[atk] AtkValue: add a testvalue example, with a small AtkValue implementation

[Alejandro Piñeiro Iglesias <apinheiro src gnome org>]

commit 27418197b7bf8492f0c839d62611d4c6c451e1f6
Author: Alejandro Piñeiro <apinheiro igalia com>
Date:   Wed Mar 5 18:33:06 2014 +0100

    AtkValue: add a testvalue example, with a small AtkValue
     implementation
    
    https://bugzilla.gnome.org/show_bug.cgi?id=684576

 tests/Makefile.am |    4 +-
 tests/testvalue.c |  324 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 327 insertions(+), 1 deletions(-)
---
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 806a360..2f50a32 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -15,7 +15,8 @@ DEPS = \
 noinst_PROGRAMS = testdocument \
                  testrole  \
                  testrelation  \
-                 teststateset
+                 teststateset  \
+                 testvalue
 
 LDADD = $(libatk) $(DEP_LIBS)
 
@@ -23,6 +24,7 @@ testdocument_SOURCES = testdocument.c
 testrole_SOURCES = testrole.c
 testrelation_SOURCES = testrelation.c
 teststateset_SOURCES = teststateset.c
+teststateset_SOURCES = testvalue.c
 
 testatk_vc.mak: testatk_vc.makin $(top_srcdir)/build/atk_msvc_files.py $(top_srcdir)/build/msvcfiles.py
        $(PYTHON) $(top_srcdir)/build/atk_msvc_files.py -t nmake-exe
diff --git a/tests/testvalue.c b/tests/testvalue.c
new file mode 100644
index 0000000..7ec0a29
--- /dev/null
+++ b/tests/testvalue.c
@@ -0,0 +1,324 @@
+/* ATK -  Accessibility Toolkit
+ * Copyright 2001 Sun Microsystems Inc.
+ * Copyright 2014 Igalia S.L.
+ *
+ * Author: Alejandro Piñeiro Iglesias <apinheiro igalia com>
+ *
+ * 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, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+#include <atk/atk.h>
+
+/**
+ * SECTION:testvalue
+ * @Short_description: this example serves as a unit test for AtkValue
+ *  and also as an example of how to implement #AtkValue on a given
+ *  GObject.
+ *
+ *  This test will represent a volume slider, smart enough to have
+ *  classify the values on the global range [0,1] with the
+ *  descriptions "low", "medium", "high" and "very high".  As the
+ *  clasification is fixed, it also expose all the four possible
+ *  subranges. To fill the description name it will use some of the
+ *  already defined #AtkValueType.
+ *
+ *  This will implement all the methods of #AtkValue, but note that
+ *  this is not mandatory on all the cases. In several cases it is not
+ *  needed to implement the subranges methods. See #AtkValue
+ *  documentation for further information.
+ *
+ */
+
+#define EXPECTED_NUMBER 7
+
+#define LOWER_LIMIT 0
+#define LOW_THRESHOLD 0.2
+#define NORMAL_THRESHOLD 0.4
+#define HIGH_THRESHOLD 0.8
+#define RISKY_THRESHOLD 1.0
+#define UPPER_LIMIT 1.0
+#define INCREMENT 0.15
+
+GMainLoop *global_loop = NULL;
+gint global_number_emissions = 0;
+gboolean test_success = TRUE;
+GObject *my_value;
+
+#define TEST_TYPE_VALUE                         (test_value_get_type ())
+#define TEST_VALUE(obj)                         (G_TYPE_CHECK_INSTANCE_CAST ((obj), TEST_TYPE_VALUE, 
TestValue))
+#define TEST_VALUE_CLASS(klass)                 (G_TYPE_CHECK_CLASS_CAST ((klass), TEST_TYPE_VALUE, 
TestValueClass))
+#define TEST_IS_VALUE(obj)                      (G_TYPE_CHECK_INSTANCE_TYPE ((obj), TEST_TYPE_VALUE))
+#define TEST_IS_VALUE_CLASS(klass)              (G_TYPE_CHECK_CLASS_TYPE ((klass), TEST_TYPE_VALUE))
