Find Horizontal Midpoint of Chart

[ramckay]

Hello,
I'm modifying an NT drawing tool. For debugging I need to draw a horizontal line on a chart from the drawing tool modification. I tried to access High[0] and Low[0] but that doesn't compile. So, how can I find the chart horizontal midpoint to use with Draw.HorizontalLine()?
Thanks in Advance.

[ninZa]

Hi ramckay,

Please put the code below in the OnRender() function:

protected override void OnRender(ChartControl chartControl, ChartScale chartScale) {
    if (ChartControl == null) return;

    double middle = (chartScale.MaxValue + chartScale.MinValue) / 2;

    Draw.HorizontalLine(this, "test", middle, Brushes.Cyan);

    base.OnRender(chartControl, chartScale);

    if (IsInHitTest) return;
}

Regards,
William

[ramckay]

Hi William,
I put the code in OnRender() and the compiler is complaining about 'this' in Draw.Horizontal(). Error is:

Argument1: cannot convert from 'NinjaTrader.NinjaScript.DrawingTools.TestLoseFocu s' to 'NinjaTrader.NinjaScript.NinjaScriptBase'.

I tried:
'NinjaTrader.NinjaScript.NinjaScriptBase.this' - compiler complains.
'Draw.HorizontalLine((NinjaTrader.NinjaScript.Ninj aScriptBase)this, "test", middle, Brushes.Cyan);' - compiler complains.

Is there a using namespace that needs to be included?

Thanks for the help. I'm in new territory with DrawingTools. You're saving me hours of research.
Rod

[ninZa]

Hi ramckay,

You can use the RenderTarget.DrawLine() function from the SharpDX library to draw a horizontal line on a chart.

Please place the following code inside the OnRender() function:

protected override void OnRender(ChartControl chartControl, ChartScale chartScale) {
    if (ChartControl == null) return;

    double middle = (chartScale.MaxValue + chartScale.MinValue) / 2;

    float y = chartScale.GetYByValue(middle);
    int largeNumber = (int)Math.Pow(10, 8);
    float x1 = ChartControl.GetXByBarIndex(ChartBars, ChartBars.FromIndex) + largeNumber;
    float x2 = ChartControl.GetXByBarIndex(ChartBars, ChartBars.ToIndex) - largeNumber;

    SharpDX.Vector2 point0 = new SharpDX.Vector2(x1, y);
    SharpDX.Vector2 point1 = new SharpDX.Vector2(x2, y);

    RenderTarget.DrawLine(point0, point1, Brushes.Yellow.ToDxBrush(RenderTarget));
    base.OnRender(chartControl, chartScale);

    if (IsInHitTest) return;
}

Regards,
William

[ramckay]

Hi William,
I added the code to OnRender and then selected the name of the drawing tool from the Drawing Tool menu. A line is not drawn. I set breakpoint in OnRender and the process ends up in Dispatcher.cs at this while block:

                while (frame.Continue && GetMessage(ref msg, IntPtr.Zero, 0, 0))
                {
                    TranslateAndDispatchMessage(ref msg);
                }
                if (_frameDepth == 1 && _hasShutdownStarted)
                {
                    ShutdownImpl();
                }
​

I don't know what it is waiting for. I do not have any drawing methods in the drawing tool I'm working with so I'm guessing Dispatcher is waiting for a mouse point. If that sounds plausible I'll copy the methods for drawing a horizontal line into the Drawing Tool to give the disatcher something to work with.
Thanks,
Rod

[ramckay]

Hi William,
I added the code to and existing and working Drawing Tool and it works as advertised - horizontal line in the middle of the chart.
I appreciate the help.
Thanks,
Rod

[ninZa]

Hi ramckay,
You are welcome!
I'm glad to hear that I helped solve your problem.

Regards,
William