Bug 545587 - [GTK] Incorrect COLOR_INFO_FOREGROUND on Ubuntu 18.10

Fix 1:
------
Old approach no longer works, because GTK changed the way of specifying
CSS classes. I think it happened in this GTK commit:
	6f6e5365 by Emmanuele Bassi at 2015-11-08 18:10:00
	Use CSS node name for GtkTooltipWindow instead of a style class.

The new way is to use 'GtkWidgetPath' and set CSS name explicitly, see
'gtk_widget_class_set_css_name' in 'gtk_tooltip_window_class_init'.

Fix 2:
------
'styleContextGetBackgroundColor' now uses ARGB surface to obtain correct
alpha component of the color.

Fix 3:
------
'styleContextGetBackgroundColor' now correctly works around
premultiplied
colors in cairo.

Refactoring:
------------
1) Renamed 'getBackgroundColor' 'styleContextGetBackgroundColor' to
match
the other function, 'styleContextGetColor'

Change-Id: Ie93fa71addd16133989be81ebf8e0d0fb1e55e12
Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>

5 files changed, 293 insertions, 39 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os.c b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os.c
index 4a562b022d..8bb7f2fcae 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os.c
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os.c
@@ -6845,6 +6845,18 @@ JNIEXPORT jint JNICALL GTK_NATIVE(_1gtk_1label_1get_1mnemonic_1keyval)
 }
 #endif
 
+#ifndef NO__1gtk_1label_1get_1type
+JNIEXPORT jlong JNICALL GTK_NATIVE(_1gtk_1label_1get_1type)
+	(JNIEnv *env, jclass that)
+{
+	jlong rc = 0;
+	GTK_NATIVE_ENTER(env, that, _1gtk_1label_1get_1type_FUNC);
+	rc = (jlong)gtk_label_get_type();
+	GTK_NATIVE_EXIT(env, that, _1gtk_1label_1get_1type_FUNC);
+	return rc;
+}
+#endif
+
 #ifndef NO__1gtk_1label_1new
 JNIEXPORT jlong JNICALL GTK_NATIVE(_1gtk_1label_1new)
 	(JNIEnv *env, jclass that, jbyteArray arg0)
@@ -9332,6 +9344,18 @@ JNIEXPORT void JNICALL GTK_NATIVE(_1gtk_1style_1context_1invalidate)
 }
 #endif
 
+#ifndef NO__1gtk_1style_1context_1new
+JNIEXPORT jlong JNICALL GTK_NATIVE(_1gtk_1style_1context_1new)
+	(JNIEnv *env, jclass that)
+{
+	jlong rc = 0;
+	GTK_NATIVE_ENTER(env, that, _1gtk_1style_1context_1new_FUNC);
+	rc = (jlong)gtk_style_context_new();
+	GTK_NATIVE_EXIT(env, that, _1gtk_1style_1context_1new_FUNC);
+	return rc;
+}
+#endif
+
 #ifndef NO__1gtk_1style_1context_1remove_1class
 JNIEXPORT void JNICALL GTK_NATIVE(_1gtk_1style_1context_1remove_1class)
 	(JNIEnv *env, jclass that, jlong arg0, jbyteArray arg1)
@@ -9366,6 +9390,16 @@ JNIEXPORT void JNICALL GTK_NATIVE(_1gtk_1style_1context_1save)
 }
 #endif
 
+#ifndef NO__1gtk_1style_1context_1set_1path
+JNIEXPORT void JNICALL GTK_NATIVE(_1gtk_1style_1context_1set_1path)
+	(JNIEnv *env, jclass that, jlong arg0, jlong arg1)
+{
+	GTK_NATIVE_ENTER(env, that, _1gtk_1style_1context_1set_1path_FUNC);
+	gtk_style_context_set_path((GtkStyleContext *)arg0, (GtkWidgetPath *)arg1);
+	GTK_NATIVE_EXIT(env, that, _1gtk_1style_1context_1set_1path_FUNC);
+}
+#endif
+
 #ifndef NO__1gtk_1style_1context_1set_1state
 JNIEXPORT void JNICALL GTK_NATIVE(_1gtk_1style_1context_1set_1state)
 	(JNIEnv *env, jclass that, jlong arg0, jlong arg1)
@@ -12348,6 +12382,64 @@ JNIEXPORT void JNICALL GTK_NATIVE(_1gtk_1widget_1override_1font)
 }
 #endif
 
