Customizing the standard “File” main menu

Note: this relies on earlier articles about customizing the figure menubar, so if you are not comfortable with this topic you might benefit from reading these earlier articles.
Customizing the standard “File” main menu is easy. First, let’s find the “File” main menu’s handle, and add an MRU sub-menu directly to it:

hFileMenu = findall(gcf, 'tag', 'figMenuFile');
hMruMenu = uimenu('Label','Recent files', 'Parent',hFileMenu);

Our new MRU menu item is created at the end (in this case, at the bottom of the “File” main menu list). Let’s move it upward, between “New” and “Open…”, by reordering hFileMenu‘s Children menu items:

hAllMenuItems = allchild(hFileMenu);
set(hFileMenu, 'Children',fliplr(hAllMenuItems([2:end-1,1,end])));  % place in 2nd position, just above the "Open" item

Now let’s fix the “Open…” menu item’s callback to point to our custom openFile() function (unfortunately, the “Open…” menu item has no tag, so we must rely on its label to get its handle):

hOpenMenu = findall(hFileMenu, 'Label', '&Open...');
set(hOpenMenu, 'Callback',@openFile);

Finally, let’s add the MRU list as a sub-menu of the new hMruMenu. I assume that we have a getMRU() function in our code, which returns a cell-array of filenames:

% Add the list of recent files, one item at a time
filenames = getMRU();
for fileIdx = 1 : length(filenames)
    uimenu(hMruMenu, 'Label',filenames{fileIdx}, 'Callback',{@openFile,filenames{fileIdx}});
end

% Callback for the open-file functionality (toolbar and menubar)
function openFile(hObject,eventData,filename)
    % If no filename specified, ask for it from the user
    if nargin < 3
        filename = uigetfile({'*.csv','Data files (*.csv)'}, 'Open data file');
        if isempty(filename) || isequal(filename,0)
            return;
        end
    end
    % Open the selected file and read the data
    data = readDataFile(filename);
    % Update the display
    updateGUI(data)
end

We can take this idea even further by employing HTML formatting, as I have shown in my first article of the menubar mini-series:

Customizing the standard toolbar's "Open File" button

Note: this relies on earlier articles about customizing the figure toolbar, so if you are not comfortable with this topic you might benefit from reading these earlier articles.
The basic idea here is to replace the standard toolbar's "Open File" pushbutton with a new uisplittool button that will contain the MRU list in its picker-menu.
The first step is to get the handle of the toolbar's "Open File" button:

hOpen = findall(gcf, 'tooltipstring', 'Open File');
hOpen = findall(gcf, 'tag', 'Standard.FileOpen');  % Alternative

The second alternative is better for non-English Matlab installations where the tooltip text may be different, or in cases where we might have another GUI control with this specific tooltip. On the other hand, the 'Standard.FileOpen' tag may be different in different Matlab releases. So choose whichever option is best for your specific needs.
Assuming we have a valid (non-empty) hOpen handle, we get its properties data for later use:

open_data = get(hOpen);
hToolbar = open_data.Parent;

We have all the information we need, so we can now simply delete the existing toolbar open button, and create a new split-button with the properties data that we just got:

delete(hOpen);
hNewOpen = uisplittool('Parent',hToolbar, ...
                       'CData',open_data.CData, ...
                       'Tooltip',open_data.TooltipString, ...
                       'ClickedCallback',@openFile);

As with the menubar, the button is now created, but it appears on the toolbar’s right edge. Let’s move it to the far left. We could theoretically reorder hToolbar‘s Children as for the menubar above, but Matlab has an internal bug that causes some toolbar buttons to misbehave upon rearranging. Using Java solves this:

drawnow;  % this innocent drawnow is *very* important, otherwise Matlab might crash!
jToolbar = get(get(hToolbar,'JavaContainer'),'ComponentPeer');
jButtons = jToolbar.getComponents;
jToolbar.setComponentZOrder(jButtons(end),2);  % Move to the position between "New" and "Save"
jToolbar.revalidate;  % update the toolbar's appearance (drawnow will not do this)

Finally, let’s add the list of recent files to the new split-button’s picker menu:

% (Use the same list of filenames as for the menubar's MRU list)
jNewOpen = get(hNewOpen,'JavaContainer');
jNewOpenMenu = jNewOpen.getMenuComponent;
for fileIdx = 1 : length(filenames)
    jMenuItem = handle(jNewOpenMenu.add(filenames{fileIdx}),'CallbackProperties');
    set(jMenuItem,'ActionPerformedCallback',{@openFile,filenames{fileIdx}});
end

The post Customizing the standard figure toolbar, menubar appeared first on Undocumented Matlab.

