NT8 color to Brush conversion with Opacity

[NinjaTrader_ChelseaB]

Hi turbofib,

BackBrush lets you change the color of the background behind a specific bar (not the entire chart).

Even in State.DataLoaded, OnBarUpdate has not started processing bars yet. There needs to be at least one bar on the chart to be able to change the background behind it.

From my understanding, this code will not work in OnStateChange().

[turbofib]

excuse me...but i 've problem to code it..

i want to do this :

if (Open[0] < Close[0])
{
BarBrushes[-displacement] = trendColor;
BarBrushes[-displacement].Opacity = alpha;
}

but i can't to change Opacity because this property is only read..

how i do it?..

thanks..

[NinjaTrader_ChelseaB]

Hello turbofib,

As a heads up, using negative indexes are not officially supported.

To set opacity on a brush, you will need to make a new brush that isn't frozen, set the color and opacity and then set the property you are wanting to set to that new brush object.

This is what you were doing in post #14 though this being done at the wrong time. Cloning the brush, setting the new brushes opacity, freezing, is correct. Doing this in OnStateChange is not correct.

Brush newBrush = BackBrush.Clone();
newBrush.Opacity = 1;
newBrush.Freeze();
BackBrush = newBrush;

[turbofib]

Excuse me... but i want to change body candle color...not background....
Backbrush class is not correct

[NinjaTrader_ChelseaB]

Hello turbofib,

To change the color of a bar use BarBrush.

http://ninjatrader.com/support/helpGuides/nt8/en-us/barbrush.htm

[turbofib]

Originally in nt7

BarColorSeries[-displacement] = Color.FromArgb(alpha, trendColor);

ok..finally i've code in following mode

BarBrushes[displacement] = trendColor;

Brush newBrush = BarBrushes[displacement].Clone();
newBrush.Opacity = opacity;// alpha;
newBrush.Freeze();

BarBrushes[displacement] = newBrush;

i ask you 2 question :

1)My above code is too expensive or is ok?

2)another question...

i can't to set directly BarBrus with BarBrush.=Opacity because is property only read

but in guide of .net i read that :

https://msdn.microsoft.com/it-it/library/system.windows.media.brush.opacity(v=vs.110).aspx

public double Opacity { get; set; }

So why this?

[NinjaTrader_ChelseaB]

Hello turbofib,

I do not understand your meaning when you ask if the code is "expensive".
If you are asking if the code will cause high CPU I cannot answer this question because I don't know when or how often this code is called.
However, to set the brush of a bar with opacity this is required. If you want opacity you must use this.

A get and set does not mean that an object is not read-only.

A set is required to set an object that is not read-only.Any property without a set is basically read-only simply because it doesn't have a setter.
A property that is read-only cannot be set even if it has a get and set.

https://www.dotnetperls.com/readonly

https://msdn.microsoft.com/en-us/library/w86s7x04.aspx

[seykool]

Try adding the following to OnBarUpdate()

BackBrush = Brushes.Green;
Brush newBrush = BackBrush.Clone();
newBrush.Opacity = 0.25;
newBrush.Freeze();
BackBrush = newBrush;

Hi guys,

how could I rewrite the above code from Chelsea to change the opacity of a plot? The best would be to create a color with applied opacity during the on State.DataLoaded.

I tried:

Brush color = originalColor;
color.Opacity = colorOpacity / 100;
color.Freeze();

which doesn't work

This one here does work but only if I use Color.xxxxxx. When I use originalColor, it throws an error that I can't convert a Media.Brush to a Media.Color.

color1 = new SolidColorBrush(originalColor) { Opacity = colorOpacity / 100 };
color1 .Freeze();

How could I apply opacity to a color used for a plot?


Greetings

[NinjaTrader_Kate]

Hello seykool,

Thank you for your reply.

I'm attaching an example that demonstrates how to set the opacity of a plot.

Please let us know if we may be of further assistance to you.

[nothingbutprofits]

Here's the code snippets that work well:

public variables in if (State == State.SetDefaults):

BackgroundOpacity = 15; // 15% as default value
BackgroundUpColor = Brushes.DarkGreen;
BackgroundDownColor = Brushes.DarkRed;

else if (State == State.Configure):

Brush temp = BackgroundUpColor.Clone();
temp.Opacity = BackgroundOpacity / 100.0;
temp.Freeze();
BackgroundUpColor = temp;

Brush temp1 = BackgroundDownColor.Clone();
temp1.Opacity = BackgroundOpacity / 100.0;
temp1.Freeze();
BackgroundDownColor = temp1;

You add the properties and function to update the background color.

