ginput doesn't accept keyboard entry as first input

Hello all,

I have a figure in which I use ginput() to have coordinates. I ask the user to use left click, right click or keyboard's space in order to have coordinates of three specifics points. But ginput doesn't respond to any keyboard input till I click on the axes. After the first click it will accept all keyboard inputs.

My code:

    [clicX, clicY, clicButton] = ginput(1);
    while isempty(clicButton) ~= 1      % ENTER to quit
      switch clicButton
        case 1     % Left click
          ...
        case 2     % Right click
          ...
        case 32    % SPACE key
          ...
      end
      [clicX, clicY, clicButton] = ginput(1);
    end

I try to add figure(handle) before ginput() in order to Matlab to focus, but whithout any results.

Is someone have a solution ?

Thanks

Answer 1

[Walter Roberson]

dbtype ginput

At around line 87 does it have a comment that begins with g467403 ? If so then I suspect that section to be the difficulty, that possibly before the click the wrong figure is the first child.

Possibly what might work is

uistack(handle, 'top')

[gdell0]

You were right and your solution works perfectly.

Thanks!

Answer 2

[Denis LE BRET]

Hello,

I have the same problem, the first ginput can't be interrupted with keyboard. Your solution don't work for me, maybe I use it the wrong way. Is "handle" the handle of the figure or the handle of the axes ? I used both of them with no result. My code is attached to this answer if you please can have a look. Thank you.

[Walter Roberson]

Denis, which MATLAB release are you using? There was a change in R2016a that might have affected this, so I do not want to try to debug against a different version than you are using.

[Denis LE BRET]

I use the R2013a version.

[Walter Roberson]

Please describe the circumstances in more detail. How many figures exist at the time you issue the ginput() ? Is it possible that the one you wish to ginput on is not the top figure? Which operating system are you using and which operating system release?

For example I just started R2012a (I had it handy) in OS-X El Capitan and with no existing figure at all (so impossible that any figure had focus) gave the command

[clicX, clicY, clicButton] = ginput(1);

and without clicking anywhere in the figure, typed a character. The ginput worked and clickButton had exactly the data that would be expected (that is, char(clickButton) was exactly what I had typed.)

... I just installed R2013a on the system described above and the results were exactly the same.

[Denis LE BRET]

Hello Walter,

I confirm your example works perfectly on my configuration. the function code is attached with my first message (the uistack call is commented but I tried uncommented and the result was the same). The main difference is that the ginput function is called by a button. You are certainly right, there is a focus problem but I don't manage to solve it. Maybe because I don't use the right handle?