+#ifndef NO__1gtk_1widget_1path_1append_1type
+JNIEXPORT jlong JNICALL GTK_NATIVE(_1gtk_1widget_1path_1append_1type)
+	(JNIEnv *env, jclass that, jlong arg0, jlong arg1)
+{
+	jlong rc = 0;
+	GTK_NATIVE_ENTER(env, that, _1gtk_1widget_1path_1append_1type_FUNC);
+	rc = (jlong)gtk_widget_path_append_type((GtkWidgetPath *)arg0, (GType)arg1);
+	GTK_NATIVE_EXIT(env, that, _1gtk_1widget_1path_1append_1type_FUNC);
+	return rc;
+}
+#endif
+
+#ifndef NO__1gtk_1widget_1path_1free
+JNIEXPORT void JNICALL GTK_NATIVE(_1gtk_1widget_1path_1free)
+	(JNIEnv *env, jclass that, jlong arg0)
+{
+	GTK_NATIVE_ENTER(env, that, _1gtk_1widget_1path_1free_FUNC);
+	gtk_widget_path_free((GtkWidgetPath *)arg0);
+	GTK_NATIVE_EXIT(env, that, _1gtk_1widget_1path_1free_FUNC);
+}
+#endif
+
+#ifndef NO__1gtk_1widget_1path_1iter_1set_1object_1name
+JNIEXPORT jlong JNICALL GTK_NATIVE(_1gtk_1widget_1path_1iter_1set_1object_1name)
+	(JNIEnv *env, jclass that, jlong arg0, jlong arg1, jbyteArray arg2)
+{
+	jbyte *lparg2=NULL;
+	jlong rc = 0;
+	GTK_NATIVE_ENTER(env, that, _1gtk_1widget_1path_1iter_1set_1object_1name_FUNC);
+	if (arg2) if ((lparg2 = (*env)->GetByteArrayElements(env, arg2, NULL)) == NULL) goto fail;
+/*
+	rc = (jlong)gtk_widget_path_iter_set_object_name((GtkWidgetPath *)arg0, (gint)arg1, (const char *)lparg2);
+*/
+	{
+		GTK_LOAD_FUNCTION(fp, gtk_widget_path_iter_set_object_name)
+		if (fp) {
+			rc = (jlong)((jlong (CALLING_CONVENTION*)(GtkWidgetPath *, gint, const char *))fp)((GtkWidgetPath *)arg0, (gint)arg1, (const char *)lparg2);
+		}
+	}
+fail:
+	if (arg2 && lparg2) (*env)->ReleaseByteArrayElements(env, arg2, lparg2, 0);
+	GTK_NATIVE_EXIT(env, that, _1gtk_1widget_1path_1iter_1set_1object_1name_FUNC);
+	return rc;
+}
+#endif
+
+#ifndef NO__1gtk_1widget_1path_1new
+JNIEXPORT jlong JNICALL GTK_NATIVE(_1gtk_1widget_1path_1new)
+	(JNIEnv *env, jclass that)
+{
+	jlong rc = 0;
+	GTK_NATIVE_ENTER(env, that, _1gtk_1widget_1path_1new_FUNC);
+	rc = (jlong)gtk_widget_path_new();
+	GTK_NATIVE_EXIT(env, that, _1gtk_1widget_1path_1new_FUNC);
+	return rc;
+}
+#endif
+
 #ifndef NO__1gtk_1widget_1queue_1draw
 JNIEXPORT void JNICALL GTK_NATIVE(_1gtk_1widget_1queue_1draw)
 	(JNIEnv *env, jclass that, jlong arg0)
diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.c b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.c
index 8ea3bc8038..675554b9b1 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.c
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.c
@@ -552,6 +552,7 @@ char * GTK_nativeFunctionNames[] = {
 #endif
 	"_1gtk_1label_1get_1layout",
 	"_1gtk_1label_1get_1mnemonic_1keyval",
+	"_1gtk_1label_1get_1type",
 	"_1gtk_1label_1new",
 	"_1gtk_1label_1new_1with_1mnemonic",
 	"_1gtk_1label_1set_1attributes",
@@ -749,9 +750,11 @@ char * GTK_nativeFunctionNames[] = {
 	"_1gtk_1style_1context_1get_1padding__JILorg_eclipse_swt_internal_gtk_GtkBorder_2",
 	"_1gtk_1style_1context_1get_1padding__JLorg_eclipse_swt_internal_gtk_GtkBorder_2",
 	"_1gtk_1style_1context_1invalidate",
+	"_1gtk_1style_1context_1new",
 	"_1gtk_1style_1context_1remove_1class",
 	"_1gtk_1style_1context_1restore",
 	"_1gtk_1style_1context_1save",
+	"_1gtk_1style_1context_1set_1path",
 	"_1gtk_1style_1context_1set_1state",
 	"_1gtk_1target_1list_1new",
 	"_1gtk_1target_1list_1unref",
@@ -975,6 +978,10 @@ char * GTK_nativeFunctionNames[] = {
 	"_1gtk_1widget_1override_1background_1color",
 	"_1gtk_1widget_1override_1color",
 	"_1gtk_1widget_1override_1font",
+	"_1gtk_1widget_1path_1append_1type",
+	"_1gtk_1widget_1path_1free",
+	"_1gtk_1widget_1path_1iter_1set_1object_1name",
+	"_1gtk_1widget_1path_1new",
 	"_1gtk_1widget_1queue_1draw",
 	"_1gtk_1widget_1queue_1resize",
 	"_1gtk_1widget_1realize",
diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.h b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.h
index 98a58f57ba..9714551869 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.h
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.h
@@ -550,6 +550,7 @@ typedef enum {
 #endif
 	_1gtk_1label_1get_1layout_FUNC,
 	_1gtk_1label_1get_1mnemonic_1keyval_FUNC,
+	_1gtk_1label_1get_1type_FUNC,
 	_1gtk_1label_1new_FUNC,
 	_1gtk_1label_1new_1with_1mnemonic_FUNC,
 	_1gtk_1label_1set_1attributes_FUNC,
@@ -747,9 +748,11 @@ typedef enum {
 	_1gtk_1style_1context_1get_1padding__JILorg_eclipse_swt_internal_gtk_GtkBorder_2_FUNC,