The symptom

In the compiled application, docking could be accomplished by accessing the figure frame’s underlying Java level:

% get java frame for sophisticated modifications
jframe = get(handle(figure_handle), 'JavaFrame');
% allow docking
jframe.fHG1Client.setClientDockable(true)

Using this modification, the user is now allowed to dock and undock the figures manually. For initial docking of the figure,

javaFrame.fHG1Client.setClientWindowStyle(true,false)

could be used during figure creation. Unfortunately, there are menu entries in the Figures container which are either unwanted (since not usable) or even directly crash the standalone applications:

The unsuccessful solution

Unfortunately, the straight forward solution of getting the handle to the Figures containers’ menu bar and remove the unwanted items does not work. The reason for this is the (to me unexpected behavior) that the menu bar seems to be rebuilt whenever a figure is docked/undocked.
This is actually the same behavior that automatically rebuilds the Editor’s menu bar whenever an editor file is added/removed. The Editor container is basically the same docking container as the Figures container, as shown by Yair’s setFigDockGroup utility:

The working solution

For the working solution, many pieces presented by Yair should be put together. The first piece results from the question how to detect a dock/undock event. Since no such callback is defined, we need to use a property listener as Yair showed in his post about the continuous slider callback:

% listen to the WindowStyle property to detect docking / undocking events
hProp = findprop(handle(figure_handle),'WindowStyle');  % a schema.prop object
% if the event occurs, invoke the callback
hlistener = handle.listener(handle(figure_handle), hProp, 'PropertyPostSet',{@(source, event) Callback_DockingFcn});
% attach listener to the GUI since it needs to be known (as long as the figure exists)
setappdata(figure_handle, 'Handle_Listener', hlistener);

Now, whenever the figure’s WindowStyle property (which controls the docking state) is changed, our docking callback is invoked.
The next piece of the puzzle takes care of the menu rebuild whenever any document bar button is pressed. To overcome this behavior, the idea is to define the MousePressed callback of theses buttons to (again) invoke the docking callback. This is necessary for two reasons: First, pressing the button (i.e., changing the current figure) rebuilds the menu, overwriting our changed menu entries. Secondly, all other buttons are also somehow rebuilt and the callbacks are removed if a new figure is docked.
The handles to the document bar buttons could be found using Yair’s findjobj utility. We have already seen that the Editor container is analogous to the Figures docking container. So let’s use the method described by Yair for accessing the Editor container, to access the Figures container:

figures_container = javaObjectEDT(matlab_instance.getGroupContainer('Figures'));
figures_frame = javaObjectEDT(figures_container.getTopLevelAncestor);

Once we get the Java Frame for the Figures container, the buttons could be found by digging through its children. This finally allows to set the callback using

DTDocumentBar = javaObjectEDT(figures_frame.getRootPane.getLayeredPane.getComponent(1).getComponent(1).getComponent(0).getComponent(0).getComponent(1).getComponent(0));
ContentPanel = javaObjectEDT(DTDocumentBar.getComponent(0).getComponent(0).getViewport.getView);
if ~isempty(ContentPanel.getComponents) % less than two documents are open and no DTDocumentbar exists
    drawnow; pause(0.05)
    GroupPanel = javaObjectEDT(ContentPanel.getComponent(0));
    GroupPanel_Elements = javaObjectEDT(GroupPanel.getComponents);
    % change the MousePressed Callback for each of the buttons to invoke the function which disables the menu
    for n = 1 : GroupPanel.getComponentCount
        thisElement = GroupPanel_Elements(n);
        if isequal(char(thisElement.getClass.toString), 'class com.mathworks.widgets.desk.DTDocumentBar$DocumentButton')
            set(handle(thisElement, 'CallbackProperties'), 'MousePressedCallback', {@(source, event) Cbrake_Callback_Diagrams_DockingFcn})
        end
    end
    drawnow; pause(0.05)
end

where the loop runs through the current buttons in the document bar.
As the last step of our procedure, we finally remove (or disable) the menu entries which are unwanted. This is achieved by extracting the handle to the Figures menu by:

figures_menu = javaObjectEDT(figures_frame.getJMenuBar);

Running through the menu items, searching for the unwanted entries (as long as they have pre-defined menu-item names) at the end sets us into the position to take care of the menu items:

% run through top-level menu items
for n = 1 : figures_menu.getMenuCount
    % completely deactivate Debugging options
    if isequal(char(figures_menu.getMenu(n-1).getName), 'DesktopDebugMenu')
        DesktopDebugMenuPos = n - 1;
    end
    % Remove some items from the Desktop menu
    if isequal(char(figures_menu.getMenu(n-1).getName), 'DesktopMenu')
        desktop_menu = javaObjectEDT(figures_menu.getMenu(n-1));
        DeletePos = [];
        for m = 1: desktop_menu.getMenuComponentCount
            if ismember({char(desktop_menu.getMenuComponent(m-1).getName)}, ...
                        {'ToggleFigure PaletteCheckBoxMenuItem', 'TogglePlot BrowserCheckBoxMenuItem', 'ToggleProperty EditorCheckBoxMenuItem'})
                DeletePos(end+1) = m - 1;
            end
        end
        for m = length(DeletePos) : -1 : 1
            desktop_menu.remove(DeletePos(m))
        end
    end
end
% finally remove the "Debug" menu
if ~isempty(DesktopDebugMenuPos)
    figures_menu.remove(DesktopDebugMenuPos)
end

Since this callback is invoked whenever a figure is docked/undocked, or the currently shown figure is changed (by pressing the document bar button), all unwanted menu items within the Figures menu could be removed.
As a result, the new Figures container menu looks like:

Remarks

I must admit that above solution is still imperfect. For instance, sometimes there is a larger delay between the docking (or button press event) and the removing of the menu item. Nevertheless, this solution allows me to distribute my standalone with docked figures without having menu items directly leading to a fatal error.
Obviously, the solution has some positive side effects:

• As could be seen from the screen shot, the Matlab desktop becomes available also within your compiled applications. This might be wanted. If not, it could be removed the same way as the other menu items. One drawback of making the desktop available should be mentioned: In my tests, the standalone Matlab desktop shows the whole list of recent files I have in the Matlab editor at compile time. This is somehow ugly but not that problematic.
• Additional menu items could be added, giving more possibilities for modifications.

