Javacomponent background color

In this website, I have often shown how Matlab application functionality can be significantly enhanced by including Java components in the Matlab GUI, using the built-in semi-documented javacomponent function (which I described here last year).

Using java components in Matlab is simple and easy, but there are a few annoying catches. One of these is the fact that the default Matlab figure background color ([0.8, 0.8, 0.8]) is a different shade of gray than the default uicontrol background color ([0.9255, 0.9137, 0.847]). javacomponents use the same background color as uicontrols.

hPanel = uipanel('units','pixe', 'pos',[30,30,200,100], 'title','Matlab uipanel');
jLabel = javax.swing.JLabel('Java Label');
[jhlabel,jContainer]=javacomponent(jLabel, [250,50,100,50], gcf);

Javacomponents use different default background color than figures

While Matlab users are familiar with updating Matlab colors, doing so with Java colors is a bit different. We have two basic ways to align the javacomponent background color with the figure’s: either change the figure’s Color property to the Java component’s bgcolor, or vice versa:

Changing the javacomponent‘s background color to the figure color

% Fix the Java component:
% Variant #1
bgcolor = get(gcf, 'Color');
jLabel.setBackground(java.awt.Color(bgcolor(1),bgcolor(2),bgcolor(3)));
 
% Variant #2
bgcolor = num2cell(get(gcf, 'Color'));
jLabel.setBackground(java.awt.Color(bgcolor{:}));
 
% Fix the Matlab panel uicontrol
set(hPanel, 'BackgroundColor', get(gcf,'Color'));

controls with fixed background colors

Changing the figure’s color to the javacomponent‘s background color

bgcolor = jLabel.getBackground.getComponents([]);
set(gcf, 'Color', bgcolor(1:3));

figure with modified color to match the controls

Look at the list of related posts below for other articles related to colors in Matlab.