public HelpBox ShowStage(HelpWorkflow workflow, HelpStage stage)
{
if (_currentHelpBox != null)
{
_host.Controls.Remove(_currentHelpBox);
}
_highlight = stage.HighlightControl;
_currentHelpBox = new HelpBox(workflow, stage.HelpText, stage.OptionButtonText);
_currentHelpBox.Location = stage.UseDefaultPosition ? GetGoodLocationForHelpBox(_currentHelpBox) : stage.HostLocationForStageBox;
_host.Controls.Add(_currentHelpBox);
_currentHelpBox.BringToFront();
_host.Invalidate();
return(_currentHelpBox);
}
private Point GetGoodLocationForHelpBox(HelpBox currentHelpBox)
{
var screenCoordinates = _highlight.PointToScreen(new Point(0, 0));
var highlightTopLeft = _host.PointToClient(screenCoordinates);
var highlightBottomLeft = new Point(highlightTopLeft.X, highlightTopLeft.Y + _highlight.ClientRectangle.Height);
//First lets try to place it like this
/**************HOST CONTROL BOUNDS*************
*
* HIGHLIGHT
* HIGHLIGHT
* MSG
*
*********************************************/
/**************HOST CONTROL BOUNDS*************
*
* HIGHLIGHT
* _ HIGHLIGHT
* ^ MSG<------availableSpaceHorizontally->
* |
* V availableSpaceBelowHighlight
*********************************************/
var availableSpaceBelowHighlight = _host.ClientRectangle.Height - highlightBottomLeft.Y;
var availableSpaceHorizontally = _host.ClientRectangle.Width - highlightBottomLeft.X;
//fallback
var availableSpaceAboveHighlight = highlightTopLeft.Y;
//there is enough space below
if (currentHelpBox.Height < availableSpaceBelowHighlight)
{
if (_currentHelpBox.Width < availableSpaceHorizontally)
{
return(highlightBottomLeft);
}
//not enough space horizontally so try to move MSG to left till there is enough space
/**************HOST CONTROL BOUNDS***********
*
* HIGHLIGHT
* <---|HIGHLIGHT
* MSG_MSG_MSGMSG_MSG_MSGMSG_MSG_MSGMSG_MSG_MSG
*
*********************************************/
return(new Point(Math.Max(0, _host.ClientRectangle.Width - currentHelpBox.Width), highlightBottomLeft.Y));
}
else if (currentHelpBox.Height < availableSpaceAboveHighlight)
{
//No space below so go above it
if (_currentHelpBox.Width < availableSpaceHorizontally)
{
return(new Point(highlightTopLeft.X, highlightTopLeft.Y - currentHelpBox.Height));
}
//consider moving X back because message box is so wide (See diagram above)
return(new Point(Math.Max(0, _host.ClientRectangle.Width - currentHelpBox.Width), highlightTopLeft.Y - currentHelpBox.Height));
}
var screenCoordinatesTopRight = _highlight.PointToScreen(new Point(_highlight.ClientRectangle.Width, 0));
var highlightTopRight = _host.PointToClient(screenCoordinatesTopRight);
var spaceToLeft = highlightTopLeft.X;
var spaceToRight = _host.ClientRectangle.Width - highlightTopRight.X;
//there is no space at all for this help box (so just overlap it on the bottom left of the screen space available)
if (spaceToRight < _currentHelpBox.Width && spaceToLeft < _currentHelpBox.Width)
{
return(new Point(0, _host.ClientRectangle.Height - _currentHelpBox.Height));
}
//there is space to the right or left so put it in whichever is greater
if (spaceToRight > spaceToLeft)
{
return(highlightTopRight);
}
return(new Point(highlightTopLeft.X - _currentHelpBox.Width, 0));
}