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Terminal.Gui/Terminal.Gui/View/Layout/Dim.cs
2024-05-17 16:26:00 -07:00

277 lines
12 KiB
C#

#nullable enable
using System.Diagnostics;
namespace Terminal.Gui;
/// <summary>
/// <para>
/// A Dim object describes the dimensions of a <see cref="View"/>. Dim is the type of the
/// <see cref="View.Width"/> and <see cref="View.Height"/> properties of <see cref="View"/>. Dim objects enable
/// Computed Layout (see <see cref="LayoutStyle.Computed"/>) to automatically manage the dimensions of a view.
/// </para>
/// <para>
/// Integer values are implicitly convertible to an absolute <see cref="Dim"/>. These objects are created using
/// the static methods described below. The <see cref="Dim"/> objects can be combined with the addition and
/// subtraction operators.
/// </para>
/// </summary>
/// <remarks>
/// <para>
/// <list type="table">
/// <listheader>
/// <term>Dim Object</term> <description>Description</description>
/// </listheader>
/// <item>
/// <term>
/// <see cref="Dim.Auto"/>
/// </term>
/// <description>
/// Creates a <see cref="Dim"/> object that automatically sizes the view to fit
/// the view's Text, SubViews, or ContentArea.
/// </description>
/// </item>
/// <item>
/// <term>
/// <see cref="Func"/>
/// </term>
/// <description>
/// Creates a <see cref="Dim"/> object that computes the dimension by executing the provided
/// function. The function will be called every time the dimension is needed.
/// </description>
/// </item>
/// <item>
/// <term>
/// <see cref="Dim.Percent(int, DimPercentMode)"/>
/// </term>
/// <description>
/// Creates a <see cref="Dim"/> object that is a percentage of the width or height of the
/// SuperView.
/// </description>
/// </item>
/// <item>
/// <term>
/// <see cref="Dim.Fill(int)"/>
/// </term>
/// <description>
/// Creates a <see cref="Dim"/> object that fills the dimension from the View's X position
/// to the end of the super view's width, leaving the specified number of columns for a margin.
/// </description>
/// </item>
/// <item>
/// <term>
/// <see cref="Dim.Width(View)"/>
/// </term>
/// <description>
/// Creates a <see cref="Dim"/> object that tracks the Width of the specified
/// <see cref="View"/>.
/// </description>
/// </item>
/// <item>
/// <term>
/// <see cref="Dim.Height(View)"/>
/// </term>
/// <description>
/// Creates a <see cref="Dim"/> object that tracks the Height of the specified
/// <see cref="View"/>.
/// </description>
/// </item>
/// </list>
/// </para>
/// <para></para>
/// </remarks>
public abstract class Dim
{
#region static Dim creation methods
/// <summary>Creates an Absolute <see cref="Dim"/> from the specified integer value.</summary>
/// <returns>The Absolute <see cref="Dim"/>.</returns>
/// <param name="size">The value to convert to the <see cref="Dim"/>.</param>
public static Dim? Absolute (int size) { return new DimAbsolute (size); }
/// <summary>
/// Creates a <see cref="Dim"/> object that automatically sizes the view to fit all the view's Content, Subviews, and/or Text.
/// </summary>
/// <remarks>
/// <para>
/// See <see cref="DimAutoStyle"/>.
/// </para>
/// </remarks>
/// <example>
/// This initializes a <see cref="View"/> with two SubViews. The view will be automatically sized to fit the two
/// SubViews.
/// <code>
/// var button = new Button () { Text = "Click Me!", X = 1, Y = 1, Width = 10, Height = 1 };
/// var textField = new TextField { Text = "Type here", X = 1, Y = 2, Width = 20, Height = 1 };
/// var view = new Window () { Title = "MyWindow", X = 0, Y = 0, Width = Dim.Auto (), Height = Dim.Auto () };
/// view.Add (button, textField);
/// </code>
/// </example>
/// <returns>The <see cref="Dim"/> object.</returns>
/// <param name="style">
/// Specifies how <see cref="Dim.Auto"/> will compute the dimension. The default is <see cref="DimAutoStyle.Auto"/>.
/// </param>
/// <param name="minimumContentDim">The minimum dimension the View's ContentSize will be constrained to.</param>
/// <param name="maximumContentDim">The maximum dimension the View's ContentSize will be fit to. NOT CURRENTLY SUPPORTED.</param>
public static Dim? Auto (DimAutoStyle style = DimAutoStyle.Auto, Dim? minimumContentDim = null, Dim? maximumContentDim = null)
{
if (maximumContentDim is { })
{
Debug.WriteLine (@"WARNING: maximumContentDim is not fully implemented.");
}
return new DimAuto ()
{
MinimumContentDim = minimumContentDim,
MaximumContentDim = maximumContentDim,
Style = style
};
}
/// <summary>
/// Creates a <see cref="Dim"/> object that fills the dimension, leaving the specified margin.
/// </summary>
/// <returns>The Fill dimension.</returns>
/// <param name="margin">Margin to use.</param>
public static Dim? Fill (int margin = 0) { return new DimFill (margin); }
/// <summary>
/// Creates a function <see cref="Dim"/> object that computes the dimension by executing the provided function.
/// The function will be called every time the dimension is needed.
