Steema Central

Posted: **Mon Mar 03, 2008 7:07 am**

Hi

I want to be able to force the drawline to remain horizontal, if for example the user is holding down a specific key while drawing. I tried the following line of code in the OnDrawLineToolLineDrag event:

Chart1.Tools.Items(Chart1.Tools.Count - 1).asDrawLine.ToPoint.Y = Chart1.Tools.Items(Chart1.Tools.Count - 1).asDrawLine.FromPoint.Y

It's a bit 'messy' though. Is there some way to do this?

Thanks

Posted: **Mon Mar 03, 2008 11:13 am**

Hi Rossmc,

It wasn't as easy as seemed. I tested using different events and always appeared both normal line and horizontal line while drawing. And trying to solve this, I tried to deactivate the tool, but then the old lines disappeared too.

So, the best way I can think to do this is to draw directly to the canvas the temporal line and add the line to the tool in OnMouseUp event. Note that I use KeyCode 16 (Left Shift key) to enable "horizontal forcing". And also note that I use OnMouseDown event to store the origin of the line in xx and yy variables. And I use OnMouseMove event to draw the temporal line I mentioned above.

Code: Select all

Dim KeyActivation, LineDrawing As Boolean
Dim xx, yy As Integer

Private Sub Form_Load()
  TeeCommander1.Chart = TChart1
  KeyActivation = False
  LineDrawing = False
  TChart1.Tools.Items(0).asDrawLine.EnableDraw = False
  TChart1.Zoom.Enable = False
End Sub

Private Sub TChart1_OnKeyDown(ByVal KeyCode As Long, ByVal Shift As TeeChart.EShiftState)
  If KeyCode = 16 Then
    KeyActivation = True
  End If
End Sub

Private Sub TChart1_OnKeyUp(ByVal KeyCode As Long, ByVal Shift As TeeChart.EShiftState)
  If KeyCode = 16 Then
    KeyActivation = False
  End If
End Sub

Private Sub TChart1_OnMouseDown(ByVal Button As TeeChart.EMouseButton, ByVal Shift As TeeChart.EShiftState, ByVal X As Long, ByVal Y As Long)
  xx = X
  yy = Y
  If TChart1.Tools.Items(0).asDrawLine.Clicked(X, Y) < 0 Then
    LineDrawing = True
  End If
End Sub

Private Sub TChart1_OnMouseMove(ByVal Shift As TeeChart.EShiftState, ByVal X As Long, ByVal Y As Long)
  If LineDrawing Then
    TChart1.Repaint
    If KeyActivation Then
      TChart1.Canvas.DrawLine xx, yy, X, yy
    Else
      TChart1.Canvas.DrawLine xx, yy, X, Y
    End If
  End If
End Sub

Private Sub TChart1_OnMouseUp(ByVal Button As TeeChart.EMouseButton, ByVal Shift As TeeChart.EShiftState, ByVal X As Long, ByVal Y As Long)
  If LineDrawing Then
    If KeyActivation Then
      TChart1.Tools.Items(0).asDrawLine.AddLine TChart1.Axis.Bottom.CalcPosPoint(xx), _
                TChart1.Axis.Left.CalcPosPoint(yy), _
                TChart1.Axis.Bottom.CalcPosPoint(X), _
                TChart1.Axis.Left.CalcPosPoint(yy)
    Else
      TChart1.Tools.Items(0).asDrawLine.AddLine TChart1.Axis.Bottom.CalcPosPoint(xx), _
                TChart1.Axis.Left.CalcPosPoint(yy), _
                TChart1.Axis.Bottom.CalcPosPoint(X), _
                TChart1.Axis.Left.CalcPosPoint(Y)
    End If
    
    LineDrawing = False
  End If
End Sub

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Horizontal Drawline

Horizontal Drawline