Steema Central

Hi Steema
Delphi 10.3.3
TeeChart Pro v.2020.29.200113 32 bit VCL

I do not know whether my reply to an old post (2018) have been read.
The title of the post is:
Draw Multiple Transparent Bands with DateTime Bottom Axis

I do have the same problem, and I thereby found the above mentioned post as my solution
However, it's written in Java and I do not know how to translate the code into Delphi
The java code:
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<script type="text/javascript">

var Chart1;

function draw() {
Chart1 = new Tee.Chart("canvas1");

Chart1.legend.visible = false;
var line1 = Chart1.addSeries(new Tee.Line([50,30,20,70,10,60,40,50,10,0,100]) );
line1.format.stroke.size=4;

var oneDay = 86400000, oneHour = 60 * 60 * 1000, today = new Date().getTime();
line1.data.x = [];
for (var i=0; i<line1.count(); i++) {
line1.data.x.push(new Date(today + i * oneDay));
}

Chart1.axes.bottom.labels.dateFormat = "dd mmm";
Chart1.axes.bottom.increment = oneDay;

var myFormat1 = new Tee.Format(Chart1);
myFormat1.gradient.visible=true;
myFormat1.gradient.colors=["white","lime"];
myFormat1.transparency=0.5;

var myFormat2 = new Tee.Format(Chart1);
//myFormat1.gradient.visible=true;
myFormat2.fill="red";
myFormat2.transparency=0.2;

line1.beforeDraw=function() {

var x1 = Chart1.axes.bottom.calc(line1.data.x[2]),
y1 = Chart1.chartRect.y,
x2 = Chart1.axes.bottom.calc(line1.data.x[4]),
y2 = Chart1.chartRect.y + Chart1.chartRect.height;

// X,Y, Width, Height
myFormat1.rectangle(x1,y1, x2-x1, y2-y1);

x1 = Chart1.axes.bottom.calc(today + 7 * oneDay + 5 * oneHour),
y1 = Chart1.chartRect.y,
x2 = Chart1.axes.bottom.calc(today + 8 * oneDay + 2 * oneHour),
y2 = Chart1.chartRect.y + Chart1.chartRect.height;

// X,Y, Width, Height
myFormat2.rectangle(x1,y1, x2-x1, y2-y1);
}

Chart1.draw();
}
</script>
----------

Do you think it's possible to provide same solution in VCL (Delphi) - or - translate the Java code into Delphi

br.

Anders Balslev

Hello Anders,

The code is very similar in Delphi. I'm not sure exactly which part you need, but bear in mind that TeeChart VCL/FMX has a Colorband tool that may be used to plot the rectangles. If you wish to do so manually, then use the OnBeforDrawSeries event in a similar way.

eg. Please look at the TeeChart code samples for examples of setting the Brush in different ways, etc.
https://github.com/Steema/TeeChart-VCL-samples

The tutorials include details of variations on how to draw to the Canvas:
https://www.steema.com/docs/TeeChartVCLTutorials.htm

Regards,
Marc Meumann