 	_1gtk_1style_1context_1get_1padding__JLorg_eclipse_swt_internal_gtk_GtkBorder_2_FUNC,
 	_1gtk_1style_1context_1invalidate_FUNC,
+	_1gtk_1style_1context_1new_FUNC,
 	_1gtk_1style_1context_1remove_1class_FUNC,
 	_1gtk_1style_1context_1restore_FUNC,
 	_1gtk_1style_1context_1save_FUNC,
+	_1gtk_1style_1context_1set_1path_FUNC,
 	_1gtk_1style_1context_1set_1state_FUNC,
 	_1gtk_1target_1list_1new_FUNC,
 	_1gtk_1target_1list_1unref_FUNC,
@@ -973,6 +976,10 @@ typedef enum {
 	_1gtk_1widget_1override_1background_1color_FUNC,
 	_1gtk_1widget_1override_1color_FUNC,
 	_1gtk_1widget_1override_1font_FUNC,
+	_1gtk_1widget_1path_1append_1type_FUNC,
+	_1gtk_1widget_1path_1free_FUNC,
+	_1gtk_1widget_1path_1iter_1set_1object_1name_FUNC,
+	_1gtk_1widget_1path_1new_FUNC,
 	_1gtk_1widget_1queue_1draw_FUNC,
 	_1gtk_1widget_1queue_1resize_FUNC,
 	_1gtk_1widget_1realize_FUNC,
diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk/GTK.java b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk/GTK.java
index c6e05cfdba..250785978c 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk/GTK.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk/GTK.java
@@ -3743,6 +3743,15 @@ public class GTK extends OS {
 			lock.unlock();
 		}
 	}
+	public static final native long _gtk_label_get_type();
+	public static final long gtk_label_get_type() {
+		lock.lock();
+		try {
+			return _gtk_label_get_type();
+		} finally {
+			lock.unlock();
+		}
+	}
 	/** @param label cast=(GtkLabel *) */
 	public static final native int _gtk_label_get_mnemonic_keyval(long label);
 	public static final int gtk_label_get_mnemonic_keyval(long label) {
@@ -4025,6 +4034,28 @@ public class GTK extends OS {
 			lock.unlock();
 		}
 	}
+	public static final native long _gtk_style_context_new ();
+	public static final long gtk_style_context_new() {
+		lock.lock();
+		try {
+			return _gtk_style_context_new();
+		} finally {
+			lock.unlock();
+		}
+	}
+	/**
+	 * @param context cast=(GtkStyleContext *)
+	 * @param path cast=(GtkWidgetPath *)
+	 */
+	public static final native void _gtk_style_context_set_path (long context, long path);
+	public static final void gtk_style_context_set_path(long context, long path) {
+		lock.lock();
+		try {
+			_gtk_style_context_set_path(context, path);
+		} finally {
+			lock.unlock();
+		}
+	}
 	/**
 	 * @param list_store cast=(GtkListStore *)
 	 * @param iter cast=(GtkTreeIter *)
@@ -8858,6 +8889,56 @@ public class GTK extends OS {
 			lock.unlock();
 		}
 	}
+	/**
+	 * @param path cast=(GtkWidgetPath *)
+	 * @param type cast=(GType)
+	 */
+	public static final native long _gtk_widget_path_append_type (long path, long type);
+	public static final long gtk_widget_path_append_type(long path, long type) {
+		lock.lock();
+		try {
+			return _gtk_widget_path_append_type(path, type);
+		} finally {
+			lock.unlock();
+		}
+	}
+	/**
+	 * @param path cast=(GtkWidgetPath *)
+	 */
+	public static final native void _gtk_widget_path_free (long path);
+	public static final void gtk_widget_path_free(long path) {
+		lock.lock();
+		try {
+			_gtk_widget_path_free(path);
+		} finally {
+			lock.unlock();
+		}
+	}
+	/**
+	 * @method flags=dynamic
+	 * @param path cast=(GtkWidgetPath *)
+	 * @param pos cast=(gint)
+	 * @param name cast=(const char *)
+	 */
+	public static final native long _gtk_widget_path_iter_set_object_name (long path, long pos, byte[] name);
+	/** [since 3.20] */
+	public static final long gtk_widget_path_iter_set_object_name(long path, long pos, byte[] name) {
+		lock.lock();
+		try {
+			return _gtk_widget_path_iter_set_object_name(path, pos, name);
+		} finally {
+			lock.unlock();
+		}
+	}
+	public static final native long _gtk_widget_path_new ();
+	public static final long gtk_widget_path_new() {
+		lock.lock();
+		try {
+			return _gtk_widget_path_new();
+		} finally {
+			lock.unlock();
+		}
+	}
 	/** @param widget cast=(GtkWidget *) */
 	public static final native void _gtk_widget_queue_resize(long widget);
 	public static final void gtk_widget_queue_resize(long widget) {
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Display.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Display.java
index 1d2ef21557..997bffac97 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Display.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Display.java
@@ -3174,28 +3174,50 @@ GdkRGBA toGdkRGBA (GdkRGBA rgba, double brightness) {
 	return newRGBA;
 }
 