+#define TEST_VALUE_GET_CLASS(obj)               (G_TYPE_INSTANCE_GET_CLASS ((obj), TEST_TYPE_VALUE, 
TestValueClass))
+
+typedef struct _TestValue        TestValue;
+typedef struct _TestValueClass   TestValueClass;
+
+struct _TestValue
+{
+  AtkObject parent;
+
+  gdouble value;
+};
+
+struct _TestValueClass
+{
+  AtkObjectClass parent_class;
+};
+
+GType       test_value_get_type (void) G_GNUC_CONST;
+static void test_value_interface_init (AtkValueIface *iface);
+
+G_DEFINE_TYPE_WITH_CODE (TestValue,
+                         test_value,
+                         ATK_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (ATK_TYPE_VALUE,
+                                                test_value_interface_init));
+
+static void
+test_value_class_init (TestValueClass *klass)
+{
+}
+
+static void
+test_value_init (TestValue *value)
+{
+}
+
+
+static const gchar*
+get_description (gdouble value)
+{
+  const gchar *description = NULL;
+
+  if (value < LOW_THRESHOLD)
+    description = atk_value_type_get_localized_name (ATK_VALUE_LOW);
+  else if (value < NORMAL_THRESHOLD)
+    description = atk_value_type_get_localized_name (ATK_VALUE_MEDIUM);
+  else if (value < HIGH_THRESHOLD)
+    description = atk_value_type_get_localized_name (ATK_VALUE_HIGH);
+  else description = atk_value_type_get_localized_name (ATK_VALUE_VERY_HIGH);
+
+  return description;
+}
+
+static void
+test_value_get_value_and_text (AtkValue *value,
+                               gdouble *current_value,
+                               gchar **description)
+{
+  g_return_if_fail (TEST_IS_VALUE (value));
+
+  TestValue *self = TEST_VALUE (value);
+
+  if (current_value != NULL)
+    *current_value = self->value;
+
+  if (description != NULL)
+    *description = g_strdup (get_description (self->value));
+}
+
+AtkRange*
+test_value_get_range (AtkValue *value)
+{
+  g_return_val_if_fail (TEST_IS_VALUE (value), NULL);
+
+  AtkRange *result = atk_range_new (LOWER_LIMIT,
+                                    UPPER_LIMIT,
+                                    NULL);
+
+  return result;
+}
+
+gdouble
+test_value_get_increment (AtkValue *value)
+{
+  g_return_val_if_fail (TEST_IS_VALUE (value), 0.0);
+
+  return INCREMENT;
+}
+
+GSList*
+test_value_get_sub_ranges (AtkValue *value)
+{
+  g_return_val_if_fail (TEST_IS_VALUE (value), NULL);
+
+  GSList *result = NULL;
+  AtkRange *range = NULL;
+
+  /* low */
+  range = atk_range_new (LOWER_LIMIT, LOW_THRESHOLD,
+                         get_description (LOWER_LIMIT));
+
+  result = g_slist_append (result, range);
+
+  /* normal */
+  range = atk_range_new (LOW_THRESHOLD, NORMAL_THRESHOLD,
+                         get_description (LOW_THRESHOLD));
+  result = g_slist_append (result, range);
+
+  /* high */
+  range = atk_range_new (NORMAL_THRESHOLD, HIGH_THRESHOLD,
+                         get_description (NORMAL_THRESHOLD));
+  result = g_slist_append (result, range);
+
+  /* very high */
+  range = atk_range_new (HIGH_THRESHOLD, UPPER_LIMIT,
+                         get_description (HIGH_THRESHOLD));
+  result = g_slist_append (result, range);
+
+  return result;
+}
+
+void
+test_value_set_value (AtkValue *value,
+                      double new_value)
+{
+  g_return_if_fail (TEST_IS_VALUE (value));
+
+  TestValue *self = TEST_VALUE (value);
+
+  if (new_value < LOWER_LIMIT)
+    new_value = LOWER_LIMIT;
+
+  if (new_value > UPPER_LIMIT)
+    new_value = UPPER_LIMIT;
+
