select_object.m

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%  Script file: select_object.m
%
%  Purpose: 
%    This program illustrates the use of waitforbuttonpress
%    and gco to select graphics objects.  It creates a plot
%    of sin(x) and cos(x), and then allows a user to select 
%    any object and examine its properties.  The program 
%    terminates when a key press occurs.
%
%  Record of revisions:
%      Date       Programmer          Description of change
%      ====       ==========          =====================
%    04/02/07    S. J. Chapman        Original code
%
% Define variables:
%   details      -- Object details
%   h1           -- handle of sine line
%   h2           -- handle of cosine line
%   handle       -- handle of current object
%   k            -- Result of waitforbuttonpress
%   type         -- Object type
%   x            -- Independent variable
%   y1           -- sin(x)
%   y2           -- cos(x)
%   yn           -- Yes/No

% Calculate sin(x) and cos(x)
x = -3*pi:pi/10:3*pi;
y1 = sin(x);
y2 = cos(x);

% Plot the functions.
h1 = plot(x,y1);
set(h1,'LineWidth',2);
hold on;
h2 = plot(x,y2);
set(h2,'LineWidth',2,'LineStyle',':','Color','r');
title('\bfPlot of sin \itx \rm\bf and cos \itx');
xlabel('\bf\itx');
ylabel('\bfsin \itx \rm\bf and cos \itx');
legend('sine','cosine');
hold off;

% Now set up a loop and wait for a mouse click.
k = waitforbuttonpress;

while k == 0

   % Get the handle of the object
   handle = gco;
   
   % Get the type of this object.
   type = get(handle,'Type');
   
   % Display object type
   disp (['Object type = ' type '.']);
   
   % Do we display the details?
   yn = input('Do you want to display details? (y/n) ','s');
   
   if yn == 'y'
      details = get(handle);
      disp(details);
   end
   
   % Check for another mouse click
   k = waitforbuttonpress;
end