-GdkRGBA getBackgroundColor (long context, int state) {
+/**
+ * Calculates original color from RGBA with premultiplied alpha.
+ *
+ * NOTE: Calculating inverse gives a range of possible colors due to rounding that
+ * occurs with integer calculations. However, alpha-blend formula only has the
+ * multiplied component, so all of those inverses are equivalent.
+ */
+static int inversePremultipliedColor(int color, int alpha) {
+	return (255*color + alpha-1) / alpha;
+}
+
+GdkRGBA styleContextGetBackgroundColor(long context, int state) {
 	/*
-	* Draw the context background to an offset screen surface and get the color
-	* in the middle of the surface.
+	* Background in GTK theme can be more complex then just solid color:
+	* it can have 'background-image', 'background-position', 'background-repeat', etc.
+	* One example is 'tooltip' in 'Ambiance' theme, which doesn't have 'background-color'.
+	* The workaround is to draw the context background to a temporary image and
+	* get the color of the pixel in the middle.
 	*/
-	GdkRGBA rgba = new GdkRGBA ();
 	GTK.gtk_style_context_save (context);
 	GTK.gtk_style_context_set_state (context, state);
-	long surface = Cairo.cairo_image_surface_create (Cairo.CAIRO_FORMAT_RGB24, 1, 1);
+	long surface = Cairo.cairo_image_surface_create (Cairo.CAIRO_FORMAT_ARGB32, 1, 1);
 	long cairo = Cairo.cairo_create (surface);
 	GTK.gtk_render_background (context, cairo, -50, -50, 100, 100);
 	Cairo.cairo_fill (cairo);
 	Cairo.cairo_surface_flush (surface);
-	byte[] buffer = new byte[3];
+	byte[] buffer = new byte[4];
 	C.memmove (buffer, Cairo.cairo_image_surface_get_data(surface), buffer.length);
-	rgba.red = Byte.toUnsignedInt(buffer[2]) / 255f;
-	rgba.green = Byte.toUnsignedInt(buffer[1]) / 255f;
-	rgba.blue = Byte.toUnsignedInt(buffer[0]) / 255f;
-	rgba.alpha = 1.0;
 	Cairo.cairo_surface_destroy (surface);
 	Cairo.cairo_destroy (cairo);
 	GTK.gtk_style_context_restore (context);
+
+	int a = Byte.toUnsignedInt(buffer[3]);
+	int r = Byte.toUnsignedInt(buffer[2]);
+	int g = Byte.toUnsignedInt(buffer[1]);
+	int b = Byte.toUnsignedInt(buffer[0]);
+
+	// NOTE: cairo uses premultiplied alpha (see CAIRO_FORMAT_ARGB32)
+	GdkRGBA rgba = new GdkRGBA ();
+	rgba.alpha = a / 255f;
+	rgba.red   = inversePremultipliedColor(r, a) / 255f;
+	rgba.green = inversePremultipliedColor(g, a) / 255f;
+	rgba.blue  = inversePremultipliedColor(b, a) / 255f;
+
 	return rgba;
 }
 
