protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
if (View == null)
{
SetMeasuredDimension(0, 0);
return;
}
if (!View.IsVisible)
{
View.Measure(0, 0);
SetMeasuredDimension(0, 0);
return;
}
var width = MeasureSpecFactory.GetSize(widthMeasureSpec);
var height = MeasureSpecFactory.GetSize(heightMeasureSpec);
var measureWidth = width > 0 ? Context.FromPixels(width) : double.PositiveInfinity;
var measureHeight = height > 0 ? Context.FromPixels(height) : double.PositiveInfinity;
_shellViewRenderer.LayoutView(measureWidth, measureHeight);
SetMeasuredDimension((MatchWidth && width != 0) ? width : (int)Context.ToPixels(View.Width),
(MatchHeight && height != 0) ? height : (int)Context.ToPixels(View.Height));
}
protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
base.OnMeasure(widthMeasureSpec, heightMeasureSpec);
var measureWidth = MeasureSpecFactory.GetSize(widthMeasureSpec);
var measureHeight = MeasureSpecFactory.GetSize(heightMeasureSpec);
SetMeasuredDimension(measureWidth, (int)Context.ToPixels(35));
}
public override SizeRequest GetDesiredSize(int widthConstraint, int heightConstraint)
{
if (_lastSizeRequest.HasValue)
{
// if we are measuring the same thing, no need to waste the time
bool canRecycleLast = widthConstraint == _lastConstraintWidth && heightConstraint == _lastConstraintHeight;
if (!canRecycleLast)
{
// if the last time we measured the returned size was all around smaller than the passed constraint
// and the constraint is bigger than the last size request, we can assume the newly measured size request
// will not change either.
int lastConstraintWidthSize = MeasureSpecFactory.GetSize(_lastConstraintWidth);
int lastConstraintHeightSize = MeasureSpecFactory.GetSize(_lastConstraintHeight);
int currentConstraintWidthSize = MeasureSpecFactory.GetSize(widthConstraint);
int currentConstraintHeightSize = MeasureSpecFactory.GetSize(heightConstraint);
bool lastWasSmallerThanConstraints = _lastSizeRequest.Value.Request.Width < lastConstraintWidthSize && _lastSizeRequest.Value.Request.Height < lastConstraintHeightSize;
bool currentConstraintsBiggerThanLastRequest = currentConstraintWidthSize >= _lastSizeRequest.Value.Request.Width && currentConstraintHeightSize >= _lastSizeRequest.Value.Request.Height;
canRecycleLast = lastWasSmallerThanConstraints && currentConstraintsBiggerThanLastRequest;
}
if (canRecycleLast)
{
return(_lastSizeRequest.Value);
}
}
//We need to clear the Hint or else it will interfere with the sizing of the Label
var hint = Control.Hint;
if (!string.IsNullOrEmpty(hint))
{
Control.Hint = string.Empty;
}
SizeRequest result = base.GetDesiredSize(widthConstraint, heightConstraint);
//Set Hint back after sizing
Control.Hint = hint;
result.Minimum = new Size(Math.Min(Context.ToPixels(10), result.Request.Width), result.Request.Height);
_lastConstraintWidth = widthConstraint;
_lastConstraintHeight = heightConstraint;
_lastSizeRequest = result;
return(result);
}
protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
SetMeasuredDimension(MeasureSpec.GetSize(widthMeasureSpec), MeasureSpec.GetSize(heightMeasureSpec));
var width = MeasureSpecFactory.GetSize(widthMeasureSpec);
var height = MeasureSpecFactory.GetSize(heightMeasureSpec);
for (int i = 0; i < ChildCount; i++)
{
var child = GetChildAt(i);
child.Measure(MeasureSpecFactory.MakeMeasureSpec(width, MeasureSpecMode.Exactly),
MeasureSpecFactory.MakeMeasureSpec(height, MeasureSpecMode.Exactly));
}
}
public void LayoutView(double width, double height)
{
_width = width;
_height = height;
Context context;