+  if (new_value != self->value) {
+    gchar *description = g_strdup (get_description (new_value));
+    self->value = new_value;
+    g_signal_emit_by_name (value, "value-changed", new_value, description, NULL);
+    g_free (description);
+  }
+}
+
+static void
+test_value_interface_init (AtkValueIface *iface)
+{
+  iface->get_value_and_text = test_value_get_value_and_text;
+  iface->get_range = test_value_get_range;
+  iface->get_increment = test_value_get_increment;
+  iface->get_sub_ranges = test_value_get_sub_ranges;
+  iface->set_value = test_value_set_value;
+}
+
+static void
+value_page_changed_cb (AtkValue *value,
+                       gdouble new_value,
+                       gchar *new_description,
+                       gpointer data)
+{
+  g_print ("value-changed callback=(%f,%s)\n", new_value, new_description);
+  global_number_emissions++;
+}
+
+/**
+ * This call simulates a user interacting with the slider.
+ *
+ */
+static gboolean
+do_value_changed (gpointer data)
+{
+  TestValue* test_value = TEST_VALUE (data);
+
+  atk_value_set_value (ATK_VALUE (test_value),
+                       test_value->value + INCREMENT);
+
+  if (global_number_emissions == EXPECTED_NUMBER) {
+    g_main_loop_quit (global_loop);
+    return G_SOURCE_REMOVE;
+  } else
+    return G_SOURCE_CONTINUE;
+}
+
+/**
+ * Prints all the info from an AtkValue
+ */
+static void
+print_info (AtkValue *atk_value)
+{
+  double value;
+  gchar *description;
+  AtkRange *range;
+  GSList *sub_ranges;
+  GSList *iter;
+  gdouble increment;
+  gint i = 0;
+
+  atk_value_get_value_and_text (atk_value, &value, &description);
+  range = atk_value_get_range (atk_value);
+  increment = atk_value_get_increment (atk_value);
+  atk_value_set_value (atk_value, 0);
+
+  g_print ("Current AtkValue data:\n");
+  g_print ("\t (value,description)=(%f,%s) \n", value, description);
+  if (range != NULL)
+    g_print ("\t (min,max,description)=(%f, %f, %s)\n",
+             atk_range_get_lower_limit (range), atk_range_get_upper_limit (range), atk_range_get_description 
(range));
+  else
+    test_success = FALSE; /* Any AtkValue implementation should provide a range */
+  g_print ("\t minimum increment=%f\n", increment);
+
+  if (range)
+    atk_range_free (range);
+
+  sub_ranges = atk_value_get_sub_ranges (atk_value);
+  for (iter = sub_ranges; iter != NULL; iter = g_slist_next (iter),i++) {
+    range = iter->data;
+    g_print ("\t\t sub_range%i = (%f, %f, %s)\n", i,
+             atk_range_get_lower_limit (range), atk_range_get_upper_limit (range), atk_range_get_description 
(range));
+  }
+
+  g_slist_free_full (sub_ranges, (GDestroyNotify) atk_range_free);
+}
+
+
+static gboolean
+init_test_value (void)
+{
+  my_value = g_object_new (TEST_TYPE_VALUE, NULL);
+
+  g_signal_connect (my_value, "value-changed",
+                    G_CALLBACK (value_page_changed_cb),
+                    NULL);
+
+  print_info (ATK_VALUE (my_value));
+
+  g_idle_add (do_value_changed, my_value);
+
+  return TRUE;
+}
+
+
+int
+main (gint  argc,
+      char* argv[])
+{
+  global_loop = g_main_loop_new (NULL, FALSE);
+
+  g_print("Starting Value test suite\n\n\n");
+
+  init_test_value ();
+  g_main_loop_run (global_loop);
+
+  if (global_number_emissions == EXPECTED_NUMBER && test_success)
+    g_print ("\n\nValue tests succeeded\n\n\n");
+  else
+    g_print ("\n\nValue tests failed\n\n\n");
+
+  print_info (ATK_VALUE (my_value));
+
+  return 0;
+}