using System;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;
using Vanara.Drawing;
using Vanara.Extensions;
using static Vanara.PInvoke.ComCtl32;
using static Vanara.PInvoke.UxTheme;
using static Vanara.PInvoke.Macros;
using static Vanara.PInvoke.User32;
using ComboBoxStyle = System.Windows.Forms.ComboBoxStyle;
namespace Vanara.Windows.Forms
{
/// Interface that exposes an Enabled property for an item supplied to .
public interface IEnableable
{
/// Gets a value indicating whether an item is enabled.
/// true if enabled; otherwise, false.
bool Enabled { get; }
}
/// A version of that allows for disabled items.
[ToolboxBitmap(typeof(DisabledItemComboBox), "Control")]
public class DisabledItemComboBox : ComboBox
{
private const TextFormatFlags tff = TextFormatFlags.Default | TextFormatFlags.VerticalCenter | TextFormatFlags.SingleLine | TextFormatFlags.NoPadding;
private bool animationsNeedCleanup;
private ComboBoxState currentState = ComboBoxState.Normal, newState = ComboBoxState.Normal;
private ListBoxNativeWindow dropDownWindow;
private readonly VisualStyleRenderer vsr;
/// Initializes a new instance of the class.
public DisabledItemComboBox()
{
SetStyle(/*ControlStyles.Opaque |*/ ControlStyles.UserPaint | ControlStyles.AllPaintingInWmPaint, true);
DrawMode = DrawMode.OwnerDrawFixed;
DropDownStyle = ComboBoxStyle.DropDownList;
if (Environment.OSVersion.Version.Major >= 6 && VisualStyleRenderer.IsSupported && Application.RenderWithVisualStyles)
vsr = new VisualStyleRenderer("COMBOBOX", 5, 0);
}
///
/// Gets or sets a value indicating whether your code or the operating system will handle drawing of elements in the list.
///
/// One of the enumeration values. The default is .
///
[DefaultValue(DrawMode.OwnerDrawFixed), Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]
public new DrawMode DrawMode
{
get => base.DrawMode;
set => base.DrawMode = value;
}
/// Gets or sets a value specifying the style of the combo box.
/// One of the values. The default is DropDown.
///
[DefaultValue(ComboBoxStyle.DropDownList), Browsable(false), EditorBrowsable(EditorBrowsableState.Never)]
public new ComboBoxStyle DropDownStyle
{
get => base.DropDownStyle;
set => base.DropDownStyle = value;
}
/// Gets or sets the state of the combobox.
/// The state.
private ComboBoxState State
{
get => currentState;
set
{
var diff = !Equals(currentState, value);
newState = value;
if (diff)
{
if (animationsNeedCleanup && IsHandleCreated && !IsDisposed)
BufferedPaintStopAllAnimations(Handle);
Invalidate();
}
}
}
/// Determines whether an item is enabled.
/// The index of the item.
/// true if enabled; otherwise, false.
public bool IsItemEnabled(int idx) => !(idx > -1 && idx < Items.Count && Items[idx] is IEnableable && !((IEnableable)Items[idx]).Enabled);
///
/// Releases the unmanaged resources used by the and optionally releases the managed resources.
///
/// true to release both managed and unmanaged resources; false to release only unmanaged resources.
protected override void Dispose(bool disposing)
{
if (animationsNeedCleanup && !IsDisposed)
{
BufferedPaintUnInit();
animationsNeedCleanup = false;
}
base.Dispose(disposing);
}
/// Raises the event.
/// A that contains the event data.
protected override void OnDrawItem(DrawItemEventArgs e)
{
var itemString = e.Index >= 0 ? GetItemText(Items[e.Index]) : string.Empty;
if ((e.State & DrawItemState.ComboBoxEdit) != DrawItemState.ComboBoxEdit)
{
if (e.Index >= 0)
{
var iEnabled = IsItemEnabled(e.Index);
if (iEnabled)
{
e.DrawBackground();
e.DrawFocusRectangle();
}
else
{
using (var bb = new SolidBrush(e.BackColor))
e.Graphics.FillRectangle(bb, e.Bounds);
}
TextRenderer.DrawText(e.Graphics, itemString, e.Font, Rectangle.Inflate(e.Bounds, -2, 0), iEnabled ? e.ForeColor : SystemColors.GrayText, tff);
}
}
base.OnDrawItem(e);
}
/// Raises the event.
/// An that contains the event data.
protected override void OnDropDown(EventArgs e)
{
base.OnDropDown(e);
State = ComboBoxState.Pressed;
}
/// Raises the event.
/// An that contains the event data.
protected override void OnDropDownClosed(EventArgs e)
{
base.OnDropDownClosed(e);
State = ComboBoxState.Normal;
}
/// Raises the event.
