Use datatips within App Designer

I am creating a GUI with App Designer and I want to add datatips so that the user can move their mouse over a table and see additional information that is not in the table column headers, i.e. units. Is this possible?

Answer 1

[Ayush Singh]

Hey ScottE,

Adding custom datatips (tooltips) directly to UITable components for individual cells is not natively supported in the same way as it is for plots. However, you can achieve a similar effect by using uitable properties and callbacks.

Here’s an approach to simulate datatips for a UITable in App Designer by using the CellSelectionCallback and TooltipString properties:

You can follow below steps to acheive the same:

1. Add a UITable to Your App:

Drag a UITable component onto your app from the Component Library.

2. Define Your Data and Units:

Store the information (like units) in a separate structure or cell array.

3. Implement the CellSelectionCallback:

Use the `CellSelectionCallback` to update the tooltip based on the selected cell.

Here’s an example to illustrate how you can implement this:

Here is the complete example:

classdef MyApp < matlab.apps.AppBase
    
    % Properties that correspond to app components
    properties (Access = public)
        UIFigure  matlab.ui.Figure
        UITable   matlab.ui.control.Table
    end
    
    properties (Access = private)
        Units % Cell array to store units or additional info
    end
    
    methods (Access = private)
        
        % Function to initialize the table and units
        function initializeTable(app)
            % Example data for the table
            data = {
                'Item1', 10, 20.5;
                'Item2', 15, 30.75;
                'Item3', 20, 40.25
                };
            
            % Set the data to the UITable
            app.UITable.Data = data;
            
            % Define the units or additional information
            app.Units = {
                'Item Name', 'Count (units)', 'Value (USD)'
                };
        end
        
        % Cell selection callback function
        function UITableCellSelection(app, event)
            % Get the indices of the selected cell
            indices = event.Indices;
            
            if ~isempty(indices)
                % Get the column index of the selected cell
                colIndex = indices(2);
                
                % Update the tooltip based on the selected column
                tooltipText = app.Units{colIndex};
                app.UITable.Tooltip = tooltipText;
            else
                % Clear the tooltip if no cell is selected
                app.UITable.Tooltip = '';
            end