This feature is supported in wearable applications only.

The GLView component renders OpenGL® in an Elementary object, which hides Evas GL complexity.

For more information, see the OpenGL® ES guide and the GLView API.

Figure: GLView component

GLView component

Figure: GLView hierarchy

GLView hierarchy

Adding a GLView Component

To create a GLView component:

  1. Add a GLView component using the elm_glview_add() function:

    Evas_Object *glview;
    Evas_Object *parent;
    glview = elm_glview_add(parent);
  2. Set the size of the GLView.

    To set the size to 200 x 200 pixels:

    elm_glview_size_set(glview, 200, 200);

Configuring the GLView

To configure the GLView:

  • Enable the appropriate GLView rendering modes. The Elm_GLView_Mode enumerator defines the available modes.

    To enable the alpha channel and depth buffer rendering modes:

    elm_glview_mode_set(glview, ELM_GLVIEW_ALPHA | ELM_GLVIEW_DEPTH);
  • Set the resize policy.

    To set a policy that decides what to do with the OpenGL® ES surface when the GLView component is resized:

    elm_glview_resize_policy_set(glview, ELM_GLVIEW_RESIZE_POLICY_RECREATE);

    The OpenGL® ES surface is destroyed and recreated in the new size (default function). The resize policy can also be set to ELM_GLVIEW_RESIZE_POLICY_SCALE, in which case only the image object is scaled, not the underlying OpenGL® ES surface.

  • Set the GLView rendering policy.

    To always redraw the GLView component during the rendering loop:

    elm_glview_render_policy_set(glview, ELM_GLVIEW_RENDER_POLICY_ALWAYS);

    The rendering policy can also be set to ELM_GLVIEW_RENDER_POLICY_ON_DEMAND (default function), in which case the GLView component is redrawn only when it is visible.

  • Register callbacks for managing changes in the GLView component state:

    • The initialization callback is called at the GLView component creation.
    • The deletion callback is called when the GLView component is deleted.
    • The resize callback is called during the rendering loop when the GLView component is resized.
    • The render callback is called when the GLView component must be redrawn.
    elm_glview_init_func_set(glview, _init_gl_cb);
    elm_glview_del_func_set(glview, _del_gl_cb);
    elm_glview_resize_func_set(glview, _resize_gl_cb);
    elm_glview_render_func_set(glview, _draw_gl_cb);

Using the GLView Callbacks

To receive notifications about the GLView events, listen for the following signals:

  • focused: The GLView component is focused.
    The event_info callback parameter points at an Elm_Focus_Info object.

  • unfocused: The GLView object is unfocused.

The signal list in the API reference can be more extensive, but only the above signals are actually supported in Tizen.

To register and define a callback for the focused signal:

    evas_object_smart_callback_add(glview, "focused", focused_cb, data);

/* Callback for the "focused" signal */
/* Called when the GLView is focused */
focused_cb(void *data, Evas_Object *obj, void  *event_info)
    Elm_Focus_Info *fi = event_info;

    dlog_print(DLOG_INFO, LOG_TAG, "GLView is focused\n");

Except as noted, this content is licensed under LGPLv2.1+.

  • Dependencies
    • Tizen 2.3.1 and Higher for Wearable