[gnome-desktop] tests: Add gtk-reftest to compare GTK+ outputs

[Bastien Nocera <hadess src gnome org>]

commit dc61705eda1c446cf8751b64fe39432699b92730
Author: Bastien Nocera <hadess hadess net>
Date:   Fri May 30 11:35:26 2014 +0200

    tests: Add gtk-reftest to compare GTK+ outputs
    
    For each UI file, we'll compare the GTK+ output from the wall-clock for
    that particular locale with a reference UI file.
    
    This way, we can test whether we regress in terms of RTL handling.

 tests/Makefile.am   |    1 +
 tests/gtk-reftest.c |  622 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 623 insertions(+), 0 deletions(-)
---
diff --git a/tests/Makefile.am b/tests/Makefile.am
index dc9c10a..934b3a2 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -12,6 +12,7 @@ AM_CFLAGS = -g $(WARN_CFLAGS)
 
 test_programs =                        \
        wall-clock              \
+       gtk-reftest             \
        $(NULL)
 
 -include $(top_srcdir)/git.mk
diff --git a/tests/gtk-reftest.c b/tests/gtk-reftest.c
new file mode 100644
index 0000000..0964a1d
--- /dev/null
+++ b/tests/gtk-reftest.c
@@ -0,0 +1,622 @@
+/*
+ * Copyright (C) 2011 Red Hat Inc.
+ *
+ * Author:
+ *      Benjamin Otte <otte gnome org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <string.h>
+#include <glib/gstdio.h>
+#include <locale.h>
+#include <gtk/gtk.h>
+#define GNOME_DESKTOP_USE_UNSTABLE_API 1
+#include <libgnome-desktop/gnome-wall-clock.h>
+
+typedef enum {
+  SNAPSHOT_WINDOW,
+  SNAPSHOT_DRAW
+} SnapshotMode;
+
+/* This is exactly the style information you've been looking for */
+#define GTK_STYLE_PROVIDER_PRIORITY_FORCE G_MAXUINT
+
+static char *arg_output_dir = NULL;
+static char *arg_base_dir = NULL;
+static char *arg_direction = NULL;
+
+static const GOptionEntry test_args[] = {
+  { "output",         'o', 0, G_OPTION_ARG_FILENAME, &arg_output_dir,
+    "Directory to save image files to", "DIR" },
+  { "directory",        'd', 0, G_OPTION_ARG_FILENAME, &arg_base_dir,
+    "Directory to run tests from", "DIR" },
+  { "direction",       0, 0, G_OPTION_ARG_STRING, &arg_direction,
+    "Set text direction", "DIRECTION" },
+  { NULL }
+};
+
+static const char *
+get_output_dir (void)
+{
+  static const char *output_dir = NULL;
+  GError *error = NULL;
+
+  if (output_dir)
+    return output_dir;
+
+  if (arg_output_dir)
+    {
+      GFile *file = g_file_new_for_commandline_arg (arg_output_dir);
+      output_dir = g_file_get_path (file);
+      g_object_unref (file);
+    }
+  else
+    {
+      output_dir = g_get_tmp_dir ();
+    }
+
+  if (!g_file_test (output_dir, G_FILE_TEST_EXISTS))
+    {
+      GFile *file;
+
+      file = g_file_new_for_path (output_dir);
+      g_assert (g_file_make_directory_with_parents (file, NULL, &error));
+      g_assert_no_error (error);
+      g_object_unref (file);
+    }
+
+  return output_dir;
+}
+
+static char *
+get_output_file (const char *test_file,
+                 const char *extension)
+{
+  const char *output_dir = get_output_dir ();
+  char *result, *base;
+
+  base = g_path_get_basename (test_file);
+  if (g_str_has_suffix (base, ".ui"))
+    base[strlen (base) - strlen (".ui")] = '\0';
+
+  result = g_strconcat (output_dir, G_DIR_SEPARATOR_S, base, extension, NULL);
+  g_free (base);
+
+  return result;
+}
+
+static char *
+get_test_file (const char *test_file,
+               const char *extension,
+               gboolean    must_exist)
+{
+  GString *file = g_string_new (NULL);
+
+  if (g_str_has_suffix (test_file, ".ui"))
