|
// 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.Drawing.Interop;
using System.Runtime.CompilerServices;
using Windows.Win32.UI.Controls.Dialogs;
namespace System.Windows.Forms;
/// <summary>
/// Represents a common dialog box that displays a list of fonts that are currently installed on the system.
/// </summary>
[DefaultEvent(nameof(Apply))]
[DefaultProperty(nameof(Font))]
[SRDescription(nameof(SR.DescriptionFontDialog))]
public class FontDialog : CommonDialog
{
protected static readonly object EventApply = new();
private const int DefaultMinSize = 0;
private const int DefaultMaxSize = 0;
private CHOOSEFONT_FLAGS _options;
private Font? _font;
private Color _color;
private int _minSize = DefaultMinSize;
private int _maxSize = DefaultMaxSize;
private bool _usingDefaultIndirectColor;
/// <summary>
/// Initializes a new instance of the <see cref="FontDialog"/> class.
/// </summary>
public FontDialog() => Reset();
/// <summary>
/// Gets or sets a value indicating whether the dialog box allows graphics device interface
/// (GDI) font simulations.
/// </summary>
[SRCategory(nameof(SR.CatBehavior))]
[DefaultValue(true)]
[SRDescription(nameof(SR.FnDallowSimulationsDescr))]
public bool AllowSimulations
{
get => !GetOption(CHOOSEFONT_FLAGS.CF_NOSIMULATIONS);
set => SetOption(CHOOSEFONT_FLAGS.CF_NOSIMULATIONS, !value);
}
/// <summary>
/// Gets or sets a value indicating whether the dialog box allows vector font selections.
/// </summary>
[SRCategory(nameof(SR.CatBehavior))]
[DefaultValue(true)]
[SRDescription(nameof(SR.FnDallowVectorFontsDescr))]
public bool AllowVectorFonts
{
get => !GetOption(CHOOSEFONT_FLAGS.CF_NOVECTORFONTS);
set => SetOption(CHOOSEFONT_FLAGS.CF_NOVECTORFONTS, !value);
}
/// <summary>
/// Gets or sets a value indicating whether
/// the dialog box displays both vertical and horizontal fonts or only
/// horizontal fonts.
/// </summary>
[SRCategory(nameof(SR.CatBehavior))]
[DefaultValue(true)]
[SRDescription(nameof(SR.FnDallowVerticalFontsDescr))]
public bool AllowVerticalFonts
{
get => !GetOption(CHOOSEFONT_FLAGS.CF_NOVERTFONTS);
set => SetOption(CHOOSEFONT_FLAGS.CF_NOVERTFONTS, !value);
}
/// <summary>
/// Gets or sets a value indicating whether the user can change the character set specified in the Script combo
/// box to display a character set other than the one currently displayed.
/// </summary>
[SRCategory(nameof(SR.CatBehavior))]
[DefaultValue(true)]
[SRDescription(nameof(SR.FnDallowScriptChangeDescr))]
public bool AllowScriptChange
{
get => !GetOption(CHOOSEFONT_FLAGS.CF_SELECTSCRIPT);
set => SetOption(CHOOSEFONT_FLAGS.CF_SELECTSCRIPT, !value);
}
/// <summary>
/// Gets or sets a value indicating the selected font color.
/// </summary>
[SRCategory(nameof(SR.CatData))]
[SRDescription(nameof(SR.FnDcolorDescr))]
[DefaultValue(typeof(Color), "Black")]
public Color Color
{
get
{
// Convert to RGB and back to resolve indirect colors like SystemColors.ControlText
// to real color values like Color.Lime
return !_usingDefaultIndirectColor ? _color : ColorTranslator.FromWin32(ColorTranslator.ToWin32(_color));
}
set
{
if (!value.IsEmpty)
{
_color = value;
_usingDefaultIndirectColor = false;
}
else
{
_color = SystemColors.ControlText;
_usingDefaultIndirectColor = true;
}
}
}
/// <summary>
/// Gets or sets a value indicating whether the dialog box allows only the selection of fixed-pitch fonts.