I have uploaded a first version of the docking and creation functions, together with a small test project, to the Matlab file Exchange. Readers are welcome to download the code and send me improvement suggestions. Or you could simply leave a comment below.

The post Disabling menu entries in deployed docked figures appeared first on Undocumented Matlab.

A reminder: accessing the underlying Java object

Matlab menus (uimenu) are basically simple wrappers for the much more powerful and flexible Java Swing JMenu and JMenuItem on which they are based. Many important functionalities that are available in Java menus are missing from the Matlab uimenus.
Getting the Java reference for the figure window’s main menu is very easy:

jFrame = get(handle(hFig),'JavaFrame');
try
    % R2008a and later
    jMenuBar = jFrame.fHG1Client.getMenuBar;
catch
    % R2007b and earlier
    jMenuBar = jFrame.fFigureClient.getMenuBar;
end

There are many customizations that can only be done using the Java handle: setting icons, several dozen callback types, tooltips, background color, font, text alignment, and so on. etc. Interested readers may wish to get/set/inspect/methodsview/uiinspect the jSave reference handle and/or to read the documentation for JMenuItem. Today’s article will focus on icon customizations.

Setting simple menu item icons

Many of Matlab’s icons reside in either the [matlabroot ‘/toolbox/matlab/icons/’] folder or the [matlabroot ‘/java/jar/mwt.jar’] file (a JAR file is simply a zip file that includes Java classes and resources such as icon images). Let us create icons from the latter, to keep a consistent look-and-feel with the rest of Matlab (we could just as easily use our own external icon files):

% External icon file example
jSave.setIcon(javax.swing.ImageIcon('C:\Yair\save.gif'));
% JAR resource example
jarFile = fullfile(matlabroot,'/java/jar/mwt.jar');
iconsFolder = '/com/mathworks/mwt/resources/';
iconURI = ['jar:file:/' jarFile '!' iconsFolder 'save.gif'];
iconURI = java.net.URL(iconURI);  % not necessary for external files
jSave.setIcon(javax.swing.ImageIcon(iconURI));

Note that setting a menu item’s icon automatically re-aligns all other items in the menu, including those that do not have an icon (an internal bug that was introduced in R2010a causes a misalignment, as shown below):

   

Checkmark icon

The empty space on the left of the menu is reserved for the check mark. Each Matlab menu item is check-able, since it is an object that extends the com.mathworks.mwswing.MJCheckBoxMenuItem class. I have not found a way to eliminate this empty space, which is really unnecessary in the File-menu case (it is only actually necessary in the View and Tools menus). Note that if an icon is set for the item, both the icon and the checkmark will be displayed, side by side.
The check mark is controlled by the State property of the Java object (which accepts logical true/false values), or the Checked property of the Matlab handle (which accepts the regular ‘on’/’off’ string values):

% Set the check mark at the Matlab level
set(findall(hFig,'tag','figMenuFileSave'), 'Checked','on');
% Equivalent - set the checkmark at the Java level
jSave.setState(true);

   

Customizing menu icons

Icons can be customized: modify the gap between the icon and the label with the IconTextGap property (default = 4 [pixels]); place icons to the right of the label by setting HorizontalTextPosition to jSave.LEFT (=2), or centered using jSave.CENTER (=0). Note that the above-mentioned misalignment bug does not appear in these cases:

   

myIcon = fullfile(matlabroot,'/toolbox/matlab/icons/matlabicon.gif');
imageToolkit = java.awt.Toolkit.getDefaultToolkit;
iconImage = imageToolkit.createImage(myIcon);
iconImage = iconImage.getScaledInstance(32,32,iconImage.SCALE_SMOOTH);
jSave.setIcon(javax.swing.ImageIcon(iconImage));

Remember when rescaling images, particularly small ones with few pixels, that it is always better to shrink than to enlarge images: enlarging a small icon image might introduce a significant pixelization effect:

myIcon = 'C:\Yair\Undocumented Matlab\Images\save_disabled.gif';
jSaveAs.setDisabledIcon(javax.swing.ImageIcon(myIcon));
jSaveAs.setEnabled(false);

   

   

The post Customizing menu items part 3 appeared first on Undocumented Matlab.

Accessing the underlying Java object

Matlab menus (uimenu) are basically simple wrappers for the much more powerful and flexible Java Swing JMenu and JMenuItem on which they are based. Many important functionalities that are available in Java menus are missing from the Matlab uimenus.
Getting the Java reference for the figure window’s main menu is very easy:

jFrame = get(handle(hFig),'JavaFrame');
try
    % R2008a and later
    jMenuBar = jFrame.fHG1Client.getMenuBar;
catch
    % R2007b and earlier
    jMenuBar = jFrame.fFigureClient.getMenuBar;
end

Note that we have used the figure handle’s hidden JavaFrame property, accessed through the reference’s handle() wrapper, to prevent an annoying warning message.
There are many customizations that can only be done using the Java handle: setting icons, several dozen callback types, tooltips, background color, font, text alignment, and so on. etc. Interested readers may wish to get/set/inspect/methodsview/uiinspect the jSave reference handle and/or to read the documentation for JMenuItem. Some useful examples are provided below.

