namespace Terminal.Gui;
///
/// Describes the position of a which can be an absolute value, a percentage, centered, or
/// relative to the ending dimension. Integer values are implicitly convertible to an absolute . These
/// objects are created using the static methods Percent, AnchorEnd, and Center. The objects can be
/// combined with the addition and subtraction operators.
///
///
/// Use the objects on the X or Y properties of a view to control the position.
///
/// These can be used to set the absolute position, when merely assigning an integer value (via the implicit
/// integer to conversion), and they can be combined to produce more useful layouts, like:
/// Pos.Center - 3, which would shift the position of the 3 characters to the left after
/// centering for example.
///
///
/// Reference coordinates of another view by using the methods Left(View), Right(View), Bottom(View), Top(View).
/// The X(View) and Y(View) are aliases to Left(View) and Top(View) respectively.
///
///
///
///
/// Pos Object Description
///
/// -
///
///
///
///
/// Creates a object that computes the position by executing the provided
/// function. The function will be called every time the position is needed.
///
///
/// -
///
///
///
///
/// Creates a object that is a percentage of the width or height of the
/// SuperView.
///
///
/// -
///
///
///
///
/// Creates a object that is anchored to the end (right side or bottom) of
/// the dimension, useful to flush the layout from the right or bottom.
///
///
/// -
///
///
///
/// Creates a object that can be used to center the .
///
/// -
///
///
///
///
/// Creates a object that is an absolute position based on the specified
/// integer value.
///
///
/// -
///
///
///
///
/// Creates a object that tracks the Left (X) position of the specified
/// .
///
///
/// -
///
///
///
///
/// Creates a object that tracks the Left (X) position of the specified
/// .
///
///
/// -
///
///
///
///
/// Creates a object that tracks the Top (Y) position of the specified
/// .
///
///
/// -
///
///
///
///
/// Creates a object that tracks the Top (Y) position of the specified
/// .
///
///
/// -
///
///
///
///
/// Creates a object that tracks the Right (X+Width) coordinate of the
/// specified .
///
///
/// -
///
///
///
///
/// Creates a object that tracks the Bottom (Y+Height) coordinate of the
/// specified
///
///
///
///
///
public class Pos
{
///
/// Creates a object that is anchored to the end (right side or bottom) of the dimension, useful
/// to flush the layout from the right or bottom.
///
/// The object anchored to the end (the bottom or the right side).
/// The view will be shifted left or up by the amount specified.
///
/// This sample shows how align a to the bottom-right of a .
///
/// // See Issue #502
/// anchorButton.X = Pos.AnchorEnd () - (Pos.Right (anchorButton) - Pos.Left (anchorButton));
/// anchorButton.Y = Pos.AnchorEnd (1);
///
///
public static Pos AnchorEnd (int offset = 0)
{
if (offset < 0)
{
throw new ArgumentException (@"Must be positive", nameof (offset));
}
return new PosAnchorEnd (offset);
}
/// Creates a object that is an absolute position based on the specified integer value.
/// The Absolute .
/// The value to convert to the .
public static Pos At (int n) { return new PosAbsolute (n); }
///
/// Creates a object that tracks the Bottom (Y+Height) coordinate of the specified
///
///
/// The that depends on the other view.
/// The that will be tracked.
public static Pos Bottom (View view) { return new PosView (view, 3); }
/// Creates a object that can be used to center the .
/// The center Pos.
///
/// This creates a that is centered horizontally, is 50% of the way down, is 30% the height, and
/// is 80% the width of the it added to.
///
/// var textView = new TextView () {
/// X = Pos.Center (),
/// Y = Pos.Percent (50),
/// Width = Dim.Percent (80),
/// Height = Dim.Percent (30),
/// };
///
///
public static Pos Center () { return new PosCenter (); }
/// Determines whether the specified object is equal to the current object.
/// The object to compare with the current object.
///
/// if the specified object is equal to the current object; otherwise,
/// .
///
public override bool Equals (object other) { return other is Pos abs && abs == this; }
///
/// Creates a object that computes the position by executing the provided function. The function
/// will be called every time the position is needed.
///
/// The function to be executed.
/// The returned from the function.
public static Pos Function (Func function) { return new PosFunc (function); }
/// Serves as the default hash function.
/// A hash code for the current object.
public override int GetHashCode () { return Anchor (0).GetHashCode (); }
/// Creates a object that tracks the Left (X) position of the specified .
/// The that depends on the other view.
