Creating Graphical User Interfaces

How the GUI and Dialog Work

This section describes what occurs when you click the Close button on the GUI:

1. User clicks the Close button. Its callback then
• Gets the current position of the GUI from the handles structure with the command

• pos_size = get(handles.figure1,'Position')
  

• Calls the modal dialog with the command

• user_response = modaldlg('Title','Confirm Close');
  

• This is an example of calling a GUI with a property value pair. In this case, the figure property is 'Title', and its value is the string 'Confirm Close'. Opening modaldlg with this syntax displays the text "Confirm Close" at the top of the dialog. See Input and Output Arguments for more information about the options for calling a GUI.

2. The modal dialog opens with the 'Position' obtained from the GUI that calls it.
3. The opening function in the modal dialog M-file:
• Makes the dialog modal.
• Executes the uiwait command, which causes the dialog to wait for the user to click the Yes button or the No button, or click the close box (X) on the window border.
4. When a user clicks one of the two push buttons, the callback for the push button
• Updates the output field in the handles structure
• Executes uiresume to return control to the opening function where uiwait is called.
5. The output function is called, which returns the string Yes or No as an output argument, and deletes the dialog with the command

1. delete(handles.figure1)

6. When the GUI with the Close button regains control, it receives the string Yes or No. If the answer is 'No', it does nothing. If the answer is 'Yes', the close button callback closes the GUI with the command

1. delete(handles.figure1)

For more information on programming GUIs, see Programming GUIs.

Running the GUI with the Close Button

Example: Displaying an Image File