Accessing the Matlab Editor

Matlab’s built-in editor, like most other Matlab GUI, is Java-based. As such, it can easily be accessed programmatically. ImageAnalyst, a well-respected member of the Matlab community and a frequent CSSM (newsgroup) and FEX (File Exchange) contributor, recently asked whether it is possible to retrieve the name of the Editor’s currently edited file. The answer is that this is very easy, but I decided to use this opportunity to show how other interesting things can be done with the Editor.

Before we start, it should be made clear that this entire article relies on MathWorks internal implementation of the Editor and Desktop, which may change without prior notice in future Matlab releases. The code below appears to work under Matlab 6 & 7, but users who rely on forward compatibility should be aware of this warning.

We start by retrieving the Editor handle. This can be done in a number of ways. The easiest is via the Matlab desktop:

try
    % Matlab 7
    desktop = com.mathworks.mde.desk.MLDesktop.getInstance;
    jEditor = desktop.getGroupContainer('Editor').getTopLevelAncestor;
    % we get a com.mathworks.mde.desk.MLMultipleClientFrame object
catch
    % Matlab 6
    % Unfortunately, we can't get the Editor handle from the Desktop handle in Matlab 6:
    %desktop = com.mathworks.ide.desktop.MLDesktop.getMLDesktop;
 
    % So here's the workaround for Matlab 6:
    openDocs = com.mathworks.ide.editor.EditorApplication.getOpenDocuments;  % a java.util.Vector
    firstDoc = openDocs.elementAt(0);  % a com.mathworks.ide.editor.EditorViewContainer object
    jEditor = firstDoc.getParent.getParent.getParent;
    % we get a com.mathworks.mwt.MWTabPanel or com.mathworks.ide.desktop.DTContainer object
end

Now that we have the Editor handle, let’s retrieve its currently open (active) file name from the Editor’s title:

title = jEditor.getTitle;
currentFilename = char(title.replaceFirst('Editor - ',''));

The entire list of open file names can be retrieved in several ways:

% Alternative #1:
edhandle = com.mathworks.mlservices.MLEditorServices;
allEditorFilenames = char(edhandle.builtinGetOpenDocumentNames);
 
% Alternative #2:
openFiles = desktop.getWindowRegistry.getClosers.toArray.cell;
allEditorFilenames = cellfun(@(c)c.getTitle.char,openFiles,'un',0);

At the top-level Editor-window level, we can prevent its resizing, update its status bar, modify its toolbar/menu-bar, control docking and do other similar fun things:

% Actions via built-in methods:
jEditor.setResizable(0);
jEditor.setStatusText('testing 123...');
jEditor.setTitle('This is the Matlab Editor');
 
% Equivalent actions via properties:
set(jEditor, 'Resizable', 'off');
set(jEditor, 'StatusText', 'testing 123...');
set(jEditor, 'Title', 'This is the Matlab Editor');

Actually, the jEditor handle has over 300 invokable methods and close to 200 properties that we can get/set. Perhaps the easiest way to find interesting things we can programmatically do with the Editor handle, is to use my UIInspect utility on the File Exchange:

uiinspect(jEditor);  % or: jEditor.uiinspect
Matlab Editor methods, callbacks and properties as seen by uiinspect (click to zoom)

Matlab Editor methods, callbacks and properties as seen by uiinspect
(click to zoom)

The Editor handle is actually a container for many internal panels (toolbars etc.) and documents. The entire object hierarchy can be seen with another of my File Exchange utilities, FindJObj:

findjobj(jEditor);  % or: jEditor.findjobj
Matlab Editor object hierarchy as seen by findjboj (click to zoom)

Matlab Editor object hierarchy as seen by findjboj (click to zoom)

We can modify text within the open Editor documents, and instrument these document to handle event callbacks. To see how, I refer users to my EditorMacro utility on the Matlab File Exchange.

