/// <summary>
/// Searches for a subrange of text that has the specified attribute.
/// To search the entire document use the text pattern's document range.
/// </summary>
/// <param name="attribute">The attribute to search for.</param>
/// <param name="value">The value of the specified attribute to search for. The value must be of the exact type specified for the
/// attribute. For example when searching for font size you must specify the size in points as a double.
/// If you specify the point size as an integer then you will never get any matches due to the differing types.</param>
/// <param name="backward">true if the last occurring range should be returned instead of the first.</param>
/// <returns>A subrange with the specified attribute, or null if no such subrange exists.</returns>
public TextPatternRange FindAttribute(AutomationTextAttribute attribute, object value, bool backward)
{
Misc.ValidateArgumentNonNull(attribute, "attribute");
Misc.ValidateArgumentNonNull(value, "value"); // no text attributes can have null as a valid value
// Check that attribute value is of expected type...
AutomationAttributeInfo ai;
if (!Schema.GetAttributeInfo(attribute, out ai))
{
throw new ArgumentException(SR.Get(SRID.UnsupportedAttribute));
}
if (value.GetType() != ai.Type)
{
throw new ArgumentException(SR.Get(SRID.TextAttributeValueWrongType, attribute, ai.Type.Name, value.GetType().Name), "value");
}
// note: if we implement attributes whose values are logical elements, patterns,
// or ranges then we'll need to unwrap the objects here before passing them on to
// the provider.
if (attribute == TextPattern.CultureAttribute)
{
if (value is CultureInfo)
{
value = ((CultureInfo)value).LCID;
}
}
SafeTextRangeHandle hResultTextRange = UiaCoreApi.TextRange_FindAttribute(_hTextRange, attribute.Id, value, backward);
return(Wrap(hResultTextRange, _pattern));
}
internal static TextPatternRange Wrap(SafeTextRangeHandle hTextRange, TextPattern pattern)
{
if (hTextRange.IsInvalid)
{
return(null);
}
return(new TextPatternRange(hTextRange, pattern));
}
//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
#region Constructors
internal TextPatternRange(SafeTextRangeHandle hTextRange, TextPattern pattern)
{
Debug.Assert(!hTextRange.IsInvalid);
Debug.Assert(pattern != null);
_hTextRange = hTextRange;
_pattern = pattern;
}
internal static TextPatternRange Wrap(SafeTextRangeHandle hTextRange, TextPattern pattern)
{
if (hTextRange.IsInvalid)
{
return null;
}
return new TextPatternRange(hTextRange, pattern);
}
//------------------------------------------------------
//
// Constructors
//
//------------------------------------------------------
#region Constructors
internal TextPatternRange(SafeTextRangeHandle hTextRange, TextPattern pattern)
{
Debug.Assert(!hTextRange.IsInvalid);
Debug.Assert(pattern != null);
_hTextRange = hTextRange;
_pattern = pattern;
}
/// <summary>
/// Searches for an occurrence of text within the range.
/// </summary>
/// <param name="text">The text to search for.</param>
/// <param name="backward">true if the last occurring range should be returned instead of the first.</param>
/// <param name="ignoreCase">true if case should be ignored for the purposes of comparison.</param>
/// <returns>A subrange with the specified text, or null if no such subrange exists.</returns>
public TextPatternRange FindText(string text, bool backward, bool ignoreCase)
{
// PerSharp/PreFast will flag this as warning 6507/56507: Prefer 'string.IsNullOrEmpty(text)' over checks for null and/or emptiness.
// A null string is not should throw an ArgumentNullException while an empty string should throw an ArgumentException.
// Therefore we can not use IsNullOrEmpty() here, suppress the warning.
Misc.ValidateArgumentNonNull(text, "text");
#pragma warning suppress 6507
Misc.ValidateArgument(text.Length != 0, SRID.TextMustNotBeNullOrEmpty);
SafeTextRangeHandle hResultTextRange = UiaCoreApi.TextRange_FindText(_hTextRange, text, backward, ignoreCase);
return(Wrap(hResultTextRange, _pattern));
}
//------------------------------------------------------
//
// Public Methods
//
//------------------------------------------------------
#region Public Methods
/// <summary>
/// Retrieves a new range covering an identical span of text. The new range can be manipulated independently from the original.
/// </summary>
/// <returns>The new range.</returns>
public TextPatternRange Clone()
{
SafeTextRangeHandle hResultTextRange = UiaCoreApi.TextRange_Clone(_hTextRange);
return(Wrap(hResultTextRange, _pattern));
}
internal static TextPatternRange [] Wrap(SafeTextRangeHandle [] hTextRanges, TextPattern pattern)
{
if (hTextRanges == null)
return null;
TextPatternRange[] ranges = new TextPatternRange[hTextRanges.Length];
for (int i = 0; i < hTextRanges.Length; i++)
{
// if invalid, leave as null
if (!hTextRanges[i].IsInvalid)
{
ranges[i] = new TextPatternRange(hTextRanges[i], pattern);
}
}
return ranges;
}