An interesting uitree utility

March 30, 2011 5 Comments

“uitree” is consistently one of the most-popular search terms on this site, together with “uitable” and “uitab”. I also receive frequent questions about tree components in Matlab.
I already wrote a series of articles on Matlab’s built-in semi-documented uitree (starting here), and I am on a constant lookout for additional interesting angles on uitree to post here. Brett Shoelson’s recent review of 2005’s Pick-of-the-Week utilities, provided me with such an opportunity.
One of 2005’s featured utilities, Structure Explorer by Hassan Lahdili, originally written using Microsoft’s TreeView ActiveX control, was apparently rewritten using Matlab’s Java-based uitree. This enables the utility to run on non-Windows platforms and have a more consistent look-and-feel with Matlab’s Java-based GUI:

Hassan Lahdili's Structure Explorer (click to enlarge)

Hassan’s ExploreStruct utility, in addition to being useful as-is, provides a very useful learning tool for uitree integration in Matlab GUI. This utility uses custom icons for different node types, custom callbacks for node expansion (NodeWillExpandCallback) and node selection (NodeSelectedCallback), and tree context (right-click) menu.
Unfortunately, it appears that the ExploreStruct utility has not been updated for compatibility with the latest Matlab releases. This causes numerous warning messages about not using ‘v0’ when calling uitree and uitreenode. I also had to add a call to drawnow following the uitree‘s creation in line #30, otherwise the tree did not appear (due to EDT issues). Also, I had to comment out line #83 (set(root,’UIContextMenu’, cmenu);) which caused an error (“There is no ‘UIContextMenu’ property in the ‘com.mathworks.hg.peer.UITreeNode’ class”) – the tree’s context-menu actually works even without this line.
Finally, I had to fix line #182 so that the node icons will appear correctly:

%pth = [matlabroot, '\work\exp_struct_icons\'];  %old
pth = [fileparts(which(mfilename)) '\exp_struct_icons\'];  %new

ExploreStruct is not documented and does not have extensive error-checking that I would like to see in real-world applications. But it is relatively easy to read and understand due to its use of internal functions and meaningful variable names.
Altogether, aside from the minor nuances mentioned above, I believe that readers who are interested in implementing custom tree objects in their Matlab GUI can learn a lot from this utility, and you can easily adapt its code for your own needs (or if you can’t, I am always willing to help).

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Aurélien April 4, 2011 at 01:03 Reply

I often use this utility in my GUIs that I call directly from uimenu . It allows me to check very quickly the contents of my structures. I also added another cell in the right panel (like Name, Size , Class) to display the current value of selected item. Currently it is the best explorer of structure that I found on the FEX.

I am not really surprised that uitable , uitree are the most-popular search terms. IMHO, these features should have been officially implemented and documented in a MATLAB release for a while since they are really helpful.
Amir May 17, 2015 at 01:48 Reply

Hello Yair,

First your blog is really useful and helpful.
I’m working on a GUI that contain a uitree, now I wanted to export that uitree to enable user to save it to an external variable.
but, there is known problem that the java class is not serializable.
Now I’m try to use that uitree utility in order to convert a struct to a uitree, but the utility is not working. (I’m working with R2015a release)
It getting me an error message:
“Error using set
The name ‘UserData’ is not an accessible property for an instance of class
‘com.mathworks.mwswing.MJScrollPane’.

Error in explorestruct (line 37)
set(tmp, ‘UserData’, cell_Data);”

It looks like there is no ‘UserData’ field for MJScrollPane, do you know why this field is unavailable and how to solve it?

Yair Altman May 17, 2015 at 01:56 Reply

MathWorks removed the UserData property (and some other generic properties such as ApplicationData) from Java components a few releases ago. In general, code that relies on undocumented features cannot be expected to work forever, it may indeed break in some future release.

You will need to contact the utility’s creator to adapt it for new Matlab releases, or modify the relevant utility yourself, or hire a consultant to help you.