Dynamic menu behavior

As a first example of Java-based customization, let us add DHTML-like behavior to the menu, such that the menu items will automatically be displayed when the mouse hovers over the item, without waiting for a user mouse click. First, get the jMenuBar reference as described above. Now, set the MouseEnteredCallback to automatically simulate a user mouse click on each menu item using its doClick() method. Setting the callback should be done separately to each of the top-level menu components:

for menuIdx = 1 : jMenuBar.getComponentCount
    jMenu = jMenuBar.getComponent(menuIdx-1);
    hjMenu = handle(jMenu,'CallbackProperties');
    set(hjMenu,'MouseEnteredCallback','doClick(gcbo)');
end

Note that using this mechanism may be awkward if the top-level menu does not have a sub-menu but is rather a stand-alone menu item. For example, if the top-level menu-item “Help” is a stand-alone menu button (i.e., there are no help menu-items, just the single Help item), then moving the mouse over this item will trigger the help event, although the user did not actually click on the item. To prevent this behavior, we should modify the code snippet above to only work on those menu items that have sub-items.

Custom accelerator shortcut keys

As another example, Matlab automatically assigns a non-modifiable keyboard accelerator key modifier of , while JMenus allow any combination of Alt/Ctrl/Shift/Meta (depending on the platform). Let us modify the default File/Save accelerator key from ‘Ctrl-S’ to ‘Alt-Shift-S’ as an example. We need a reference for the “Save” menu item. Note that unlike regular Java components, menu items are retrieved using the getMenuComponent() method and not getComponent():

% File main menu is the first main menu item => index=0
jFileMenu = jMenuBar.getComponent(0);
% Save menu item is the 5th menu item (separators included)
jSave = jFileMenu.getMenuComponent(4); %Java indexes start with 0!
inspect(jSave) 	% just to be sure: label='Save' => good!
% Finally, set a new accelerator key for this menu item:
jAccelerator = javax.swing.KeyStroke.getKeyStroke('alt shift S');
jSave.setAccelerator(jAccelerator);

That is all there is to it – the label is modified automatically to reflect the new keyboard accelerator key. More info on setting different combinations of accelerator keys and modifiers can be found in the official Java documentation for KeyStroke.

% Simulate mouse clicks to force the File main-menu to open & close
jFileMenu.doClick; % open the File menu
jFileMenu.doClick; % close the menu
% Now the Save menu is accessible:
jSave = jFileMenu.getMenuComponent(4);

Tooltip and highlight

For some unknown reason, MathWorks did not include a tooltip property in its Matlab menu handle, contrary to all the other Matlab GUI components. So we must use the Java handle, specifically the ToolTipText property:

jSave.setToolTipText('modified menu item with tooltip');

Java menu items also contain a property called Armed, which is a logical value (default=false). When turned on, the menu item is highlighted just as when it is selected (see the Save As… menu item in the screenshot above). On a Windows system, this means a blue background:

jSave.setArmed(true);

When the item is actually selected and then de-selected, Armed reverts to a false (off) value. Alternating the Armed property value can achieve an effect of flashing the menu item.

Callbacks

In addition to the standard Swing control callbacks discussed in an earlier article, menu items possess several additional callbacks that are specific to menu items, including:

• ActionPerformedCallback – fired when the menu item is invoked
• StateChangedCallback – fired when the menu item is selected or deselected
• MenuDragMouseXXXCallback (XXX=Dragged/Entered/Exited/Released) – fired when the menu item is dragged, for the corresponding event
• MenuKeyXXXCallback (XXX=Pressed/Released/Typed) – fired when a keyboard click event occurs (the menu item’s accelerator was typed)

Using these callbacks, together with the 30-odd standard Swing callbacks, we can control our menu’s behavior to a much higher degree than possible using the standard Matlab handle.
Next week, I will conclude this mini-series with an article explaining how to customize menu item icons.

The post Customizing menu items part 2 appeared first on Undocumented Matlab.

Invoking menu item callbacks

As noted above, a figure window’s menu items can be directly accessed. Once we access a menu item’s handle, we can extract its Callback property and directly invoke it (for example, using the semi-documented hgfeval function). Note that menu callbacks are kept in Callback, while toolbar callbacks are kept in ClickedCallback.
Menu callbacks generally use internal semi-documented functions (i.e., having a readable help section but no doc, online help, or official support), which are part of Matlab’s uitools folder. These functions are specific to each top-level menu tree: filemenufcn, editmenufcn, viewmenufcn, insertmenufcn, toolsmenufcn, desktopmenufcn, winmenu, and helpmenufcn implement the figure’s eight respective top-level menu trees’ callbacks. These functions accept an optional figure handle (otherwise, gcbf is assumed), followed by a string specifying the specific menu item whose action needs to be run. webmenufcn implements the Help menu’s Web Resources sub-menu callbacks in a similar manner.
Use of these functions makes it easy to invoke a menu action directly from our Matlab code: instead of accessing the relevant menu item and invoking its Callback, we simply find out the menu item string in advance and use it directly. For example,

filemenufcn FileClose;
editmenufcn(hFig,'EditPaste');

uimenufcn is a related fully-undocumented (built-in) function, available since Matlab R11 (late 1990s). It accepts a figure handle (or the zero [0] handle to indicate the desktop) and action name. For example, the fully-documented commandwindow function uses the following code to bring the Command Window into focus:

uimenufcn(0, 'WindowCommandWindow');

