/// <summary>
/// Defines the common dialog box hook procedure that is overridden to add specific functionality to a common dialog box.
/// </summary>
/// <returns>
/// A zero value if the default dialog box procedure processes the message; a nonzero value if the default dialog box procedure ignores the message.
/// </returns>
/// <param name="hWnd">The handle to the dialog box window. </param><param name="msg">The message being received. </param><param name="wparam">Additional information about the message. </param><param name="lparam">Additional information about the message. </param>
protected override IntPtr HookProc(IntPtr hWnd, int msg, IntPtr wparam, IntPtr lparam)
{
// This code is lifted directly from System.Windows.Forms.FontDialog
switch (msg)
{
case NativeMethods.WM_COMMAND:
if ((int)wparam == 0x402)
{
NativeMethods.LOGFONT lf = new NativeMethods.LOGFONT();
NativeMethods.SendMessage(new HandleRef(null, hWnd), NativeMethods.WM_CHOOSEFONT_GETLOGFONT, 0, lf);
this.UpdateFont(lf);
int index = (int)NativeMethods.SendDlgItemMessage(new HandleRef(null, hWnd), 0x473, NativeMethods.CB_GETCURSEL, IntPtr.Zero, IntPtr.Zero);
if (index != NativeMethods.CB_ERR)
{
this.UpdateColor((int)NativeMethods.SendDlgItemMessage(new HandleRef(null, hWnd), 0x473, NativeMethods.CB_GETITEMDATA, (IntPtr)index, IntPtr.Zero));
}
try
{
this.OnApply(EventArgs.Empty);
}
catch (Exception e)
{
Application.OnThreadException(e);
}
}
break;
case NativeMethods.WM_INITDIALOG:
if (!this.ShowColor)
{
IntPtr hWndCtl = NativeMethods.GetDlgItem(new HandleRef(null, hWnd), NativeMethods.cmb4);
NativeMethods.ShowWindow(new HandleRef(null, hWndCtl), NativeMethods.SW_HIDE);
hWndCtl = NativeMethods.GetDlgItem(new HandleRef(null, hWnd), NativeMethods.stc4);
NativeMethods.ShowWindow(new HandleRef(null, hWndCtl), NativeMethods.SW_HIDE);
}
break;
}
return(base.HookProc(hWnd, msg, wparam, lparam));
}
/// <summary>
/// Updates the font described by the specified LOGFONT structure
/// </summary>
/// <param name="lf"> The source font. </param>
private void UpdateFont(NativeMethods.LOGFONT lf)
{
Font font;
try
{
// This one line is the whole point of having to write this class as it can
// throw an exception, which System.Windows.Forms.FontDialog doesn't handle
font = Font.FromLogFont(lf);
}
catch
{
font = null;
}
if (font != null)
{
this.Font = font;
}
}
/// <summary>
/// When overridden in a derived class, specifies a common dialog box.
/// </summary>
/// <returns>
/// true if the dialog box was successfully run; otherwise, false.
/// </returns>
/// <param name="hwndOwner">A value that represents the window handle of the owner window for the common dialog box. </param>
protected override bool RunDialog(IntPtr hwndOwner)
{
NativeMethods.LOGFONT lf;
NativeMethods.CHOOSEFONT cf;
IntPtr plf;
bool result;
int minSize;
int maxSize;
bool showColor;
lf = new NativeMethods.LOGFONT();
this.Font.ToLogFont(lf);
plf = Marshal.AllocHGlobal(Marshal.SizeOf(lf));
Marshal.StructureToPtr(lf, plf, false);
showColor = this.ShowColor || this.ShowEffects;
cf = new NativeMethods.CHOOSEFONT();
cf.lStructSize = Marshal.SizeOf(typeof(NativeMethods.CHOOSEFONT));
cf.Flags = this.GetFlags();
cf.hwndOwner = hwndOwner;
cf.lpfnHook = this.HookProc;
minSize = this.MinSize;
maxSize = this.MaxSize;
if (minSize > 0 || maxSize > 0)
{
cf.nSizeMin = minSize;
cf.nSizeMax = maxSize > 0 ? maxSize : int.MaxValue;
}
cf.rgbColors = ColorTranslator.ToWin32(showColor ? this.Color : Color.Black);
cf.lpLogFont = plf;
try
{
result = NativeMethods.ChooseFont(ref cf);
if (result)
{
// create a managed font from the updated LOGFONT
lf = (NativeMethods.LOGFONT)Marshal.PtrToStructure(plf, typeof(NativeMethods.LOGFONT));
if (!string.IsNullOrEmpty(lf.lfFaceName))
{
this.UpdateFont(lf);
}
// and update the color
if (showColor)
{
this.UpdateColor(cf.rgbColors);
}
}
}
finally
{
// always be freein' allocated memory!
Marshal.FreeHGlobal(plf);
}
return(result);
}
