static LRESULT WindowProcedure(WindowHandle window, WindowMessage message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WindowMessage.InputLanguageChange:
dwCharSet = (CharacterSet)(uint)wParam;
goto case WindowMessage.Create;
case WindowMessage.Create:
using (DeviceContext dc = window.GetDeviceContext())
{
using (FontHandle font = Windows.CreateFont(0, 0, 0, 0, FontWeight.DoNotCare, false, false, false, dwCharSet,
OutputPrecision.Default, ClippingPrecision.Default, Quality.Default, FontPitch.FixedPitch, FontFamily.DoNotCare, null))
{
dc.SelectObject(font);
dc.GetTextMetrics(out TEXTMETRIC tm);
cxChar = tm.tmAveCharWidth;
cyChar = tm.tmHeight;
dc.SelectObject(StockFont.System);
}
}
goto CalculateSize;
case WindowMessage.Size:
cxClient = lParam.LowWord;
cyClient = lParam.HighWord;
CalculateSize:
// calculate window size in characters
cxBuffer = Math.Max(1, cxClient / cxChar);
cyBuffer = Math.Max(1, cyClient / cyChar);
// allocate memory for buffer and clear it
pBuffer = new char[cxBuffer, cyBuffer];
// set caret to upper left corner
xCaret = 0;
yCaret = 0;
if (window == Windows.GetFocus())
{
Windows.SetCaretPosition(xCaret * cxChar, yCaret * cyChar);
}
window.Invalidate(true);
return(0);
case WindowMessage.SetFocus:
// create and show the caret
window.CreateCaret(null, cxChar, cyChar);
Windows.SetCaretPosition(xCaret * cxChar, yCaret * cyChar);
window.ShowCaret();
return(0);
case WindowMessage.KillFocus:
// hide and destroy the caret
window.HideCaret();
Windows.DestroyCaret();
return(0);
case WindowMessage.KeyDown:
switch ((VirtualKey)wParam)
{
case VirtualKey.Home:
xCaret = 0;
break;
case VirtualKey.End:
xCaret = cxBuffer - 1;
break;
case VirtualKey.Prior:
yCaret = 0;
break;
case VirtualKey.Next:
yCaret = cyBuffer - 1;
break;
case VirtualKey.Left:
xCaret = Math.Max(xCaret - 1, 0);
break;
case VirtualKey.Right:
xCaret = Math.Min(xCaret + 1, cxBuffer - 1);
break;
case VirtualKey.Up:
yCaret = Math.Max(yCaret - 1, 0);
break;
case VirtualKey.Down:
yCaret = Math.Min(yCaret + 1, cyBuffer - 1);
break;
case VirtualKey.Delete:
for (int x = xCaret; x < cxBuffer - 1; x++)
{
pBuffer[x, yCaret] = pBuffer[x + 1, yCaret];
}
pBuffer[cxBuffer - 1, yCaret] = ' ';
window.HideCaret();
using (DeviceContext dc = window.GetDeviceContext())
{
using (FontHandle font = Windows.CreateFont(0, 0, 0, 0, FontWeight.DoNotCare, false, false, false, dwCharSet,
OutputPrecision.Default, ClippingPrecision.Default, Quality.Default, FontPitch.FixedPitch, FontFamily.DoNotCare, null))
{
dc.SelectObject(font);
unsafe
{
fixed(char *c = &pBuffer[xCaret, yCaret])
dc.TextOut(xCaret * cxChar, yCaret * cyChar, c, cxBuffer - xCaret);
}
dc.SelectObject(StockFont.System);
}
window.ShowCaret();
}
break;
}
Windows.SetCaretPosition(xCaret * cxChar, yCaret * cyChar);
return(0);
case WindowMessage.Char:
for (int i = 0; i < lParam.LowWord; i++)
{
switch ((char)wParam)
{
case '\b': // backspace
if (xCaret > 0)
{
xCaret--;
window.SendMessage(WindowMessage.KeyDown, (uint)VirtualKey.Delete, 1);
}
break;
case '\t': // tab
do
{
window.SendMessage(WindowMessage.Char, ' ', 1);
} while (xCaret % 8 != 0);
break;
case '\n': // line feed
if (++yCaret == cyBuffer)
{
yCaret = 0;
}
break;
case '\r': // carriage return
xCaret = 0;
if (++yCaret == cyBuffer)
{
yCaret = 0;
}
break;
case '\x1B': // escape
for (int y = 0; y < cyBuffer; y++)
{
for (int x = 0; x < cxBuffer; x++)
{
pBuffer[x, y] = ' ';
}
}
xCaret = 0;
yCaret = 0;
window.Invalidate(false);
break;
default: // character codes
pBuffer[xCaret, yCaret] = (char)wParam;
window.HideCaret();
using (DeviceContext dc = window.GetDeviceContext())
{
using (FontHandle font = Windows.CreateFont(0, 0, 0, 0, FontWeight.DoNotCare, false, false, false, dwCharSet,
OutputPrecision.Default, ClippingPrecision.Default, Quality.Default, FontPitch.FixedPitch, FontFamily.DoNotCare, null))
{
dc.SelectObject(font);
unsafe
{
fixed(char *c = &pBuffer[xCaret, yCaret])
dc.TextOut(xCaret * cxChar, yCaret * cyChar, c, 1);
}
dc.SelectObject(StockFont.System);
}
window.ShowCaret();
}
if (++xCaret == cxBuffer)
{
xCaret = 0;
if (++yCaret == cyBuffer)
{
yCaret = 0;
}
}
break;
}
}
Windows.SetCaretPosition(xCaret * cxChar, yCaret * cyChar);
return(0);
case WindowMessage.Paint:
using (DeviceContext dc = window.BeginPaint())
{
using (FontHandle font = Windows.CreateFont(0, 0, 0, 0, FontWeight.DoNotCare, false, false, false, dwCharSet,
OutputPrecision.Default, ClippingPrecision.Default, Quality.Default, FontPitch.FixedPitch, FontFamily.DoNotCare, null))
{
dc.SelectObject(font);
unsafe
{
for (int y = 0; y < cyBuffer; y++)
fixed(char *c = &pBuffer[0, y])
dc.TextOut(0, y * cyChar, c, cxBuffer);
}
dc.SelectObject(StockFont.System);
}
}
return(0);
case WindowMessage.Destroy:
Windows.PostQuitMessage(0);
return(0);
}
return(Windows.DefaultWindowProcedure(window, message, wParam, lParam));
}
