Check if mouse is above an axes

Is there a quick way to check if the mouse is currently positioned over an axes? I'm working on a GUI that sets the 'WindowScrollWheelFcn' property of the figure. However, I only want the callback function to do something if the mouse is currently over a given axes. I've been using the 'CurrentPoint' property of the figure, and then using the position property of the axes to check if the mouse is over the axes. This works fine when the axes' parent is the figure. However, for my GUI, its possible that the axes is contained in several hierarchies of uipanels, thus the axes' position property is relative to its parent panel, not the figure. This makes figuring out if the mouse is over the axes more complicated. I need this to work, independent if the axes is contained in the figure, or in a uipanel that is a descendent of the figure. Any clever ideas out there? Thanks in advance for any tips.

Answer 1

[Joseph Cheng]

Here is a little thing i threw together.

function test()
h = figure(1);
hp = uipanel('Title','Main Panel','FontSize',12,...
             'BackgroundColor','white',...
             'Position',[.1 .1 .9 .9]);
hsp = uipanel('Parent',hp,'Title','Subpanel','FontSize',12,...
              'Position',[.1 .1 .9 .9]);
hax = axes('Parent',hsp,'position',[.1 .1 .8 .8]);
plot(randi(10,4,2));
set(h,'windowbuttonmotionfcn',@mousemove);

function mousemove(hobject,eventdata)
C = get(gca,'currentpoint');
P = get(gca,'position');
xlim = get(gca,'xlim');
ylim = get(gca,'ylim');
outX = ~any(diff([xlim(1) C(1,1) xlim(2)])<0);
outY = ~any(diff([ylim(1) C(1,2) ylim(2)])<0);
if outX&outY
    set(gca,'color',[0 1 0])
else
    set(gca,'color',[1 0 0])
end
title(gca, {['(X,Y) = (', num2str(C(1,1)), ', ',num2str(C(1,2)), ')'];...
    [num2str([outX outY])]})

now obviously you'll have to adapt and see if it is what you're looking to do. I didn't have time to add some robustness checks for multiple axes but this mayget you where you need to go. So instead of looking at whether the mouse is within the axes position, i chose to check to see if the point is within the x and y limits of the axes.

[Joseph Cheng]

oh and i changed the logic checks so the outX and outY actually should be inX and inY. Just didn't get around to changing it when i put the ~ infront of the any.

[Justin Solomon]

Thanks for the example. I recall that I previously had some trouble with using the 'currentpoint' property of the axes. I think this came about when I had multiple axes in the figure. Anyways, it seems to be working now so I'll deal with those problems if they arise again.

Answer 2

[Jan]

overobj helps to check if the mouse is on top of an axes. See http://undocumentedmatlab.com/blog/undocumented-mouse-pointer-functions

[Justin Solomon]

Thanks for the tip. Unfortunately, overobj can only search for the immediate child of the figure. Thus if my axes is embedded in a uipanel, overobj won't find it. :(

[Walter Roberson]

Current link is http://undocumentedmatlab.com/articles/undocumented-mouse-pointer-functions