// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.ComponentModel;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms.Layout;
 
namespace System.Windows.Forms;
 
/// <summary>
///  Represents a <see cref="Panel"/> control.
/// </summary>
[DefaultProperty(nameof(BorderStyle))]
[DefaultEvent(nameof(Paint))]
[Docking(DockingBehavior.Ask)]
[Designer($"System.Windows.Forms.Design.PanelDesigner, {Assemblies.SystemDesign}")]
[SRDescription(nameof(SR.DescriptionPanel))]
public partial class Panel : ScrollableControl
{
    private BorderStyle _borderStyle = BorderStyle.None;
 
    /// <summary>
    ///  Initializes a new instance of the <see cref="Panel"/> class.
    /// </summary>
    public Panel() : base()
    {
        // this class overrides GetPreferredSizeCore, let Control automatically cache the result
        SetExtendedState(ExtendedStates.UserPreferredSizeCache, true);
        TabStop = false;
        SetStyle(ControlStyles.Selectable | ControlStyles.AllPaintingInWmPaint, false);
        SetStyle(ControlStyles.SupportsTransparentBackColor, true);
    }
 
    /// <summary>
    ///  Override to re-expose AutoSize.
    /// </summary>
    [Browsable(true)]
    [EditorBrowsable(EditorBrowsableState.Always)]
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
    public override bool AutoSize
    {
        get => base.AutoSize;
        set => base.AutoSize = value;
    }
 
    [SRCategory(nameof(SR.CatPropertyChanged))]
    [SRDescription(nameof(SR.ControlOnAutoSizeChangedDescr))]
    [Browsable(true)]
    [EditorBrowsable(EditorBrowsableState.Always)]
    public new event EventHandler? AutoSizeChanged
    {
        add => base.AutoSizeChanged += value;
        remove => base.AutoSizeChanged -= value;
    }
 
    /// <summary>
    ///  Allows the control to optionally shrink when AutoSize is true.
    /// </summary>
    [SRDescription(nameof(SR.ControlAutoSizeModeDescr))]
    [SRCategory(nameof(SR.CatLayout))]
    [Browsable(true)]
    [DefaultValue(AutoSizeMode.GrowOnly)]
    [Localizable(true)]
    public virtual AutoSizeMode AutoSizeMode
    {
        get => GetAutoSizeMode();
        set
        {
            SourceGenerated.EnumValidator.Validate(value);
 
            if (GetAutoSizeMode() != value)
            {
                SetAutoSizeMode(value);
                if (ParentInternal is not null)
                {
                    // DefaultLayout does not keep anchor information until it needs to. When
                    // AutoSize became a common property, we could no longer blindly call into
                    // DefaultLayout, so now we do a special InitLayout just for DefaultLayout.
                    if (ParentInternal.LayoutEngine == DefaultLayout.Instance)
                    {
                        ParentInternal.LayoutEngine.InitLayout(this, BoundsSpecified.Size);
                    }
 
                    LayoutTransaction.DoLayout(ParentInternal, this, PropertyNames.AutoSize);
                }
            }
        }
    }
 
    /// <summary>
    ///  Indicates the border style for the control.
    /// </summary>
    [SRCategory(nameof(SR.CatAppearance))]
    [DefaultValue(BorderStyle.None)]
    [DispId(PInvokeCore.DISPID_BORDERSTYLE)]
    [SRDescription(nameof(SR.PanelBorderStyleDescr))]
    public BorderStyle BorderStyle
    {
        get => _borderStyle;
        set
        {
            if (_borderStyle != value)
            {
                SourceGenerated.EnumValidator.Validate(value);
 
                _borderStyle = value;
                UpdateStyles();
            }
        }
    }
 
