private static YogaSize MeasureText(ReactTextShadowNode textNode, YogaNode node, float width, YogaMeasureMode widthMode, float height, YogaMeasureMode heightMode)
{
// TODO: Measure text with DirectWrite or other API that does not
// require dispatcher access. Currently, we're instantiating a
// second CoreApplicationView (that is never activated) and using
// its Dispatcher thread to calculate layout.
var textBlock = new TextBlock
{
TextAlignment = TextAlignment.Left,
TextWrapping = TextWrapping.Wrap,
TextTrimming = TextTrimming.CharacterEllipsis,
};
textNode.UpdateTextBlockCore(textBlock, true);
for (var i = 0; i < textNode.ChildCount; ++i)
{
var child = textNode.GetChildAt(i);
textBlock.Inlines.Add(ReactInlineShadowNodeVisitor.Apply(child));
}
var normalizedWidth = YogaConstants.IsUndefined(width) ? double.PositiveInfinity : width;
var normalizedHeight = YogaConstants.IsUndefined(height) ? double.PositiveInfinity : height;
textBlock.Measure(new Size(normalizedWidth, normalizedHeight));
return(MeasureOutput.Make(
(float)Math.Ceiling(textBlock.DesiredSize.Width),
(float)Math.Ceiling(textBlock.DesiredSize.Height)));
}
private static MeasureOutput MeasureText(CSSNode node, float width, CSSMeasureMode widthMode, float height, CSSMeasureMode heightMode)
{
// This is not a terribly efficient way of projecting the height of
// the text elements. It requires that we have access to the
// dispatcher in order to do measurement, which, for obvious
// reasons, can cause perceived performance issues as it will block
// the UI thread from handling other work.
//
// TODO: determine another way to measure text elements.
var task = DispatcherHelpers.CallOnDispatcher(() =>
{
var textBlock = new TextBlock
{
TextAlignment = TextAlignment.Left,
TextTrimming = TextTrimming.CharacterEllipsis,
};
var textNode = (ReactTextShadowNode)node;
textNode.UpdateTextBlockCore(textBlock, true);
foreach (var child in textNode.Children)
{
textBlock.Inlines.Add(ReactInlineShadowNodeVisitor.Apply(child));
}
var normalizedWidth = CSSConstants.IsUndefined(width) ? double.PositiveInfinity : width;
var normalizedHeight = CSSConstants.IsUndefined(height) ? double.PositiveInfinity : height;
textBlock.Measure(new Size(normalizedWidth, normalizedHeight));
return(new MeasureOutput(
(float)textBlock.DesiredSize.Width,
(float)textBlock.DesiredSize.Height));
});
return(task.Result);
}
private static YogaSize MeasureText(ReactTextShadowNode textNode, YogaNode node, float width, YogaMeasureMode widthMode, float height, YogaMeasureMode heightMode)
{
// This is not a terribly efficient way of projecting the height of
// the text elements. It requires that we have access to the
// dispatcher in order to do measurement, which, for obvious
// reasons, can cause perceived performance issues as it will block
// the UI thread from handling other work.
//
// TODO: determine another way to measure text elements.
var task = DispatcherHelpers.CallOnDispatcher(() =>
{
var textBlock = new RichTextBlock
{
TextWrapping = TextWrapping.Wrap,
TextAlignment = TextAlignment.DetectFromContent,
TextTrimming = TextTrimming.CharacterEllipsis,
};
textNode.UpdateTextBlockCore(textBlock, true);
var block = new Paragraph();
for (var i = 0; i < textNode.ChildCount; ++i)
{
var child = textNode.GetChildAt(i);
block.Inlines.Add(ReactInlineShadowNodeVisitor.Apply(child));
}
textBlock.Blocks.Add(block);
var normalizedWidth = YogaConstants.IsUndefined(width) ? double.PositiveInfinity : width;
var normalizedHeight = YogaConstants.IsUndefined(height) ? double.PositiveInfinity : height;
textBlock.Measure(new Size(normalizedWidth, normalizedHeight));
return(MeasureOutput.Make(
(float)Math.Ceiling(textBlock.DesiredSize.Width),
(float)Math.Ceiling(textBlock.DesiredSize.Height)));
});
return(task.Result);
}