If you find some other nifty and/or useful things that can be done using the Editor handle, please post them in the comments section below.

Related posts:

  1. EditorMacro – assign a keyboard macro in the Matlab editor EditorMacro is a new utility that enables setting keyboard macros in the Matlab editor. this post details its inner workings....
  2. Non-textual editor actions The UIINSPECT utility can be used to expand EditorMacro capabilities to non-text-insertion actions. This is how:...
  3. Variables Editor scrolling The Matlab Variables Editor can be accessed to provide immediate scrolling to a specified cell location. ...
  4. Recovering previous editor state Recovering the previous state of the Matlab editor and its loaded documents is possible using a built-in backup config file. ...
  5. Accessing plot brushed data Plot data brushing can be accessed programmatically using very simple pure-Matlab code...
  6. Accessing private object properties Private properties of Matlab class objects can be accessed (read and write) using some undocumented techniques. ...

Categories: Desktop, High risk of breaking in future versions, Java

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39 Responses to Accessing the Matlab Editor

  1. To close all M-files in the editor, I use:

     
    com.mathworks.mlservices.MLEditorServices.closeAll
  2. Ruben Faibish says:

    Do you know how can I find the bookmarks in the editor? I would like to get all bookmarks and save them on closing Matlab, so that on reopening, they could be restored.
    Thx

    • Ruben – that was a hard question that kept me digging for hours. I discovered (via the FindJObj utility) that the bookmarks are displayed in a panel called ‘ExecutionArrowDisplay’ of class com.mathworks.mde.editor.ExecutionArrowDisplay$ExecutionPanel. I do not know whether the list of bookmarks are contained within this object, although I suspect they are. In any case, I did not find a method to programmatically retrieve this list since the ExecutionPanel object does not expose any method to do so.

      So, the only way I could find is to loop over all the editor’s open files, and invoke the editor’s default action for <F2> (which is the ‘next-bookmark’ action reported by the EditorMacro utility) in a loop until you detect coming back to an earlier line number. It’s ugly, but it should work. The reverse, setting bookmarks, could be done in a similar fashion, using the ‘toggle-bookmark’ action.

      I think it could be a great File Exchange utility. Care to try it? If you get stuck I can help out.

  3. Matthew Arthington says:

    My editor window is docked and that stops title being the ‘Editor – ‘… form. I wanted to get the active document so I could invoke a command to open the directory of the current editor’s file.

    Thanks to Aurélien I discovered the following to get the current editor’s file path:

    d = com.mathworks.mlservices.MLEditorServices;
    fName = d.builtinGetActiveDocument;
    path=fileparts(fName.toCharArray');
  4. For anyone interested, Jan Simon has just posted a few more useful things that can be done using the Editor handle:

    Bring the editor to front:

    jEditor.toFront;

    Is the editor active currently:

    jEditor.isActive;

    Perform an action whenever the user activate the editor:

    set(jEditor, 'WindowGainFocusCallback', 'disp(''Editor activated'')')

    Or the usual function handle callback style.

    See further properties:

    get(jEditor)

    and

    methods(jEditor, '-full')
  5. Jan Simon says:

    This does not work on my Matlab 6.5.1, WinXP SP3, JavaVM 1.3.1_01

    % So here's the workaround for Matlab 6:
    openDocs = com.mathworks.ide.editor.EditorApplication.getOpenDocuments;

    There is no getOpenDocuments method for the EditorApplication.
    The solution is trivial: Do not use Matlab 6.5… Thanks, Jan

    • @Jan – I’m willing to bet that the solution for 6.5 is simply a variant of the Matlab 6 syntax. Try to run the following command in Matlab 6.5 to check whether the getOpenDocuments() method was renamed:

      methodsview('com.mathworks.ide.editor.EditorApplication')
    • Jan Simon says:

      Nope. The EditorApplication knows: closeAll, closeDocument, equals, getClass, hashCode, isDocumentDirty, isStandalone, main, newDocument, newDocumentWithString, notify, notifyAll, openDocument, openDocumentToFunction, openDocumentToLine, reloadDocument, saveDocument, showJitZones (what’s that?!), toString and wait.
      Surprising. Jan

  6. christian rock says:

    Hi Yair!,

    thank you for the undocumented stuff! really great!
    Now i have one question: would it be possible to add a uitree to the editor? It would be great to browse through the opened files which are grouped by “projects” or something, especially if you opened large number of files…better than then a simple list.