/// The that will be tracked.
public static Pos Left (View view) { return new PosView (view, 0); }
/// Adds a to a , yielding a new .
/// The first to add.
/// The second to add.
/// The that is the sum of the values of left and right.
public static Pos operator + (Pos left, Pos right)
{
if (left is PosAbsolute && right is PosAbsolute)
{
return new PosAbsolute (left.Anchor (0) + right.Anchor (0));
}
var newPos = new PosCombine (true, left, right);
SetPosCombine (left, newPos);
return newPos;
}
/// Creates an Absolute from the specified integer value.
/// The Absolute .
/// The value to convert to the .
public static implicit operator Pos (int n) { return new PosAbsolute (n); }
///
/// Subtracts a from a , yielding a new
/// .
///
/// The to subtract from (the minuend).
/// The to subtract (the subtrahend).
/// The that is the left minus right.
public static Pos operator - (Pos left, Pos right)
{
if (left is PosAbsolute && right is PosAbsolute)
{
return new PosAbsolute (left.Anchor (0) - right.Anchor (0));
}
var newPos = new PosCombine (false, left, right);
SetPosCombine (left, newPos);
return newPos;
}
/// Creates a percentage object
/// The percent object.
/// A value between 0 and 100 representing the percentage.
///
/// This creates a that is centered horizontally, is 50% of the way down, is 30% the height, and
/// is 80% the width of the it added to.
///
/// var textView = new TextView () {
/// X = Pos.Center (),
/// Y = Pos.Percent (50),
/// Width = Dim.Percent (80),
/// Height = Dim.Percent (30),
/// };
///
///
public static Pos Percent (float n)
{
if (n is < 0 or > 100)
{
throw new ArgumentException ("Percent value must be between 0 and 100");
}
return new PosFactor (n / 100);
}
///
/// Creates a object that tracks the Right (X+Width) coordinate of the specified
/// .
///
/// The that depends on the other view.
/// The that will be tracked.
public static Pos Right (View view) { return new PosView (view, 2); }
/// Creates a object that tracks the Top (Y) position of the specified .
/// The that depends on the other view.
/// The that will be tracked.
public static Pos Top (View view) { return new PosView (view, 1); }
/// Creates a object that tracks the Left (X) position of the specified .
/// The that depends on the other view.
/// The that will be tracked.
public static Pos X (View view) { return new PosView (view, 0); }
/// Creates a object that tracks the Top (Y) position of the specified .
/// The that depends on the other view.
/// The that will be tracked.
public static Pos Y (View view) { return new PosView (view, 1); }
internal virtual int Anchor (int width) { return 0; }
private static void SetPosCombine (Pos left, PosCombine newPos)
{
var view = left as PosView;
if (view is { })
{
view.Target.SetNeedsLayout ();
}
}
internal class PosAbsolute : Pos
{
private readonly int _n;
public PosAbsolute (int n) { _n = n; }
public override bool Equals (object other) { return other is PosAbsolute abs && abs._n == _n; }
public override int GetHashCode () { return _n.GetHashCode (); }
public override string ToString () { return $"Absolute({_n})"; }
internal override int Anchor (int width) { return _n; }
}
internal class PosAnchorEnd : Pos
{
private readonly int _offset;
public PosAnchorEnd (int offset) { _offset = offset; }
public override bool Equals (object other) { return other is PosAnchorEnd anchorEnd && anchorEnd._offset == _offset; }
public override int GetHashCode () { return _offset.GetHashCode (); }
public override string ToString () { return $"AnchorEnd({_offset})"; }
internal override int Anchor (int width) { return width - _offset; }
}
internal class PosCenter : Pos
{
public override string ToString () { return "Center"; }
internal override int Anchor (int width) { return width / 2; }
}
internal class PosCombine : Pos
{
internal bool _add;
internal Pos _left, _right;
public PosCombine (bool add, Pos left, Pos right)
{
_left = left;
_right = right;
_add = add;
}
public override string ToString () { return $"Combine({_left}{(_add ? '+' : '-')}{_right})"; }
internal override int Anchor (int width)
{
int la = _left.Anchor (width);
int ra = _right.Anchor (width);
if (_add)
{
return la + ra;
}
return la - ra;
}
}
internal class PosFactor : Pos
{
private readonly float _factor;
public PosFactor (float n) { _factor = n; }
public override bool Equals (object other) { return other is PosFactor f && f._factor == _factor; }
public override int GetHashCode () { return _factor.GetHashCode (); }
public override string ToString () { return $"Factor({_factor})"; }
internal override int Anchor (int width) { return (int)(width * _factor); }
}
// Helper class to provide dynamic value by the execution of a function that returns an integer.
