[Gtk4] Implement Control.print

Implementation of this method had no port to Gtk 4 api and was causing
troubles by calling into no-longer existing 3.x APIs

Author: akurtakov

bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/gtk4.c

@@ -601,6 +601,16 @@ JNIEXPORT void JNICALL GTK4_NATIVE(gdk_1content_1serializer_1set_1task_1data)
 }
 #endif
 
+#ifndef NO_gdk_1paintable_1snapshot
+JNIEXPORT void JNICALL GTK4_NATIVE(gdk_1paintable_1snapshot)
+	(JNIEnv *env, jclass that, jlong arg0, jlong arg1, jint arg2, jint arg3)
+{
+	GTK4_NATIVE_ENTER(env, that, gdk_1paintable_1snapshot_FUNC);
+	gdk_paintable_snapshot((GdkPaintable *)arg0, (GdkSnapshot *)arg1, (double)arg2, (double)arg3);
+	GTK4_NATIVE_EXIT(env, that, gdk_1paintable_1snapshot_FUNC);
+}
+#endif
+
 #ifndef NO_gdk_1toplevel_1focus
 JNIEXPORT void JNICALL GTK4_NATIVE(gdk_1toplevel_1focus)
 	(JNIEnv *env, jclass that, jlong arg0, jint arg1)
@@ -682,6 +692,26 @@ JNIEXPORT void JNICALL GTK4_NATIVE(gdk_1toplevel_1size_1set_1size)
 }
 #endif
 
+#ifndef NO_gsk_1render_1node_1draw
+JNIEXPORT void JNICALL GTK4_NATIVE(gsk_1render_1node_1draw)
+	(JNIEnv *env, jclass that, jlong arg0, jlong arg1)
+{
+	GTK4_NATIVE_ENTER(env, that, gsk_1render_1node_1draw_FUNC);
+	gsk_render_node_draw((GskRenderNode *)arg0, (cairo_t *)arg1);
+	GTK4_NATIVE_EXIT(env, that, gsk_1render_1node_1draw_FUNC);
+}
+#endif
+
+#ifndef NO_gsk_1render_1node_1unref
+JNIEXPORT void JNICALL GTK4_NATIVE(gsk_1render_1node_1unref)
+	(JNIEnv *env, jclass that, jlong arg0)
+{
+	GTK4_NATIVE_ENTER(env, that, gsk_1render_1node_1unref_FUNC);
+	gsk_render_node_unref((GskRenderNode *)arg0);
+	GTK4_NATIVE_EXIT(env, that, gsk_1render_1node_1unref_FUNC);
+}
+#endif
+
 #ifndef NO_gtk_1box_1append
 JNIEXPORT void JNICALL GTK4_NATIVE(gtk_1box_1append)
 	(JNIEnv *env, jclass that, jlong arg0, jlong arg1)
@@ -2322,6 +2352,30 @@ JNIEXPORT jlong JNICALL GTK4_NATIVE(gtk_1snapshot_1append_1cairo)
 }
 #endif
 
+#ifndef NO_gtk_1snapshot_1free_1to_1node
+JNIEXPORT jlong JNICALL GTK4_NATIVE(gtk_1snapshot_1free_1to_1node)
+	(JNIEnv *env, jclass that, jlong arg0)
+{
+	jlong rc = 0;
+	GTK4_NATIVE_ENTER(env, that, gtk_1snapshot_1free_1to_1node_FUNC);
+	rc = (jlong)gtk_snapshot_free_to_node((GtkSnapshot *)arg0);
+	GTK4_NATIVE_EXIT(env, that, gtk_1snapshot_1free_1to_1node_FUNC);
+	return rc;
+}
+#endif
+
+#ifndef NO_gtk_1snapshot_1new
+JNIEXPORT jlong JNICALL GTK4_NATIVE(gtk_1snapshot_1new)
+	(JNIEnv *env, jclass that)
+{
+	jlong rc = 0;
+	GTK4_NATIVE_ENTER(env, that, gtk_1snapshot_1new_FUNC);
+	rc = (jlong)gtk_snapshot_new();
+	GTK4_NATIVE_EXIT(env, that, gtk_1snapshot_1new_FUNC);
+	return rc;
+}
+#endif
+
 #ifndef NO_gtk_1style_1context_1add_1provider_1for_1display
 JNIEXPORT void JNICALL GTK4_NATIVE(gtk_1style_1context_1add_1provider_1for_1display)
 	(JNIEnv *env, jclass that, jlong arg0, jlong arg1, jint arg2)
@@ -2697,6 +2751,18 @@ JNIEXPORT void JNICALL GTK4_NATIVE(gtk_1widget_1measure)
 }
 #endif
 
