Image to java button

I have multiple questions to ask considering Matlab use

Thank you in advance

Prog Description:

-I am creating a prog that draws the influence line of a : Beam, Truss and Frame

-I have a Main menu in which there are 3 buttons -When the user clicks a button another matlab proj opens

My questions are:

1-How can I put an image background to a java button here's my button :

btLinePropsPos = [0.1,0.6,0.32,0.2];
btLineprops = com.mathworks.mwswing.MJButton('Beam');
btLineprops.setBorder([]);
uiColor = get(handles.figure1,'Color');
btLineprops.setBackground(java.awt.Color(uiColor(1),uiColor(2),uiColor(3)));
btLineprops.setFont(java.awt.Font('Vivaldi',java.awt.Font.PLAIN,60))
btLineprops.setCursor(java.awt.Cursor(java.awt.Cursor.HAND_CURSOR));
btLineprops.setFlyOverAppearance(true);
btLineprops.setToolTipText('Modify properties of plot lines');
[dummy,btContainer] = javacomponent(btLineprops,[0 0 1 1]); %#ok
set(btContainer, 'Units','Norm', 'Position',btLinePropsPos);
set(btLineprops, 'ActionPerformedCallback',@beamCallback);

2-When the user opens the project related to beam button for example, how can I forbid him from opening it another time ? (I want the beam project to be opened only one time on button click from main menu if it is open )

Answer 1

[Image Analyst]

Here's the official Mathworks solution: http://www.mathworks.com/matlabcentral/answers/98593-how-do-i-display-an-image-on-a-gui-component-eg-pushbutton

For your #2. Just set a flag

global userOpenedBeam;
userOpenedBeam = true;

and check it wherever you need to

global userOpenedBeam;
if userOpenedBeam
  uiwait(warndlg('You cannot open beam project again!'));
  return;
end