Customizing menus via uitools

makemenu is another semi-documented uitool function that enables easy creation of hierarchical menu trees with separators and accelerators. It is a simple and effective wrapper for uimenu. makemenu is a useful function that has been made obsolete (grandfathered) without any known replacement.
makemenu accepts four parameters: a figure handle, a char matrix of labels (‘>’ indicating sub item, ‘>>’ indicating sub-sub items etc.; ‘&’ indicating keyboard shortcut; ‘^x’ indicating an accelerator key; ‘-‘ indicating a separator line), a char matrix of callbacks, and an optional char matrix of tags (empty by default). makemenu makes use of another semi-documented grandfathered function, menulabel, to parse the specified label components. makemenu returns an array of handles of the created uimenu items:

labels = str2mat('&File', ...    % File top menu
           '>&New^n', ...           % File=>New
           '>&Open', ...            % File=>Open
           '>>Open &document^d', ...    % File=>Open=>doc
           '>>Open &graph^g', ...       % File=>Open=>graph
           '>-------', ...          % File=>separator line
           '>&Save^s', ...          % File=>Save
           '&Edit', ...		% Edit top menu
           '&View', ...		% View top menu
           '>&Axis^a', ...          % View=>Axis
           '>&Selection region^r'); % View=>Selection
calls = str2mat('', ...		% no action: File top menu
           'disp(''New'')', ...
           '', ...			% no action: Open sub-menu
           'disp(''Open doc'')', ...
           'disp(''Open graph'')', ...
           '', ...			% no action: Separator
           'disp(''Save'')', ...
           '', ...			% no action: Edit top menu
           '', ...			% no action: View top menu
           'disp(''View axis'')', ...
           'disp(''View selection region'')');
handles = makemenu(hFig, labels, calls);
set(hFig,'menuBar','none');

Customizing menus via HTML

Since menu items share the same HTML/CSS support feature as all Java Swing labels, we can specify font size/face/color, bold, italic, underline, superscript/subscript, and practically any HTML formatting.
Note that some features, such as the font or foreground/background colors, have specific properties that we can set using the Java handle, instead of using HTML. The benefit of using HTML is that it enables setting all the formatting in a single property. HTML does not require using Java – just pure Matlab (see the following example).
Multi-line menu items can easily be done with HTML: simply include a <br> element in the label – the menu item will split into two lines and automatically resize vertically when displayed:

txt1 = 'Save';
txt2 = 'this file';
txt3 = '
this file as...';
set(findall(hFig,'tag','figMenuFileSave'),   'Label',[txt1,txt2]);
set(findall(hFig,'tag','figMenuFileSaveAs'), 'Label',[txt1,txt3]);

set(hMenuItem, 'Label',['&2: C:\My Documents\doc.txt
'
   '   '
   'Date: 15-Jun-2011 13:23:45
   Size: 123 KB']);

The post Customizing menu items part 1 appeared first on Undocumented Matlab.

handle2struct

Under the hood, hgsave uses the semi-documented built-in handle2struct function to convert the figure handle into a Matlab struct that is then stored with a simple save (the same function that saves MAT files) function call.
The fact that handle2struct is semi-documented means that the function is explained in a help comment (which can be seen via the help command), that is nonetheless not part of the official doc sections. It is an unsupported feature originally intended only for internal Matlab use (which of course doesn’t mean we can’t use it).
handle2struct merits a dedicated mention, since I can envision several use-cases for storing only a specific GUI handle (for example, a uipanel, a specific graph, or a set of GUI controls’ state). In this case, all we need to do is to call handle2struct with the requested parent handle, then save the returned structure. So simple, so powerful. handle2struct automatically returns all the non-default property information, recursively in all the handle’s children.
Note that features that are not properties of displayed handles (camera position, 3D rotation/pan/zoom states, annotations, axes-linking etc.) are not processed by handle2struct. For storing the states of these features, you need to use some specific handling – see the code within %matlabroot%\toolbox\matlab\graphics\private\hgsaveStructDbl.m for details. Basically, hgsaveStructDbl.m reads the state of all these features and temporarily stores them in the base handle’s ApplicationData property; handle2struct then reads them as any other regular handle property data, and then hgsaveStructDbl.m clears the temporary data from the handle’s ApplicationData. We can use the same trick for any other application state, of course.

struct2handle

handle2struct has a reverse function – the semi-documented struct2handle. I use it for creating dynamic preference panels: As in Matlab’s Preferences window, I have a list of preference topics and a set of corresponding options panels. In my case, it was easy to design each panel as a separate FIG file using GUIDE. In run-time, I simply load the relevant panel from its FIG file as described above, and place it onscreen in a dedicated uipanel using struct2handle. This enables very easy maintenance of preference panels, without sacrificing any functionality.