+    g_string_append_len (file, test_file, strlen (test_file) - strlen (".ui"));
+  else
+    g_string_append (file, test_file);
+  
+  g_string_append (file, extension);
+
+  if (must_exist &&
+      !g_file_test (file->str, G_FILE_TEST_EXISTS))
+    {
+      g_string_free (file, TRUE);
+      return NULL;
+    }
+
+  return g_string_free (file, FALSE);
+}
+
+static GtkStyleProvider *
+add_extra_css (const char *testname,
+               const char *extension)
+{
+  GtkStyleProvider *provider = NULL;
+  char *css_file;
+  
+  css_file = get_test_file (testname, extension, TRUE);
+  if (css_file == NULL)
+    return NULL;
+
+  provider = GTK_STYLE_PROVIDER (gtk_css_provider_new ());
+  gtk_css_provider_load_from_path (GTK_CSS_PROVIDER (provider),
+                                   css_file,
+                                   NULL);
+  gtk_style_context_add_provider_for_screen (gdk_screen_get_default (),
+                                             provider,
+                                             GTK_STYLE_PROVIDER_PRIORITY_FORCE);
+
+  g_free (css_file);
+  
+  return provider;
+}
+
+static void
+remove_extra_css (GtkStyleProvider *provider)
+{
+  if (provider == NULL)
+    return;
+
+  gtk_style_context_remove_provider_for_screen (gdk_screen_get_default (),
+                                                provider);
+}
+
+static GtkWidget *
+builder_get_toplevel (GtkBuilder *builder)
+{
+  GSList *list, *walk;
+  GtkWidget *window = NULL;
+
+  list = gtk_builder_get_objects (builder);
+  for (walk = list; walk; walk = walk->next)
+    {
+      if (GTK_IS_WINDOW (walk->data) &&
+          gtk_widget_get_parent (walk->data) == NULL)
+        {
+          window = walk->data;
+          break;
+        }
+    }
+  
+  g_slist_free (list);
+
+  return window;
+}
+
+static gboolean
+quit_when_idle (gpointer loop)
+{
+  g_main_loop_quit (loop);
+
+  return G_SOURCE_REMOVE;
+}
+
+static void
+check_for_draw (GdkEvent *event, gpointer loop)
+{
+  if (event->type == GDK_EXPOSE)
+    {
+      g_idle_add (quit_when_idle, loop);
+      gdk_event_handler_set ((GdkEventFunc) gtk_main_do_event, NULL, NULL);
+    }
+
+  gtk_main_do_event (event);
+}
+
+static cairo_surface_t *
+snapshot_widget (GtkWidget *widget, SnapshotMode mode)
+{
+  cairo_surface_t *surface;
+  cairo_pattern_t *bg;
+  GMainLoop *loop;
+  cairo_t *cr;
+
+  g_assert (gtk_widget_get_realized (widget));
+
+  loop = g_main_loop_new (NULL, FALSE);
+  /* We wait until the widget is drawn for the first time.
+   * We can not wait for a GtkWidget::draw event, because that might not
+   * happen if the window is fully obscured by windowed child widgets.
+   * Alternatively, we could wait for an expose event on widget's window.
+   * Both of these are rather hairy, not sure what's best. */
+  gdk_event_handler_set (check_for_draw, loop, NULL);
+  g_main_loop_run (loop);
+
+  surface = gdk_window_create_similar_surface (gtk_widget_get_window (widget),
+                                               CAIRO_CONTENT_COLOR,
+                                               gtk_widget_get_allocated_width (widget),
+                                               gtk_widget_get_allocated_height (widget));
+
+  cr = cairo_create (surface);
+
+  switch (mode)
+    {
+    case SNAPSHOT_WINDOW:
+      {
+        GdkWindow *window = gtk_widget_get_window (widget);
+        if (gdk_window_get_window_type (window) == GDK_WINDOW_TOPLEVEL ||
+            gdk_window_get_window_type (window) == GDK_WINDOW_FOREIGN)
+          {
+            /* give the WM/server some time to sync. They need it.
