[framework/uifw/elementary.git] / doc / examples.dox

/**
 * @page Examples Examples
 *
 * Here is a page with Elementary examples.
 *
 * @ref bg_01_example_page
 *
 * @ref bg_02_example_page
 *
 * @ref bg_03_example_page
 *
 * @ref actionslider_example_page
 *
 * @ref elm_animator_example_page_01
 *
 * @ref transit_example_01_explained
 *
 * @ref transit_example_02_explained
 *
 * @ref general_functions_example_page
 */

/**
 * @page bg_01_example_page elm_bg - Plain color background.
 * @dontinclude bg_example_01.c
 *
 * The full code for this example can be found at @ref bg_example_01_c,
 * in the function @c test_bg_plain. It's part of the @c elementar_test
 * suite, and thus has the code for the three examples referenced by this
 * documentation.
 *
 * This first example just sets a default background with a plain color. The
 * first part consists of creating an Elementary window. It's the common
 * piece of code that you'll see everywhere in Elementary: @skip elm_main
 * @until autodel_set
 *
 * Now we really create our background object, using the window object as
 * its parent:
 *
 * @skipline bg_add
 *
 * Then we set the size hints of the background object so that it will use
 * all space available for it, and then add it as a resize object to the
 * window, making it visible in the end:
 *
 * @skip size_hint_weight_set
 * @until resize_object_add
 *
 * See @ref evas_object_size_hint_weight_set and elm_win_resize_object_add()
 * for more detailed info about these functions.
 *
 * The end of the example is quite simple, just setting the minimum and
 * maximum size of the background, so the Elementary window knows that it
 * has to have at least the minimum size. The background also won't scale to
 * a size above its maximum. Then we resize the window and show it in the
 * end:
 *
 * @skip set size hints
 * @until }
 *
 * And here we finish our very simple background object usage example.
 */

/**
 * @page bg_02_example_page elm_bg - Image background.
 * @dontinclude bg_example_02.c
 *
 * The full code for this example can be found at @ref bg_example_02_c,
 * in the function @c test_bg_image. It's part of the @c elementar_test
 * suite, and thus has the code for the three examples referenced by this
 * documentation.
 *
 * This is the second example, and shows how to use the Elementary
 * background object to set an image as background of your application.
 *
 * We start this example exactly in the same way as the previous one, even
 * when creating the background object:
 *
 * @skip elm_main
 * @until bg_add
 *
 * Now it's the different part.
 *
 * Our background will have an image, that will be displayed over the
 * background color. Before loading the image, we set the load size of the
 * image. The load size is a hint about the size that we want the image
 * displayed in the screen. It's not the exact size that the image will have,
 * but usually a bit bigger. The background object can still be scaled to a
 * size bigger than the one set here. Setting the image load size to
 * something smaller than its real size will reduce the memory used to keep
 * the pixmap representation of the image, and the time to load it. Here we
 * set the load size to 20x20 pixels, but the image is loaded with a size
 * bigger than that (since it's just a hint):
 *
 * @skipline load_size_set
 *
 * And set our background image to be centered, instead of stretched or
 * scaled, so the effect of the elm_bg_load_size_set() can be easily
 * understood:
 *
 * @skipline option_set
 *
 * We need a filename to set, so we get one from the previous installed
 * images in the @c PACKAGE_DATA_DIR, and write its full path to a buffer.
 * Then we use this buffer to set the filename in the background object:
 *
 * @skip snprintf
 * @until bg_file_set
 *
 * Notice that the third argument of the elm_bg_file_set() function is @c
 * NULL, since we are setting an image to this background. This function
 * also supports setting an edje group as background, in which case the @c
 * group parameter wouldn't be @c NULL, but be the name of the group
 * instead.
 *
 * Finally, we can set the size hints, add the background as a resize
 * object, and resize the window, exactly the same thing we do in the @ref
 * bg_01_example_page example:
 *
 * @skip size_hint
 * @until }
 *
 * And this is the end of this example.
 *
 * This example will look like this:
 * @image html screenshots/bg_01.png
 * @image latex screenshots/bg_01.eps
 */