Matlab 8: Boldly going where no FIG has gone before…

Remember my post earlier this year about the new HG2 mechanism? I speculated that when MathWorks decides to release HG2, it will define this as a major Matlab release and label it Matlab 8.0.
The source code in hgsave.m appears to confirm my speculation. Here is the relevant code section (slightly edited for clarity), which speaks for itself:

% Decide which save code path to use
if ~feature('HGUsingMatlabClasses')   % <== existing HG
    % Warn if user passed in 'all' flag
    if SaveAll
        warning( 'MATLAB:hgsave:DeprecatedOption', ...
            'The ''all'' option to hgsave will be removed in a future release.');
    end
    hgS = hgsaveStructDbl(h, SaveAll);
    SaveVer = '070000';
    SaveOldFig = true;
else   % <== HG2
    % Warn if user passed in 'all' flag
    if SaveAll
        warning( 'MATLAB:hgsave:DeprecatedOption', ...
            'The ''all'' option to hgsave has been removed.');
    end
    if SaveOldFig
        hgS = hgsaveStructClass(h);
        SaveVer = '080000';
    else
        hgO = hgsaveObject(h);
        SaveVer = '080000';
    end
end
% Revision encoded as 2 digits for major revision,
% 2 digits for minor revision, and 2 digits for
% patch revision.  This is the minimum revision
% required to fully support the file format.
% e.g. 070000 means 7.0.0

As can be seen, when Matlab starts using HG2 (perhaps in 2011?), the top-level structure node will be called "hgS_080000", indicating Matlab 8.0. QED.
As a side-note, note that in HG2/Matlab8, although the comment about using 'all' indicates that it has been removed, in practice it is still accepted (although not being used). This will enable your code to be backward-compatible whenever HG2 launches, and future-compatible today.
Have you used handle2struct or struct2handle? If so, please share your experience in a comment.
Let the upcoming 2011 be a year filled with revelations, announcements and fulfillment! Happy New Year everybody!

The post handle2struct, struct2handle & Matlab 8.0 appeared first on Undocumented Matlab.

t=0:0.2:25; plot(t,sin(t),'.-');
% Now brush some data points...
uiinspect(gca);

Directly accessing brushed data

First, we notice that data brushing added data-brushing context menus, both of which are called BrushSeriesContextMenu (the duplication is an internal Matlab bug, that does not affect usability as far as I can tell).
Also, an invisible scribe overlay axes has been added to hold the new annotations (data brushing is considered an annotation; scribe axes deserve a separate article, which they will indeed get someday).
More importantly for our needs, we see a new line item called ‘Brushing’, which displays the red lines and data points that we seek. We can now easily get the brushed data using this line’s XData and YData properties: non-brushed data points simply have NaN values:

hBrushLine = findall(gca,'tag','Brushing');
brushedData = get(hBrushLine, {'Xdata','Ydata'});
brushedIdx = ~isnan(brushedData{1});
brushedXData = brushedData{1}(brushedIdx);
brushedYData = brushedData{2}(brushedIdx);
% and similarly for ZData in 3D plots

Accessing brushing callbacks

Yet another way of approaching the problem is to use the available callback functions built-into the data-brushing functionality. We can access either the BrushSeriesContextMenu or the figure’s Tools/Brushing menu. I will leave the former (context-menu) approach as an exercise to the reader, and just describe the figure’s menu approach.
As I have already explained in a dedicated article, figure menu-bar actions are accessible via their handles, and we can retrieve that using a unique tag (well, most of the time – read that article for details). In our case, the Tools/Brushing/Create-new-variable menu item has the unique tag ‘figDataManagerNewVar’. So let’s use it:

>> hNewVarMenuItem = findall(gcf,'tag','figDataManagerNewVar')
hNewVarMenuItem =
          742.000244140625
>> hNewVarCallback = get(hNewVarMenuItem,'callback')
hNewVarCallback =
    @datamanager.newvar
>> hNewVarCallback(gcf)   % activate the callback
% => set 'ans' as the new variable holding the brushed data
>> ans
ans =
                       6.4         0.116549204850494
                       6.6         0.311541363513379
                       6.8         0.494113351138609
                         7         0.656986598718789
                       7.2         0.793667863849153
                       7.4         0.898708095811627
                       7.6         0.967919672031486
                       7.8         0.998543345374605
                       ...         ...

Of course, we could also have gone the hard way, via the scribe axes and the annotations route. For masochistic people like me it could even be a worthwhile challenge. But for all other normal people, why bother when there are such simple alternatives, if we only knew how to find them. 🙂

Updates for HG2 (R2014b+)

In HG2 (R2014b+), findall(gca,'tag','Brushing') returns empty data since the way that brushed data is stored has changed. You can access the brushing data using the plot line’s hidden BrushHandles property, as follows:

hLine = plot(...);
hBrushHandles = hLine.BrushHandles;
hBrushChildrenHandles = hBrushHandles.Children;  % Marker, LineStrip

I described the new Marker objects here, and LineStrip objects here. The brushed vertex data can be retrieved from either of them. For example:

>> hBrushChildrenHandles(1).VertextData
ans =
     1     2     3     4   % X-data of 4 data points
     1     2     3     4   % Y-data of 4 data points
     0     0     0     0   % Z-data of 4 data points

If you only need the brushed data points (not the handles for the Markers and LineStrip, you can get them directly from the line handle, using the hidden BrushData property:

>> brushedIdx = logical(hLine.BrushData);  % logical array
>> brushedXData = hLine.XData(brushedIdx);
>> brushedYData = hLine.YData(brushedIdx)
brushedYData =
     1     2     3     4

Addendum 28 Feb, 2018: MathWorks posted an official post on Matlab Answers that references the BrushData functionality – see here.