Peter Cook October 4, 2017 at 02:09 Reply

Yair,
I wrote this to fill a need I’ve had for a lightweight “structure explorer” type utility that lets me navigate a struct quickly without the need to necessarily plot the data. I create the tree as I traverse the structure so I didn’t have to make an ExpandFcn/MousePressedCallback; I also wrote a version that expands all nodes initially but it can be a bit overwhelming for a broad or deep tree (e.g. a struct returned by xml2struct). Maybe you or someone reading this page will find this useful as the original utility doesn’t work in recent MATLAB releases.

function mtree = mapStruct(s)
 
    hFig1 = figure('pos',[32,32,512,960]);
    hFig1.ToolBar = 'none';
    hFig1.MenuBar = 'none';
    hFig1.Name = 'Struct Explorer';
    hFig1.NumberTitle = 'off';
 
    root = uitreenode('v0','root','root',[],false);
    mtree = uitree('v0','Root',root,'Parent',hFig1);
 
    function structTraverse(s,node)
        f = fieldnames(s);
        %explore each field in the input struct s
        for kField = 1 : length(f)
            structField = s.(f{kField}); %structField = getfield(s,f{kField});
 
            %if struct field is a cell array of structs, convert to struct array IFF structs are identical
            if iscell(structField)
                if all(cellfun(@isstruct,structField))
                    try
                        structField = [structField{:}];
                    catch
                        %add some sort of exception handling
                    end
                end
            end
 
            %if the structure field is also a struct explore each field
            if isstruct(structField) %strcmp(structFieldClass,'struct')
                %determine depth of struct field & enumerate if depth > 1
                structDepth = length(structField);
                if structDepth > 1
                    newNode = uitreenode('v0',f{kField},f{kField},[],false);
                    node.add(newNode);
                    %if the depth of the structure field is greater than 1
                    %add a blank parent node then add each layer/depth level as a node in the tree
                    for kLayer = 1:structDepth
                        nodeLayerName = sprintf('%s(%d)',f{kField},kLayer);
                        nextNode = uitreenode('v0', nodeLayerName,nodeLayerName,[],false);
                        newNode.add(nextNode);
                        structTraverse(structField(kLayer),nextNode)
                    end
                else
                    %if the depth of the structure field is 1 add it as a node
                    nextNode = uitreenode('v0',f{kField},f{kField},[],false);
                    node.add(nextNode);
                    structTraverse(structField,nextNode)
                end
            else
                %make a node for the variable/attribute and display information about the variable
                newNode = uitreenode('v0',f{kField},f{kField},[],false);
                [nRow,nCol] = size(structField);
                structFieldClass = class(structField);
                if isempty(structField)
                    displayString = 'empty';
                elseif nRow==1 && ischar(structField)
                    displayString = structField;
                elseif nRow==1 && nCol==1 && any(strcmp(structFieldClass,{'single','double','logical'}))
                    displayString = sprintf('%f',structField);
                else
                    displayString = sprintf('%dx%d %s',nRow,nCol,structFieldClass);
                end
                nextNode = uitreenode('v0',displayString,displayString,[],true);
                newNode.add(nextNode);
                node.add(newNode);
            end
        end
    end
 
    structTraverse(s,root)
    mtree.reloadNode(root)
    mtree.Position(3) = 512;
 
