Evas Textblock: Add obstacle objects feature

Summary:
Introducing a new feature for Evas Textblock. This allows the layout to
wrap around other evas objects.
The following API is added:
 - obstacle_add
 - obstacle_del
 - obstacle_update
Evas objects can now serve as textblock obstacles, if positioned and
visible on the text area. The text will wrap around the obstacles
according to the wrapping mode set to it.

This also modifies the current wrapping code to handle obstacle wrap
points as well. The wrap index query function is modified so that
forward-scanning (specific cases) may be disabled when treating
obstacle wrap point.

RTL text is currently unsupported by this feature.
Consult added docs and example for usage.

@feature

Test Plan: Evas example and test in evas_suite are provided with this.

Reviewers: tasn

Subscribers: raster, JackDanielZ, cedric

Differential Revision: https://phab.enlightenment.org/D2405

1 files changed, 88 insertions, 0 deletions

diff --git a/src/tests/evas/evas_test_textblock.c b/src/tests/evas/evas_test_textblock.c
index 1c1d5965c4..fe4dfe1895 100644
--- a/src/tests/evas/evas_test_textblock.c
+++ b/src/tests/evas/evas_test_textblock.c
@@ -3304,6 +3304,93 @@ START_TEST(evas_textblock_delete)
 }
 END_TEST;
 
+/* Runs x,y in [from,to] range */
+static void
+_obstacle_run(Evas_Object *tb, Evas_Object *obj,
+      Evas_Coord from_x, Evas_Coord to_x,
+      Evas_Coord from_y, Evas_Coord to_y,
+      Evas_Coord bh)
+{
+   Evas_Coord fw, fh;
+   Evas_Coord x, y;
+   for (y = from_y; y <= to_y; y += 5)
+     {
+        for (x = from_x; x <= to_x; x += 5)
+          {
+             evas_object_move(obj, x, y);
+             evas_object_textblock_obstacles_update(tb);
+             evas_object_textblock_size_formatted_get(tb, &fw, &fh);
+             /* the obstacle size is large enough to assume that adding it
+              * will at least make the formatted height value bigger */
+             ck_assert_int_ge(fh, bh);
+          }
+     }
+}
+
+START_TEST(evas_textblock_obstacle)
+{
+   START_TB_TEST();
+   Evas_Coord fw, fh;
+   Evas_Object *rect, *rect2, *rect3;
+   const char *buf =
+      "This is an example text to demonstrate the textblock object"
+      " with obstacle objects support."
+      " Any evas object <item size=72x16></item>can register itself as an obstacle to the textblock"
+      " object. Upon registring, it affects the layout of the text in"
+      " certain situations. Usually, when the obstacle shows above the text"
+      " area, it will cause the layout of the text to split and move"
+      " parts of it, so that all text area is apparent.";
+
+   rect = evas_object_rectangle_add(evas);
+   rect2 = evas_object_rectangle_add(evas);
+   rect3 = evas_object_rectangle_add(evas);
+   evas_object_resize(rect, 50, 50);
+   evas_object_resize(rect2, 50, 50);
+   evas_object_resize(rect3, 50, 50);
+   evas_object_textblock_text_markup_set(tb, buf);
+   evas_textblock_cursor_format_prepend(cur, "<wrap=word>");
+   evas_object_textblock_size_formatted_get(tb, &fw, &fh);
+
+   ck_assert(!evas_object_textblock_obstacle_del(tb, rect));
+
+   ck_assert(evas_object_textblock_obstacle_add(tb, rect));
+   ck_assert(!evas_object_textblock_obstacle_add(tb, rect));
+
+   ck_assert(evas_object_textblock_obstacle_add(tb, rect2));
+   ck_assert(evas_object_textblock_obstacle_add(tb, rect3));
+
+   evas_object_show(rect);
+   evas_object_show(rect2);
+   evas_object_show(rect3);
+
+   /* Compare formatted size with and without obstacle */
+   _obstacle_run(tb, rect, 0, fw, fh / 2, fh / 2, fh);
+   /* Now, with bigger obstacles */
+   evas_object_resize(rect, 150, 150);
+   evas_object_resize(rect3, 300, 300);
+   evas_object_hide(rect);
+   evas_object_textblock_obstacles_update(tb);
+   _obstacle_run(tb, rect, 0, fw, fh / 2, fh / 2, fh);
+
+   evas_object_textblock_obstacle_del(tb, rect);
+   /* running with rect, now that it's not observed */
+   evas_textblock_cursor_format_prepend(cur, "<wrap=mixed>");
+   _obstacle_run(tb, rect, 0, fw, fh / 2, fh / 2, fh);
+
+   evas_object_del(rect2);
+   /* running with rect again, since rect2 is deleted */
+   evas_textblock_cursor_format_prepend(cur, "<wrap=char>");
+   _obstacle_run(tb, rect, 0, fw, fh / 2, fh / 2, fh);
+
+   evas_object_del(rect);
+   _obstacle_run(tb, rect3, 0, fw, 0, 0, fh);
+   END_TB_TEST();
+   /* Deleting rect3 later, so it will be first removed from observation,
+    * during freeing of the textblock */
+   evas_object_del(rect3);
+}
+END_TEST;
+
 void evas_test_textblock(TCase *tc)
 {
    tcase_add_test(tc, evas_textblock_simple);
@@ -3325,5 +3412,6 @@ void evas_test_textblock(TCase *tc)
    tcase_add_test(tc, evas_textblock_wrapping);
    tcase_add_test(tc, evas_textblock_items);
    tcase_add_test(tc, evas_textblock_delete);
+   tcase_add_test(tc, evas_textblock_obstacle);
 }