IContextNode::GetSubNodes method

Gets the direct child nodes of the IContextNode object.

Syntax


HRESULT GetSubNodes(
  [out] IContextNodes **ppSubContextNodes
);

Parameters

ppSubContextNodes [out]

A collection of the IContextNode objects that are direct child nodes of this IContextNode.

Return value

For a description of the return values, see Classes and Interfaces - Ink Analysis.

Remarks

Caution  To avoid a memory leak, call IUnknown::Release on *ppSubContextNodes when you no longer need to use the collection of subnodes.
 

This returns only the direct child nodes, not all of the descendant nodes.

Examples

This example shows a method, ExploreContextNode, that examines an IContextNode. The method does the following:

  • Gets the context node's type.
  • Examines specific properties of the node type by calling a helper method, if the context node is an unclassified ink, analysis hint, or custom recognizer node.
  • Examines each subnode by calling itself, if the node has subnodes.
  • Examines the stroke data for the node by calling a helper method, if the node is an ink leaf node.

HRESULT CMyClass::ExploreContextNode(
    IContextNode *pContextNode)
{
    // Check for certain types of context nodes.
    GUID ContextNodeType;
    HRESULT hr = pContextNode->GetType(&ContextNodeType);

    if (SUCCEEDED(hr))
    {
        if (IsEqualGUID(GUID_CNT_UNCLASSIFIEDINK, ContextNodeType))
        {
            // Call a helper method that explores unclassified ink nodes.
            hr = this->ExploreUnclassifiedInkNode(pContextNode);
        }
        else if (IsEqualGUID(GUID_CNT_ANALYSISHINT, ContextNodeType))
        {
            // Call a helper method that explores analysis hint nodes.
            hr = this->ExploreAnalysisHintNode(pContextNode);
        }
        else if (IsEqualGUID(GUID_CNT_CUSTOMRECOGNIZER, ContextNodeType))
        {
            // Call a helper method that explores custom recognizer nodes.
            hr = this->ExploreCustomRecognizerNode(pContextNode);
        }

        if (SUCCEEDED(hr))
        {
            // Check if this node is a branch or a leaf node.
            IContextNodes *pSubNodes = NULL;
            hr = pContextNode->GetSubNodes(&pSubNodes);

            if (SUCCEEDED(hr))
            {
                ULONG ulSubNodeCount;
                hr = pSubNodes->GetCount(&ulSubNodeCount);

                if (SUCCEEDED(hr))
                {
                    if (ulSubNodeCount > 0)
                    {
                        // This node has child nodes; explore each child node.
                        IContextNode *pSubNode = NULL;
                        for (ULONG index=0; index<ulSubNodeCount; index++)
                        {
                            hr = pSubNodes->GetContextNode(index, &pSubNode);

                            if (SUCCEEDED(hr))
                            {
                                // Recursive call to explore the child node of this
                                // context node.
                                hr = this->ExploreContextNode(pSubNode);
                            }

                            // Release this reference to the child context node.
                            if (pSubNode != NULL)
                            {
                                pSubNode->Release();
                                pSubNode = NULL;
                            }

                            if (FAILED(hr))
                            {
                                break;
                            }
                        }
                    }
                    else
                    {
                        // This is a leaf node. Check if it contains stroke data.
                        ULONG ulStrokeCount;
                        hr = pContextNode->GetStrokeCount(&ulStrokeCount);

                        if (SUCCEEDED(hr))
                        {
                            if (ulStrokeCount > 0)
                            {
                                // This node is an ink leaf node; call helper
                                // method that explores available stroke data.
                                hr = this->ExploreNodeStrokeData(pContextNode);
                            }
                        }
                    }
                }
            }

            // Release this reference to the subnodes collection.
            if (pSubNodes != NULL)
            {
                pSubNodes->Release();
                pSubNodes = NULL;
            }
        }
    }

    return hr;
}


Requirements

Minimum supported client

Windows XP Tablet PC Edition [desktop apps only]

Minimum supported server

None supported

Header

IACom.h (also requires IACom_i.c)

DLL

IACom.dll

See also

IContextNode
IContextNode::GetParentNode
Ink Analysis Reference

 

 

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