LightningChart Support Forums

Posted: **Fri May 05, 2017 2:02 pm**

Hi,
I have implemented several AnnotationsXY 'Tables' based on your example.
They have size and location persistence as well as dynamic height based on content.

I need help with the resizing though.
The fonts need to scale as well as the table cell proportions.

Currently, during table creation, I am storing the creation font in the Tag object,

Code: Select all

       foreach (AnnotationXY axy in _chart.ViewXY.Annotations)
            {
                axy.Tag = axy.TextStyle.Font;
            }
            return elementCount;

Here is my Font resizing, it mostly works, keyword 'Mostly'

Could you PLEASE take a look at it please and tell me where I am going wrong?

Code: Select all

 if ((_table_prev_width != width) || (_table_prev_height != height))
            {
                float ratioWidth = _orig_Width / width;
                float ratioHeight = (float)((_orig_ActualHeight / height) * .70); //.70 was a feeble attempt to keep text from overlapping...
                float ratioMax = Math.Max(ratioWidth, ratioHeight);
                for (int index = _startingCellOfTable; index < _endingCellOfTable - 1; index++)
                {
                    AnnotationXY axy = _chart.ViewXY.Annotations[index];
                    Font origFont = (Font)axy.Tag;
                    float origSize = origFont.SizeInPoints;
                    float newSize = origSize * 1 / ratioMax;
                    Font newFont = new Font(origFont.Name, newSize, origFont.Style);
                    axy.TextStyle.Font = newFont;
                }
            }

Thanks.

Posted: **Mon May 08, 2017 10:17 am**

Hi,

I think you would benefit from MeasureText method. For example.

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_chart.MeasureText( Annotation.Text, Annotation.TextStyle.Font);    // output in DIP units

Don't forget, that for accurate reading from this method, Chart must be rendered first (_chart.EndUpdate() call or _chart.AfterRendering event). In addition, please note the units (DIP to PX conversion is important in WPF).

Next your would need to find the longest text/Annotation in each column and compare to the size you want to assign. For example, our 'Annotations 'Table' would need this comparison

Code: Select all

while (width < (AnnSize3.X + AnnSize4.X + AnnSize8.X) * DpiHelper.DpiXFactor)
{    }

Finally, you would need to reduce font size by some value and MeasureText again.

Hope this helps.
All the best,
Kestutis

LightningChart Support Forums

AnnotationsXY Table Resizing and Fonts

AnnotationsXY Table Resizing and Fonts

Re: AnnotationsXY Table Resizing and Fonts