    Greeting form Germany,

    Chris

    • @Christian – you can’t [easily] add a tree to the Editor, but you can create a simple tree in a regular Matlab figure (use the built-in uitree function), set the node callbacks to something like: edit(filename) and then dock this figure into the Editor (yes I know this sounds a bit strange) using my setFigDockGroup utility.

  7. Omid says:

    Hi,
    I sent this question on MATLAB central but received no answer, so I post it here again in case you’ve not seen it!

    I have a time tracking software that records the time I spend on each application. It recognizes the applications by their window caption. I’m used to have the MATLAB editor docked into the main window, so all my working time in MATLAB is reported under the name of “MATLAB 7.8.0 (2009a)”. I’m thinking of a way to change the main window title to the name of the document I’m currently working on. Thanks to undocumentedmatlab.com now I know how to get the name of the active document and how to change the window title by accessing related java components. What I need is to code a callback function to be triggered whenever I switch to another document in the editor. However I didn’t find the right callback property. Any idea?

    P.S. What I said I know works when the editor is undocked which is not what I’m looking for! So I correct that: I don’t even know how to get the title of the active document in the editor when the editor is docked into the main window :(

  8. Ralf says:

    Hi Yair,

    as for MATLAB 7.11 the code

    com.mathworks.mlservices.MLEditorServices.newDocument(str,true);

    does not work anymore. Do you know any workaround?

    Thank you for your constant efforts digging out the internals of MATLAB and sharing them with us.

    Ralf.

    • @Ralf – in R2010b (Matlab 7.11), the Java class interface has changed. In R2010b, we get the editor handle as follows:

      editorservices = com.mathworks.mlservices.MLEditorServices;
      jEditorApp = editorservices.getEditorApplication;

      The method names and parameters have also changed from those of the pre-R2010b Java class. Each edited document now has a separate com.mathworks.mde.editor.MatlabEditor object. The jEditorApp.getActiveEditor() method returns the MatlabEditor object for the currently-edited document; the other documents can be retrieved using jEditorApp.getOpenEditors(), which returns a java.util.Collections.UnmodifiableList of such MatlabEditors.

      Once you get your desired document (a MatlabEditor reference), its functionality can be accessed via its MatlabEditor’s methods (bringToFront(), close(), goToLine(…), reload(), replaceText(…), setEditable(…) etc.) or properties (e.g. CaretPosition, Document, Language, Length, LongName, ShortName, Selection, Text, etc.). I suggest using my CheckClass or UIInspect utilities if you want additional information about the supported properties, callbacks and methods. I may also post about this in the upcoming months, since it needs much more space than a simple comment here, so stay tuned.

      Of course, you can always continue to use the partially-documented/supported editorservices object that Mike Katz introduced last year (see his comment above).

      -Yair

  9. Punit says:

    Hi Yair,
    Thanks a lot for undocumented matlab articles, those are really helpful.
    I’m trying to build a GUI which has matlab editor in the figure. Currently I can use following program to show the editor in my GUE

    edit('test.m')
    desktop = com.mathworks.mde.desk.MLDesktop.getInstance;
    editors=desktop.getGroupMembers('Editor');
    CurrEdit=editors(end);
    hedit=javacomponent(CurrEdit,pos,gcf);

    but, a blank editor window still remains open, and when I close that window, the program displayed in the matlab figure is also closed. Is there any other way I can bring the editor in a matlab figure? I think this is not impossible because the GUI of s-function editor block in simulink has that facility.
    Thanks
    -Punit

  10. Punit says:

    Hi Yair,
    Thanks a lot. That article is really helpful
    -Punit

  11. kristian svartveit says:

    Hi

    Would it be possible to add functionality to the context menu? I would like to be able to evaluate a function with the selected text as input, i.e size() of the variable i right-clicked on.

