Xamarind.Android System.Drawing.Color != Android.Color

[Thomas]

Hi.
For xamarin android teecharts we use System.Drawing.Colors. For native controls we use Android.Graphics.Color.
But with the same argb components they look different. For example #333333 color in System.Drawing.Color on charts is darker than Android.Graphics.Color?
Maybe there is some property in TChart like shadow which can change chart look, but i can't find it. Alpha is set to opaque.
How to make equal colors?
Thanks in advance.

[Narcís]

Hi Thomas,

Where does this occur in TeeChart? By default, some TeeChart pens are automatically slightly darkened for aesthetic purposes.

BTW, you may also be interested in the Steema.TeeChart.Utils.ToAndroidColor(Color r); method that transforms a System.Drawing.Color color to Android.Graphics.Color.

Code: Select all

    /// <summary>
    ///Converts a System.Drawing.Color to Android.Graphics.Color
    /// </summary>
    public static Android.Graphics.Color ToAndroidColor(Color r)
    {
      return new Android.Graphics.Color(r.ToArgb());
    }

[Narcís]

Hi Thomas,

By default, some TeeChart pens are automatically slightly darkened for aesthetic purposes.

You can still eliminate this effect as I suggested here though.

[Thomas]

Hi!
It appears in CircularGauge.FaceBrush.Color.
Pen color doesn't help to solve this issue.
Steema.TeeChart.Utils.ToAndroidColor() returns correct color, but it looks darker on the screen.

[Narcís]

Hi Thomas,

Thanks for your reply. Ok, the problem is not about pens but brushes. I created a chart using this code:

Code: Select all

    private Steema.TeeChart.TChart tChart1;

    private void InitializeChart()
    {
      tChart1 = new Steema.TeeChart.TChart(this);
      tChart1.Aspect.View3D = false;

      Steema.TeeChart.Themes.BlackIsBackTheme myTheme = new Steema.TeeChart.Themes.BlackIsBackTheme(tChart1.Chart);
      myTheme.Apply();
	  
      string hexColor = "#333333";
      ColorConverter converter = new ColorConverter();
      Color c = (Color)converter.ConvertFromString(hexColor);

      Steema.TeeChart.Styles.CircularGauge circularGauge1 = new Steema.TeeChart.Styles.CircularGauge(tChart1.Chart);
      circularGauge1.FaceBrush.Gradient.Visible = false;
      circularGauge1.FaceBrush.Color = c;

      tChart1.Panel.Gradient.Visible = false;
      tChart1.Panel.Color = c;

      SetContentView(tChart1);
    }

Which produced this chart:

device-2014-01-30-133736.png (87.46 KiB) Viewed 11396 times

I copied a section of the CircularGauge over the panel to compare colors:

ColorComp.png (110.27 KiB) Viewed 11405 times

Honestly, using latest TeeChart for Xamarin.Android build (v4.13.12.13) from December 2013, I can not see any difference between circularGauge1.FaceBrush.Color and tChart1.Panel.Color. This can also be seen in red, for example:

device-2014-01-30-130014.png (92.56 KiB) Viewed 11401 times

Can you see any color differences? Can you reproduce the problem with the code I posted? If not, can you please modify my code snippet so that we can reproduce the problem here? Finally, which TeeChart for Xamarin.Android build are you using?

Thanks in advance.

[Thomas]

The difference appearance not between FaceBrush and Panel colors.
It appears between android LinearLayout background color and Chart Panel color.
Sorry for misleading information.

[Narcís]

Hi Thomas,

I can not reproduce the problem using the code below either:

Code: Select all

    private Steema.TeeChart.TChart tChart1;

    private void InitializeChart()
    {
      tChart1 = new Steema.TeeChart.TChart(this);

      Steema.TeeChart.Themes.BlackIsBackTheme myTheme = new Steema.TeeChart.Themes.BlackIsBackTheme(tChart1.Chart);
      myTheme.Apply();
	  
      string hexColor = "#333333";
      ColorConverter converter = new ColorConverter();
      Color c = (Color)converter.ConvertFromString(hexColor);
      //c = Color.Red;

      Steema.TeeChart.Styles.CircularGauge circularGauge1 = new Steema.TeeChart.Styles.CircularGauge(tChart1.Chart);
      circularGauge1.FaceBrush.Gradient.Visible = false;
      circularGauge1.FaceBrush.Color = c;

      tChart1.Panel.Gradient.Visible = false;
      tChart1.Panel.Color = c;

      tChart1.Aspect.View3D = false;
      tChart1.Zoom.Style = Steema.TeeChart.ZoomStyles.Classic;

      LinearLayout layout = new LinearLayout(this);
      layout.SetBackgroundColor(Steema.TeeChart.Utils.ToAndroidColor(c));
      layout.AddView(tChart1, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FillParent, 400));
      SetContentView(layout);
    }

It produces those screenshots:

device-2014-01-30-153239.png (61.47 KiB) Viewed 11388 times

device-2014-01-30-153431.png (65.51 KiB) Viewed 11396 times

Does this code work fine at your end? Can you please modify it so that we can reproduce the problem here?

Thanks in advance.