+#ifndef NO_gtk_1widget_1paintable_1new
+JNIEXPORT jlong JNICALL GTK4_NATIVE(gtk_1widget_1paintable_1new)
+	(JNIEnv *env, jclass that, jlong arg0)
+{
+	jlong rc = 0;
+	GTK4_NATIVE_ENTER(env, that, gtk_1widget_1paintable_1new_FUNC);
+	rc = (jlong)gtk_widget_paintable_new((GtkWidget *)arg0);
+	GTK4_NATIVE_EXIT(env, that, gtk_1widget_1paintable_1new_FUNC);
+	return rc;
+}
+#endif
+
 #ifndef NO_gtk_1widget_1pick
 JNIEXPORT jlong JNICALL GTK4_NATIVE(gtk_1widget_1pick)
 	(JNIEnv *env, jclass that, jlong arg0, jdouble arg1, jdouble arg2, jint arg3)

bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/gtk4_stats.h

@@ -66,13 +66,16 @@ typedef enum {
 	gdk_1content_1serializer_1return_1error_FUNC,
 	gdk_1content_1serializer_1return_1success_FUNC,
 	gdk_1content_1serializer_1set_1task_1data_FUNC,
+	gdk_1paintable_1snapshot_FUNC,
 	gdk_1toplevel_1focus_FUNC,
 	gdk_1toplevel_1get_1state_FUNC,
 	gdk_1toplevel_1lower_FUNC,
 	gdk_1toplevel_1set_1icon_1list_FUNC,
 	gdk_1toplevel_1size_1get_1bounds_FUNC,
 	gdk_1toplevel_1size_1set_1min_1size_FUNC,
 	gdk_1toplevel_1size_1set_1size_FUNC,
+	gsk_1render_1node_1draw_FUNC,
+	gsk_1render_1node_1unref_FUNC,
 	gtk_1box_1append_FUNC,
 	gtk_1box_1insert_1child_1after_FUNC,
 	gtk_1box_1prepend_FUNC,
@@ -190,6 +193,8 @@ typedef enum {
 	gtk_1shortcut_1controller_1set_1scope_FUNC,
 	gtk_1shortcut_1new_FUNC,
 	gtk_1snapshot_1append_1cairo_FUNC,
+	gtk_1snapshot_1free_1to_1node_FUNC,
+	gtk_1snapshot_1new_FUNC,
 	gtk_1style_1context_1add_1provider_1for_1display_FUNC,
 	gtk_1style_1context_1get_1border_FUNC,
 	gtk_1style_1context_1get_1color_FUNC,
@@ -218,6 +223,7 @@ typedef enum {
 	gtk_1widget_1insert_1after_FUNC,
 	gtk_1widget_1insert_1before_FUNC,
 	gtk_1widget_1measure_FUNC,
+	gtk_1widget_1paintable_1new_FUNC,
 	gtk_1widget_1pick_FUNC,
 	gtk_1widget_1set_1cursor_FUNC,
 	gtk_1widget_1set_1focusable_FUNC,

bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk4/GTK4.java

@@ -172,6 +172,7 @@ public class GTK4 {
 	/** @param surface cast=(GdkToplevel *) */
 	public static final native void gdk_toplevel_focus(long surface, int timestamp);
 
+
 	/* GtkDragSource */
 	public static final native long gtk_drag_source_new();
 	/**
@@ -725,6 +726,10 @@ public class GTK4 {
 	 * @param next_sibling cast=(GtkWidget *)
 	 */
 	public static final native void gtk_widget_insert_before(long widget, long parent, long next_sibling);
+	/**
+	 * @param widget cast=(GtkWidget *)
+	 */
+	public static final native long gtk_widget_paintable_new(long widget);
 	/**
 	 * @param widget cast=(GtkWidget *)
 	 * @param x cast=(double)
@@ -738,12 +743,19 @@ public class GTK4 {
 	public static final native long gtk_combo_box_get_child(long combo_box);
 