end

function mtree = mapStruct(s) hFig1 = figure('pos',[32,32,512,960]); hFig1.ToolBar = 'none'; hFig1.MenuBar = 'none'; hFig1.Name = 'Struct Explorer'; hFig1.NumberTitle = 'off'; root = uitreenode('v0','root','root',[],false); mtree = uitree('v0','Root',root,'Parent',hFig1); function structTraverse(s,node) f = fieldnames(s); %explore each field in the input struct s for kField = 1 : length(f) structField = s.(f{kField}); %structField = getfield(s,f{kField}); %if struct field is a cell array of structs, convert to struct array IFF structs are identical if iscell(structField) if all(cellfun(@isstruct,structField)) try structField = [structField{:}]; catch %add some sort of exception handling end end end %if the structure field is also a struct explore each field if isstruct(structField) %strcmp(structFieldClass,'struct') %determine depth of struct field & enumerate if depth > 1 structDepth = length(structField); if structDepth > 1 newNode = uitreenode('v0',f{kField},f{kField},[],false); node.add(newNode); %if the depth of the structure field is greater than 1 %add a blank parent node then add each layer/depth level as a node in the tree for kLayer = 1:structDepth nodeLayerName = sprintf('%s(%d)',f{kField},kLayer); nextNode = uitreenode('v0', nodeLayerName,nodeLayerName,[],false); newNode.add(nextNode); structTraverse(structField(kLayer),nextNode) end else %if the depth of the structure field is 1 add it as a node nextNode = uitreenode('v0',f{kField},f{kField},[],false); node.add(nextNode); structTraverse(structField,nextNode) end else %make a node for the variable/attribute and display information about the variable newNode = uitreenode('v0',f{kField},f{kField},[],false); [nRow,nCol] = size(structField); structFieldClass = class(structField); if isempty(structField) displayString = 'empty'; elseif nRow==1 && ischar(structField) displayString = structField; elseif nRow==1 && nCol==1 && any(strcmp(structFieldClass,{'single','double','logical'})) displayString = sprintf('%f',structField); else displayString = sprintf('%dx%d %s',nRow,nCol,structFieldClass); end nextNode = uitreenode('v0',displayString,displayString,[],true); newNode.add(nextNode); node.add(newNode); end end end structTraverse(s,root) mtree.reloadNode(root) mtree.Position(3) = 512; end

Yair Altman October 4, 2017 at 11:17 Reply

@Peter – Thanks for sharing

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SKM (21 days 18 hours ago): It is 10 years since the original article, but I would like to bring to attention that such issues have not yet been resolved. For example, programmatically opening and closing files in...
Yair Altman (52 days 4 hours ago): @Ken – I cannot reproduce your report, it works as expected for me even on R2022b
Yair Altman (52 days 7 hours ago): try to use the waitfor function
Danila Berezin (56 days 18 hours ago): Hi I have a similar issue. Did you find a workaround for this?
Ken Johnson (65 days 7 hours ago): Why does the second catch block in this code example not work? (It works if you restart MATLAB and then omit the first try-catch block.) try a = [0,0;0,0]\[1;1]; catch...
Santiago (69 days 22 hours ago): It works perfectly. Thanks so much.
Yair Altman (70 days 3 hours ago): Santiago – you can get the mouse X,Y positions from the Java eventData object (getX(), getY()), convert this into a point (p=java.awt.Point(x,y)), then use the JTable...
Santiago (70 days 19 hours ago): Hi Yair. I’m using the MouseReleasedCallback but I need to get the indices of the selected cell. I can get them without problems with left clicks but, if I try to do it with...
Yair Altman (88 days 23 hours ago): Adam – perhaps there is a builtin syntax-pane control for uifigures, but I am not aware of one. Perhaps you can try to implement a uihtml panel with a GeSHi...
Yair Altman (88 days 23 hours ago): Marcel – 12 years and ~25 releases since I wrote this article, it is no surprise at all that some things no longer work the same way. In fact, the surprising thing is that...
Yair Altman (88 days 23 hours ago): See the documentation of the uitree function. The text in my article refers to the legacy (Java-based) uitree version, which is not documented, whereas it is documented and...
SOULEYMANE Zakaria (94 days 5 hours ago): Hello. Thank you for sharing. I would like to know if someone could help me with the syntax it takes to use uitree on “Appdesigner”. When I use the syntax you...
Nicholas (94 days 17 hours ago): Hello Yair, Have you, or anyone else, had an opportunity to try this demo in R2022a/b? I cannot get the HTMLBrowserPanel object to update with html text (nor with an html file, if...
Marcel (107 days 5 hours ago): Hi, I am trying to set the legend to Static, but this command seems not to work in R2022a anymore: set(gca,’LegendColorbarL isteners’,[]); Any ideas? THANKS / marcel
Gres (107 days 9 hours ago): In 2018b, you can get the icons by calling [hh,icons,plots,txt] = legend({‘Line 1’});

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