tests: Add a spiced up wrapping test

* Generate 20 random strings that look like sentences.
* For each of them, measure the size at 100 random widths.
* assert that for those widths, when sorted, the measured widths
  are increasing and the heights are decreasing.

The test alsogenerates random strings in LTR, RTL or both at the same
time to spice the test up even more.
It does that by picking random words out of hunspell directories, and if
none are installed, it falls back to lorem ipsum.

2 files changed, 278 insertions, 1 deletions

diff --git a/tests/meson.build b/tests/meson.build
index 90bb94ba..81170c15 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -52,7 +52,8 @@ if cairo_dep.found()
     [ 'testmisc', [ 'testmisc.c' ], [ libpangocairo_dep, libpangoft2_dep, glib_dep, harfbuzz_dep ] ],
     [ 'cxx-test', [ 'cxx-test.cpp' ], [ libpangocairo_dep, gobject_dep, harfbuzz_dep ] ],
     [ 'test-harfbuzz', [ 'test-harfbuzz.c' ], [ libpangocairo_dep, gobject_dep, harfbuzz_dep ] ],
-    [ 'test-break', [ 'test-break.c', 'test-common.c', 'validate-log-attrs.c' ], [libpangocairo_dep, glib_dep, harfbuzz_dep ] ]
+    [ 'test-break', [ 'test-break.c', 'test-common.c', 'validate-log-attrs.c' ], [libpangocairo_dep, glib_dep, harfbuzz_dep ] ],
+    [ 'testrandom', [ 'testrandom.c' ], [ libpangocairo_dep, gio_dep ] ],
   ]
 
