8271398: GTK3 drag view image swaps red and blue color channels

Reviewed-by: pbansal, kcr

Author: Thiago Milczarek Sayao

modules/javafx.graphics/src/main/native-glass/gtk/glass_dnd.cpp

@@ -911,6 +911,13 @@ GdkPixbuf* DragView::get_drag_image(GtkWidget *widget, gboolean* is_raw_image, g
                     guchar* data = (guchar*) g_try_malloc0(nraw - whsz);
                     if (data) {
                         memcpy(data, (raw + whsz), nraw - whsz);
+
+                        if (is_raw_image) {
+                            guchar* origdata = data;
+                            data = (guchar*) convert_BGRA_to_RGBA((const int*) data, w * 4, h);
+                            g_free(origdata);
+                        }
+
                         pixbuf = gdk_pixbuf_new_from_data(data, GDK_COLORSPACE_RGB, TRUE, 8,
                                                           w, h, w * 4, pixbufDestroyNotifyFunc, NULL);
                     }
@@ -1047,26 +1054,8 @@ void DragView::View::expose()
 {
     cairo_t *context = gdk_cairo_create(gtk_widget_get_window(widget));
 
-    cairo_surface_t* cairo_surface;
-
-    guchar* pixels = is_raw_image
-            ? (guchar*) convert_BGRA_to_RGBA((const int*) gdk_pixbuf_get_pixels(pixbuf),
-                                                gdk_pixbuf_get_rowstride(pixbuf),
-                                                height)
-            : gdk_pixbuf_get_pixels(pixbuf);
-
-    cairo_surface = cairo_image_surface_create_for_data(
-            pixels,
-            CAIRO_FORMAT_ARGB32,
-            width, height, width * 4);
-
-    cairo_set_source_surface(context, cairo_surface, 0, 0);
-    cairo_set_operator(context, CAIRO_OPERATOR_SOURCE);
+    gdk_cairo_set_source_pixbuf(context, pixbuf, 0, 0);
     cairo_paint(context);
 
-    if (is_raw_image) {
-        g_free(pixels);
-    }
     cairo_destroy(context);
-    cairo_surface_destroy(cairo_surface);
 }

tests/manual/dnd/DndTestDragViewRawImage.java

@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import javafx.application.Application;
+import javafx.embed.swing.SwingFXUtils;
+import javafx.geometry.Pos;
+import javafx.scene.Scene;
+import javafx.scene.control.Label;
+import javafx.scene.image.Image;
+import javafx.scene.image.ImageView;
+import javafx.scene.input.ClipboardContent;
+import javafx.scene.input.Dragboard;
+import javafx.scene.input.TransferMode;
+import javafx.scene.layout.VBox;
+import javafx.stage.Stage;
+
+import java.awt.image.BufferedImage;
+
+public class DndTestDragViewRawImage extends Application {
+    Image image = createImage(240, 240);
+
+    public static void main(String[] args) {
+        Application.launch(args);
+    }
+
+    @Override
+    public void start(Stage stage) {
+        ImageView imageView = new ImageView(image);
+        imageView.setOnDragDetected(event -> {
+            ClipboardContent content = new ClipboardContent();
+            content.putImage(image);
+            Dragboard dragboard = imageView.startDragAndDrop(TransferMode.ANY);
+            dragboard.setContent(content);
+            dragboard.setDragView(image);
+        });
+
+        Label label = new Label("Click the image and drag. " +
+                "The drag image displayed with the cursor (drag view) " +
+                "should match the source image");
+
+        VBox vBox = new VBox(label, imageView);
+        vBox.setSpacing(5.0);
+        vBox.setAlignment(Pos.CENTER);
+        stage.setScene(new Scene(vBox, 480, 480));
+        stage.setTitle("Drag View Image Colors");
+        stage.show();
+    }
+
+    private static Image createImage(int width, int height) {
+        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
+        for (int y = 0; y < height; y++) {
+            for (int x = 0; x < width; x++) {
+                if (x < width * 0.33) {
+                    image.setRGB(x, y, 0xFF0000);
+                } else if (x < width * 0.66) {
+                    image.setRGB(x, y, 0x00FF00);
+                } else {
+                    image.setRGB(x, y, 0x0000FF);
+                }
+            }
+        }
+        return SwingFXUtils.toFXImage(image, null);
+    }
+}