Matlab GUIs

1. Matlab GUIs GUIDE

2. Laying out the GUI Use GUIDE

3. OpeningFcn • GUIDE is going to create a function called ‘NameofGUI_OpeningFcn’ • This function takes 4 variables, in this order • Handle to figure (hObject) • eventdata, which is not used • A structure called handles • varargin, command line arguments to the GUI

4. OpenFcn is the initialization function, and is where you would place basic information & global variables • For example, for simple_gui all of the original data set up falls under OpenFcn % Create the data to plot. handles.peaks=peaks(35); handles.membrane=membrane; [x,y] = meshgrid(-8:.5:8); r = sqrt(x.^2+y.^2) + eps; sinc = sin(r)./r; handles.sinc = sinc; % Set the current data value. handles.current_data = handles.peaks; surf(handles.current_data)

5. Handles • guidata(object_handle,data) • stores the variable data as GUI data • Object_handle is usually the parent figure • Data can be any MATLAB variable but is usually a structure called handle when using GUIDE • If you modify the handle you have to resave it using guidata • Following on previous slide % Set the current data value. handles.current_data = handles.peaks; surf(handles.current_data) % Update handles structure guidata(hObject, handles);

6. get and set • get – used to query handle graphics object properties • Useful in GUIs to figure out if radio buttons are on or off for example • set – used to set handle graphics object properties • Frequently used set the ‘String’ portion of the variables in the handle structure

7. GUIDE • Use the GUIDE interface to move components around • To design the components, you open Property Inspector from the ‘View’ drop-down menu • ‘String’ is used to change the text associated with the component • ‘Tag’ is used to control the name of the Callback function associated with the component

8. Available Components • (look at guide)

9. Kinds of Callbacks (incomplete list) • ButtonDownFcn– executes when the GUI user presses a mouse button while the pointer is on or near a component or figure • Callback – Control action. Executes when a user clicks a push button or selects a menu item • ClickedCallback – Control action. Executes when the push tool or toggle tool is clicked.

10. CreateFcn – Initializes the component when a function creates it. • DeleteFcn – Performs cleanup operations just before a component or figure is destroyed. • KeyPressFcn – Executes when the user presses a keyboard key and the callbacks’s component or figure as focus

11. Panels and Button Groups • uipanel: Panels arrange GUI components into groups, making the interface easier to understand. ph = uipanel(fh,'PropertyName',PropertyValue,...) • uibuttongroup: Button groups are like panels but are used to manage exclusive selection behavior for radio buttons and toggle buttons bgh = uibuttongroup(fh,'PropertyName',PropertyValue,...)

12. Panels and button groups are containers that arrange GUI components into groups. • If you move the panel or button group, its children move with it and maintain their positions relative to the panel or button group. • The panel or button group become the handle on calls to uicontrol

13. ph = uipanel('Parent',fh,'Title','My Panel',... 'Position',[.25 .1 .5 .8]); pbh1 = uicontrol(ph,'Style','pushbutton','String','Button 1',... 'Units','normalized',... 'Position',[.1 .55 .8 .3]); pbh2 = uicontrol(ph,'Style','pushbutton','String','Button 2',... 'Units','normalized',... 'Position',[.1 .15 .8 .3]);

14. Menu Bars • uimenu: add a menu bar (ie. File, Edit, View, etc) mh = uimenu(parent,'PropertyName',PropertyValue,...) Example: mh= uimenu(fh,'Label','My menu'); eh1 = uimenu(mh,'Label','Item 1'); eh2 = uimenu(mh,'Label','Item 2','Checked','on'); seh1 = uimenu(eh1,'Label','Choice 1','Accelerator','C',... 'Enable','off'); seh2 = uimenu(eh1,'Label','Choice 2','Accelerator','H')

15. Reading in SAC data • Example we will look at is speedyseis • The sac reader in this case is a script (not a function) called get_sac, which sets variables • filename • npts • sampdelta • date • hour • minu • seco • data

16. Speedyseis is written in GUIDE • It has a pushbutton called ‘Get Sac file’, which has the following callback % --- Executes on button press in getSACfilebutton. function getSACfilebutton_Callback(hObject, eventdata, handles) global hObject handles %get_sac reads sac file and puts data into workspace of calling program/routine %uses SAC_file_prompt for prompt, if it does not exist - uses default prompt % SAC_file_prompt='Select a SAC file'; get_sac

17. Next we set some handles handles.filename=filename; handles.samprate=round(1/sampdelta); samprate_str=num2str(handles.samprate); set(handles.sampratedisplay,'String',samprate_str); handles.delt=1/handles.samprate; handles.fulldata=data; handles.fulldatalen=length(handles.fulldata);

18. handles.fulldatend=length(handles.fulldata); handles.datstart=1; handles.datend=handles.fulldatalen; plotitall%function defined later in the script guidata(hObject, handles); %standard last line in a function in which handles%have been set or revised

19. Available Components • axes: Axes enable your GUI to display graphics such as graphs and images using commands such as: plot, surf, line, bar, polar, pie, contour, and mesh. ah = axes('Parent',fh,'Position',[.15 .15 .7 .7]);

20. uicontrol • Check boxes can generate an action when checked and indicate their state as checked or not checked. cbh = uicontrol(fh,'Style','checkbox',... 'String','Display file extension',... 'Value',1,'Position',[30 20 130 20]) • Edit text components are fields that enable users to enter or modify text strings. eth = uicontrol(fh,'Style','edit',... 'String','Enter your name here.',... 'Position',[30 50 130 20]);

21. uicontrol • List boxes display items and enable users to select one or more items lbh = uicontrol(fh,'Style','listbox',... 'String',{'one','two','three','four'},... 'Value',1,'Position',[30 80 130 20]); • Pop-up menus (drop down menus) open to display a list of choices pmh = uicontrol(fh,'Style','popupmenu',... 'String',{'one','two','three','four'},... 'Value',1,'Position',[30 80 130 20]);

22. uicontrol • Push buttons generate an action when clicked pbh = uicontrol(fh,'Style','pushbutton','String','Button 1',... 'Position',[50 20 60 40]); • Radio buttons are similar to check boxes, but are typically mutually exclusive within a group of related radio buttons. Use button groups to manage related radio buttons rbh = uicontrol(fh,'Style','radiobutton',... 'String','Indent nested functions.',... 'Value',1,'Position',[30 20 150 20]);

23. uicontrol • Sliders accept numeric input within a specified range by enabling the user to move a sliding bar sh = uicontrol(fh,'Style','slider',... 'Max',100,'Min',0,'Value',25,... 'SliderStep',[0.05 0.2],... 'Position',[30 20 150 30]); • Static text controls display lines of text; typically used to label other controls sth = uicontrol(fh,'Style','text',... 'String','Select a data set.',... 'Position',[30 50 130 20]);

24. uicontrol • Toggle buttons generate an action and indicate whether they are turned on or off. tbh = uicontrol(fh,'Style','togglebutton',... 'String','Left/Right Tile',... 'Value',0,'Position',[30 20 100 30]);

25. uitable: Callbacks are fired when table cells are selected or edited. Tables can be made to be user editable. th = uitable(fh,'Data',magic(5)); tpos= get(th,'Position’) texn= get(th,'Extent’) tpos(3) = texn(3); tpos(4) = texn(4); set(th, 'Position’, tpos)