/// An that contains the event data.
protected override void OnHandleCreated(EventArgs e)
{
base.OnHandleCreated(e);
if (vsr != null)
{
BufferedPaintInit();
animationsNeedCleanup = true;
}
}
/// Raises the event.
/// An that contains the event data.
protected override void OnHandleDestroyed(EventArgs e)
{
dropDownWindow?.ReleaseHandle();
dropDownWindow = null;
base.OnHandleDestroyed(e);
}
/// Raises the event.
/// A that contains the event data.
protected override void OnKeyPress(KeyPressEventArgs e)
{
var idx = FindEnabledString(e.KeyChar.ToString(), SelectedIndex);
if (idx == -1 || idx == SelectedIndex)
e.Handled = true;
base.OnKeyPress(e);
}
/// Raises the event.
/// An that contains the event data.
protected override void OnLostFocus(EventArgs e)
{
base.OnLostFocus(e);
Invalidate();
}
/// Raises the event.
/// A that contains the event data.
protected override void OnMouseDown(MouseEventArgs e)
{
base.OnMouseDown(e);
State = ComboBoxState.Pressed;
}
/// Raises the event.
/// An that contains the event data.
protected override void OnMouseEnter(EventArgs e)
{
base.OnMouseEnter(e);
State = ComboBoxState.Hot;
}
/// Raises the event.
/// An that contains the event data.
protected override void OnMouseLeave(EventArgs e)
{
base.OnMouseLeave(e);
if (State != ComboBoxState.Pressed)
State = ComboBoxState.Normal;
}
/// Raises the event.
/// A that contains the event data.
protected override void OnMouseMove(MouseEventArgs e)
{
base.OnMouseMove(e);
if (State != ComboBoxState.Pressed)
State = ComboBoxState.Hot;
}
/// Raises the event.
/// A that contains the event data.
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
if (IsDisposed)
return;
BufferedPaint.PaintAnimation(e.Graphics, this, ClientRectangle, PaintControl, currentState, Enabled ? newState : ComboBoxState.Disabled, (a, b) => (int)vsr.GetTransitionDuration((int)a, (int)b));
}
/// Paints the background of the control.
/// A that contains information about the control to paint.
protected override void OnPaintBackground(PaintEventArgs pevent)
{
// don't paint the control's background
}
/// Paints the control.
/// The dc.
/// The bounds.
/// State of the current.
/// The data.
protected virtual void PaintControl(Graphics dc, Rectangle bounds, ComboBoxState state, int data)
{
var cbi = COMBOBOXINFO.FromHandle(Handle);
var itemText = SelectedIndex >= 0 ? GetItemText(SelectedItem) : string.Empty;
Rectangle tr = cbi.rcItem;
/*Rectangle tr = bounds;
tr.Width -= (SystemInformation.VerticalScrollBarWidth + 2);
tr.Inflate(0, -2);
tr.Offset(1, 0);*/
Rectangle br = cbi.rcButton;
var vsSuccess = false;
if (vsr != null)
{
/*Rectangle r = Rectangle.Inflate(bounds, 1, 1);
if (this.DropDownStyle != ComboBoxStyle.DropDownList)
{
dc.Clear(this.BackColor);
ComboBoxRenderer.DrawTextBox(dc, r, itemText, this.Font, tr, tff, state);
ComboBoxRenderer.DrawDropDownButton(dc, br, state);
}
else*/
{
try
{
vsr.DrawParentBackground(dc, bounds, this);
vsr.DrawBackground(dc, bounds);
if (DropDownStyle != ComboBoxStyle.DropDownList) br.Inflate(1, 1);
var cr = DropDownStyle == ComboBoxStyle.DropDownList ? Rectangle.Inflate(br, -1, -1) : br;
vsr.SetState((int)(br.Contains(PointToClient(Cursor.Position)) ? state : ComboBoxState.Normal));
vsr.DrawBackground(dc, br, cr);
if (Focused && State != ComboBoxState.Pressed)
{
var sz = TextRenderer.MeasureText(dc, "Wg", Font, tr.Size, TextFormatFlags.Default);
var fr = Rectangle.Inflate(tr, 0, (sz.Height - tr.Height) / 2 + 1);
ControlPaint.DrawFocusRectangle(dc, fr);
}
TextRenderer.DrawText(dc, itemText, Font, tr, ForeColor, tff);
vsSuccess = true;
}
catch { }
}
}
if (!vsSuccess)
{
System.Diagnostics.Debug.WriteLine($"CR:{bounds};Foc:{Focused};St:{state};Tx:{itemText}");
var bgc = Enabled ? BackColor : SystemColors.Control;
dc.Clear(bgc);
ControlPaint.DrawBorder3D(dc, bounds, Border3DStyle.Sunken);
ControlPaint.DrawComboButton(dc, br, Enabled ? (state == ComboBoxState.Pressed ? ButtonState.Pushed : ButtonState.Normal) : ButtonState.Inactive);
//using (var bb = new SolidBrush(this.BackColor))
// dc.FillRectangle(bb, tr);
if (Focused)
{
var sz = TextRenderer.MeasureText(dc, "Wg", Font, tr.Size, TextFormatFlags.Default);
var fr = Rectangle.Inflate(tr, 0, (sz.Height - tr.Height) / 2 + 1);
dc.FillRectangle(SystemBrushes.Highlight, fr);
ControlPaint.DrawFocusRectangle(dc, fr); //, this.ForeColor, SystemColors.Highlight);
}
TextRenderer.DrawText(dc, itemText, Font, tr, Focused ? SystemColors.HighlightText : (Enabled ? ForeColor : SystemColors.GrayText), bgc, tff);
}
}
/// Processes a command key.
