Made JComboBox, JProgressBar, JSpinner and JXDatePicker non-opaque.

`JPasswordField`, `JScrollPane` and `JTextField` are non-opaque if they have
an outside focus border (e.g. IntelliJ and Darcula themes).
(issues #20 and #17)

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatInspector.java

@@ -58,6 +58,7 @@ public class FlatInspector
 	private Component lastComponent;
 	private int lastX;
 	private int lastY;
+	private boolean inspectParent;
 
 	private JComponent highlightFigure;
 	private JToolTip tip;
@@ -70,6 +71,7 @@ public class FlatInspector
 			public void mouseMoved( MouseEvent e ) {
 				lastX = e.getX();
 				lastY = e.getY();
+				inspectParent = e.isShiftDown();
 				inspect( lastX, lastY );
 			}
 		} );
@@ -105,6 +107,8 @@ public class FlatInspector
 	private void inspect( int x, int y ) {
 		Container contentPane = rootPane.getContentPane();
 		Component c = SwingUtilities.getDeepestComponentAt( contentPane, x, y );
+		if( inspectParent && c != null && c != contentPane )
+			c = c.getParent();
 		if( c == contentPane || (c != null && c.getParent() == contentPane) )
 			c = null;
 
@@ -237,7 +241,8 @@ public class FlatInspector
 		}
 
 		text += "Enabled: " + c.isEnabled() + '\n';
-		text += "Opaque: " + c.isOpaque() + '\n';
+		text += "Opaque: " + c.isOpaque() + (c instanceof JComponent &&
+			FlatUIUtils.hasOpaqueBeenExplicitlySet( (JComponent) c ) ? " EXPLICIT" : "") + '\n';
 		text += "Focusable: " + c.isFocusable() + '\n';
 		text += "Left-to-right: " + c.getComponentOrientation().isLeftToRight() + '\n';
 		text += "Parent: " + c.getParent().getClass().getName();

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatTestFrame.java

@@ -307,7 +307,7 @@ public class FlatTestFrame
 					c.setBackground( explicit ? Color.orange : restoreColor );
 				} else {
 					c.setForeground( explicit ? Color.blue : restoreColor );
-					c.setBackground( explicit ? Color.red : restoreColor );
+					c.setBackground( explicit ? Color.green : restoreColor );
 				}
 			} );
 
@@ -425,6 +425,14 @@ public class FlatTestFrame
 		contentPanel.getContentPane().remove( content );
 		content = contentFactory.get();
 		contentPanel.getContentPane().add( content );
+
+		if( rightToLeftCheckBox.isSelected() )
+			rightToLeftChanged();
+		if( !enabledCheckBox.isSelected() )
+			enabledChanged();
+		if( explicitColorsCheckBox.isSelected() )
+			explicitColorsChanged();
+
 		contentPanel.revalidate();
 		contentPanel.repaint();
 	}

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatTestPanel.java

@@ -29,15 +29,29 @@ public class FlatTestPanel
 {
 	@Override
 	protected void paintComponent( Graphics g ) {
-		super.paintComponent( g );
+		int width = getWidth();
+		int height = getHeight();
 
-		FlatTestFrame frame = (FlatTestFrame) SwingUtilities.getAncestorOfClass( FlatTestFrame.class, this );
-		if( frame != null && frame.isPaintBackgroundPattern() ) {
+		g.setColor( super.getBackground() );
+		g.fillRect( 0, 0, width, height );
+
+		if( isPaintBackgroundPattern() ) {
 			g.setColor( Color.magenta );
-			int width = getWidth();
-			int height = getHeight();
 			for( int y = 0; y < height; y += 2 )
 				g.drawLine( 0, y, width - 1, y );
 		}
 	}
+
+	/**
+	 * Overridden to see which components paint background with color from parent.
+	 */
+	@Override
+	public Color getBackground() {
+		return isPaintBackgroundPattern() ? Color.red : super.getBackground();
+	}
+
+	private boolean isPaintBackgroundPattern() {
+		FlatTestFrame frame = (FlatTestFrame) SwingUtilities.getAncestorOfClass( FlatTestFrame.class, this );
+		return frame != null && frame.isPaintBackgroundPattern();
+	}
 }