Customize System Block Appearance Programmatically

You can customize the icon for a MATLAB System block by adding descriptive text, port labels, and icon image.

Note

From R2023b, you can use the Mask Editor to design a MATLAB System block icon. You can also migrate existing icon customizations to the Mask Editor. This capability eliminates the need to develop or maintain the getInputNamesImpl, getOutputNamesImpl, and getIconImpl methods in a System object™ file. For more information, see Customize MATLAB System Icon and Dialog Box Using Mask Editor.

Specify Input and Output Names

Specify the names of the input and output ports of a System object–based block implemented using a MATLAB System block.

Use getInputNamesImpl and getOutputNamesImpl to specify the names of the input port as “source data” and the output port as “count.”

If you do not specify the getInputNamesImpl and getOutputNamesImpl methods, the object uses the stepImpl method input and output variable names for the input and output port names, respectively. If the stepImpl method uses varargin and varargout instead of variable names, the port names default to empty character vectors.

methods (Access = protected)
   function inputName = getInputNamesImpl(~)
          inputName = 'source data';
   end
   
   function outputName = getOutputNamesImpl(~)
          outputName = 'count';
   end
end

Complete Class Definition with Named Inputs and Outputs

Add Text to Block Icon

Add text to the block icon of a System object–based block implemented using a MATLAB System block.

Subclass from custom icon class.

classdef MyCounter < matlab.System & matlab.system.mixin.CustomIcon

Use getIconImpl to specify the block icon as New Counter with a line break between the two words.

methods (Access = protected)
    function icon = getIconImpl(~)
        icon = {'New','Counter'};
    end
end

Complete Class Definition File with Defined Icon

Add Image to Block Icon

Define an image on the block icon of a System object–based block implemented using a MATLAB System block.

Subclass from custom icon class.

classdef MyCounter < matlab.System & matlab.system.mixin.CustomIcon

Use getIconImpl method to call the matlab.system.display.Icon class and specify the image.

methods (Access = protected)
    function icon = getIconImpl(~)
        icon = matlab.system.display.Icon('counter.png');
    end
end

Complete Class Definition File with Icon Image