/// <summary>
/// Searches for custom commands in the specified range of glyphs and allows them to be evaluated
/// with the specified evaluator function.
/// </summary>
/// <param name="startGlyph">The index of the first glyph to consider.</param>
/// <param name="glyphCount">The number of glyphs to consider.</param>
/// <param name="state">A state object to pass to the evaluator.</param>
/// <param name="evaluator">The function with which to evaluate custom commands.</param>
/// <remarks>
/// This method will return custom commands which fall immediately after the last glyph in the
/// specified range, but not commands which fall immediately before that range, unless the range
/// starts at the beginning of the text.
/// </remarks>
public void GetCustomCommands(Int32 startGlyph, Int32 glyphCount, Object state, TextLayoutCommandEvaluator evaluator)
{
Contract.EnsureRange(startGlyph >= 0, nameof(startGlyph));
Contract.Require(evaluator, nameof(evaluator));
var glyphsSeen = 0;
var glyphsMax = (glyphCount == Int32.MaxValue) ? Int32.MaxValue : startGlyph + glyphCount;
var acquiredPointers = !HasAcquiredPointers;
if (acquiredPointers)
{
AcquirePointers();
}
Seek(0);
while (StreamPositionInObjects < Count)
{
var cmdType = *(TextLayoutCommandType *)Data;
switch (cmdType)
{
case TextLayoutCommandType.Text:
{
var cmd = (TextLayoutTextCommand *)Data;
glyphsSeen += cmd->TextLength;
}
break;
case TextLayoutCommandType.Icon:
{
glyphsSeen++;
}
break;
case TextLayoutCommandType.LineBreak:
{
var cmd = (TextLayoutLineBreakCommand *)Data;
if (cmd->Length > 0)
{
glyphsSeen += cmd->Length;
}
}
break;
case TextLayoutCommandType.Custom:
{
if (glyphsSeen > startGlyph || startGlyph == 0)
{
var cmd = (TextLayoutCustomCommand *)Data;
evaluator(state, glyphsSeen, *cmd);
}
}
break;
}
if (glyphsSeen > glyphsMax)
{
break;
}
SeekNextCommand();
}
if (acquiredPointers)
{
ReleasePointers();
}
}
/// <summary>
/// Searches for custom commands in the specified range of glyphs and allows them to be evaluated
/// with the specified evaluator function.
/// </summary>
/// <param name="startGlyph">The index of the first glyph to consider.</param>
/// <param name="glyphCount">The number of glyphs to consider.</param>
/// <param name="state">A state object to pass to the evaluator.</param>
/// <param name="evaluator">The function with which to evaluate custom commands.</param>
/// <remarks>
/// This method will return custom commands which fall immediately after the last glyph in the
/// specified range, but not commands which fall immediately before that range, unless the range
/// starts at the beginning of the text.
/// </remarks>
public void GetCustomCommands(Int32 startGlyph, Int32 glyphCount, Object state, TextLayoutCommandEvaluator evaluator)
{
Contract.EnsureRange(startGlyph >= 0, nameof(startGlyph));
Contract.Require(evaluator, nameof(evaluator));
var terminateOnNextNonCommandToken = false;
var glyphsSeen = 0;
var glyphsMax = (glyphCount == Int32.MaxValue) ? Int32.MaxValue : startGlyph + glyphCount;
var acquiredPointers = !HasAcquiredPointers;
if (acquiredPointers)
AcquirePointers();
Seek(0);
while (StreamPositionInObjects < Count)
{
var cmdType = *(TextLayoutCommandType*)Data;
if (cmdType != TextLayoutCommandType.Custom && terminateOnNextNonCommandToken)
break;
switch (cmdType)
{
case TextLayoutCommandType.Text:
{
var cmd = (TextLayoutTextCommand*)Data;
glyphsSeen += cmd->TextLength;
}
break;
case TextLayoutCommandType.Icon:
{
glyphsSeen++;
}
break;
case TextLayoutCommandType.LineBreak:
{
var cmd = (TextLayoutLineBreakCommand*)Data;
if (cmd->Length > 0)
{
glyphsSeen += cmd->Length;
}
}
break;
case TextLayoutCommandType.Custom:
{
if (glyphsSeen > startGlyph || startGlyph == 0)
{
var cmd = (TextLayoutCustomCommand*)Data;
if (!evaluator(state, glyphsSeen, *cmd))
terminateOnNextNonCommandToken = true;
}
}
break;
}
if (glyphsSeen > glyphsMax)
break;
SeekNextCommand();
}
if (acquiredPointers)
ReleasePointers();
}
/// <summary>
/// Searches for custom commands in stream and allows them to be evaluated
/// with the specified evaluator function.
/// </summary>
/// <param name="state">A state object to pass to the evaluator.</param>
/// <param name="evaluator">The function with which to evaluate custom commands.</param>
public void GetCustomCommands(Object state, TextLayoutCommandEvaluator evaluator)
{
GetCustomCommands(0, Int32.MaxValue, state, evaluator);
}
/// <summary>
/// Searches for custom commands in stream and allows them to be evaluated
/// with the specified evaluator function.
/// </summary>
/// <param name="state">A state object to pass to the evaluator.</param>
/// <param name="evaluator">The function with which to evaluate custom commands.</param>
public void GetCustomCommands(Object state, TextLayoutCommandEvaluator evaluator)
{
GetCustomCommands(0, Int32.MaxValue, state, evaluator);
}