@@ -3431,45 +3453,90 @@ private void initializeSystemColorsLink(String cssOutput) {
 }
 
 void initializeSystemColorsTooltip(String cssOutput) {
-	// Create a temporary Tooltip widget
-	long tooltipShellHandle = GTK.gtk_window_new (GTK.GTK_WINDOW_POPUP);
-	if (tooltipShellHandle == 0) error (SWT.ERROR_NO_HANDLES);
-	byte[] gtk_tooltip = Converter.wcsToMbcs ("gtk-tooltip", true); //$NON-NLS-1$
-	GTK.gtk_widget_set_name (tooltipShellHandle, gtk_tooltip);
-	GTK.gtk_widget_realize (tooltipShellHandle);
-
-	long context = GTK.gtk_widget_get_style_context (tooltipShellHandle);
-	GTK.gtk_style_context_add_class (context, GTK.GTK_STYLE_CLASS_TOOLTIP);
-	GTK.gtk_style_context_invalidate(context);
+	// gtk_widget_path_iter_set_object_name is available since 3.20
+	if (GTK.GTK_VERSION >= OS.VERSION(3, 20, 0)) {
+		// NOTE: One other approach would be to create a temporary 'GtkTooltipWindow'
+		// widget, obtaining its GType with 'g_type_from_name'. See snippet
+		// attached to Bug 545587 for a demo.
+
+		byte[] tooltipCssNode = Converter.javaStringToCString("tooltip"); //$NON-NLS-1$
+
+		// Separate style contexts are used to avoid complex state manipulations
+		{
+			// Foreground color is taken from 'tooltip label' css node
+			long labelType = GTK.gtk_label_get_type();
+			long context = GTK.gtk_style_context_new();
+			long widgetPath = GTK.gtk_widget_path_new();
+			GTK.gtk_widget_path_append_type(widgetPath, 0);
+			GTK.gtk_widget_path_iter_set_object_name(widgetPath, -1, tooltipCssNode);
+			GTK.gtk_widget_path_append_type(widgetPath, labelType);
+			GTK.gtk_style_context_set_path(context, widgetPath);
+			GTK.gtk_widget_path_free(widgetPath);
+
+			COLOR_INFO_FOREGROUND_RGBA = styleContextGetColor(context, GTK.GTK_STATE_FLAG_NORMAL);
+
+			// Destroy temporary style context
+			OS.g_object_unref(context);
+		}
 