   if pango_cairo_backends.contains('png')
diff --git a/tests/testrandom.c b/tests/testrandom.c
new file mode 100644
index 00000000..3f6e4ce0
--- /dev/null
+++ b/tests/testrandom.c
@@ -0,0 +1,276 @@
+/* Pango
+ * testmisc.c: Test program for miscellaneous things
+ *
+ * Copyright (C) 2021 Benjamin Otte
+ *
+ * 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 "config.h"
+
+#include <locale.h>
+#include <gio/gio.h>
+#include <pango/pangocairo.h>
+
+static char **ltr_words;
+static gsize n_ltr_words;
+static char **rtl_words;
+static gsize n_rtl_words;
+
+static const char *
+random_word (PangoDirection dir)
+{
+  switch (dir)
+    {
+      case PANGO_DIRECTION_LTR:
+        return ltr_words[g_test_rand_int_range (0, n_ltr_words)];
+      case PANGO_DIRECTION_RTL:
+        return rtl_words[g_test_rand_int_range (0, n_rtl_words)];
+      default:
+        return random_word (g_test_rand_bit () ? PANGO_DIRECTION_LTR : PANGO_DIRECTION_RTL);
+    }
+}
+
+static char *
+create_random_sentence (PangoDirection dir)
+{
+  GString *string = g_string_new (NULL);
+  gsize i, n_words;
+
+  n_words = g_test_rand_int_range (3, 15);
+  for (i = 0; i < n_words; i++)
+    {
+      if (i > 0)
+        {
+          if (g_random_int_range (0, 10) == 0)
+            g_string_append_c (string, ',');
+          g_string_append_c (string, ' ');
+        }
+      g_string_append (string, random_word (dir));
+    }
+
+  g_string_append_c (string, "!.?"[g_test_rand_int_range(0, 3)]);
+
+  return g_string_free (string, FALSE);
+}
+
+typedef struct
+{
+  int set_width;
+  int width;
+  int height;
+} Size;
+
+static int
+compare_size (gconstpointer a,
+              gconstpointer b,
+              gpointer      unused)
+{
+  return ((const Size *) a)->set_width - ((const Size *) b)->set_width;
+}
+
+static void
+layout_check_size (PangoLayout *layout,
+                   int          width,
+                   Size        *out_size)
+{
+  out_size->set_width = width;
+  pango_layout_set_width (layout, width);
+  pango_layout_get_size (layout, &out_size->width, &out_size->height);
+}
+
+static void
+test_wrap_char (gconstpointer data)
+{
+#define N_SENTENCES 20
+  PangoDirection dir = GPOINTER_TO_UINT (data);
+  PangoFontDescription *desc;
+  PangoContext *context;
+  PangoLayout *layout;
+  char *sentence;
+  Size min, max;
+  Size sizes[100];
+  gsize i, j;
+
+  context = pango_font_map_create_context (pango_cairo_font_map_get_default ());
+  desc = pango_font_description_from_string ("Sans 10");
+  layout = pango_layout_new (context);
+  pango_layout_set_font_description (layout, desc);
+  pango_font_description_free (desc);
+
+  for (j = 0; j < N_SENTENCES; j++)
+    {
+      sentence = create_random_sentence (dir);
+      pango_layout_set_text (layout, sentence, -1);
+      g_print ("%s\n", sentence);
+      g_free (sentence);
+      pango_layout_set_wrap (layout, PANGO_WRAP_WORD_CHAR);
+
+      layout_check_size (layout, -1, &max);
+      layout_check_size (layout, 0, &min);
+      g_assert_cmpint (min.width, <=, max.width);
+      g_assert_cmpint (min.height, >=, max.height);
+
+      for (i = 0; i < G_N_ELEMENTS (sizes); i++)
+        {
+          layout_check_size (layout, min.width / 2 + g_test_rand_int_range (0, max.width), &sizes[i]);
+        }
+
+      g_qsort_with_data (sizes, G_N_ELEMENTS (sizes), sizeof (Size), compare_size, NULL);
+
+      g_assert_cmpint (sizes[0].width, >=, min.width);
+      g_assert_cmpint (sizes[0].height, <=, min.height);
+
+      for (i = 1; i < G_N_ELEMENTS (sizes); i++)
+        {
+          g_assert_cmpint (sizes[i-1].set_width, <=, sizes[i].set_width);
+          g_assert_cmpint (sizes[i-1].width, <=, sizes[i].width);
+          g_assert_cmpint (sizes[i-1].height, >=, sizes[i].height);
+          if (sizes[i-1].width == sizes[i].width)
+            g_assert_cmpint (sizes[i-1].height, ==, sizes[i].height);
+        }
+
+      if (sizes[i-1].set_width >= max.width)
+        {
+          g_assert_cmpint (sizes[i-1].width, ==, max.width);
+          g_assert_cmpint (sizes[i-1].height, ==, max.height);
+        }
+      else
+        {
+          g_assert_cmpint (sizes[i-1].width, <, max.width);
+          g_assert_cmpint (sizes[i-1].height, >, max.height);
+        }
+    }
+
+  g_object_unref (layout);
+  g_object_unref (context);
+}
+
+static gboolean
+load_hunspell_words (GStrvBuilder *builder,
+                      const char  *language)
+{
+  char *path;
+  GBytes *bytes;
+  GFile *file;
+  char **words;
+  gsize i;
+
+  path = g_strdup_printf ("/usr/share/myspell/%s.dic", language);
+  file = g_file_new_for_path (path);
+  g_free (path);
+  bytes = g_file_load_bytes (file, NULL, NULL, NULL);
+  g_object_unref (file);
+  if (bytes == NULL)
+    return FALSE;
+
+  words = g_strsplit (g_bytes_get_data (bytes, NULL), "\n", -1);
+  if (words == NULL || words[0] == NULL)
+    {
+      g_free (words);
+      return FALSE;
+    }
+
+  for (i = 1; words[i]; i++)
+    {
+      char *slash = strchr (words[i], '/');
+      if (slash)
+        *slash = 0;
+
+      g_strv_builder_add (builder, words[i]);
+    }
+  
+  g_strfreev (words);
+
+  return TRUE;
+}
+
+static char **
+init_ltr_words (void)
+{
+  GStrvBuilder *builder;
+  GFile *file;
+  GBytes *bytes;
+  char **result;
+
+  builder = g_strv_builder_new ();
+
+  if (!load_hunspell_words (builder, "en_US"))
+    {
+      file = g_file_new_for_path ("/usr/share/dict/words");
+      bytes = g_file_load_bytes (file, NULL, NULL, NULL);
+      if (bytes)
+        {
+          result = g_strsplit (g_bytes_get_data (bytes, NULL), "\n", -1);
+          g_bytes_unref (bytes);
+        }
+      else
+        result = g_strsplit ("lorem ipsum dolor sit amet consectetur adipisci elit sed eiusmod tempor incidunt labore et dolore magna aliqua ut enim ad minim veniam quis nostrud exercitation ullamco laboris nisi ut aliquid ex ea commodi consequat", " ", -1);
+      g_strv_builder_addv (builder, (const char **) result);
+      g_strfreev (result);
+    }
+
+  result = g_strv_builder_end (builder);
+  g_strv_builder_unref (builder);
+
+  return result;
+}
+
+static char **
+init_rtl_words (void)
+{
+  GStrvBuilder *builder;
+  char **result;
+
+  builder = g_strv_builder_new ();
+
+  if (!load_hunspell_words (builder, "he_IL"))
+    {
+      result = g_strsplit ("לורם איפסום דולור סיט אמט קונסקטטור אדיפיסינג אלית קולורס מונפרד אדנדום סילקוף מרגשי ומרגשח עמחליף לפרומי בלוף קינץ תתיח לרעח לת צשחמי צש בליא מנסוטו צמלח לביקו ננבי צמוקו בלוקריה שיצמה ברורק להאמית קרהשק סכעיט דז מא מנכם למטכין נשואי מנורךגולר מונפרר סוברט לורם שבצק יהול לכנוץ בעריר גק ליץ ושבעגט ושבעגט לבם סולגק בראיט ולחת צורק מונחף בגורמי מגמש תרבנך וסתעד לכנו סתשם השמה - לתכי מורגם בורק? לתיג ישבעס", " ", -1);
+      g_strv_builder_addv (builder, (const char **) result);
+      g_strfreev (result);
+    }
+
+  result = g_strv_builder_end (builder);
+  g_strv_builder_unref (builder);
+
+  return result;
+}
+
+int
+main (int argc, char *argv[])
+{
+  int result;
+
+  g_test_init (&argc, &argv, NULL);
+  setlocale (LC_ALL, "");
+
+  ltr_words = init_ltr_words ();
+  n_ltr_words = g_strv_length (ltr_words);
+  rtl_words = init_rtl_words ();
+  n_rtl_words = g_strv_length (rtl_words);
+
+  g_test_add_data_func ("/layout/ltr/wrap-char", GUINT_TO_POINTER (PANGO_DIRECTION_LTR), test_wrap_char);
+  g_test_add_data_func ("/layout/rtl/wrap-char", GUINT_TO_POINTER (PANGO_DIRECTION_RTL), test_wrap_char);
+  g_test_add_data_func ("/layout/any/wrap-char", GUINT_TO_POINTER (PANGO_DIRECTION_NEUTRAL), test_wrap_char);
+
+  result = g_test_run ();
+
+  g_strfreev (ltr_words);
+  g_strfreev (rtl_words);
+
+  return result;
+}