App Designer: Setting a callback on a plot line in uiaxes disables interactivity

OK I've lost way too many hours on this one.

Using MATLAB 2018b.

Trying to make a multi-line plot using uiaxes in app designer, and then to add callbacks to the lines.

When I create the plot without callbacks, the plot has the nice default zoom-and-pan interactivity of uiaxes (which is different than the old legacy zoom() and pan()).

When I add the callbacks, the plot becomes non-interactive, no zoom or pan, although the lines are selectable and the callback is launched. That sucks.

Example:

plot(app.UIAxesMainPlot, sampleNumberVector, tgtDataTable{:,:});
% No problem, multi-line plot is populated and zoom/pan interactivity is OK.

Now add a callback to (for example) the last line on the plot:

app.UIAxesMainPlot.Children(end).ButtonDownFcn = createCallbackFcn(app, @lineSelected, true)

% Line objects are stored as ~.Children of the uiaxes object so I set the 
% callback there.

% Clicking on the plot line launches the callback. OK. Looks good so far.

% However, plot is now 'static' and does not pan/zoom.
% Calling the legacy
pan(app.UIAxesMainPlot,'on') % or
zoom(app.UIAxesMainPlot,'on')
% does not resolve the problem, and also those are not the same as the default 
% interactivity for uiaxes.

% I can hold(app.UIAxesMainPlot,'on'), plot the lines one by one, and add the 
% callbacks to specific lines as I go, but I get the same result. 

What am I missing here?

Is the way I'm applying the line callback somehow interfering with the callback hierarchy of the uiaxes object and wrecking the zoom/pan interactivity?

I've crawled through all the object properties and can't seem to isolate the issue.

[Kent Schonert]

I am vexed by this issue as well.

Within the callback I wish something like was possible (maybe it is?):

function chartClick(app, hitEvent)
            if hitEvent.Button ~= 1
                "***process default events***
                return;                
            end

I ended up putting a manual toggle in the UI so the user can toggle between the two behavoirs:

     function MouseModeSwitch_2ValueChanged(app, event)
            value = app.MouseModeSwitch_2.Value;
            if value == "Pan/Zoom"   
                %have to replot and reset to reliably get the default pan/zoom behavior back
                plot(app.UIAxes, app.DG, 'NodeLabel',table2cell(app.DG.Nodes),'Interpreter', 'none');              
                app.UIAxes.reset;
                app.UIAxes.Children(end).PickableParts = 'none'; %dont want datatips in my digraph
            else
                app.UIAxes.Children(end).ButtonDownFcn = createCallbackFcn(app, @chartClick, true);
                app.UIAxes.Children(end).PickableParts = 'visible';
                delete(findall(app.UIAxes,'Type','hggroup')); %delete datatips
            end
      end
         

It is far from perfect.

• When switching from custom-callback => default, there is a seeminly random peroid of time where it takes a while for the default behavoir to come back.
• When switching from default => custom-callback, there is about a 3 seconds time window where it works as desired (custom callback works along with default pan/zoom).

Answer 1

[yu-hung lin]

I don't know the exact reason why the pan or zoom didn't work either after the callback was added , but i guessed that when we added the customized function to the buttomdownfcn it just replace the function of pan or zoom somewhere inside the matlab.

So i put the pan inside the customized function and assign it to the mouse left-click.

function lineSelected(app, event)
    if strcmp(app.UIFigure.SelectionType,'normal')
        pan(app.UIAxesMainPlot,'on');
    end
end

It works for me. Hope that helps you.