 	/* GtkSnapshot */
+
+	public static final native long gtk_snapshot_new();
 	/**
 	 * @param snapshot cast=(GtkSnapshot *)
 	 * @param rect cast=(const graphene_rect_t *)
 	 */
 	public static final native long gtk_snapshot_append_cairo(long snapshot, long rect);
 
+	/**
+	 * @param snapshot cast=(GtkSnapshot *)
+	 */
+	public static final native long gtk_snapshot_free_to_node(long snapshot);
+
 	/* GtkImage */
 	/**
 	 * @param image cast=(GtkImage *)
@@ -1087,5 +1099,21 @@ public class GTK4 {
 	public static final native int gtk_widget_get_height(long widget);
 
 	public static final native long gtk_header_bar_new();
+	/**
+	 * @param paintable cast=(GdkPaintable *)
+	 * @param snapshot cast=(GdkSnapshot *)
+	 * @param width cast=(double)
+	 * @param height cast=(double)
+	 */
+	public static final native void gdk_paintable_snapshot(long paintable, long snapshot, int width, int height);
 
+	/**
+	 * @param renderNode cast=(GskRenderNode *)
+	 * @param cr cast=(cairo_t *)
+	 */
+	public static final native void gsk_render_node_draw(long renderNode, long cr);
+	/**
+	 * @param renderNode cast=(GskRenderNode *)
+	 */
+	public static final native void gsk_render_node_unref(long renderNode);
 }

bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Control.java

@@ -626,18 +626,54 @@ public boolean print (GC gc) {
 	if (gc.isDisposed ()) error (SWT.ERROR_INVALID_ARGUMENT);
 	long topHandle = topHandle ();
 	GTK.gtk_widget_realize (topHandle);
-	/*
-	 * Feature in GTK: gtk_widget_draw() will only draw if the
-	 * widget's priv->alloc_needed field is set to TRUE. Since
-	 * this field is private and inaccessible, get and set the
-	 * allocation to trigger it to be TRUE. See bug 530969.
-	 */
-	GtkAllocation allocation = new GtkAllocation ();
-	GTK.gtk_widget_get_allocation(topHandle, allocation);
-	// Prevent allocation warnings
-	GTK.gtk_widget_get_preferred_size(topHandle, null, null);
-	GTK3.gtk_widget_size_allocate(topHandle, allocation);
-	GTK3.gtk_widget_draw(topHandle, gc.handle);
+
+	if (GTK.GTK4) {
+        /*
+         * In GTK4 gtk_widget_draw() has been removed. Rendering is now
+         * done via GtkSnapshot and the GskRenderNode pipeline. Snapshot the widget,
+         * extract the render node, then draw it onto the GC's Cairo context using
+         * gsk_render_node_draw().
+         */
+
+        long widgetPaintable = GTK4.gtk_widget_paintable_new(topHandle);
+        if (widgetPaintable == 0) return false;
+        try {
+            int width  = GTK4.gtk_widget_get_width(topHandle);
+            int height = GTK4.gtk_widget_get_height(topHandle);
+
+            long snapshot = GTK4.gtk_snapshot_new();
+            if (snapshot == 0) return false;
+
+            try {
+                GTK4.gdk_paintable_snapshot(widgetPaintable, snapshot, width, height);
+
+                long renderNode = GTK4.gtk_snapshot_free_to_node(snapshot);
+                snapshot = 0; // freed by gtk_snapshot_free_to_node
+
+                if (renderNode == 0) return false;
+
+                GTK4.gsk_render_node_draw(renderNode, gc.handle);
+                GTK4.gsk_render_node_unref(renderNode);
+            } finally {
+                if (snapshot != 0) OS.g_object_unref(snapshot);
+            }
+        } finally {
+            OS.g_object_unref(widgetPaintable);
+        }
+    } else {
+		/*
+		 * In GTK 3 gtk_widget_draw() will only draw if the
+		 * widget's priv->alloc_needed field is set to TRUE. Since
+		 * this field is private and inaccessible, get and set the
+		 * allocation to trigger it to be TRUE. See bug 530969.
+		 */
+		GtkAllocation allocation = new GtkAllocation ();
+		GTK.gtk_widget_get_allocation(topHandle, allocation);
+		// Prevent allocation warnings
+		GTK.gtk_widget_get_preferred_size(topHandle, null, null);
+		GTK3.gtk_widget_size_allocate(topHandle, allocation);
+		GTK3.gtk_widget_draw(topHandle, gc.handle);
+    }
 	return true;
 }