Bug 543908: [GTK4] Get ControlExample to launch and run on GTK4

Fix TabFolder display issue, as well as pixbuf crashes due to
cairo_image_surface_create() being fed incorrect parameters. Snippet76
no works as expected on GTK4 just as it does on GTK3.

Change-Id: Ie1d3504eca532fdb9e33763c98434e33ca53be01
Signed-off-by: Eric Williams <ericwill@redhat.com>

7 files changed, 38 insertions, 8 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_custom.c b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_custom.c
index a09e7d521b..79ce6890a6 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_custom.c
+++ b/bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_custom.c
@@ -976,8 +976,26 @@ static AtkObject *swt_fixed_get_accessible (GtkWidget *widget) {
 
 static void swt_fixed_measure (GtkWidget *widget, GtkOrientation  orientation, int for_size, int *minimum,
 		int *natural, int *minimum_baseline, int *natural_baseline) {
+	SwtFixed *fixed = SWT_FIXED (widget);
+	SwtFixedPrivate *priv = fixed->priv;
+	GList *list;
+	int total_nat, child_nat;
+
+	total_nat = 0;
+
+	list = priv->children;
+
+	while (list) {
+		SwtFixedChild *child_data = list->data;
+		GtkWidget *child = child_data->widget;
+
+		gtk_widget_measure(child, orientation, -1, NULL, &child_nat, NULL, NULL);
+		total_nat = total_nat + child_nat;
+
+		list = list->next;
+	}
 	if (minimum) *minimum = 0;
-	if (natural) *natural = 0;
+	if (natural) *natural = total_nat;
 	if (minimum_baseline) *minimum_baseline = -1;
 	if (natural_baseline) *natural_baseline = -1;
 	return;
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/Device.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/Device.java
index 740cf4cc7b..7ca6a7a9e6 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/Device.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/Device.java
@@ -664,7 +664,7 @@ protected void init () {
 		long /*int*/ gdkResource;
 		long /*int*/ surface;
 		if (GTK.GTK4) {
-			surface = Cairo.cairo_image_surface_create(Cairo.CAIRO_CONTENT_COLOR, 10, 10);
+			surface = Cairo.cairo_image_surface_create(Cairo.CAIRO_FORMAT_RGB24, 10, 10);
 		} else {
 			gdkResource = GDK.gdk_get_default_root_window();
 			surface = GDK.gdk_window_create_similar_surface(gdkResource, Cairo.CAIRO_CONTENT_COLOR, 10, 10);
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/GC.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/GC.java
index 01532de632..05fd1a2872 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/GC.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/GC.java
@@ -2618,7 +2618,7 @@ void initCairo() {
 	if (GTK.GTK_VERSION >= 	OS.VERSION(3, 22, 0)) {
 		long /*int*/ surface;
 		if (GTK.GTK4) {
-			surface = Cairo.cairo_image_surface_create(Cairo.CAIRO_CONTENT_COLOR_ALPHA, data.width, data.height);
+			surface = Cairo.cairo_image_surface_create(Cairo.CAIRO_FORMAT_A8, data.width, data.height);
 		} else {
 			surface = GDK.gdk_window_create_similar_surface(data.drawable, Cairo.CAIRO_CONTENT_COLOR_ALPHA, data.width, data.height);
 		}
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/Image.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/Image.java
index 259d4a01e2..5b344f7f3c 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/Image.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/Image.java
@@ -1250,7 +1250,7 @@ void init(int width, int height) {
 
 	/* Create the pixmap */
 	if (GTK.GTK4) {
-		surface = Cairo.cairo_image_surface_create(Cairo.CAIRO_CONTENT_COLOR, width, height);
+		surface = Cairo.cairo_image_surface_create(Cairo.CAIRO_FORMAT_RGB24, width, height);
 	} else {
 		surface = GDK.gdk_window_create_similar_surface(GDK.gdk_get_default_root_window(), Cairo.CAIRO_CONTENT_COLOR, width, height);
 	}
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Button.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Button.java
index 0224ce8895..8dd55fcf1d 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Button.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Button.java
@@ -118,7 +118,7 @@ static int checkStyle (int style) {
 static GtkBorder getBorder (byte[] border, long /*int*/ handle, int defaultBorder) {
     GtkBorder gtkBorder = new GtkBorder();
     long /*int*/ []  borderPtr = new long /*int*/ [1];
-    GTK.gtk_widget_style_get (handle, border, borderPtr,0);
+    if (!GTK.GTK4) GTK.gtk_widget_style_get (handle, border, borderPtr,0);
     if (borderPtr[0] != 0) {
         OS.memmove (gtkBorder, borderPtr[0], GtkBorder.sizeof);
         GTK.gtk_border_free(borderPtr[0]);
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 afc2da5fea..6c2730e000 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
@@ -1499,7 +1499,7 @@ static long /*int*/ rendererClassInitProc (long /*int*/ g_class, long /*int*/ cl
 static long /*int*/ snapshotDrawProc (long /*int*/ handle, long /*int*/ snapshot) {
 	Display display = getCurrent ();
 	Widget widget = display.getWidget (handle);
-	widget.snapshotToDraw(handle, snapshot);
+	if (widget != null) widget.snapshotToDraw(handle, snapshot);
 	return 0;
 }
 
@@ -3975,7 +3975,7 @@ public long /*int*/ internal_new_GC (GCData data) {
 	long /*int*/ gc = 0;
 	long /*int*/ root = 0;
 	if (GTK.GTK4) {
-		long /*int*/ surface = Cairo.cairo_image_surface_create(Cairo.CAIRO_CONTENT_COLOR_ALPHA, data.width, data.height);
+		long /*int*/ surface = Cairo.cairo_image_surface_create(Cairo.CAIRO_FORMAT_A8, data.width, data.height);
 		gc = Cairo.cairo_create(surface);
 	} else {
 		root = GDK.gdk_get_default_root_window();
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/TabItem.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/TabItem.java
index b6f0e4afee..c8560f1135 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/TabItem.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/TabItem.java
@@ -304,7 +304,19 @@ public void setControl (Control control) {
 
 	if (control != null) {
 		// To understand why we reparent, see implementation note about bug 454936 at the start of TabFolder.
-		Control.gtk_widget_reparent (control, pageHandle);
+		if (GTK.GTK4) {
+			long /*int*/ widget = control.topHandle();
+			long /*int*/ parentContainer = GTK.gtk_widget_get_parent (widget);
+			if (parentContainer != 0) {
+				OS.g_object_ref (widget); //so that it won't get destroyed due to lack of references.
+				GTK.gtk_container_remove (parentContainer, widget);
+				GTK.gtk_container_add (pageHandle, widget);
+				OS.g_object_unref (widget);
+				GTK.gtk_widget_show(widget);
+			}
+		} else {
+			Control.gtk_widget_reparent (control, pageHandle);
+		}
 	}
 
 	Control oldControl = this.control, newControl = control;