The post Accessing plot brushed data appeared first on Undocumented Matlab.

Using the toolbar/menubar item handles

Getting the handles can be done in several different ways. In my experience, using the object’s tag string is often easiest, fastest and more maintainable. Note that the Matlab toolbar and main menu handles are normally hidden (HandleVisibility = ‘off’). Therefore, in order to access them we need to use the findall function rather than the better-known findobj function. Also note that to set the callbacks we need to access differently-named properties: ClickedCallback for toolbar buttons, and Callback for menu items:

hToolLegend = findall(gcf,'tag','Annotation.InsertLegend');
set(hToolLegend, 'ClickedCallback',{@cbLegend,hFig,myData});
hMenuLegend = findall(gcf,'tag','figMenuInsertLegend');
set(hMenuLegend, 'Callback',{@cbLegend,hFig,myData});

As a side note, two undocumented/unsupported functions, uitool(hFig,tagName) and uigettoolbar, also retrieve toolbar items. Since using findall is so simple and more supported, I suggest using the findall approach.
To see the list of available toolbar/menubar tags, use the following code snippet:

% Toolbar tag names:
>> hToolbar = findall(gcf,'tag','FigureToolBar');
>> get(findall(hToolbar),'tag')
ans =
    'FigureToolBar'
    'Plottools.PlottoolsOn'
    'Plottools.PlottoolsOff'
    'Annotation.InsertLegend'
    'Annotation.InsertColorbar'
    'DataManager.Linking'
    'Exploration.Brushing'
    'Exploration.DataCursor'
    'Exploration.Rotate'
    'Exploration.Pan'
    'Exploration.ZoomOut'
    'Exploration.ZoomIn'
    'Standard.EditPlot'
    'Standard.PrintFigure'
    'Standard.SaveFigure'
    'Standard.FileOpen'
    'Standard.NewFigure'
    ''
% Menu-bar tag names:
>> get(findall(gcf,'type','uimenu'),'tag')
ans =
    'figMenuHelp'
    'figMenuWindow'
    'figMenuDesktop'
    'figMenuTools'
    'figMenuInsert'
    'figMenuView'
    'figMenuEdit'
    'figMenuFile'
    'figMenuHelpAbout'
    'figMenuHelpPatens'
    'figMenuHelpTerms'
    'figMenuHelpActivation'
    'figMenuDemos'
    'figMenuTutorials'
    'figMenuHelpUpdates'
    'figMenuGetTrials'
    'figMenuWeb'
    'figMenuHelpPrintingExport'
    'figMenuHelpAnnotatingGraphs'
    'figMenuHelpPlottingTools'
    'figMenuHelpGraphics'
    ''
    ''                    < = Note the missing tag names...
    ''
    'figMenuToolsBFDS'    <= note the duplicate tag names...
    'figMenuToolsBFDS'
    'figDataManagerBrushTools'
    'figMenuToolsAlign'
    'figMenuToolsAlign'
    ... (plus many many more...)

Unfortunately, as seen above, Matlab developers forgot to assign tags to some default toolbar/menubar items. Luckily, in my particular case, both legend handles (toolbar, menu) have valid tag names that can be used: 'Annotation.InsertLegend' and 'figMenuInsertLegend'.
If an item's tag is missing, you can always find its handle using its Parent, Label, Tooltip or Callback properties. For example:

hPrintMenuItem = get(findall(gcf,'Label','&Print...'));

Note that property values, such as the tag names or labels, are unsupported and undocumented. They may change without warning or notice between Matlab releases, and have indeed done so in the past. Therefore, if your code needs to be compatible with older Matlab releases, ensure that you cover all the possible property values, or use a different way to access the handles. While using the tag name or label as shown above is considered “Low risk” (I don’t expect it to break in the near future), their actual values should be considered somewhat more risky and we should therefore code defensively.

Another simple example: Print Preview

As another simple and very useful example, let’s modify the default Print action (and tooltip) on the figure toolbar to display the Print-Preview window rather than send the figure directly to the printer:

hToolbar = findall(gcf,'tag','FigureToolBar');
hPrintButton = findall(hToolbar,'tag','Standard.PrintFigure');
set(hPrintButton, 'ClickedCallback','printpreview(gcbf)', 'TooltipString','Print Preview');

The post Modifying default toolbar/menubar actions appeared first on Undocumented Matlab.