/// </summary>
[SRCategory(nameof(SR.CatBehavior))]
[DefaultValue(false)]
[SRDescription(nameof(SR.FnDfixedPitchOnlyDescr))]
public bool FixedPitchOnly
{
get => GetOption(CHOOSEFONT_FLAGS.CF_FIXEDPITCHONLY);
set => SetOption(CHOOSEFONT_FLAGS.CF_FIXEDPITCHONLY, value);
}
/// <summary>
/// Gets or sets a value indicating the selected font.
/// </summary>
[SRCategory(nameof(SR.CatData))]
[SRDescription(nameof(SR.FnDfontDescr))]
public Font Font
{
get
{
Font? result = _font ?? Control.DefaultFont;
float actualSize = result.SizeInPoints;
if (_minSize != DefaultMinSize && actualSize < MinSize)
{
result = new Font(result.FontFamily, MinSize, result.Style, GraphicsUnit.Point);
}
if (_maxSize != DefaultMaxSize && actualSize > MaxSize)
{
result = new Font(result.FontFamily, MaxSize, result.Style, GraphicsUnit.Point);
}
return result;
}
set => _font = value;
}
/// <summary>
/// Gets or sets a value indicating whether the dialog box specifies an error condition if the
/// user attempts to select a font or style that does not exist.
/// </summary>
[SRCategory(nameof(SR.CatBehavior))]
[DefaultValue(false)]
[SRDescription(nameof(SR.FnDfontMustExistDescr))]
public bool FontMustExist
{
get => GetOption(CHOOSEFONT_FLAGS.CF_FORCEFONTEXIST);
set => SetOption(CHOOSEFONT_FLAGS.CF_FORCEFONTEXIST, value);
}
/// <summary>
/// Gets or sets the maximum point size a user can select.
/// </summary>
[SRCategory(nameof(SR.CatData))]
[DefaultValue(DefaultMaxSize)]
[SRDescription(nameof(SR.FnDmaxSizeDescr))]
public int MaxSize
{
get => _maxSize;
set
{
if (value < 0)
{
value = 0;
}
_maxSize = value;
if (_maxSize > 0 && _maxSize < _minSize)
{
_minSize = _maxSize;
}
}
}
/// <summary>
/// Gets or sets a value indicating the minimum point size a user can select.
/// </summary>
[SRCategory(nameof(SR.CatData))]
[DefaultValue(DefaultMinSize)]
[SRDescription(nameof(SR.FnDminSizeDescr))]
public int MinSize
{
get => _minSize;
set
{
if (value < 0)
{
value = 0;
}
_minSize = value;
if (_maxSize > 0 && _maxSize < _minSize)
{
_maxSize = _minSize;
}
}
}
/// <summary>
/// Gets the value passed to CHOOSEFONT.Flags.
/// </summary>
protected int Options => (int)_options;
/// <summary>
/// Gets or sets a value indicating whether the dialog box allows selection of fonts for all non-OEM and Symbol
/// character sets, as well as the ANSI character set.
/// </summary>
[SRCategory(nameof(SR.CatBehavior))]
[DefaultValue(false)]
[SRDescription(nameof(SR.FnDscriptsOnlyDescr))]
public bool ScriptsOnly
{
get => GetOption(CHOOSEFONT_FLAGS.CF_SCRIPTSONLY);
set => SetOption(CHOOSEFONT_FLAGS.CF_SCRIPTSONLY, value);
}
/// <summary>
/// Gets or sets a value indicating whether the dialog box contains an Apply button.
/// </summary>
[SRCategory(nameof(SR.CatBehavior))]
[DefaultValue(false)]
[SRDescription(nameof(SR.FnDshowApplyDescr))]
public bool ShowApply
{
get => GetOption(CHOOSEFONT_FLAGS.CF_APPLY);
set => SetOption(CHOOSEFONT_FLAGS.CF_APPLY, value);
}
/// <summary>
/// Gets or sets a value indicating whether the dialog box displays the color choice.