+             * Also, do use popups instead of toplevls in your tests
+             * whenever you can. */
+            gdk_display_sync (gdk_window_get_display (window));
+            g_timeout_add (500, quit_when_idle, loop);
+            g_main_loop_run (loop);
+          }
+        gdk_cairo_set_source_window (cr, window, 0, 0);
+        cairo_paint (cr);
+      }
+      break;
+    case SNAPSHOT_DRAW:
+      bg = gdk_window_get_background_pattern (gtk_widget_get_window (widget));
+      if (bg)
+        {
+          cairo_set_source (cr, bg);
+          cairo_paint (cr);
+        }
+      gtk_widget_draw (widget, cr);
+      break;
+    default:
+      g_assert_not_reached();
+      break;
+    }
+
+  cairo_destroy (cr);
+  g_main_loop_unref (loop);
+  gtk_widget_destroy (widget);
+
+  return surface;
+}
+
+static cairo_surface_t *
+snapshot_ui_file (const char *ui_file,
+                 const char *str)
+{
+  GtkWidget *window;
+  GtkBuilder *builder;
+  GtkWidget *label;
+  GError *error = NULL;
+
+  builder = gtk_builder_new ();
+  gtk_builder_add_from_file (builder, ui_file, &error);
+  g_assert_no_error (error);
+  if (strstr (ui_file, "ref.ui") == NULL)
+    {
+      label = GTK_WIDGET (gtk_builder_get_object (builder, "label1"));
+      g_assert (label);
+      gtk_label_set_label (GTK_LABEL (label), str);
+    }
+  window = builder_get_toplevel (builder);
+  g_object_unref (builder);
+  g_assert (window);
+
+  gtk_widget_show (window);
+
+  return snapshot_widget (window, SNAPSHOT_WINDOW);
+}
+
+static void
+save_image (cairo_surface_t *surface,
+            const char      *test_name,
+            const char      *extension)
+{
+  char *filename = get_output_file (test_name, extension);
+
+  g_test_message ("Storing test result image at %s", filename);
+  g_assert (cairo_surface_write_to_png (surface, filename) == CAIRO_STATUS_SUCCESS);
+
+  g_free (filename);
+}
+
+static void
+get_surface_size (cairo_surface_t *surface,
+                  int             *width,
+                  int             *height)
+{
+  GdkRectangle area;
+  cairo_t *cr;
+
+  cr = cairo_create (surface);
+  if (!gdk_cairo_get_clip_rectangle (cr, &area))
+    {
+      g_assert_not_reached ();
+    }
+
+  g_assert (area.x == 0 && area.y == 0);
+  g_assert (area.width > 0 && area.height > 0);
+
+  *width = area.width;
+  *height = area.height;
+}
+
+static cairo_surface_t *
+coerce_surface_for_comparison (cairo_surface_t *surface,
+                               int              width,
+                               int              height)
+{
+  cairo_surface_t *coerced;
+  cairo_t *cr;
+
+  coerced = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+                                        width,
+                                        height);
+  cr = cairo_create (coerced);
+  
+  cairo_set_source_surface (cr, surface, 0, 0);
+  cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
+  cairo_paint (cr);
+
+  cairo_destroy (cr);
+  cairo_surface_destroy (surface);
+
+  g_assert (cairo_surface_status (coerced) == CAIRO_STATUS_SUCCESS);
+
+  return coerced;
+}
+
+/* Compares two CAIRO_FORMAT_ARGB32 buffers, returning NULL if the
+ * buffers are equal or a surface containing a diff between the two
+ * surfaces.
+ *
+ * This function should be rewritten to compare all formats supported by
+ * cairo_format_t instead of taking a mask as a parameter.
+ *
+ * This function is originally from cairo:test/buffer-diff.c.
