reset

Class: matlab.task.LiveTask
Namespace: matlab.task

Reset instance of Live Editor task subclass

Since R2022a

Syntax

reset(obj)


Description

reset(obj) resets the state of the task. It executes when a user restores the default values of the task by clicking the options button at the top-right of the task and selecting Restore Default Values. Define this method in a method block with no arguments, along with the get.Summary, get.State, set.State, and generateCode methods.

Input Arguments

obj — Object of the class

task object

Object of the class that inherits from the matlab.task.LiveTask base class.

Attributes

Abstract

true

To learn about attributes of methods, see Method Attributes.

Examples

Display Image Using Custom Live Editor Task

Define a class called DisplayImage that creates a custom Live Editor task for displaying an image.

To define the class, create a file called DisplayImage.m that contains the following class definition with these features:

• State and Summary public properties that store the current state of the task and a dynamic summary of what the task does.

• Private properties that store the edit field and button for selecting an image.

• A setup method that initializes the task.

• A generateCode method that updates the generated code for the task when the selected image changes.

• get.Summary, get.State, and set.State methods for getting and setting the summary and state of the task.

• An inputImageFile method that prompts the user to select an image to display.

• A reset method that resets the state of the task.

classdef DisplayImage < matlab.task.LiveTask
    properties(Access = private,Transient)
        FileNameEditField           matlab.ui.control.EditField
        BrowseButton                matlab.ui.control.Button
    end

    properties(Dependent)
        State
        Summary
    end

    methods(Access = protected)
        function setup(task)
            createComponents(task);
            setComponentsToDefault(task);
        end
    end

    methods
        function [code,outputs] = generateCode(task)
            if isempty(task.FileNameEditField.Value)
                % Return empty values if there is not enough
                % information to generate code
                code = "";
                outputs = {};
                return
            end
            
            outputs = {"im"};
            code = ["% Get Image"
                outputs{1} + " = imread(""" + ...
                task.FileNameEditField.Value + """);"
                ""
                "% Visualize results"
                "figure"          
                "imshow(" + outputs{1} + ");"];
        end
        
        function summary = get.Summary(task)
            if isempty(task.FileNameEditField.Value)
                summary = "Display selected image";
            else
                [~,name,~] = fileparts(task.FileNameEditField.Value);
                summary = "Display image '" + name + "'";
            end
        end

        function state = get.State(task)
            state = struct;
            state.FileNameEditFieldValue = task.FileNameEditField.Value;
        end

        function set.State(task,state)
            task.FileNameEditField.Value = state.FileNameEditFieldValue; 
        end
        
        function reset(task)
            setComponentsToDefault(task);
        end
    end

    methods(Access = private)
        function createComponents(task)
            task.LayoutManager.RowHeight = ["fit" "fit" "fit"]; 
            task.LayoutManager.ColumnWidth = "fit";

            % Row 1: Select image section label
            uilabel(task.LayoutManager,"Text","Select image", ...
                "FontWeight","bold");

            % Row 2: Select data section components
            inputgrid = uigridlayout(task.LayoutManager,"RowHeight", ...
                "fit","ColumnWidth",{"fit",200,"fit"},"Padding",0);
            uilabel(inputgrid,"Text","Input image");
            task.FileNameEditField = uieditfield(inputgrid, ...
                "Editable",false);            
            task.BrowseButton = uibutton(inputgrid,"Text","Browse", ...
               "ButtonPushedFcn",@task.inputImageFile);
            
            % Row 3: Display results section label
            uilabel(task.LayoutManager,"Text","Display results", ...
                "FontWeight","bold");
        end

        function setComponentsToDefault(task)
            task.FileNameEditField.Value = "";    
        end

        function inputImageFile(task,~,~)
            % Display uigetfile dialog box
            filterspec = ["*.jpg;*.tif;*.png;*.gif","All Image Files"];
            [f,p] = uigetfile(filterspec);
            
            % Make sure user did not cancel uigetfile dialog box
            if (ischar(p))
               fileName = [p f];
               task.FileNameEditField.Value = fileName;
            end
            
            notify(task,"StateChanged");
        end
    end
end

Next, configure the task metadata by calling the matlab.task.configureMetadata function and selecting the DisplayImage.m file. The Task Metadata dialog box opens with all of the required task metadata details prepopulated.

Select OK to use the prepopulated metadata details. MATLAB creates a folder named resources inside the folder containing your task class definition file. Inside the resources folder, MATLAB generates a file named liveTasks.json.

Add the folder containing the task class definition file to the MATLAB path by calling the addpath function or using the Add Folder button in the Set Path dialog box.

Add the task to a live script. On a code line, type display. MATLAB shows a list of suggested matches.

Select Display Image from the list. MATLAB adds the Display Image task to the live script.

Version History

Introduced in R2022a