edje_cc: introduce "Anchors" - easy way to set parts relationship

Test Plan: compile src/examples/edc-anchors.c and run

Reviewers: zmike, raster, cedric, jpeg

Reviewed By: raster, jpeg

Subscribers: raster, barbieri, zmike, SanghyeonLee, taxi2se, Jaehyun_Cho

Differential Revision: https://phab.enlightenment.org/D4775

Signed-off-by: Cedric BAIL <cedric@osg.samsung.com>

unsorted/edje/edje-anchors.c

@@ -0,0 +1,58 @@
+/**
+ * Simple Edje example for layouting parts with anchors.
+ *
+ * You'll need at least one Evas engine built for it (excluding the
+ * buffer one). See stdout/stderr for output.
+ *
+ * @verbatim
+ * edje_cc edje-anchors.edc && gcc -o edje-anchors edje-anchors.c `pkg-config --libs --cflags evas ecore ecore-evas edje`
+ * @endverbatim
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#else
+# define EINA_UNUSED
+#endif
+
+#include <Ecore.h>
+#include <Ecore_Evas.h>
+#include <Edje.h>
+#include <libgen.h>
+
+#define WIDTH 400
+#define HEIGHT 400
+
+int
+main(int argc, char **argv)
+{
+   char path[PATH_MAX] = { 0, };
+
+   ecore_init();
+   ecore_evas_init();
+   edje_init();
+
+   Ecore_Evas *ee = ecore_evas_new(NULL, 0, 0, WIDTH, HEIGHT, NULL);
+   Evas *e = ecore_evas_get(ee);
+   ecore_evas_show(ee);
+
+   Evas_Object *bg = evas_object_rectangle_add(e);
+   evas_object_color_set(bg, 64, 64, 64, 255);
+   evas_object_resize(bg, WIDTH, HEIGHT);
+   evas_object_show(bg);
+
+   snprintf(path, sizeof(path), "%s/edje-anchors.edj", dirname(*argv));
+
+   Evas_Object *edje = edje_object_add(e);
+   edje_object_file_set(edje, path, "main");
+   evas_object_resize(edje, WIDTH, HEIGHT);
+   evas_object_show(edje);
+
+   ecore_main_loop_begin();
+
+   edje_shutdown();
+   ecore_evas_shutdown();
+   ecore_shutdown();
+
+   return 0;
+}

unsorted/edje/edje-anchors.edc

@@ -0,0 +1,58 @@
+collections {
+   group { "main";
+      parts {
+         rect { "rect1";
+            desc {
+               anchors.top: GROUP TOP;
+               anchors.left: GROUP; // anchors.left: GROUP LEFT;
+               color: "#f00";
+               min: 50 50;
+            }
+         }
+         rect { "rect2";
+            desc {
+               anchors.top: "rect1" BOTTOM;
+               anchors.left: "rect1" RIGHT;
+               color: "#00f";
+               min: 50 50;
+            }
+         }
+         rect { "rect3";
+            desc {
+               anchors.left: "rect2"; // anchors.left: "rect1" RIGHT;
+               anchors.fill: "rect2" VERTICAL;
+               anchors.margin: 20 0 0 0;
+               color: "#0f0";
+               min: 100 0;
+            }
+         }
+         rect { "rect4";
+            desc {
+               anchors {
+                  top: "rect3";
+                  left: "rect3";
+                  right: GROUP;
+                  bottom: GROUP;
+                  margin: 0 10 0 50;
+               }
+            }
+         }
+         rect { "rect5";
+            desc {
+               anchors.vertical_center: "rect4";
+               anchors.fill: "rect4" HORIZONTAL;
+               min: 0 50;
+               color: "#000";
+            }
+         }
+         rect { "rect6";
+            desc {
+               anchors.right: "rect5" HORIZONTAL_CENTER;
+               anchors.fill: "rect5" VERTICAL;
+               min: 30 0;
+               color: "#ff0";
+            }
+         }
+      }
+   }
+}