Creating Graphical User Interfaces

Launching the GUI

The GUI is nonblocking and nonmodal since it is designed to be used as an analysis tool.

Application Options Settings

This GUI uses the following application option settings:

• Resize behavior: Non-resizable
• Command-line accessibility: Off
• Application M-file options selected:

Generate callback function prototypes

Application allows only one instance to run

Use system color scheme for background

Opening the Simulink Block Diagrams

This example is designed to work with the F14 Simulink model. Since the GUI sets parameters and runs the simulation, the F14 model must be open when the GUI is displayed. When the application M-file launches the GUI, it executes the model_open subfunction. The purpose of the subfunction is to:

• Determine if the model is open (find_system).
• Open the block diagram for the model and the subsystem where the parameters are being set, if not open already (open_system).
• Change the size of the controller Gain block so the gain value can be displayed (set_param).
• Bring the GUI forward so it is displayed on top of the Simulink diagrams (figure).
• Set the block parameters to match the current settings in the GUI.

This is the code for the model_open subfunction:

function model_open(handles)
if  isempty(find_system('Name','f14')),
    open_system('f14'); open_system('f14/Controller')
    set_param('f14/Controller/Gain','Position',[275 14 340 56])
    figure(handles.F14ControllerEditor)
    set_param('f14/Controller Gain','Gain',...
        get(handles.KfCurrentValue,'String'))
    set_param('f14/Controller/Proportional plus integral compensator',...
        'Numerator',...
        get(handles.KiCurrentValue,'String'))
end

How to Use the GUI (Text of GUI Help)

Programming the Slider and Edit Text Components