topic Re: Composite graphic symbol in Qt Maps SDK Questions

Composite graphic symbol

RainerFarsch — Mon, 07 Sep 2015 00:49:38 GMT

I would like to render a circular graphic symbol, but with text inside the circle. For a simple example, I have the following class break example where I would like to set text inside the circle:

ClassBreakInfo {

minimum: 11.9

maximum: 12.1

symbol: SimpleMarkerSymbol {

color: "limegreen"

size: 2

}

Is there a way to add text to a SimpleMarkerSymbol. I see there isn't a property for text. Is there a way to composite SimpleMarkerSymbol and TextSymbol that I can bind to 'symbol:' ?

Thanks.

Re: Composite graphic symbol

ThomasDunn — Mon, 14 Sep 2015 16:28:41 GMT

Ranier,

Question: Would your text be static or supplied from an attribute or other dynamic source?

Thanks.

Re: Composite graphic symbol

RainerFarsch — Mon, 14 Sep 2015 16:59:55 GMT

Thomas,

That's a good question. If the text is static, then I would need a good number of ClassBreakInfo components - one for each unique text case!? If the text is set as an attribute then that would reduce the number of ClassBreakInfo components that I would need. Once the text is set for the graphic, it won't change for the life of the graphic.

So my answer is: it depends. I would be interested in hearing both solutions (if they exist) for the static and dynamic case.

Thanks.

-Rainer

Re: Composite graphic symbol

ThomasDunn — Mon, 14 Sep 2015 18:09:50 GMT

Ranier,

No, many class breaks for many text strings is not what I had in mind. Rather, I was thinking of static text for each class break, such as "small", "medium" and "large". This would be an unusual scenario.

As you have noted, there is no built-in provision for adding label text to a class break renderer's symbols. If you were displaying features from a dynamic map service, you could label features in various ways using DynamicLayerInfo.DrawingInfo.LabelingInfo.

The best you can do with graphics now is to display two co-located graphics per feature, one a marker symbol and another a text symbol built using an attribute from the graphic.

Re: Composite graphic symbol

RainerFarsch — Mon, 14 Sep 2015 21:41:30 GMT

Thomas,

Thanks. Here's a related question. Is it possible to change the color of a symbol based on a graphic's attribute given that a SimpleRenderer is used? Using sample code from ArcGIS Runtime SDK for Qt QML API: SimpleRenderer Class Reference (below), is it possible to use JS for the 'color:' binding to select color based on a graphic's attribute, or do I need to use a ClassBreakRender?

GraphicsLayer {

id: graphicsLayer

renderer: simple

}

SimpleRenderer {

id: simple

symbol: SimpleFillSymbol {

style: Enums.SimpleFillSymbolStyleForwardDiagonal

color: "#9050d5"

outline: SimpleLineSymbol {

color: "darkgrey"

width: 1

}

Re: Composite graphic symbol

ThomasDunn — Mon, 14 Sep 2015 22:39:29 GMT

Ranier,

Sorry, not through the renderer. You cannot bind the color property of a shared symbol to varying attribute values of individual graphics. You could instead create a new symbol for each graphic, where the color of the symbol is based on a graphic attribute.