    K

  12. Rex Deng says:

    hi, Yair Altman, i want to add a run function of VBScript codes in the editor, now i just make a shortcut in the matlab desktop like this. can you give me some help? thanks a lot!

    try
        % Matlab 7
        desktop = com.mathworks.mde.desk.MLDesktop.getInstance;
        jEditor = desktop.getGroupContainer('Editor').getTopLevelAncestor;
        % we get a com.mathworks.mde.desk.MLMultipleClientFrame object
    catch
        % Matlab 6
        % Unfortunately, we can't get the Editor handle from the Desktop handle in Matlab 6:
        %desktop = com.mathworks.ide.desktop.MLDesktop.getMLDesktop;
        % So here's the workaround for Matlab 6:
        openDocs = com.mathworks.ide.editor.EditorApplication.getOpenDocuments;  % a java.util.Vector
        firstDoc = openDocs.elementAt(0);  % a com.mathworks.ide.editor.EditorViewContainer object
        jEditor = firstDoc.getParent.getParent.getParent;
        % we get a com.mathworks.mwt.MWTabPanel or com.mathworks.ide.desktop.DTContainer object
    end
    jEditor.toFront;
    title = jEditor.getTitle;
    currentFilename = char(title.replaceFirst('Editor - ',''));
    if isequal(lower(currentFilename(end-3:end)),'.vbs')
        [s,w]=dos(currentFilename);
    else
        error('The current file is not *.vbs file!');
    end
    • @Rex – Windows shortcuts cannot be run via the dos function, as far as I know. Instead, you need to refer to the actual file location (not a shortcut). Also, you might need to use winopen rather than dos.

  13. Rex says:

    Hi, Yair
    This function works. I want to add a button to the Editor, with the same function. Or change the function of “Run” button.

  14. Anubhav Jain says:

    Hi,
    Thanks a lot for the undocumented articles , those are really very helpful .
    I am trying to highlight the line number of the editor which has errors/warnings(syntax or runtime) using the object of the editor . Is there any specific property of the editor object(jEditor), which on being accessed can highlight particular line of the editor.
    I have tried this using “matlab.desktop.editor.openAndGoToLine” but it doesnt work in lower versions of matlab.
    Can you please help me out with this.

  15. Bluesmaster says:

    Hello Yair,

    I would like to know, how register when the editor changes the
    active document. (e.g. closing the current one, or opening a new one)

    com.mathworks.mde.editor.MatlabEditorApplication has the method

    “addEditorApplication” but i can create the needed object
    due I do not know its constructor arguments

    I also thought of listening to a change of its “ActiveEditor” property
    but i dont know how to implement a property-listener for a java-object-property

    and let me say: you are doing a great work at all!
    You are making our matlab lifes much more comfortable. Thank you

    Bluesmaster

    • @Bluesmaster – you can set the Editor object’s ComponentAddedCallback (=new doc) and ComponentRemovedCallback (=closed doc) properties with your own code. See the code in the EditorMacro functions getJEditor(), getJMainPane() and the main function for specifics. Here’s a bare-bones snippet that works for Matlab 7+ with a detached (non-docked) Editor window:

      jEditor = com.mathworks.mde.desk.MLDesktop.getInstance.getGroupContainer('Editor');
      jMainPane = jEditor.getComponent(1);
      set(jMainPane,'ComponentAddedCallback',@processNewDocFunction);
    • Bluesmaster says:

