Bug 540357 - [10.14] Make SWT adapt to switching to dark mode (and back)

The patch sets the appearance of SWT application to dark or light based
on the system setting. The patch reads the setting only at startup,
changing the system setting dynamically doesn't cause any change in SWT.

Change-Id: I0d49f2995f55dae2a6349504a2a63e1c3723319f

5 files changed, 33 insertions, 2 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/AppKitFull.bridgesupport.extras b/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/AppKitFull.bridgesupport.extras
index 26a9992f71..90fa40ec2d 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/AppKitFull.bridgesupport.extras
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/AppKitFull.bridgesupport.extras
@@ -58,6 +58,9 @@
 			<arg swt_gen="true"></arg>
 			<retval swt_gen="true"></retval>
 		</method>
+		<method class_method="true" selector="currentAppearance" swt_gen="true">
+			<retval swt_gen="true"></retval>
+		</method>
 		<method selector="name" swt_gen="true">
 			<retval swt_gen="true"></retval>
 		</method>
diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/NSAppearance.java b/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/NSAppearance.java
index 172c1a9563..870f4b1ba2 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/NSAppearance.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/NSAppearance.java
@@ -32,6 +32,11 @@ public static NSAppearance appearanceNamed(NSString name) {
 	return result != 0 ? new NSAppearance(result) : null;
 }
 
+public static NSAppearance currentAppearance() {
+	long /*int*/ result = OS.objc_msgSend(OS.class_NSAppearance, OS.sel_currentAppearance);
+	return result != 0 ? new NSAppearance(result) : null;
+}
+
 public NSString name() {
 	long /*int*/ result = OS.objc_msgSend(this.id, OS.sel_name);
 	return result != 0 ? new NSString(result) : null;
diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/OS.java b/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/OS.java
index 93cbd45fb4..06e7414bf2 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/OS.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/OS.java
@@ -220,6 +220,22 @@ public class OS extends C {
 	public static void setTheme(boolean isDarkTheme) {
 		OS.objc_msgSend(NSApplication.sharedApplication().id, sel_appAppearanceChanged, isDarkTheme ? 1 : 0);
 	}
+	public static boolean isAppDarkAppearance() {
+		if (OS.VERSION_MMB >= OS.VERSION_MMB(10, 14, 0)) {
+			NSAppearance currentAppearance = NSAppearance.currentAppearance();
+			if (currentAppearance != null) {
+				return "NSAppearanceNameDarkAqua".equals(currentAppearance.name().getString());
+			}
+		}
+		return false;
+	}
+	public static boolean isSystemDarkAppearance() {
+		if (OS.VERSION_MMB >= OS.VERSION_MMB(10, 14, 0)) {
+			NSString osxMode = NSUserDefaults.standardUserDefaults ().stringForKey (NSString.stringWith ("AppleInterfaceStyle"));
+			return osxMode != null && "Dark".equals (osxMode.getString ());
+		}
+		return false;
+	}
 
 /** JNI natives */
 
@@ -1242,6 +1258,7 @@ public static final long /*int*/ sel_createFileAtPath_contents_attributes_ = Sel
 public static final long /*int*/ sel_credentialWithUser_password_persistence_ = Selector.sel_credentialWithUser_password_persistence_.value;
 public static final long /*int*/ sel_crosshairCursor = Selector.sel_crosshairCursor.value;
 public static final long /*int*/ sel_ctrlKey = Selector.sel_ctrlKey.value;
+public static final long /*int*/ sel_currentAppearance = Selector.sel_currentAppearance.value;
 public static final long /*int*/ sel_currentApplication = Selector.sel_currentApplication.value;
 public static final long /*int*/ sel_currentContext = Selector.sel_currentContext.value;
 public static final long /*int*/ sel_currentCursor = Selector.sel_currentCursor.value;
diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/Selector.java b/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/Selector.java
index ccd2053469..ef483afb8e 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/Selector.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/cocoa/org/eclipse/swt/internal/cocoa/Selector.java
@@ -354,6 +354,7 @@ public enum Selector {
 	, sel_credentialWithUser_password_persistence_("credentialWithUser:password:persistence:")
 	, sel_crosshairCursor("crosshairCursor")
 	, sel_ctrlKey("ctrlKey")
+	, sel_currentAppearance("currentAppearance")
 	, sel_currentApplication("currentApplication")
 	, sel_currentContext("currentContext")
 	, sel_currentCursor("currentCursor")
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/widgets/Display.java b/bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/widgets/Display.java
index 84c4a40b40..7f996ebb9f 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/widgets/Display.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/widgets/Display.java
@@ -110,7 +110,7 @@ public class Display extends Device {
 	enum APPEARANCE {
 		Dark, Light,
 	}
-	APPEARANCE appAppearance = null;
+	APPEARANCE appAppearance;
 
 	/* Windows and Events */
 	Event [] eventQueue;
@@ -1897,7 +1897,7 @@ double /*float*/ [] getWidgetColorRGB (int id) {
 			break;
 		case SWT.COLOR_WIDGET_HIGHLIGHT_SHADOW: color = NSColor.controlLightHighlightColor(); break;
 		case SWT.COLOR_WIDGET_BACKGROUND:
-			color = OS.VERSION_MMB >= OS.VERSION_MMB (10, 14, 0) ? NSColor.windowBackgroundColor()
+			color = OS.VERSION_MMB >= OS.VERSION_MMB (10, 14, 0) ? NSColor.controlBackgroundColor()
 					: NSColor.controlHighlightColor();
 			break;
 		case SWT.COLOR_WIDGET_FOREGROUND: color = NSColor.controlTextColor(); break;
@@ -2224,6 +2224,11 @@ boolean hasDefaultButton () {
 @Override
 protected void init () {
 	super.init ();
+
+	if (OS.isSystemDarkAppearance()) {
+		setAppAppearance(APPEARANCE.Dark);
+	}
+
 	initClasses ();
 	initColors ();
 	initFonts ();