    /// <summary>
    ///  Returns the parameters needed to create the handle. Inheriting classes can override
    ///  this to provide extra functionality. They should not, however, forget to call
    ///  base.getCreateParams() first to get the struct filled up with the basic info.
    /// </summary>
    protected override CreateParams CreateParams
    {
        get
        {
            CreateParams cp = base.CreateParams;
            cp.Style &= ~(int)WINDOW_STYLE.WS_BORDER;
            cp.ExStyle |= (int)WINDOW_EX_STYLE.WS_EX_CONTROLPARENT;
            cp.ExStyle &= ~(int)WINDOW_EX_STYLE.WS_EX_CLIENTEDGE;
 
            switch (_borderStyle)
            {
                case BorderStyle.Fixed3D:
                    cp.ExStyle |= (int)WINDOW_EX_STYLE.WS_EX_CLIENTEDGE;
                    break;
                case BorderStyle.FixedSingle:
                    cp.Style |= (int)WINDOW_STYLE.WS_BORDER;
                    break;
            }
 
            return cp;
        }
    }
 
    /// <summary>
    ///  Deriving classes can override this to configure a default size for their control.
    ///  This is more efficient than setting the size in the control's constructor.
    /// </summary>
    protected override Size DefaultSize => new(200, 100);
 
    internal override Size GetPreferredSizeCore(Size proposedSize)
    {
        // Translating 0,0 from ClientSize to actual Size tells us how much space
        // is required for the borders.
        Size borderSize = SizeFromClientSize(Size.Empty);
        Size totalPadding = borderSize + Padding.Size;
 
        return LayoutEngine.GetPreferredSize(this, proposedSize - totalPadding) + totalPadding;
    }
 
    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public new event KeyEventHandler? KeyUp
    {
        add => base.KeyUp += value;
        remove => base.KeyUp -= value;
    }
 
    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public new event KeyEventHandler? KeyDown
    {
        add => base.KeyDown += value;
        remove => base.KeyDown -= value;
    }
 
    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public new event KeyPressEventHandler? KeyPress
    {
        add => base.KeyPress += value;
        remove => base.KeyPress -= value;
    }
 
    internal override bool SupportsUiaProviders => true;
 
    [DefaultValue(false)]
    public new bool TabStop
    {
        get => base.TabStop;
        set => base.TabStop = value;
    }
 
    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    [Bindable(false)]
    [AllowNull]
    public override string Text
    {
        get => base.Text;
        set => base.Text = value;
    }
 
    [Browsable(false)]
    [EditorBrowsable(EditorBrowsableState.Never)]
    public new event EventHandler? TextChanged
    {
        add => base.TextChanged += value;
        remove => base.TextChanged -= value;
    }
 
    /// <summary>
    ///  Fires the event indicating that the panel has been resized.
    ///  Inheriting controls should use this in favour of actually listening to
    ///  the event, but should not forget to call base.onResize() to
    ///  ensure that the event is still fired for external listeners.
    /// </summary>
    protected override void OnResize(EventArgs eventargs)
    {
        if (DesignMode && _borderStyle == BorderStyle.None)
        {
            Invalidate();
        }
 
        base.OnResize(eventargs);
    }
 
    private protected override void PrintToMetaFileRecursive(HDC hDC, IntPtr lParam, Rectangle bounds)
    {
        base.PrintToMetaFileRecursive(hDC, lParam, bounds);
 
        using DCMapping mapping = new(hDC, bounds);
        using Graphics g = hDC.CreateGraphics();
        ControlPaint.PrintBorder(g, new Rectangle(Point.Empty, Size), BorderStyle, Border3DStyle.Sunken);
    }
 
    /// <summary>
    ///  Returns a string representation for this control.
    /// </summary>
    public override string ToString()
    {
        return $"{base.ToString()}, BorderStyle: {typeof(BorderStyle)}.{_borderStyle}";
    }
 
    /// <summary>
    ///  Creates a new AccessibleObject for this <see cref="Panel"/> instance.
    ///  The AccessibleObject instance returned by this method supports ControlType UIA property.
    /// </summary>
    /// <returns>
    ///  <see cref="AccessibleObject"/> for this <see cref="Panel"/> instance.
    /// </returns>
    protected override AccessibleObject CreateAccessibilityInstance()
       => new PanelAccessibleObject(this);
}