public FlatComboAdapter(ComboBox comboBox, bool smallButton)
{
// adapter is re-created when combobox is resized, see IsValid method, thus we don't need to handle DPI changed explicitly
s_offsetPixels = comboBox.LogicalToDeviceUnits(OFFSET_2PIXELS);
_clientRect = comboBox.ClientRectangle;
int dropDownButtonWidth = SystemInformation.GetHorizontalScrollBarArrowWidthForDpi(comboBox._deviceDpi);
_outerBorder = new Rectangle(_clientRect.Location, new Size(_clientRect.Width - 1, _clientRect.Height - 1));
_innerBorder = new Rectangle(_outerBorder.X + 1, _outerBorder.Y + 1, _outerBorder.Width - dropDownButtonWidth - 2, _outerBorder.Height - 2);
_innerInnerBorder = new Rectangle(_innerBorder.X + 1, _innerBorder.Y + 1, _innerBorder.Width - 2, _innerBorder.Height - 2);
_dropDownRect = new Rectangle(_innerBorder.Right + 1, _innerBorder.Y, dropDownButtonWidth, _innerBorder.Height + 1);
// fill in several pixels of the dropdown rect with white so that it looks like the combo button is thinner.
if (smallButton)
{
_whiteFillRect = _dropDownRect;
_whiteFillRect.Width = WhiteFillRectWidth;
_dropDownRect.X += WhiteFillRectWidth;
_dropDownRect.Width -= WhiteFillRectWidth;
}
_origRightToLeft = comboBox.RightToLeft;
if (_origRightToLeft == RightToLeft.Yes)
{
_innerBorder.X = _clientRect.Width - _innerBorder.Right;
_innerInnerBorder.X = _clientRect.Width - _innerInnerBorder.Right;
_dropDownRect.X = _clientRect.Width - _dropDownRect.Right;
_whiteFillRect.X = _clientRect.Width - _whiteFillRect.Right + 1; // since we're filling, we need to move over to the next px.
}
}