Clipping Objects

Limiting Visibility

An Evas object can be clipped – in other words, its visible area is restricted with the clipper object.

It is often necessary to show only parts of an object, and while it may be possible to create an object that corresponds only to the part that must be shown (which is not always possible), it is usually easier to use a clipper. A clipper is a rectangle that defines what is visible and what is not. The way to do this is to create a solid white rectangle (by default, so you need not use evas_object_color_set()) and give it a position and size of what is wanted visible. The following code exemplifies showing the center half of my_evas_object:

Evas_Object *clipper = evas_object_rectangle_add(evas_canvas);
evas_object_move(clipper, my_evas_object_x / 4, my_evas_object_y / 4);
evas_object_resize(clipper, my_evas_object_width / 2, my_evas_object_height / 2);
evas_object_clip_set(my_evas_object, clipper);

Layer of Color

A solid white clipper does not produce a change in the color of the clipped object, only hides what is outside the clipper's area. Changing the color of an object is accomplished by using a colored clipper. Clippers with color function by multiplying the colors of the clipped object. The following code shows how to remove all the red from an object.

Evas_Object *clipper = evas_object_rectangle_add(evas);
evas_object_move(clipper, my_evas_object_x, my_evas_object_y);
evas_object_resize(clipper, my_evas_object_width, my_evas_object_height);
evas_object_color_set(clipper, 0, 255, 255, 255);
evas_object_clip_set(obj, clipper);