public void Add(View view, Expression <Func <Rectangle> > bounds)
{
if (bounds == null)
{
throw new ArgumentNullException(nameof(bounds));
}
SetBoundsConstraint(view, BoundsConstraint.FromExpression(bounds, fromExpression: true));
base.Add(view);
}
internal static BoundsConstraint FromExpression(Expression <Func <Rectangle> > expression, bool fromExpression, IEnumerable <View> parents = null)
{
Func <Rectangle> compiled = expression.Compile();
var result = new BoundsConstraint
{
_measureFunc = compiled,
RelativeTo = parents ?? ExpressionSearch.Default.FindObjects <View>(expression).ToArray(), // make sure we have our own copy
CreatedFromExpression = fromExpression
};
return(result);
}
static Rectangle SolveView(View view)
{
BoundsConstraint boundsConstraint = GetBoundsConstraint(view);
if (boundsConstraint == null)
{
throw new Exception("BoundsConstraint should not be null at this point");
}
var result = boundsConstraint.Compute();
return(result);
}
protected override void OnAdded(View view)
{
BoundsConstraint boundsConstraint = GetBoundsConstraint(view);
if (boundsConstraint == null || !boundsConstraint.CreatedFromExpression)
{
// user probably added the view through the strict Add method.
CreateBoundsFromConstraints(view, GetXConstraint(view), GetYConstraint(view), GetWidthConstraint(view), GetHeightConstraint(view));
}
_childrenInSolveOrder = null;
base.OnAdded(view);
}
bool CanSolveView(View view, Dictionary <View, bool> solveTable)
{
BoundsConstraint boundsConstraint = GetBoundsConstraint(view);
var parents = new List <View>();
if (boundsConstraint == null)
{
throw new Exception("BoundsConstraint should not be null at this point");
}
parents.AddRange(boundsConstraint.RelativeTo);
// expressions probably referenced the base layout somewhere
while (parents.Remove(this)) // because winphone does not have RemoveAll...
{
;
}
if (!parents.Any())
{
return(true);
}
for (var i = 0; i < parents.Count; i++)
{
View p = parents[i];
bool solvable;
if (!solveTable.TryGetValue(p, out solvable))
{
throw new InvalidOperationException("Views that have relationships to or from them must be kept in the RelativeLayout.");
}
if (!solvable)
{
return(false);
}
}
return(true);
}
public void Add(View view, Expression <Func <double> > x = null, Expression <Func <double> > y = null, Expression <Func <double> > width = null, Expression <Func <double> > height = null)
{
Func <double> xCompiled = x != null?x.Compile() : () => 0;
Func <double> yCompiled = y != null?y.Compile() : () => 0;
Func <double> widthCompiled = width != null?width.Compile() : () => view.Measure(Parent.Width, Parent.Height, MeasureFlags.IncludeMargins).Request.Width;
Func <double> heightCompiled = height != null?height.Compile() : () => view.Measure(Parent.Width, Parent.Height, MeasureFlags.IncludeMargins).Request.Height;
var parents = new List <View>();
parents.AddRange(ExpressionSearch.Default.FindObjects <View>(x));
parents.AddRange(ExpressionSearch.Default.FindObjects <View>(y));
parents.AddRange(ExpressionSearch.Default.FindObjects <View>(width));
parents.AddRange(ExpressionSearch.Default.FindObjects <View>(height));
BoundsConstraint bounds = BoundsConstraint.FromExpression(() => new Rectangle(xCompiled(), yCompiled(), widthCompiled(), heightCompiled()), fromExpression: true, parents: parents.Distinct().ToArray());
SetBoundsConstraint(view, bounds);
base.Add(view);
}
void CreateBoundsFromConstraints(View view, Constraint xConstraint, Constraint yConstraint, Constraint widthConstraint, Constraint heightConstraint)
{
var parents = new List <View>();
Func <double> x;
if (xConstraint != null)
{
x = () => xConstraint.Compute(this);
if (xConstraint.RelativeTo != null)
{
parents.AddRange(xConstraint.RelativeTo);
}
}
else
{
x = () => 0;
}
Func <double> y;
if (yConstraint != null)
{
y = () => yConstraint.Compute(this);
if (yConstraint.RelativeTo != null)
{
parents.AddRange(yConstraint.RelativeTo);
}
}
else
{
y = () => 0;
}
Func <double> width;
Func <double> height = null;
if (widthConstraint != null)
{
width = () => widthConstraint.Compute(this);
if (widthConstraint.RelativeTo != null)
{
parents.AddRange(widthConstraint.RelativeTo);
}
}
else
{
width = () => view.Measure(Width, heightConstraint != null ? height() : Height, MeasureFlags.IncludeMargins).Request.Width;
}
if (heightConstraint != null)
{
height = () => heightConstraint.Compute(this);
if (heightConstraint.RelativeTo != null)
{
parents.AddRange(heightConstraint.RelativeTo);
}
}
else
{
height = () => view.Measure(widthConstraint != null ? width() : Width, Height, MeasureFlags.IncludeMargins).Request.Height;
}
BoundsConstraint bounds = BoundsConstraint.FromExpression(() => new Rectangle(x(), y(), width(), height()), parents.Distinct().ToArray());
SetBoundsConstraint(view, bounds);
}
public static void SetBoundsConstraint(BindableObject bindable, BoundsConstraint value)
{
bindable.SetValue(BoundsConstraintProperty, value);
}
