ITreeNodeAdapter
{
    string Title {get;set;}
    void Add(ITreeNodeAdapter adapter);
}

public class TreeNodeAdapter : ITreeNodeAdapter
{    
    public AbstractTreeNode(TreeNode node)
    {
        this.Node = node;
    }

    private TreeNode Node {get;set;}

    public string Title
    {
        get { return _node.Text; }
        set { _node.Text = value; }
    }

    public void Add(ITreeNodeAdapter adapter)
    {
        // What should i do here?
        var treeNodeAdapter = adapter as TreeNodeAdapter;
        if(treeNodeAdapter != null)
        {
            this.Node.Nodes.Add(treeNodeAdapter.Node);
        }
    }
}

I am having problems with extending the class to accept child nodes... the approach i have used above doesn't feel very nice. Any idea how i could improve?

Upvotes: 0

Views: 169

Answers (2)

call me Steve
call me Steve

Reputation: 1727

You could use the Abstract factory pattern.

In case you might wonder it's not limited to new object, you can use it to existing objects.

Upvotes: 1

tster
tster

Reputation: 18237

  1. Change your interface name to ITreeNode or something like that. You are creating an abstraction with the interface. An adapter is what takes one implementation and makes it look like a desired abstraction

  2. Where are you having problems adding children? Add a method to the ITreeNode interface you defined and then implement it in the adapter.

Upvotes: 0

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