Update Background colour Button

Hello,

I would like to change the background colour of a button depending of the value of a variable. This variable changes every 3 s from the script:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

global flag
global estado

button; %% run gui  %%
flag=0;
estado=0;
while flag==0
    check(estado) %%displays the value of the variable %%
    estado=not(estado);
    pause(3)
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

This is my callback code:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% --- Executes on button press in boton.
function boton_Callback(hObject, eventdata, handles)
% hObject    handle to boton (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

global estado;
boton_estado=estado;
if (boton_estado == 1)
set(handles.boton,'BackgroundColor','r');
else
set(handles.boton,'BackgroundColor','g');
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

but it only works when I press the button :S would it be possible that the colour change at the same time that 'estado' without pressing any key??

Thanks a lot guys!

Answer 1

[Jan]

Does a drawnow after setting the color help?

Using a timer() would be smarter, because it does not block Matlab with lazy pause statements.

[Jan]

Move from asnwer to comment section:

ferfer wrote: Thanks for your answer. " Drawnow " does not work , It changes the colour only when I press the button instead of automatically :(

[Jan]

@ferfer: Please post comments to answers in the corresponding section. Thanks.

Sorry, I did not read the code carefully enough. The change in the color appears in the button's callback. This callback is called, when the button is pressed. But why not changing the color directly:

while flag==0
   check(estado) %%displays the value of the variable %%
   estado=not(estado);
   if boton_estado
      set(handles.boton,'BackgroundColor','r');
   else
      set(handles.boton,'BackgroundColor','g');
   end
   pause(3)   % This implies a DRAWNOW already!
end

Answer 2

[ferfer]

It still does not work :S . I have written:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  global estado
  global flag
  boton;
  flag=0;
  estado=0;
  while flag==0
      check(estado)
          estado=not(estado);

      if boton_estado==0
          set(handles.boton,'BackgroundColor','r');

       pause(3)   % This implies a DRAWNOW already!

      end
    end
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

And then:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  function varargout = boton(varargin)
  % BOTON MATLAB code for boton.fig
  %      BOTON, by itself, creates a new BOTON or raises the existing
  %      singleton*.
  %
  %      H = BOTON returns the handle to a new BOTON or the handle to
  %      the existing singleton*.
  %
  %      BOTON('CALLBACK',hObject,eventData,handles,...) calls the local
  %      function named CALLBACK in BOTON.M with the given input arguments.
  %
  %      BOTON('Property','Value',...) creates a new BOTON or raises the
  %      existing singleton*.  Starting from the left, property value pairs are
  %      applied to the GUI before boton_OpeningFcn gets called.  An
  %      unrecognized property name or invalid value makes property application
  %      stop.  All inputs are passed to boton_OpeningFcn via varargin.
  %
  %      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
  %      instance to run (singleton)".
  %
  % See also: GUIDE, GUIDATA, GUIHANDLES

    % Edit the above text to modify the response to help boton

    % Last Modified by GUIDE v2.5 10-Jul-2013 12:52:22

    % Begin initialization code - DO NOT EDIT
    gui_Singleton = 1;
    gui_State = struct('gui_Name',       mfilename, ...
                       'gui_Singleton',  gui_Singleton, ...
                       'gui_OpeningFcn', @boton_OpeningFcn, ...
                       'gui_OutputFcn',  @boton_OutputFcn, ...
                       'gui_LayoutFcn',  [] , ...
                       'gui_Callback',   []);
    if nargin && ischar(varargin{1})
        gui_State.gui_Callback = str2func(varargin{1});
    end

    if nargout
        [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
    else
        gui_mainfcn(gui_State, varargin{:});
    end
    % End initialization code - DO NOT EDIT

    % --- Executes just before boton is made visible.
    function boton_OpeningFcn(hObject, eventdata, handles, varargin)
    % This function has no output args, see OutputFcn.
    % hObject    handle to figure
    % eventdata  reserved - to be defined in a future version of MATLAB
    % handles    structure with handles and user data (see GUIDATA)
    % varargin   command line arguments to boton (see VARARGIN)

    % Choose default command line output for boton
    handles.output = hObject;

    % Update handles structure
    guidata(hObject, handles);

    % UIWAIT makes boton wait for user response (see UIRESUME)
    % uiwait(handles.figure1);

    % --- Outputs from this function are returned to the command line.
    function varargout = boton_OutputFcn(hObject, eventdata, handles) 
    % varargout  cell array for returning output args (see VARARGOUT);
    % hObject    handle to figure
    % eventdata  reserved - to be defined in a future version of MATLAB
    % handles    structure with handles and user data (see GUIDATA)

    % Get default command line output from handles structure
    varargout{1} = handles.output;

    % --- Executes on button press in boton.
    function boton_Callback(hObject, eventdata, handles)
    % hObject    handle to boton (see GCBO)
    % eventdata  reserved - to be defined in a future version of MATLAB
    % handles    structure with handles and user data (see GUIDATA)

    global estado

    boton_estado=estado;

    % --- Executes on button press in salida.
    function salida_Callback(hObject, eventdata, handles)
    % hObject    handle to salida (see GCBO)
    % eventdata  reserved - to be defined in a future version of MATLAB
    % handles    structure with handles and user data (see GUIDATA)
    global flag
    flag=1;
    close

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

When I run the script, Matlab displays: "Error in a (line 11) Undefined variable "handles" or function "handles.boton. set(handles.boton,'BackgroundColor','r');"

Thank you so much for your help!!!