/// </summary>
[SRCategory(nameof(SR.CatBehavior))]
[DefaultValue(false)]
[SRDescription(nameof(SR.FnDshowColorDescr))]
public bool ShowColor { get; set; }
/// <summary>
/// Gets or sets a value indicating whether the dialog box contains controls that allow the
/// user to specify strikethrough, underline, and text color options.
/// </summary>
[SRCategory(nameof(SR.CatBehavior))]
[DefaultValue(true)]
[SRDescription(nameof(SR.FnDshowEffectsDescr))]
public bool ShowEffects
{
get => GetOption(CHOOSEFONT_FLAGS.CF_EFFECTS);
set => SetOption(CHOOSEFONT_FLAGS.CF_EFFECTS, value);
}
/// <summary>
/// Gets or sets a value indicating whether the dialog box displays a Help button.
/// </summary>
[SRCategory(nameof(SR.CatBehavior))]
[DefaultValue(false)]
[SRDescription(nameof(SR.FnDshowHelpDescr))]
public bool ShowHelp
{
get => GetOption(CHOOSEFONT_FLAGS.CF_SHOWHELP);
set => SetOption(CHOOSEFONT_FLAGS.CF_SHOWHELP, value);
}
/// <summary>
/// Occurs when the user clicks the Apply button in the font dialog box.
/// </summary>
[SRDescription(nameof(SR.FnDapplyDescr))]
public event EventHandler? Apply
{
add => Events.AddHandler(EventApply, value);
remove => Events.RemoveHandler(EventApply, value);
}
/// <summary>
/// Returns the state of the given option flag.
/// </summary>
internal bool GetOption(CHOOSEFONT_FLAGS option) => (_options & option) != 0;
/// <summary>
/// Specifies the common dialog box hook procedure that is overridden to add
/// specific functionality to a common dialog box.
/// </summary>
protected override IntPtr HookProc(IntPtr hWnd, int msg, IntPtr wparam, IntPtr lparam)
{
switch ((uint)msg)
{
case PInvoke.WM_COMMAND:
if (wparam != 0x402)
{
break;
}
LOGFONT logFont = default;
PInvoke.SendMessage((HWND)hWnd, PInvoke.WM_CHOOSEFONT_GETLOGFONT, (WPARAM)0, ref logFont);
UpdateFont(ref logFont);
int index = (int)PInvoke.SendDlgItemMessage((HWND)hWnd, (int)PInvoke.cmb4, PInvoke.CB_GETCURSEL, 0, 0);
if (index != PInvoke.CB_ERR)
{
UpdateColor((COLORREF)(int)PInvoke.SendDlgItemMessage(
(HWND)hWnd,
(int)PInvoke.cmb4,
PInvoke.CB_GETITEMDATA,
(WPARAM)index,
0));
}
if (NativeWindow.WndProcShouldBeDebuggable)
{
OnApply(EventArgs.Empty);
}
else
{
try
{
OnApply(EventArgs.Empty);
}
catch (Exception e)
{
Application.OnThreadException(e);
}
}
break;
case PInvoke.WM_INITDIALOG:
if (!ShowColor)
{
HWND hWndCtl = PInvoke.GetDlgItem((HWND)hWnd, (int)PInvoke.cmb4);
PInvoke.ShowWindow(hWndCtl, SHOW_WINDOW_CMD.SW_HIDE);
hWndCtl = PInvoke.GetDlgItem((HWND)hWnd, (int)PInvoke.stc4);
PInvoke.ShowWindow(hWndCtl, SHOW_WINDOW_CMD.SW_HIDE);
}
break;
}
return base.HookProc(hWnd, msg, wparam, lparam);
}
/// <summary>
/// Raises the <see cref="Apply"/> event.