internal class PosFunc : Pos
{
private readonly Func _function;
public PosFunc (Func n) { _function = n; }
public override bool Equals (object other) { return other is PosFunc f && f._function () == _function (); }
public override int GetHashCode () { return _function.GetHashCode (); }
public override string ToString () { return $"PosFunc({_function ()})"; }
internal override int Anchor (int width) { return _function (); }
}
internal class PosView : Pos
{
public readonly View Target;
private readonly int side;
public PosView (View view, int side)
{
Target = view;
this.side = side;
}
public override bool Equals (object other) { return other is PosView abs && abs.Target == Target; }
public override int GetHashCode () { return Target.GetHashCode (); }
public override string ToString ()
{
string tside;
switch (side)
{
case 0:
tside = "x";
break;
case 1:
tside = "y";
break;
case 2:
tside = "right";
break;
case 3:
tside = "bottom";
break;
default:
tside = "unknown";
break;
}
if (Target is null)
{
throw new NullReferenceException (nameof (Target));
}
return $"View(side={tside},target={Target})";
}
internal override int Anchor (int width)
{
switch (side)
{
case 0: return Target.Frame.X;
case 1: return Target.Frame.Y;
case 2: return Target.Frame.Right;
case 3: return Target.Frame.Bottom;
default:
return 0;
}
}
}
}
///
///
/// A Dim object describes the dimensions of a . Dim is the type of the
/// and properties of . Dim objects enable
/// Computed Layout (see ) to automatically manage the dimensions of a view.
///
///
/// Integer values are implicitly convertible to an absolute . These objects are created using
/// the static methods described below. The objects can be combined with the addition and
/// subtraction operators.
///
///
///
///
///
///
/// Dim Object Description
///
/// -
///
///
///
///
/// Creates a object that computes the dimension by executing the provided
/// function. The function will be called every time the dimension is needed.
///
///
/// -
///
///
///
///
/// Creates a object that is a percentage of the width or height of the
/// SuperView.
///
///
/// -
///
///
///
///
/// Creates a object that fills the dimension, leaving the specified number
/// of columns for a margin.
///
///
/// -
///
///
///
///
/// Creates a object that tracks the Width of the specified
/// .
///
///
/// -
///
///
///
///
/// Creates a object that tracks the Height of the specified
/// .
///
///
///
///
///
///
public class Dim
{
/// Determines whether the specified object is equal to the current object.
/// The object to compare with the current object.
///
/// if the specified object is equal to the current object; otherwise,
/// .
///
public override bool Equals (object other) { return other is Dim abs && abs == this; }
///
/// Creates a object that fills the dimension, leaving the specified number of columns for a
/// margin.
///
/// The Fill dimension.
/// Margin to use.
public static Dim Fill (int margin = 0) { return new DimFill (margin); }
///
/// Creates a function object that computes the dimension by executing the provided function.
/// The function will be called every time the dimension is needed.
///
/// The function to be executed.
/// The returned from the function.
public static Dim Function (Func function) { return new DimFunc (function); }
/// Serves as the default hash function.
/// A hash code for the current object.
public override int GetHashCode () { return Anchor (0).GetHashCode (); }
/// Creates a object that tracks the Height of the specified .
/// The height of the other .
/// The view that will be tracked.
public static Dim Height (View view) { return new DimView (view, 0); }
/// Adds a to a , yielding a new .
/// The first to add.
/// The second to add.
/// The that is the sum of the values of left and right.
public static Dim operator + (Dim left, Dim right)
{
if (left is DimAbsolute && right is DimAbsolute)
{
return new DimAbsolute (left.Anchor (0) + right.Anchor (0));
}
var newDim = new DimCombine (true, left, right);
SetDimCombine (left, newDim);
return newDim;
}
/// Creates an Absolute from the specified integer value.
/// The Absolute .
/// The value to convert to the pos.
public static implicit operator Dim (int n) { return new DimAbsolute (n); }
///
/// Subtracts a from a , yielding a new
/// .
///
/// The to subtract from (the minuend).
/// The to subtract (the subtrahend).