/// </summary>
/// <param name="function">The function to be executed.</param>
/// <returns>The <see cref="Dim"/> returned from the function.</returns>
public static Dim Func (Func<int> function) { return new DimFunc (function); }
/// <summary>Creates a <see cref="Dim"/> object that tracks the Height of the specified <see cref="View"/>.</summary>
/// <returns>The height <see cref="Dim"/> of the other <see cref="View"/>.</returns>
/// <param name="view">The view that will be tracked.</param>
public static Dim Height (View view) { return new DimView (view, Dimension.Height); }
/// <summary>Creates a percentage <see cref="Dim"/> object that is a percentage of the width or height of the SuperView.</summary>
/// <returns>The percent <see cref="Dim"/> object.</returns>
/// <param name="percent">A value between 0 and 100 representing the percentage.</param>
/// <param name="mode">
/// If <see cref="DimPercentMode.Position"/> the dimension is computed using the View's position (<see cref="View.X"/> or
/// <see cref="View.Y"/>).
/// If <see cref="DimPercentMode.ContentSize"/> the dimension is computed using the View's <see cref="View.ContentSize"/>.
/// </param>
/// <example>
/// This initializes a <see cref="TextField"/> that will be centered horizontally, is 50% of the way down, is 30% the
/// height,
/// and is 80% the width of the SuperView.
/// <code>
/// var textView = new TextField {
/// X = Pos.Center (),
/// Y = Pos.Percent (50),
/// Width = Dim.Percent (80),
/// Height = Dim.Percent (30),
/// };
/// </code>
/// </example>
public static Dim? Percent (int percent, DimPercentMode mode = DimPercentMode.ContentSize)
{
if (percent is < 0 /*or > 100*/)
{
throw new ArgumentException ("Percent value must be positive.");
}
return new DimPercent (percent, mode);
}
/// <summary>Creates a <see cref="Dim"/> object that tracks the Width of the specified <see cref="View"/>.</summary>
/// <returns>The width <see cref="Dim"/> of the other <see cref="View"/>.</returns>
/// <param name="view">The view that will be tracked.</param>
public static Dim Width (View view) { return new DimView (view, Dimension.Width); }
#endregion static Dim creation methods
#region virtual methods
/// <summary>
/// Gets a dimension that is anchored to a certain point in the layout.
/// This method is typically used internally by the layout system to determine the size of a View.
/// </summary>
/// <param name="size">The width of the area where the View is being sized (Superview.ContentSize).</param>
/// <returns>
/// An integer representing the calculated dimension. The way this dimension is calculated depends on the specific
/// subclass of Dim that is used. For example, DimAbsolute returns a fixed dimension, DimFactor returns a
/// dimension that is a certain percentage of the super view's size, and so on.
/// </returns>
internal virtual int GetAnchor (int size) { return 0; }
/// <summary>
/// Calculates and returns the dimension of a <see cref="View"/> object. It takes into account the location of the
/// <see cref="View"/>, it's SuperView's ContentSize, and whether it should automatically adjust its size based on its
/// content.
/// </summary>
/// <param name="location">
/// The starting point from where the size calculation begins. It could be the left edge for width calculation or the
/// top edge for height calculation.
/// </param>
/// <param name="superviewContentSize">The size of the SuperView's content. It could be width or height.</param>
/// <param name="us">The View that holds this Pos object.</param>
/// <param name="dimension">Width or Height</param>
/// <returns>
/// The calculated size of the View. The way this size is calculated depends on the specific subclass of Dim that
/// is used.
/// </returns>
internal virtual int Calculate (int location, int superviewContentSize, View us, Dimension dimension)
{
return Math.Max (GetAnchor (superviewContentSize - location), 0);
}
/// <summary>
/// Diagnostics API to determine if this Dim object references other views.
/// </summary>
/// <returns></returns>
internal virtual bool ReferencesOtherViews () { return false; }
#endregion virtual methods
#region operators
/// <summary>Adds a <see cref="Dim"/> to a <see cref="Dim"/>, yielding a new <see cref="Dim"/>.</summary>
/// <param name="left">The first <see cref="Dim"/> to add.</param>
/// <param name="right">The second <see cref="Dim"/> to add.</param>
/// <returns>The <see cref="Dim"/> that is the sum of the values of <c>left</c> and <c>right</c>.</returns>
public static Dim operator + (Dim? left, Dim? right)
{
if (left is DimAbsolute && right is DimAbsolute)
{
return new DimAbsolute (left.GetAnchor (0) + right.GetAnchor (0));
}
var newDim = new DimCombine (AddOrSubtract.Add, left, right);
(left as DimView)?.Target.SetNeedsLayout ();
return newDim;
}
/// <summary>Creates an Absolute <see cref="Dim"/> from the specified integer value.</summary>
/// <returns>The Absolute <see cref="Dim"/>.</returns>
/// <param name="n">The value to convert to the pos.</param>
public static implicit operator Dim (int n) { return new DimAbsolute (n); }
/// <summary>
/// Subtracts a <see cref="Dim"/> from a <see cref="Dim"/>, yielding a new
/// <see cref="Dim"/>.
/// </summary>
/// <param name="left">The <see cref="Dim"/> to subtract from (the minuend).</param>
/// <param name="right">The <see cref="Dim"/> to subtract (the subtrahend).</param>
/// <returns>The <see cref="Dim"/> that is the <c>left</c> minus <c>right</c>.</returns>
public static Dim operator - (Dim? left, Dim? right)
{
if (left is DimAbsolute && right is DimAbsolute)
{
return new DimAbsolute (left.GetAnchor (0) - right.GetAnchor (0));
}
var newDim = new DimCombine (AddOrSubtract.Subtract, left, right);
(left as DimView)?.Target.SetNeedsLayout ();
return newDim;
}
#endregion operators
}