+ * Copyright © 2004 Richard D. Worth
+ */
+static cairo_surface_t *
+buffer_diff_core (const guchar *buf_a,
+                  int           stride_a,
+                 const guchar *buf_b,
+                  int           stride_b,
+                 int           width,
+                 int           height)
+{
+  int x, y;
+  guchar *buf_diff = NULL;
+  int stride_diff = 0;
+  cairo_surface_t *diff = NULL;
+
+  for (y = 0; y < height; y++)
+    {
+      const guint32 *row_a = (const guint32 *) (buf_a + y * stride_a);
+      const guint32 *row_b = (const guint32 *) (buf_b + y * stride_b);
+      guint32 *row = (guint32 *) (buf_diff + y * stride_diff);
+
+      for (x = 0; x < width; x++)
+        {
+          int channel;
+          guint32 diff_pixel = 0;
+
+          /* check if the pixels are the same */
+          if (row_a[x] == row_b[x])
+            continue;
+        
+          if (diff == NULL)
+            {
+              diff = cairo_image_surface_create (CAIRO_FORMAT_RGB24,
+                                                 width,
+                                                 height);
+              g_assert (cairo_surface_status (diff) == CAIRO_STATUS_SUCCESS);
+              buf_diff = cairo_image_surface_get_data (diff);
+              stride_diff = cairo_image_surface_get_stride (diff);
+              row = (guint32 *) (buf_diff + y * stride_diff);
+            }
+
+          /* calculate a difference value for all 4 channels */
+          for (channel = 0; channel < 4; channel++)
+            {
+              int value_a = (row_a[x] >> (channel*8)) & 0xff;
+              int value_b = (row_b[x] >> (channel*8)) & 0xff;
+              guint diff;
+
+              diff = ABS (value_a - value_b);
+              diff *= 4;  /* emphasize */
+              if (diff)
+                diff += 128; /* make sure it's visible */
+              if (diff > 255)
+                diff = 255;
+              diff_pixel |= diff << (channel*8);
+            }
+
+          if ((diff_pixel & 0x00ffffff) == 0)
+            {
+              /* alpha only difference, convert to luminance */
+              guint8 alpha = diff_pixel >> 24;
+              diff_pixel = alpha * 0x010101;
+            }
+          
+          row[x] = diff_pixel;
+      }
+  }
+
+  return diff;
+}
+
+static cairo_surface_t *
+compare_surfaces (cairo_surface_t *surface1,
+                  cairo_surface_t *surface2)
+{
+  int w1, h1, w2, h2, w, h;
+  cairo_surface_t *diff;
+  
+  get_surface_size (surface1, &w1, &h1);
+  get_surface_size (surface2, &w2, &h2);
+  w = MAX (w1, w2);
+  h = MAX (h1, h2);
+  surface1 = coerce_surface_for_comparison (surface1, w, h);
+  surface2 = coerce_surface_for_comparison (surface2, w, h);
+
+  diff = buffer_diff_core (cairo_image_surface_get_data (surface1),
+                           cairo_image_surface_get_stride (surface1),
+                           cairo_image_surface_get_data (surface2),
+                           cairo_image_surface_get_stride (surface2),
+                           w, h);
+
+  return diff;
+}
+
+static char *
+get_locale_for_file (const char *ui_file)
+{
+  char *dot, *slash;
+
+  if (!g_str_has_suffix (ui_file, ".ui"))
+    return NULL;
+  dot = strstr (ui_file, ".ui");
+  slash = g_strrstr (ui_file, "/");
+  return g_strndup (slash + 1, dot - slash - 1);
+}
+
+static void
+test_ui_file (GFile *file)
+{
+  char *ui_file, *reference_file, *locale;
+  cairo_surface_t *ui_image, *reference_image, *diff_image;
+  GtkStyleProvider *provider;
+  GnomeWallClock *clock;
+  GDateTime *datetime;
+  char *str;
+
+  ui_file = g_file_get_path (file);
+
+  locale = get_locale_for_file (ui_file);
+  g_assert (locale);
+  setlocale (LC_ALL, locale);
+
+  clock = gnome_wall_clock_new();
