Compute fg and bg colors for setEditable for StyledText

This commit adds the foreground and background color computation for
setEditable. Earlier this was handled only for setEnabled. This commit
also adds a different foreground and background color for StyledText
when background is not editable.

Fixes :#3132

Author: elsazac

bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/StyledText.java

@@ -8280,7 +8280,7 @@ public void setBackground(Color color) {
 	boolean backgroundDisabled = false;
 	if (!this.enabled && color == null) {
 		if (background != null) {
-			Color disabledBg = getDisplay().getSystemColor(SWT.COLOR_TEXT_DISABLED_BACKGROUND);
+			Color disabledBg = new Color(COLOR_DISABLED_STATE);
 			if (background.equals(disabledBg)) {
 				return;
 			} else {
@@ -8910,7 +8910,7 @@ public void setForeground(Color color) {
 	boolean foregroundDisabled = false;
 	if (!this.enabled && color == null) {
 		if (foreground != null) {
-			Color disabledFg = getDisplay().getSystemColor(SWT.COLOR_WIDGET_DISABLED_FOREGROUND);
+			Color disabledFg = getDisplay().getSystemColor(SWT.COLOR_DARK_GRAY);
 			if (foreground.equals(disabledFg)) {
 				return;
 			} else {

tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_custom_StyledText.java

@@ -66,6 +66,7 @@
 import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.graphics.GlyphMetrics;
 import org.eclipse.swt.graphics.Point;
+import org.eclipse.swt.graphics.RGB;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.internal.BidiUtil;
 import org.eclipse.swt.layout.FillLayout;
@@ -101,6 +102,7 @@ public class Test_org_eclipse_swt_custom_StyledText extends Test_org_eclipse_swt
 final static String PLATFORM_LINE_DELIMITER = System.lineSeparator();
 private boolean listenerCalled;
 private boolean listener2Called;
+private static final RGB COLOR_DISABLED_STATE = new RGB(54, 54, 54);
 
 @Override
 @BeforeEach
@@ -3245,8 +3247,8 @@ public void test_setDoubleClickEnabledZ(){
 @Test
 public void test_setEnabled(){
 	// Get colors
-	Color disabledBg = text.getDisplay().getSystemColor(SWT.COLOR_TEXT_DISABLED_BACKGROUND);
-	Color disabledFg = text.getDisplay().getSystemColor(SWT.COLOR_WIDGET_DISABLED_FOREGROUND);
+	Color disabledBg = new Color(text.getDisplay(), COLOR_DISABLED_STATE);
+	Color disabledFg = text.getDisplay().getSystemColor(SWT.COLOR_DARK_GRAY);
 	Color enabledBg = text.getDisplay().getSystemColor(SWT.COLOR_LIST_BACKGROUND);
 	Color enabledFg = text.getDisplay().getSystemColor(SWT.COLOR_LIST_FOREGROUND);