Happy Holidays!

[seykool]

Hi,

you both wrote in the same moment.

nothingbutprofits, this only works for BackBrushes. On Plots it appears to not work.
But therefore Kate, your script works well.

Thanks to you both!
Happy new year!

[dj22522]

Here's the code snippets that work well:

public variables in if (State == State.SetDefaults):

BackgroundOpacity = 15; // 15% as default value
BackgroundUpColor = Brushes.DarkGreen;
BackgroundDownColor = Brushes.DarkRed;

else if (State == State.Configure):

Brush temp = BackgroundUpColor.Clone();
temp.Opacity = BackgroundOpacity / 100.0;
temp.Freeze();
BackgroundUpColor = temp;

Brush temp1 = BackgroundDownColor.Clone();
temp1.Opacity = BackgroundOpacity / 100.0;
temp1.Freeze();
BackgroundDownColor = temp1;

You add the properties and function to update the background color.

Happy Holidays!

Many thanks for this:

I put the above code in the respective sections.
The chart background does colour as it's supposed to and the opacity also works.

The problem is when I restart/re open NT8 the indicator I added the above code to is gone from the chart and I have to add it from the indicator list each time. In other words the indicator I added the above code to doesn't save to the chart.

Generally speaking:
All I'm trying to do is have background colour with opacity function.
I can add background colour pretty easily to most of my indicators however things get in a mess when trying to have the opacity function.

As stated, doing the above does give me opacity function but the indicator isn't saving to the chart when I next open/start NT8.


Any help appreciated.

Many thanks

[NinjaTrader_Kate]

Hello dj22522,

Thank you for your reply.

Did you create inputs for the brush colors? If so, you'll need to make certain those inputs are properly serialized, or the indicator will not be able to be restored when a workspace is saved, closed and reopened.

I recommend reviewing this page of our help guide on serializing brushes:

https://ninjatrader.com/support/helpGuides/nt8/user_definable_color_inputs.htm

Please let us know if we may be of further assistance to you.

[dj22522]

Hello dj22522,

Thank you for your reply.

Did you create inputs for the brush colors? If so, you'll need to make certain those inputs are properly serialized, or the indicator will not be able to be restored when a workspace is saved, closed and reopened.

I recommend reviewing this page of our help guide on serializing brushes:

https://ninjatrader.com/support/help...lor_inputs.htm

Please let us know if we may be of further assistance to you.

Thank you for the reply Kate

Yes I have created inputs.

Assuming I've done this correctly I have the following :

protected override void OnStateChange()
{
if (State == State.SetDefaults) :

 protected override void OnStateChange()
{
if (State == State.SetDefaults)

 BackColourUp = Brushes.Blue;
BackColourDn = Brushes.Red;
BackgroundOpacity = 15; // 15% as default value

{

I then have the following in
else if (State == State.Configure)

else if (State == State.Configure)
{

Brush temp = BackColourUp.Clone();
temp.Opacity = BackgroundOpacity / 100.0;
temp.Freeze();
BackColourUp = temp;

Brush temp1 = BackColourDn.Clone();
temp1.Opacity = BackgroundOpacity / 100.0;
temp1.Freeze();
BackColourDn = temp1;


}

I have the following in Properties:

[NinjaScriptProperty]
[Display(Name="Back colour Up", Description="", Order=3, GroupName="Back Colour")]
public Brush BackColourUp
{ get; set; }

[Browsable(false)]
public string BackColourUpSerializable
{
get { return Serialize.BrushToString(BackColourUp); }
set { BackColourUp = Serialize.StringToBrush(value); }
}

[NinjaScriptProperty]
[Display(Name="Back colour Down", Description="", Order=4, GroupName="Back Colour")]
public Brush BackColourDn
{ get; set; }

[Browsable(false)]
public string BackColourDnSerializable
{
get { return Serialize.BrushToString(BackColourDn); }
set { BackColourDn = Serialize.StringToBrush(value); }
}


//Opacity
[Range(0, 100)]
[Display(Name="Back colour Opacity", Description="", Order=5, GroupName="Back Colour")]
public int BackgroundOpacity
{ get; set; }

What am I doing wrong ?

Many thanks

[NinjaTrader_Kate]

Hello dj22522,

Thank you for your reply.

This all looks correct - can you supply an export of the script so we may test on our end? You can export it from Tools > Export > NinjaScript Addon. Do not check the box to export as a compiled assembly or we will not be able to review the logic. Please attach the resulting .Zip file to your reply.

Thanks in advance; I look forward to assisting you further.