+  datetime = g_date_time_new_local (2014, 5, 28, 23, 59, 59);
+  str = gnome_wall_clock_string_for_datetime (clock,
+                                             datetime,
+                                             G_DESKTOP_CLOCK_FORMAT_24H,
+                                             TRUE, TRUE, TRUE);
+  /* If you need to copy/paste to a .ref.ui file, uncomment here
+   * g_message ("str: %s", str); */
+  g_date_time_unref (datetime);
+  g_object_unref (clock);
+
+  provider = add_extra_css (ui_file, ".css");
+
+  ui_image = snapshot_ui_file (ui_file, str);
+
+  reference_file = get_test_file (ui_file, ".ref.ui", TRUE);
+  if (reference_file)
+    reference_image = snapshot_ui_file (reference_file, str);
+  else
+    {
+      reference_image = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, 1, 1);
+      g_test_message ("No reference image.");
+      g_test_fail ();
+    }
+  g_free (reference_file);
+  g_free (str);
+
+  diff_image = compare_surfaces (ui_image, reference_image);
+
+  save_image (ui_image, ui_file, ".out.png");
+  save_image (reference_image, ui_file, ".ref.png");
+  if (diff_image)
+    {
+      save_image (diff_image, ui_file, ".diff.png");
+      g_test_fail ();
+    }
+
+  remove_extra_css (provider);
+}
+
+static int
+compare_files (gconstpointer a, gconstpointer b)
+{
+  GFile *file1 = G_FILE (a);
+  GFile *file2 = G_FILE (b);
+  char *path1, *path2;
+  int result;
+
+  path1 = g_file_get_path (file1);
+  path2 = g_file_get_path (file2);
+
+  result = strcmp (path1, path2);
+
+  g_free (path1);
+  g_free (path2);
+
+  return result;
+}
+
+static void
+add_test_for_file (GFile *file)
+{
+  GFileEnumerator *enumerator;
+  GFileInfo *info;
+  GList *files;
+  GError *error = NULL;
+
+
+  if (g_file_query_file_type (file, 0, NULL) != G_FILE_TYPE_DIRECTORY)
+    {
+      g_test_add_vtable (g_file_get_path (file),
+                         0,
+                         g_object_ref (file),
+                         NULL,
+                         (GTestFixtureFunc) test_ui_file,
+                         (GTestFixtureFunc) g_object_unref);
+      return;
+    }
+
+
+  enumerator = g_file_enumerate_children (file, G_FILE_ATTRIBUTE_STANDARD_NAME, 0, NULL, &error);
+  g_assert_no_error (error);
+  files = NULL;
+
+  while ((info = g_file_enumerator_next_file (enumerator, NULL, &error)))
+    {
+      const char *filename;
+
+      filename = g_file_info_get_name (info);
+
+      if (!g_str_has_suffix (filename, ".ui") ||
+          g_str_has_suffix (filename, ".ref.ui"))
+        {
+          g_object_unref (info);
+          continue;
+        }
+
+      files = g_list_prepend (files, g_file_get_child (file, filename));
+
+      g_object_unref (info);
+    }
+  
+  g_assert_no_error (error);
+  g_object_unref (enumerator);
+
+  files = g_list_sort (files, compare_files);
+  g_list_foreach (files, (GFunc) add_test_for_file, NULL);
+  g_list_free_full (files, g_object_unref);
+}
+
+int
+main (int argc, char **argv)
+{
+  const char *basedir;
+  GFile *file;
+
+  /* I don't want to fight fuzzy scaling algorithms in GPUs,
+   * so unless you explicitly set it to something else, we
+   * will use Cairo's image surface.
+   */
+  g_setenv ("GDK_RENDERING", "image", FALSE);
+
+  setlocale (LC_ALL, "");
+  g_test_init (&argc, &argv, NULL);
+  gtk_init (&argc, &argv);
+
+  basedir = g_test_get_dir (G_TEST_DIST);
+  file = g_file_new_for_commandline_arg (basedir);
+  add_test_for_file (file);
+  g_object_unref (file);
+
+  /* We need to ensure the process' current working directory
+   * is the same as the reftest data, because we're using the
+   * "file" property of GtkImage as a relative path in builder files.
+   */
+  chdir (basedir);
+
+  return g_test_run ();
+}