if (_renderer == null || !(_context.TryGetTarget(out context)) || !_renderer.View.IsAlive())
{
return;
}
if (View == null)
{
var empty = MeasureSpecFactory.GetSize(0);
_renderer.View.Measure(empty, empty);
return;
}
var request = View.Measure(width, height, MeasureFlags.None);
var layoutParams = NativeView.LayoutParameters;
if (height == -1)
{
height = request.Request.Height;
}
if (width == -1)
{
width = request.Request.Width;
}
if (layoutParams.Width != LP.MatchParent)
{
layoutParams.Width = (int)context.ToPixels(width);
}
if (layoutParams.Height != LP.MatchParent)
{
layoutParams.Height = (int)context.ToPixels(height);
}
NativeView.LayoutParameters = layoutParams;
View.Layout(new Rectangle(0, 0, width, height));
_renderer.UpdateLayout();
}
protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
if (View == null)
{
SetMeasuredDimension(0, 0);
return;
}
// chain on down
_renderer.View.Measure(widthMeasureSpec, heightMeasureSpec);
var width = MeasureSpecFactory.GetSize(widthMeasureSpec);
var height = MeasureSpecFactory.GetSize(heightMeasureSpec);
var measureWidth = width > 0 ? _context.FromPixels(width) : double.PositiveInfinity;
var measureHeight = height > 0 ? _context.FromPixels(height) : double.PositiveInfinity;
var sizeReq = View.Measure(measureWidth, measureHeight);
SetMeasuredDimension((MatchWidth && width != 0) ? width : (int)_context.ToPixels(sizeReq.Request.Width),
(MatchHeight && height != 0) ? height : (int)_context.ToPixels(sizeReq.Request.Height));
}
protected override void OnMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
if (_child?.Element == null)
{
SetMeasuredDimension(0, 0);
return;
}
VisualElement element = _child.Element;
Context ctx = Context;
var width = (int)ctx.FromPixels(MeasureSpecFactory.GetSize(widthMeasureSpec));
SizeRequest request = element.Measure(width, double.PositiveInfinity, MeasureFlags.IncludeMargins);
Xamarin.Forms.Layout.LayoutChildIntoBoundingRegion(element, new Rectangle(0, 0, width, request.Request.Height));
int widthSpec = MeasureSpecFactory.MakeMeasureSpec((int)ctx.ToPixels(width), MeasureSpecMode.Exactly);
int heightSpec = MeasureSpecFactory.MakeMeasureSpec((int)ctx.ToPixels(request.Request.Height), MeasureSpecMode.Exactly);
_child.View.Measure(widthMeasureSpec, heightMeasureSpec);
SetMeasuredDimension(widthSpec, heightSpec);
}
public void LayoutView(double x, double y, double width, double height, double?maxWidth = null, double?maxHeight = null)
{
if (width == -1)
{
width = double.PositiveInfinity;
}
if (height == -1)
{
height = double.PositiveInfinity;
}
Width = width;
Height = height;
MaxWidth = maxWidth;
MaxHeight = maxHeight;
X = x;
Y = y;
Context context;
if (Renderer == null || !(_context.TryGetTarget(out context)) || !Renderer.View.IsAlive())
{
return;
}
if (View == null)
{
var empty = MeasureSpecFactory.GetSize(0);
Renderer.View.Measure(empty, empty);
return;
}
var request = View.Measure(width, height, MeasureFlags.None);
var layoutParams = NativeView.LayoutParameters;
if (double.IsInfinity(height))
{
height = request.Request.Height;
}
if (double.IsInfinity(width))
{
width = request.Request.Width;
}
if (height > maxHeight)
{
height = maxHeight.Value;
}
if (width > maxWidth)
{
width = maxWidth.Value;
}
if (layoutParams.Width != LP.MatchParent)
{
layoutParams.Width = (int)context.ToPixels(width);
}
if (layoutParams.Height != LP.MatchParent)
{
layoutParams.Height = (int)context.ToPixels(height);
}
NativeView.LayoutParameters = layoutParams;
View.Layout(new Rectangle(x, y, width, height));
Renderer.UpdateLayout();
}
