topic Re: How do I resize symbols from a 2525 dictionary renderer? in Qt Maps SDK Questions

How do I resize symbols from a 2525 dictionary renderer?

TroyFoster — Fri, 22 Oct 2021 14:28:40 GMT

I finally got my runtime qt app converted over from 100.4 to 100.11. I remember from one of the devsummit briefs that 2525 dictionary symbols were able to be resized in a later release. Is there a sample or code snippet displaying how to resize those dictionary symbols?

Re: How do I resize symbols from a 2525 dictionary renderer?

LucasDanzinger — Fri, 22 Oct 2021 18:28:45 GMT

There is no sample at the moment. Here is the doc - https://developers.arcgis.com/qt/cpp/api-reference/esri-arcgisruntime-dictionaryrenderer.html#setScaleExpression

Here is an example we have in our tests:

// Simple case... double the size ArcadeExpression* arcadeExpression = new ArcadeExpression("2", this); dictionaryRenderer->setScaleExpression(arcadeExpression); // More advanced case... double the size if the identity_code attribute is 4 ArcadeExpression* arcadeExpression = new ArcadeExpression("iif($feature.Identity_code == 4, 2,1)", this); dictionaryRenderer->setScaleExpression(arcadeExpression);

Here is an Arcade reference you can use to write your expressions - https://developers.arcgis.com/arcade/

Re: How do I resize symbols from a 2525 dictionary renderer?

KerryRobinson — Fri, 22 Oct 2021 18:37:58 GMT

Hi Troy. Yes, as Lucas mentioned, there is a new `scaleExpression` method on the Dictionary Renderer that can accept either a constant or an Arcade expression. So it doesn't set your symbol to a specific size, but you can scale all symbols based on a specific value, or use the expression to scale based on an attribute, map scale, etc.

Re: How do I resize symbols from a 2525 dictionary renderer?

TroyFoster — Mon, 25 Oct 2021 17:00:43 GMT

That just cleaned up about 130 lines of janky workaround to resize the symbols

Re: How do I resize symbols from a 2525 dictionary renderer?

VittorioBarulli — Fri, 18 Nov 2022 10:38:13 GMT

I'm using ArcGis 100.15(Qt) but I'm not able to use 'scaleExpression",

to be clearer:

I'm able to put on the map graphical elements from dictionarySymbolStyle(created with mil2525d.stylx),
Symbols generated from dictionarySymbolStyle are rendered inside a GraphicsOverlay by using a Graphic object
the GraphicsOverlay object is rendered (setRenderer) with DictionaryRenderer create with dictionarySymbolStyle (at point 1)

But if I try to use:

ArcadeExpression* arcadeExpression = new ArcadeExpression("2", this);
renderer->setScaleExpression(arcadeExpression);

nothing happens on the screen, the symbol is always drawn with default dimension.

I tryed to setScaleExpression during initialization and during runtime, but also the same result!

Do you have some advice?

Re: How do I resize symbols from a 2525 dictionary renderer?

VittorioBarulli — Fri, 18 Nov 2022 11:06:38 GMT

It' funny,

I found the solution just after my question.
The issue was that I used fetchSymbol to create the symbol inside the Graphics.
Instead, the correct way is to fill attribute() of the Graphics with proper properties.

Re: How do I resize symbols from a 2525 dictionary renderer?

KerryRobinson — Tue, 29 Nov 2022 02:25:52 GMT

Hi- If you don't need to set the scale based on an attribute value, you can also just use a constant value for setScaleExpression, like this:

renderer->setScaleExpression(2);

Otherwise, yes, you can set the attribute of the graphic and use that in an arcade expression to set the scale.

Kerry