MATLAB: Index of the items in a listbox

app designerlistboxorder

Using app designer, is it possible to get the index of the selected items from the listbox?

Example: I have 6 items in the listbox; data1, data2, vector1, vector2, vector3 and emc.

If data1, vector1, vector2 and emc are selected, I want to read the location of these items in the listbox, which is 1, 3, 4, 6.

Best Answer

I'm not sure what you mean by order. The value property of the listbox tells you which items are selected, so in your example you'll get {'data1', 'vector1', 'vector2', 'emc'}. If you want the index of selected elements, you can either pass your selection to ismember and get its second output, or fill the ItemsData property with the indices:

using ismember:

listitems = {'data1', 'data2', 'vector1', 'vector2', 'vector3', 'emc'};
hfig = uifigure;
hbox = uilistbox(hfig, 'Items', listitems, 'Multiselect', 'on');
hbox.Value = {'data1', 'vector1', 'vector2', 'emc'};  %simulate user selection

%get index of selected values

[~, index] = ismember(hbox.Value, hbox.Items)

using ItemsData:

listitems = {'data1', 'data2', 'vector1', 'vector2', 'vector3', 'emc'};
hfig = uifigure;
hbox = uilistbox(hfig, 'Items', listitems, 'ItemsData', 1:numel(listitems), 'Multiselect', 'on');
hbox.Value = [1 3 4 6];  %simulate user selection
%get index of selected values
index = hbox.Value  %returns corresponding ItemsData

Related Solutions

MATLAB: How to create a listbox with a scrollbar starting at the bottom of the listbox, when using GUIDE in MATLAB

One way to have the scroll bar begin at the bottom of the Listbox is to set the 'Value' property of the Listbox to the number of elements in the list through the Property Inspector. The Property Inspector is a separate user interface that can be found as one of the menu items when right-clicking on the Listbox when designing the GUI. For example, if you have 6 elements choices in a list, setting the 'Value' property of the Listbox to '6' displays the starting point of the scroll bar at the bottom of the Listbox.

An alternative way to set the position of the scroll bar is to use the commands set(handles.listbox1,'Value',x) or set(handles.listbox1,'ListboxTop',x) in the Callback function, where x is the index of the last list item in the Listbox. For example,

set(handles.listbox1,'String',data); %populate the list with data

index = size(get(handles.listbox1,'string'), 1); %get how many items are in the list box

set(handles.listbox1,'ListboxTop',index); %set the index of last item to be the index of the top-most string displayed in list box.

set(handles.listbox1,'Value',index);

When setting the 'Value' parameter, the last element in the list gets highlighted. On the other hand, setting the 'ListboxTop' parameter does not highlight the last element in the Listbox.

MATLAB: Display trailing edge of a long strings of a listbox by hovering the mouse over the string

See https://undocumentedmatlab.com/blog/setting-listbox-mouse-actions

% Prepare the Matlab listbox uicontrol
hFig = figure;
listItems = {'apple','orange','banana','lemon','cherry','pear','melon'};
hListbox = uicontrol(hFig, 'style','listbox', 'pos',[20,20,60,60], 'string',listItems);
 
% Get the listbox's underlying Java control
jScrollPane = findjobj(hListbox);
 
% We got the scrollpane container - get its actual contained listbox control
jListbox = jScrollPane.getViewport.getComponent(0);
 
% Convert to a callback-able reference handle
jListbox = handle(jListbox, 'CallbackProperties');
% Set the mouse-movement event callback
set(jListbox, 'MouseMovedCallback', {@mouseMovedCallback,hListbox});
 
% Mouse-movement callback
function mouseMovedCallback(jListbox, jEventData, hListbox)
   % Get the currently-hovered list-item
   mousePos = java.awt.Point(jEventData.getX, jEventData.getY);
   hoverIndex = jListbox.locationToIndex(mousePos) + 1;
   listValues = get(hListbox,'string');
   hoverValue = listValues{hoverIndex};
 
   % Modify the tooltip based on the hovered item
   msgStr = sprintf('<html>item #%d: <b>%s</b></html>', hoverIndex, hoverValue);
   set(hListbox, 'Tooltip',msgStr);
end  % mouseMovedCallback

Best Answer

Related Solutions

MATLAB: How to create a listbox with a scrollbar starting at the bottom of the listbox, when using GUIDE in MATLAB

MATLAB: Display trailing edge of a long strings of a listbox by hovering the mouse over the string

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