-	if (GTK.GTK_VERSION >= OS.VERSION(3, 14, 0)) {
-		String colorInfoForeground = gtk_css_default_theme_values(SWT.COLOR_INFO_FOREGROUND, cssOutput);
-		if (!colorInfoForeground.isEmpty()) {
-			if (colorInfoForeground != "parsed") {
-				COLOR_INFO_FOREGROUND_RGBA = gtk_css_property_to_rgba (colorInfoForeground);
+		// Separate style contexts are used to avoid complex state manipulations
+		{
+			// Background color is taken from 'tooltip.background' css node
+			byte[] backgroundClass = Converter.javaStringToCString("background"); //$NON-NLS-1$
+			long context = GTK.gtk_style_context_new();
+			long widgetPath = GTK.gtk_widget_path_new();
+			GTK.gtk_widget_path_append_type(widgetPath, 0);
+			GTK.gtk_widget_path_iter_set_object_name(widgetPath, -1, tooltipCssNode);
+			GTK.gtk_style_context_set_path(context, widgetPath);
+			GTK.gtk_style_context_add_class(context, backgroundClass);
+			GTK.gtk_widget_path_free(widgetPath);
+
+			COLOR_INFO_BACKGROUND_RGBA = styleContextGetBackgroundColor(context, GTK.GTK_STATE_FLAG_NORMAL);
+
+			// Destroy temporary style context
+			OS.g_object_unref(context);
+		}
+	} else {
+		// Create a temporary Tooltip widget
+		long tooltipShellHandle = GTK.gtk_window_new (GTK.GTK_WINDOW_POPUP);
+		if (tooltipShellHandle == 0) error (SWT.ERROR_NO_HANDLES);
+		byte[] gtk_tooltip = Converter.wcsToMbcs ("gtk-tooltip", true); //$NON-NLS-1$
+		GTK.gtk_widget_set_name (tooltipShellHandle, gtk_tooltip);
+		GTK.gtk_widget_realize (tooltipShellHandle);
+
+		long context = GTK.gtk_widget_get_style_context (tooltipShellHandle);
+		GTK.gtk_style_context_add_class (context, GTK.GTK_STYLE_CLASS_TOOLTIP);
+		GTK.gtk_style_context_invalidate(context);
+
+		if (GTK.GTK_VERSION >= OS.VERSION(3, 14, 0)) {
+			String colorInfoForeground = gtk_css_default_theme_values(SWT.COLOR_INFO_FOREGROUND, cssOutput);
+			if (!colorInfoForeground.isEmpty()) {
+				if (colorInfoForeground != "parsed") {
+					COLOR_INFO_FOREGROUND_RGBA = gtk_css_property_to_rgba (colorInfoForeground);
+				}
+			} else {
+				COLOR_INFO_FOREGROUND_RGBA = styleContextGetColor (context, GTK.GTK_STATE_FLAG_NORMAL);
 			}
 		} else {
 			COLOR_INFO_FOREGROUND_RGBA = styleContextGetColor (context, GTK.GTK_STATE_FLAG_NORMAL);
 		}
-	} else {
-		COLOR_INFO_FOREGROUND_RGBA = styleContextGetColor (context, GTK.GTK_STATE_FLAG_NORMAL);
-	}
 
-	if (GTK.GTK_VERSION >= OS.VERSION(3, 14, 0)) {
-		String colorInfoBackground = gtk_css_default_theme_values(SWT.COLOR_INFO_BACKGROUND, cssOutput);
-		if (!colorInfoBackground.isEmpty()) {
-			if (colorInfoBackground != "parsed") {
-				COLOR_INFO_BACKGROUND_RGBA = gtk_css_property_to_rgba (colorInfoBackground);
+		if (GTK.GTK_VERSION >= OS.VERSION(3, 14, 0)) {
+			String colorInfoBackground = gtk_css_default_theme_values(SWT.COLOR_INFO_BACKGROUND, cssOutput);
+			if (!colorInfoBackground.isEmpty()) {
+				if (colorInfoBackground != "parsed") {
+					COLOR_INFO_BACKGROUND_RGBA = gtk_css_property_to_rgba (colorInfoBackground);
+				}
+			} else {
+				COLOR_INFO_BACKGROUND_RGBA = styleContextGetBackgroundColor(context, GTK.GTK_STATE_FLAG_NORMAL);
 			}
 		} else {
-			COLOR_INFO_BACKGROUND_RGBA = getBackgroundColor (context, GTK.GTK_STATE_FLAG_NORMAL);
+			COLOR_INFO_BACKGROUND_RGBA = styleContextGetBackgroundColor(context, GTK.GTK_STATE_FLAG_NORMAL);
 		}
-	} else {
-		COLOR_INFO_BACKGROUND_RGBA = getBackgroundColor (context, GTK.GTK_STATE_FLAG_NORMAL);
-	}
 
-	// Destroy temporary Tooltip widget
-	GTK.gtk_widget_destroy (tooltipShellHandle);
+		// Destroy temporary Tooltip widget
+		GTK.gtk_widget_destroy (tooltipShellHandle);
+	}
 }
 
 GdkRGBA styleContextGetColor(long context, int flag) {