      Hello Yair,

      unfortunately this is not what I need due to the following lacks:

      - not working for docked windows
      - not working for multiple editor windows
      - not working for switching to a document that is already open (sorry didn’t made that clear)

      I need to assure, that I always know the active document.
      So I think the graphic-container-layer is the wrong place.
      I would like to do it though the data-model, and it is possible through:

      e = com.mathworks.mlservices.MLEditorServices.getEditorApplication
      e.addEditorApplicationListener( ??what to put in here??  )

      OR

      Observing

      e.ActiveEditor (But I don’t know how to implement such a listener)

      Kind regards

      Bluesmaster

    • @Bluemaster – read the parts of EditorMacro that I mentioned above, they handle the cases of docked and detached editor window(s). You can also look at the callbacks of the EditorApplication (that you’ve shown you know how to get) – there’s probably a callback in there that could help you. Regarding listeners, search my website for the term “listener” and you’ll find plenty of examples. If you’d like me to spend real time on investigating this for you, send me an offline email and I’ll investigate this issue for you for a small consulting fee.

  16. ruthy says:

    Hi Yair,

    I have some questions which are related to this post but not quit….
    I am using Git as source control.
    I want to see a comment with the current working branch on the command window.
    Is there a way
    1) Changing only the title of the command window (such that all other things will work normally)
    2) Updating the current branch every time the branch file is changes (something like that the opened files are updated if I edit them in the background with a different text editor)?

    Thanks in advance,

    Ruthy

    • ruthy says:

      Hi Yair,

      I know this is not directly related to the content of this post but it is close…

      I am using Git as the source control.
      I would like that the current branch will be displayed on the workspace\editor as the name of the window (only title displayed so that matlab will keep working as usual).
      I know where to find the current branch.
      My question is how do I keep track on a specific file and each time it changes to update the view. My second question is how to change only the display and not the window name for the system.

      Thanks!

      Ruthy

  17. Pingback: JGit-Matlab integration | Undocumented Matlab

  18. Bruce says:

    Cool idea… Combine the ability to “mess with the editor” and the interface to git and make a complete, platform independent “project switcher”.

    Hmmmm… Off to scratch my head and see what comes out :-)

    Bruce

  19. Pingback: Variables Editor scrolling | Undocumented Matlab

  20. gil_rafalovich says:

    hi Yair 
    is there a way to open a function and then save the function as text or load it as a text in order to make some analysis over the function (like counting how much for loops there is in a function).
    BTW , your work on undocumented Matlab is great :-)
    Thanks
    Gil Rafalovich  

    • @Gil – I don’t understand the problem:

      fpath = which('myFilename');
      fid = fopen(fpath, 'rt');
      %  parse the file using fread etc.
      fclose(fid);
  21. Andre says:

    Hi Yair
    I try to reset file code folding settings stored in ‘MATLAB_Editor_State.xml’ following your suggestions in your book: “the editor will need to be closed and reopened for changes
    to take effect” by
    1. closing Editor
    2. manipulating xml file
    3. reopen all editor files

    Unfortunately closing and reopening might be not enough that changes in ‘MATLAB_Editor_State.xml’ take effect. (I tested in R2014b)
    Do you have any suggestions how to reset code folding? or how to force MATLAB to read ‘MATLAB_Editor_State.xml’?

    Hope that the function I wrote helps somehow.

    function resetCodeFolding()
      %% get open documents
      docAllHndl = matlab.desktop.editor.getAll();
      docActiveDoc = matlab.desktop.editor.getActive();
      editorFilenames = arrayfun(@(c)c.Filename,docAllHndl,'uniform',false);
      editorSelection = arrayfun(@(c)c.Selection,docAllHndl,'uniform',false);
      editorModified  = arrayfun(@(c)c.Modified,docAllHndl,'uniform',false);
      editorText      = arrayfun(@(c)c.Text,docAllHndl,'uniform',false);
     
      editorActiveFilename = docActiveDoc.Filename;
      editorActiveSelection = docActiveDoc.Selection;
     
