/*
* Purely invalidating the layout as text is added to the TextBox will not cause it to expand.
* If the TextBox is set to WordWrap and it is part of the layout it will refuse to Measure itself beyond its established width.
* Even giving it infinite constraints will cause it to always set its DesiredSize to the same width but with a vertical growth.
* The only way I was able to grow it was by setting layout renderers width explicitly to some value but then it just set its own Width to that Width which is not helpful.
* Even vertically it would measure oddly in cases of rapid text changes.
* Holding down the backspace key or enter key would cause the final result to be not quite right.
* Both of these issues were fixed by just creating a static TextBox that is not part of the layout which let me just measure
* the size of the text as it would fit into the TextBox unconstrained and then just return that Size from the GetDesiredSize call.
* */
Size GetCopyOfSize(FormsTextBox control, global::Windows.Foundation.Size constraint)
{
if (_copyOfTextBox == null)
{
_copyOfTextBox = CreateTextBox();
// This causes the copy to be initially setup correctly.
// I found that if the first measure of this copy occurs with Text then it will just keep defaulting to a measure with no text.
_copyOfTextBox.Measure(_zeroSize);
}
_copyOfTextBox.Text = control.Text;
_copyOfTextBox.FontSize = control.FontSize;
_copyOfTextBox.FontFamily = control.FontFamily;
_copyOfTextBox.FontStretch = control.FontStretch;
_copyOfTextBox.FontStyle = control.FontStyle;
_copyOfTextBox.FontWeight = control.FontWeight;
_copyOfTextBox.Margin = control.Margin;
_copyOfTextBox.Padding = control.Padding;
// have to reset the measure to zero before it will re-measure itself
_copyOfTextBox.Measure(_zeroSize);
_copyOfTextBox.Measure(constraint);
Size result = new Size
(
Math.Ceiling(_copyOfTextBox.DesiredSize.Width),
Math.Ceiling(_copyOfTextBox.DesiredSize.Height)
);
return(result);
}
SizeRequest CalculateDesiredSizes(FormsTextBox control, global::Windows.Foundation.Size constraint, EditorAutoSizeOption sizeOption)
{
if (sizeOption == EditorAutoSizeOption.TextChanges)
{
Size result = GetCopyOfSize(control, constraint);
control.Measure(constraint);
return(new SizeRequest(result));
}
else
{
control.Measure(constraint);
Size result = new Size(Math.Ceiling(control.DesiredSize.Width), Math.Ceiling(control.DesiredSize.Height));
return(new SizeRequest(result));
}
}
public override SizeRequest GetDesiredSize(double widthConstraint, double heightConstraint)
{
if (Children.Count == 0 || Control == null)
{
return(new SizeRequest());
}
var constraint = new global::Windows.Foundation.Size(widthConstraint, heightConstraint);
FormsTextBox child = Control;
child.Measure(constraint);
var result = new Size(Math.Ceiling(child.DesiredSize.Width), Math.Ceiling(child.DesiredSize.Height));
return(new SizeRequest(result));
}