///
/// A , passed by reference, that represents the window message to process.
///
/// One of the values that represents the key to process.
/// true if the character was processed by the control; otherwise, false.
protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
var visItems = DropDownHeight / ItemHeight;
switch (keyData)
{
case Keys.Down:
case Keys.Right:
SelectedIndex = GetNextEnabledItemIndex(SelectedIndex, true);
return true;
case Keys.Up:
case Keys.Left:
SelectedIndex = GetNextEnabledItemIndex(SelectedIndex, false);
return true;
case Keys.PageDown:
if (SelectedIndex + visItems > Items.Count)
SelectedIndex = GetNextEnabledItemIndex(Items.Count, false);
else
SelectedIndex = GetNextEnabledItemIndex(SelectedIndex + visItems, true);
return true;
case Keys.PageUp:
if (SelectedIndex - visItems < 0)
SelectedIndex = GetNextEnabledItemIndex(-1, true);
else
SelectedIndex = GetNextEnabledItemIndex(SelectedIndex - visItems, false);
return true;
case Keys.Home:
SelectedIndex = GetNextEnabledItemIndex(-1, true);
return true;
case Keys.End:
SelectedIndex = GetNextEnabledItemIndex(Items.Count, false);
return true;
case Keys.Enter:
var pt = dropDownWindow?.MapPointToClient(Cursor.Position) ?? default;
var idx = dropDownWindow?.IndexFromPoint(pt.X, pt.Y) ?? default;
if (idx >= 0 && IsItemEnabled(idx))
return false;
DroppedDown = false;
return true;
case Keys.Escape:
DroppedDown = false;
return true;
}
return base.ProcessCmdKey(ref msg, keyData);
}
/// Processes Windows messages.
/// The Windows to process.
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
if ((int)(long)m.WParam == 0x3e80001 && !IsDisposed)
{
dropDownWindow = new ListBoxNativeWindow(m.LParam, this);
}
}
private int FindEnabledString(string str, int startIndex)
{
if (str != null)
{
if (startIndex < -1 || startIndex >= Items.Count)
return -1;
var length = str.Length;
var num2 = 0;
for (var i = (startIndex + 1) % Items.Count; num2 < Items.Count; i = (i + 1) % Items.Count)
{
num2++;
if (IsItemEnabled(i) && string.Compare(str, 0, GetItemText(Items[i]), 0, length, true, System.Globalization.CultureInfo.CurrentUICulture) == 0)
return i;
}
}
return -1;
}
private int GetNextEnabledItemIndex(int startIndex, bool forward = true)
{
if (forward)
{
for (var i = startIndex + 1; i < Items.Count; i++)
{
if (IsItemEnabled(i))
return i;
}
return startIndex;
}
else
{
for (var i = startIndex - 1; i >= 0; i--)
{
if (IsItemEnabled(i))
return i;
}
return startIndex;
}
}
private class ListBoxNativeWindow : NativeWindow
{
private readonly DisabledItemComboBox Parent;
public ListBoxNativeWindow(IntPtr handle, DisabledItemComboBox parent)
{
Parent = parent;
AssignHandle(handle);
}
public int IndexFromPoint(int x, int y)
{
var n = SendMessage(Handle, 0x1a9u /* LB_ITEMFROMPOINT */, IntPtr.Zero, MAKELPARAM((ushort)x, (ushort)y));
if (HIWORD(n) == 0)
return LOWORD(n);
return -1;
}
protected override void WndProc(ref Message m)
{
if (!Parent.IsDisposed && m.Msg == 0x0202 || m.Msg == 0x0201 || m.Msg == 0x0203) /* WM_LBUTTONUP or WM_LBUTTONDOWN or WM_LBUTTONDBLCLK */
{
var idx = IndexFromPoint(SignedLOWORD(m.LParam), SignedHIWORD(m.LParam));
if (idx >= 0 && !Parent.IsItemEnabled(idx))
return;
}
base.WndProc(ref m);
}
}
}
}