GUI ButtonDownFcn for clicking on axes

Hi all, I've got 2 axes in my GUI, and I want to be able to launch a different .m file when the user clicks either axes.

Currently I can launch a function, but I'm unable to differentiate between the different axes, and I'd rather directly run a .m script if possible.

I currently have:

setappdata(gcf,'bdfcnhandle',load_stuff);

        axes(handles.axes3)
        h(1)=imshow(thumb_1, [])

        axes(handles.axes4)
        h(2)=imshow(thumb_2, [])

set(h,'buttondownfcn','feval(getappdata(gcf,''bdfcnhandle''));');%

function load_stuff(hObject, eventdata, handles) X=100;

Also using the code above, I seem to be unable to access the handles structure in my "load_stuff" function!

Can anyone help my plight?

Thanks, Jim

Answer 1

[Patrick Kalita]

I would use the 'ButtonDownFcn' property on each axes, and make the callback function be a call to the run function which will execute your script.

So let's say you have to scripts named s1.m and s2.m. Assuming they're both on the MATLAB path, you can do this:

a1 = axes('Position', [0.1 0.1 0.4 0.4], 'ButtonDownFcn', @(s,e) run('s1'));
a2 = axes('Position', [0.5 0.5 0.4 0.4], 'ButtonDownFcn', @(s,e) run('s2'));

(I'm setting the position property there just so you can see both of the axes in the same figure.)

If the scripts s1.m and s2.m are not on the path, then you can specify the full path to them in the call to run.

Answer 2

[Walter Roberson]

setappdata(gcf,'bdfcnhandle',load_stuff);

is going to run load_stuff (with no parameters), and take its return value and set that as bdfcnhandle in the app data.

I would have to do some digging to figure out what you could do along the lines you have been working.

Note that imshow() returns the handle of an image object, not the handle of an axes. When you are setting the buttondownfcn you are doing so for the images, not for the axes. If you want it to be the axes, you should set(h,'HitTest','off') and set the buttondownfcn against the axes.

What I would do is

set([handles.axes3, handles.axes4], 'buttondownfcn', @load_stuff)

function load_stuff(hObject, eventdata)
  handles = guidata(hObject);
  theaxes = ancestor(hObject,'axes');
  if theaxes == handles.axes3
    %axes3 stuff
  elseif theaxes == handles.axes4
    %axes4 stuff
  end
end

and I wouldn't use bdfcnhandle at all. This code is also designed for calling for either the image object or the axes object.

[Jim O'Doherty]

Hi Walter,

Thanks for your reply. I just tried your solution, and although it didn't throw up any errors, clicking on my handles.axes3 or handles.axes4 didn't do anything at all. So I stripped it back, and the function "load_stuff" isn't actually being ran at all, i.e. clicking on either axes doesn't cause the function to run

function load_stuff(hObject, eventdata)

X=1

any further ideas?

[Robert Cumming]

walters example is adding a callback to the AXIS, not the image. If the image covers the complete axis then you wont be able to trigger the axis callback.

Add a callback to the images and you will that it gets called.

[Walter Roberson]

Quite. That's why I spoke of setting HitTest off for the images.

[Jim O'Doherty]

Just wanted to follow up on this, I managed to implement the above code for my image handle (rather than the axes handle) and it works fairly well. I can run the function no problem.

Would you know how I can differentiate between which image was pressed in my function through the handle h? I'd like something alsong the lines of :

axes(handles.axes3)

h(1)=imshow(thumb_1, [])

axes(handles.axes4)

h(2)=imshow(thumb_2, [])

set(h, 'ButtonDownFcn', @load_stuff)

function load_stuff(hObject, eventdata)

handles = guidata(hObject);

if handle press = h(1)

image 1 stuff

elseif handle press = h(2)

image 2 stuff

I'm guessing something like the "ancestor" command liek that for axes but I'm not sure how to access which image was clicked

Thanks,

Jim

[Walter Roberson]

In your setup routine,

handles.h = h;

guidata(hObject,handles).

Then in load_stuff,

h = handles.h;

if hObject == h(1)

%image 1 stuff

elseif hObject == h(2)

%image 2 stuff

else

%something went wrong

end

[Patrick Kalita]

Generally it would be better to have each image implement it's own ButtionDownFcn, precisely to avoid the "else ... % something went wrong" case.

Answer 3

[Robert Cumming]

Why dont you just do:

    set ( h(1), 'ButtonDownFcn', {@mfile_1} );
    set ( h(2), 'ButtonDownFcn', {@mfile_2} );

[Jim O'Doherty]

Hi Robert,

I liked your simple solution, which I think I've already tried before. It throws back the following error:

??? Attempt to execute SCRIPT mfile_1 as a function:

Removing the @ symbol doesn't help, its like the command is expecting a function

[Robert Cumming]

yes the command is expecting a function. Change your script to a function and it will work.

[Walter Roberson]

The load_stuff example you should was a function ?

Beware that when you run the script, the workspace will be... ummm, probably the base workspace.