61 lines
2.8 KiB
XML
61 lines
2.8 KiB
XML
<part id="eek-overview">
|
|
<title>Usage Overview</title>
|
|
<partintro>
|
|
|
|
<para>libeek is a library to create keyboard-like user interface.
|
|
Since it is designed as simple as possible, it provides only two
|
|
kinds of objects. One is <emphasis>keyboard element</emphasis>
|
|
(derived from #EekElement) and another is <emphasis>keyboard
|
|
layout engine</emphasis> (which implements the #EekLayout
|
|
interface).</para>
|
|
|
|
<para>A keyboard element represents either a keyboard
|
|
(#EekKeyboard), a section (#EekSection), or a key (#EekKey). Each
|
|
element implements the Builder design pattern so that it can be
|
|
converted into a UI widget (#ClutterActor, #GtkDrawingArea,
|
|
aso).</para>
|
|
|
|
<para>A layout engine arranges keyboard elements using information
|
|
from external configuration mechanisms (libxklavier, XKB,
|
|
matchbox-keyboard layouts in XML, aso)</para>
|
|
|
|
<para>Here is a sample code which creates a keyboard-like #ClutterActor using the system keyboard layout using libxklavier:</para>
|
|
|
|
<informalexample>
|
|
<programlisting>
|
|
EekKeyboard *keyboard;
|
|
EekLayout *layout;
|
|
|
|
/* Create a keyboard layout using libxklavier configuration. */
|
|
layout = eek_xkl_layout_new ();
|
|
|
|
/* Create a keyboard implemented as ClutterActor. */
|
|
keyboard = eek_clutter_keyboard_new ();
|
|
|
|
/* Apply the layout to the keyboard. */
|
|
eek_keyboard_set_layout (keyboard, layout);
|
|
|
|
clutter_group_add (CLUTTER_GROUP(stage),
|
|
eek_clutter_keyboard_get_actor (EEK_CLUTTER_KEYBOARD(keyboard)));
|
|
</programlisting>
|
|
</informalexample>
|
|
|
|
<para>One of the most interesting features of libeek is that UI
|
|
backends can be switched easily. For example, to create a
|
|
keyboard-like #GtkWidget instead of #ClutterActor, all you need is
|
|
to replace eek_clutter_keyboard_new() with eek_gtk_keyboard_new()
|
|
and eek_clutter_keyboard_get_actor() with
|
|
eek_gtk_keyboard_get_widget().</para>
|
|
|
|
<para>There is logical represention (model) of keyboard distinct from the UI widget (view). More precisely, a keyboard is represented as a tree of #EekElement -- #EekKeyboard contains one or more #EekSection's and #EekSection contains one or more #EekKey's. Each element can be event source when user events on the UI widget occurs. For example, with the following code, when a user pushed a key widget with keycode 0x38 assigned, on_a_pressed will be called.</para>
|
|
<informalexample>
|
|
<programlisting>
|
|
/* Find a key element in the logical keyboard. */
|
|
EekKey *key = eek_keyboard_find_key_by_keycode (keyboard, 0x38);
|
|
g_signal_connect (key, "pressed", on_a_pressed);
|
|
</programlisting>
|
|
</informalexample>
|
|
<para>In this way, application developers do not need to know the differences between the underlying UI widgets after creation.</para>
|
|
</partintro>
|
|
</part>
|