% Retrieve redo/undo object
undoObj = getappdata(hFig,'uitools_FigureToolManager');
if isempty(undoObj)
   try
      % R2014a and earlier
      undoObj = uitools.FigureToolManager(hFig);
   catch
      % R2014b and newer
      undoObj = matlab.uitools.internal.FigureToolManager(hFig);
   end
   setappdata(hFig,'uitools_FigureToolManager',undoObj);
end
>> get(undoObj)
    CommandManager: [1x1 uiundo.CommandManager]
            Figure: [1x1 figure]
        UndoUIMenu: [1x1 uimenu]
        RedoUIMenu: [1x1 uimenu]

There are several interesting things we can do with this undoObj. First, let’s modify the main-menu items (I will discuss menu customization in more detail in another post):

% Modify the main menu item (similarly for redo/undo)
if ~isempty(undoObj.RedoUIMenu)
   undoObj.RedoUIMenu.Position =1; %default=2 (undo above redo)
   undoObj.RedoUIMenu.Enable = 'off';     % default='on'
   undoObj.RedoUIMenu.Checked = 'on';     % default='off'
   undoObj.RedoUIMenu.ForegroundColor = [1,0,0];  % =red
end
if ~isempty(undoObj.UndoUIMenu)
   undoObj.UndoUIMenu.Label = 'Undo action';
   % Note: &Undo underlines 'U' and adds a keyboard accelerator
   % but unfortunately only if the label is non-HTML ...
   undoObj.UndoUIMenu.Separator = 'on';   % default='off'
   undoObj.UndoUIMenu.Checked = 'on';     % default='off'
   undoObj.UndoUIMenu.ForegroundColor = 'blue'; % default=black
end

>> undoObj.CommandManager.get
             UndoStack: [13x1 uiundo.FunctionCommand]
             RedoStack: [1x1 uiundo.FunctionCommand]
    MaxUndoStackLength: []
               Verbose: []
>> undoObj.CommandManager.UndoStack(end).get
             Parent: []
       MCodeComment: []
               Name: 'slider update (0.48 to 0.38)'
           Function: @internal_update
           Varargin: {[53.0037841796875]  [0.38]  [1x1 double]}
    InverseFunction: @internal_update
    InverseVarargin: {[53.0037841796875]  [0.48]  [1x1 double]}

This looks familiar: In fact, it is exactly the cmd data structure being passed to the uiundo function, with the additional (apparently unused) properties Parent and MCodeComment. CommandManager‘s UndoStack and RedoStack child objects contain all stored undo/redo actions such that the latest action is at the end of these arrays. In the snippet above, there are 13 undo-able actions, with the latest action in UndoStack(end). UndoStack and RedoStack have the same structure:

• Name contains the action description (presented in the figure’s menu)
• Function is the function handle that will be invoked if the action is redone
• Varargin are the arguments passed to Function during redo
• InverseFunction is the function handle that will be invoked if the action is undone
• InverseVarargin are the arguments passed to InverseFunction during undo
• Parent and MCodeComment – I could not determine what these are used for

We can inspect the latest undo/redo actions, without activating them, by using CommandManager‘s peekundo() and peekredo() methods (which return empty [] if no undo/redo action is available):

>> undoObj.CommandManager.peekredo.get % first check if isempty
             Parent: []
       MCodeComment: []
               Name: 'slider update (0.38 to 0.28)'
           Function: @internal_update
           Varargin: {[53.0037841796875]  [0.28]  [1x1 double]}
    InverseFunction: @internal_update
    InverseVarargin: {[53.0037841796875]  [0.38]  [1x1 double]}
>> undoObj.CommandManager.peekundo.get
             Parent: []
       MCodeComment: []
               Name: 'slider update (0.48 to 0.38)'
           Function: @internal_update
           Varargin: {[53.0037841796875]  [0.38]  [1x1 double]}
    InverseFunction: @internal_update
    InverseVarargin: {[53.0037841796875]  [0.48]  [1x1 double]}
>> undoObj.CommandManager.peekundo.Name
ans =
slider update (0.48 to 0.38)

We can undo/redo the latest action (last element of the UndoStack/RedoStack) by invoking CommandManager‘s undo()/redo() methods. This is actually what uiundo is doing behind the scenes when it is called with the ‘execUndo’ and ‘execRedo’ arguments:

undoObj.CommandManager.undo;
undoObj.CommandManager.redo;

We can clear the entire actions stack by using CommandManager‘s empty() method. This can be useful, for example, after a ‘Save’ or ‘Apply’ operation in our GUI:

undoObj.CommandManager.empty;

If we set CommandManager‘s Verbose property to any non-empty value, debug information is spilled onto the Command Window when new uiundo actions are added:

>> undoObj.CommandManager.Verbose = 1;
% now move the slider and see the debug info below:
internal_update(h_uicontrol, [0.48,], h_uicontrol); % Called by slider update (0.28 to 0.48)
internal_update(h_uicontrol, [0.58,], h_uicontrol); % Called by slider update (0.48 to 0.58)

Finally, CommandManager uses its MaxUndoStackLength property to limit the size of the undo/redo stacks. This property is defined as read-only in %matlabroot%\toolbox\matlab\uitools\@uiundo\@CommandManager\schema.m line #12, so if you wish to programmatically modify this property from its default value of empty (=unlimited), you will need to comment out that line.

The post Customizing uiundo appeared first on Undocumented Matlab.