IContextNodes::GetContextNode method

Retrieves the IContextNode object at the specified index within this collection.

Syntax

HRESULT GetContextNode(
  [in]  ULONG        ulIndex,
  [out] IContextNode **ppContextNode
);

Parameters

ulIndex [in]

The zero-based index of the IContextNode object to get.

ppContextNode [out]

Pointer to the IContextNode referenced at the specified index.

Return value

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

Remarks

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

See also

IContextNodes

Ink Analysis Reference