ITfContext::TrackProperties method (msctf.h)

Article
10/13/2021

Obtains a special property that can enumerate multiple properties over multiple ranges.

Syntax

HRESULT TrackProperties(
  [in]  const GUID          **prgProp,
  [in]  ULONG               cProp,
  [in]  const GUID          **prgAppProp,
  [in]  ULONG               cAppProp,
  [out] ITfReadOnlyProperty **ppProperty
);

Parameters

[in] prgProp

Contains an array of property identifiers that specify the properties to track.

[in] cProp

Contains the number of property identifiers in the prgProp array.

[in] prgAppProp

Contains an array of application property identifiers that specify the application properties to track.

[in] cAppProp

Contains the number of application property identifiers in the prgAppProp array.

[out] ppProperty

Pointer to an ITfReadOnlyProperty interface pointer that receives the tracking property.

Return value

This method can return one of these values.

Value	Description
S_OK	The method was successful.
TF_E_DISCONNECTED	The context object is not on a document stack.
E_OUTOFMEMORY	A memory allocation failure occurred.
E_INVALIDARG	One or more parameters are invalid.

Remarks

This method is used to quickly identify ranges with consistent property values for multiple properties. While this method could be duplicated using only the ITfContext::GetProperty method, the TSF manager can accomplish this task more quickly.

The property obtained by this method is a VT_UNKNOWN type. This property can be used to obtain an IEnumTfPropertyValue enumerator by calling the QueryInterface method with IID_IEnumTfPropertyValue. This enumerator contains property values specified by prgProp and prgAppProp.

Examples


const GUID *rgGuids[2] = {  &GUID_PROP_COMPOSING,
                            &GUID_PROP_ATTRIBUTE };
HRESULT hr;
ITfReadOnlyProperty *pTrackProperty;
TF_SELECTION sel;
IEnumTfRanges *pEnumRanges;
ITfRange *pRangeValue;

// Get the tracking property. 
hr = pContext->TrackProperties(NULL, 0, rgGuids, 2, &pTrackProperty);

// Get the selection range. 
hr = pContext->GetSelection(ec, TF_DEFAULT_SELECTION, 1, &sel, &cFetched);

// Use the property from TrackProperties to get an enumeration of the ranges  
// within the selection range that have the same property values. 
hr = pTrackProperty->EnumRanges(ec, &pEnumRanges, sel.range);

// Enumerate the ranges of text. 
while(pEnumRanges->Next(1, &pRangeValue, NULL) == S_OK)
{
    VARIANT varTrackerValue;
    TF_PROPERTYVAL tfPropertyVal;
    IEnumTfPropertyValue *pEnumPropVal;

    // Get the values for this range of text. 
    hr = pTrackProperty->GetValue(ec, pRangeValue, &varTrackerValue);

    // Because pTrackProperties originates from TrackProperties, 
    // varTrackerValue can be identified as a VT_UNKNOWN/IEnumTfPropertyValue. 
    varTrackerValue.punkVal->QueryInterface(    IID_IEnumTfPropertyValue,
                                                (void **)&pEnumPropVal);

    while(pEnumPropVal->Next(1, &tfPropertyVal, NULL) == S_OK)
    {
        BOOL fComposingValue;
        TfGuidAtom gaDispAttrValue;
        
        // Is this the composition property? 
        if (IsEqualGUID(tfPropertyVal.guidId, GUID_PROP_COMPOSING))
        {
            fComposingValue = (BOOL)tfPropertyVal.varValue.lVal;
        }
        // Or is this the attribute property? 
        else if (IsEqualGUID(tfPropertyVal.guidId, GUID_PROP_ATTRIBUTE))
        {
            gaDispAttrValue = (TfGuidAtom)tfPropertyVal.varValue.lVal;
        }
        
        // Clear the property. 
        VariantClear(&tfPropertyVal.varValue);
    }

    // Clear the tracker property. 
    VariantClear(&varTrackerValue);

    // Release the property enumerator. 
    pEnumPropVal->Release();

    // Release the range. 
    pRangeValue->Release();
}

// Release the selection range. 
sel.range->Release();

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps \| UWP apps]
Minimum supported server	Windows 2000 Server [desktop apps \| UWP apps]
Target Platform	Windows
Header	msctf.h
DLL	Msctf.dll
Redistributable	TSF 1.0 on Windows 2000 Professional

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