      % close editor
      docAllHndl.closeNoPrompt()
     
      % edit [prefdir 'MATLAB_Editor_State.xml'] to remove code folding enties 
      if isunix; tte=regexpi(editorActiveFilename,'/'); else tte=regexpi(editorActiveFilename,'\'); end
      Filename = editorActiveFilename(tte(end)+1:end);
      Pathname = editorActiveFilename(1:tte(end)-1);
      % read MATLAB_Editor_State.xml
      fid = fopen([prefdir '\MATLAB_Editor_State.xml'],'r');
      myCounter = 1; txt = [];
      while  ~feof(fid)
        tline = fgetl(fid);
        txt{myCounter} = tline;
        myCounter = myCounter + 1;
        % remove code folding info
        if  ~isempty(regexpi(tline, strrep(['&lt;File absPath=&quot;&#039; Pathname &#039;&quot;&#039;],&#039;\&#039;,&#039;\\&#039;))) &amp;&amp; ~isempty(regexpi(tline, [&#039;name=&quot;&#039; Filename &#039;&quot;&#039;]))
          txt{myCounter} = &#039;      ';
          myCounter = myCounter + 1;
          txt{myCounter} = '   ';
          myCounter = myCounter + 1;
          while  isempty(regexpi(tline, ''))
            tline = fgetl(fid);
          end
        end
      end
      fclose(fid);
      % rewrite MATLAB_Editor_State.xml
      fid = fopen([prefdir '\MATLAB_Editor_State.xml'],'w');
      for ll = 1:length(txt)
        fprintf(fid,'%s\n',txt{ll}); %strrep(txt{ll},'\','\\')
      end
      fclose(fid);
     
      % open editor
      for fn = 1:length(docAllHndl)
        %edit(editorFilenames{fn})
        if strcmp(editorFilenames{fn}(1:8),'Untitled')
          matlab.desktop.editor.newDocument(editorText{fn});
        else
          matlab.desktop.editor.openAndGoToLine(editorFilenames{fn}, editorSelection{fn}(1));
        end
      end
      % replace text of unsaved documents
      docAllHndl = matlab.desktop.editor.getAll();
      for fn = 1:length(docAllHndl)
        if strcmp(editorActiveFilename,docAllHndl(fn).Filename)
          docAllHndl(fn).makeActive;
        end
        if editorModified{fn}
          docAllHndl(fn).Text = editorText{fn};
        end
      end
    end
    • Andre says:

      Sorry, some parts of the pasted code (mainly in the ‘remove code folding info’ section) are not displayed correctly – due to html.

          if  ~isempty(regexpi(tline, strrep(['&lt;File absPath=&quot;' Pathname '&quot;'],'\','\\'))) &amp;&amp; ~isempty(regexpi(tline, ['name=&quot;' Filename '&quot;']))
            txt{myCounter} = '      &lt;CodeFolds version="1.0"/&gt;';
            myCounter = myCounter + 1;
            txt{myCounter} = '   &lt;/File&gt;';
            myCounter = myCounter + 1;
            while  isempty(regexpi(tline, '&lt;/File&gt;'))
              tline = fgetl(fid);
            end
          end
    • Yair Altman says:

      @Andre – Try to restart Matlab (not just the editor)

    • Andre says:

      Hi Yair
      thanks for your immediate answer. you are totally right, but when restarting matlab I have hardly a chance to edit ‘MATLAB_Editor_State.xml’ using matlab code after it is updated by matlab during closing procedure or before it is read during matlab start.

      I am rather searching for a function to actively reread ‘MATLAB_Editor_State.xml’ while matlab is running. Do you have any suggestion?

      Thanks
      Andre

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<pre lang="matlab">
a = magic(3);
sum(a)
</pre>