/// The that is the left minus right.
public static Dim operator - (Dim left, Dim right)
{
if (left is DimAbsolute && right is DimAbsolute)
{
return new DimAbsolute (left.Anchor (0) - right.Anchor (0));
}
var newDim = new DimCombine (false, left, right);
SetDimCombine (left, newDim);
return newDim;
}
/// Creates a percentage object that is a percentage of the width or height of the SuperView.
/// The percent object.
/// A value between 0 and 100 representing the percentage.
///
/// If true the Percent is computed based on the remaining space after the X/Y anchor positions. If
/// false is computed based on the whole original space.
///
///
/// This initializes a that is centered horizontally, is 50% of the way down, is 30% the height,
/// and is 80% the width of the it added to.
///
/// var textView = new TextView () {
/// X = Pos.Center (),
/// Y = Pos.Percent (50),
/// Width = Dim.Percent (80),
/// Height = Dim.Percent (30),
/// };
///
///
public static Dim Percent (float n, bool r = false)
{
if (n is < 0 or > 100)
{
throw new ArgumentException ("Percent value must be between 0 and 100");
}
return new DimFactor (n / 100, r);
}
/// Creates an Absolute from the specified integer value.
/// The Absolute .
/// The value to convert to the .
public static Dim Sized (int n) { return new DimAbsolute (n); }
/// Creates a object that tracks the Width of the specified .
/// The width of the other .
/// The view that will be tracked.
public static Dim Width (View view) { return new DimView (view, 1); }
internal virtual int Anchor (int width) { return 0; }
// BUGBUG: newPos is never used.
private static void SetDimCombine (Dim left, DimCombine newPos) { (left as DimView)?.Target.SetNeedsLayout (); }
internal class DimAbsolute : Dim
{
private readonly int _n;
public DimAbsolute (int n) { _n = n; }
public override bool Equals (object other) { return other is DimAbsolute abs && abs._n == _n; }
public override int GetHashCode () { return _n.GetHashCode (); }
public override string ToString () { return $"Absolute({_n})"; }
internal override int Anchor (int width) { return _n; }
}
internal class DimCombine : Dim
{
internal bool _add;
internal Dim _left, _right;
public DimCombine (bool add, Dim left, Dim right)
{
_left = left;
_right = right;
_add = add;
}
public override string ToString () { return $"Combine({_left}{(_add ? '+' : '-')}{_right})"; }
internal override int Anchor (int width)
{
int la = _left.Anchor (width);
int ra = _right.Anchor (width);
if (_add)
{
return la + ra;
}
return la - ra;
}
}
internal class DimFactor : Dim
{
private readonly float _factor;
private readonly bool _remaining;
public DimFactor (float n, bool r = false)
{
_factor = n;
_remaining = r;
}
public override bool Equals (object other) { return other is DimFactor f && f._factor == _factor && f._remaining == _remaining; }
public override int GetHashCode () { return _factor.GetHashCode (); }
public bool IsFromRemaining () { return _remaining; }
public override string ToString () { return $"Factor({_factor},{_remaining})"; }
internal override int Anchor (int width) { return (int)(width * _factor); }
}
internal class DimFill : Dim
{
private readonly int _margin;
public DimFill (int margin) { _margin = margin; }
public override bool Equals (object other) { return other is DimFill fill && fill._margin == _margin; }
public override int GetHashCode () { return _margin.GetHashCode (); }
public override string ToString () { return $"Fill({_margin})"; }
internal override int Anchor (int width) { return width - _margin; }
}
// Helper class to provide dynamic value by the execution of a function that returns an integer.
internal class DimFunc : Dim
{
private readonly Func _function;
public DimFunc (Func n) { _function = n; }
public override bool Equals (object other) { return other is DimFunc f && f._function () == _function (); }
public override int GetHashCode () { return _function.GetHashCode (); }
public override string ToString () { return $"DimFunc({_function ()})"; }
internal override int Anchor (int width) { return _function (); }
}
internal class DimView : Dim
{
private readonly int _side;
public DimView (View view, int side)
{
Target = view;
_side = side;
}
public View Target { get; init; }
public override bool Equals (object other) { return other is DimView abs && abs.Target == Target; }
public override int GetHashCode () { return Target.GetHashCode (); }
public override string ToString ()
{
if (Target is null)
{
throw new NullReferenceException ();
}
string tside = _side switch
{
0 => "Height",
1 => "Width",
_ => "unknown"
};
return $"View({tside},{Target})";
}
internal override int Anchor (int width)
{
return _side switch
{
0 => Target.Frame.Height,
1 => Target.Frame.Width,
_ => 0
};
}
}
}