/// </summary>
protected virtual void OnApply(EventArgs e) => (Events[EventApply] as EventHandler)?.Invoke(this, e);
/// <summary>
/// Resets all dialog box options to their default values.
/// </summary>
public override void Reset()
{
_options = CHOOSEFONT_FLAGS.CF_SCREENFONTS | CHOOSEFONT_FLAGS.CF_EFFECTS;
_font = null;
_color = SystemColors.ControlText;
_usingDefaultIndirectColor = true;
ShowColor = false;
_minSize = DefaultMinSize;
_maxSize = DefaultMaxSize;
SetOption(CHOOSEFONT_FLAGS.CF_TTONLY, true);
}
private void ResetFont() => _font = null;
protected override unsafe bool RunDialog(IntPtr hWndOwner)
{
using var dc = GetDcScope.ScreenDC;
using Graphics graphics = Graphics.FromHdcInternal(dc);
LOGFONTW logFont = Font.ToLogicalFont(graphics);
CHOOSEFONTW cf = new()
{
lStructSize = (uint)sizeof(CHOOSEFONTW),
hwndOwner = (HWND)hWndOwner,
lpLogFont = &logFont,
Flags = (CHOOSEFONT_FLAGS)Options | CHOOSEFONT_FLAGS.CF_INITTOLOGFONTSTRUCT | CHOOSEFONT_FLAGS.CF_ENABLEHOOK,
lpfnHook = HookProcFunctionPointer,
hInstance = PInvoke.GetModuleHandle((PCWSTR)null),
nSizeMin = _minSize,
nSizeMax = _maxSize == 0 ? int.MaxValue : _maxSize,
rgbColors = ShowColor || ShowEffects ? _color : SystemColors.ControlText
};
if (_minSize > 0 || _maxSize > 0)
{
cf.Flags |= CHOOSEFONT_FLAGS.CF_LIMITSIZE;
}
// if ShowColor=true then try to draw the sample text in color,
// if ShowEffects=false then we will draw the sample text in standard control text color regardless.
// (limitation of windows control)
Debug.Assert(cf.nSizeMin <= cf.nSizeMax, "min and max font sizes are the wrong way around");
// The native font dialog does not currently support Per Monitor V2 mode. We are setting DpiAwareness
// to SystemAware as a workaround. This action has no effect when the application is not running in
// Per Monitor V2 mode.
//
// https://microsoft.visualstudio.com/OS/_workitems/edit/42835582
using (ScaleHelper.EnterDpiAwarenessScope(DPI_AWARENESS_CONTEXT.DPI_AWARENESS_CONTEXT_SYSTEM_AWARE))
{
if (!PInvoke.ChooseFont(&cf))
{
return false;
}
}
if (!logFont.FaceName.IsEmpty)
{
UpdateFont(ref Unsafe.As<LOGFONTW, LOGFONT>(ref logFont));
UpdateColor(cf.rgbColors);
}
return true;
}
/// <summary>
/// Sets the given option to the given boolean value.
/// </summary>
internal void SetOption(CHOOSEFONT_FLAGS option, bool value)
{
if (value)
{
_options |= option;
}
else
{
_options &= ~option;
}
}
/// <summary>
/// Indicates whether the <see cref="Font"/> property should be persisted.
/// </summary>
private bool ShouldSerializeFont() => !Font.Equals(Control.DefaultFont);
public override string ToString() => $"{base.ToString()}, Font: {Font}";
private void UpdateColor(Color color)
{
if (_color != color)
{
_color = color;
_usingDefaultIndirectColor = false;
}
}
private void UpdateFont(ref LOGFONT lf)
{
using var dc = GetDcScope.ScreenDC;
using Font fontInWorldUnits = Font.FromLogFont(in lf, dc);
// The dialog claims its working in points (a device-independent unit),
// but actually gives us something in world units (device-dependent).
_font = ControlPaint.FontInPoints(fontInWorldUnits);
}
}
|