/**
 * @page bg_03_example_page elm_bg - Background properties.
 * @dontinclude bg_example_03.c
 *
 * The full code for this example can be found at @ref bg_example_03_c, in the
 * function @c test_bg_options, with the callbacks @c _cb_overlay_changed, @c
 * _cb_color_changed and @c _cb_radio_changed defined in the beginning of the
 * file. It's part of the @c elementar_test suite, and thus has the code for
 * the three examples referenced by this documentation.
 *
 * This example will show the properties available for the background object,
 * and will use of some more widgets to set them.
 *
 * In order to do this, we will set some callbacks for these widgets. The
 * first is for the radio buttons that will be used to choose the option
 * passed as argument to elm_bg_option_set():
 *
 * @skip _cb_radio_changed
 * @until }
 *
 * The next callback will be used when setting the overlay (using
 * elm_bg_overlay_set()):
 *
 * @skip _cb_overlay_changed
 * @until }
 * @until }
 *
 * And the last one, used to set the color (with elm_bg_color_set()):
 *
 * @skip _cb_color_changed
 * @until }
 *
 * We will get back to what these functions do soon. If you want to know more
 * about how to set these callbacks and what these widgets are, look for:
 * @li elm_radio_add()
 * @li elm_check_add()
 * @li elm_spinner_add()
 *
 * Now going to the main function, @c test_bg_options, we have the common
 * code with the other examples:
 *
 * @skip bg-options
 * @until autodel_set
 *
 * We add a plain background to this window, so it will have the default
 * background color behind everything:
 *
 * @skip bg = elm_bg_add
 * @until evas_object_show(bg)
 *
 * Then we add a vertical box (elm_box_add()) that will hold the background
 * object that we are going to play with, as well as a horizontal box that
 * will hold widgets:
 *
 * @skip elm_box_add
 * @until evas_object_show
 *
 * Now we add the background object that is going to be of use for our
 * example. It is an image background, as used in @ref bg_02_example_page ,
 * so the code should be familiar:
 *
 * @skip elm_bg_add
 * @until evas_object_show
 *
 * Notice the call to elm_box_pack_end(): it will pack the background object
 * in the end of the Elementary box declared above. Just refer to that
 * documentation for more info.
 *
 * Since this Elementary background is already an image background, we are
 * going to play with its other properties. We will change its option
 * (CENTER, SCALE, STRETCH, TILE), its color (RGB), and add an overlay to it.
 * For all of these properties, we are going to add widgets that will
 * configure them.
 *
 * First, lets add the horizontal box that will hold these widgets:
 * @skip hbox
 * @until align_set
 *
 * For now, just consider this @c hbox as a rectangle that will contain the
 * widgets, and will distribute them horizontally inside its content. Then we
 * add radio buttons that will allow us to choose the property to use with
 * this background:
 *
 * @skip radio_add
 * @until evas_object_show
 *
 * Again, I won't give details about the use of these widgets, just look for
 * their documentation if necessary. It's enough to know for now that we are
 * packing them in the @c hbox, setting a label for them, and the most
 * important parts: setting its value to @c ELM_BG_OPTION_CENTER and its
 * callback to @c _cb_radio_changed (the function defined in the beginning of
 * this example). We do this for the next 3 radio buttons added after this
 * one, each of them with a different value.
 *
 * Now taking a look at the code of the callback @c _cb_radio_changed again,
 * it will call elm_bg_option_set() with the value set from the checked radio
 * button, thus setting the option for this background. The background is
 * passed as argument to the @p data parameter of this callback, and is
 * referenced here as @c o_bg.
 *
 * Later we set the default value for this radio button:
 *
 * @skipline elm_radio_value_set
 *
 * Then we add a checkbox for the elm_bg_overlay_set() function:
 *
 * @skip check_add
 * @until evas_object_show
 *
 * Now look at the code of the @c _cb_overlay_changed again. If the checkbox
 * state is checked, an overlay will be added to the background. It's done by
 * creating an Edje object, and setting it with elm_bg_overlay_set() to the
 * background object. For information about what are and how to set Edje
 * object, look at the Edje documentation.
 *
 * Finally we add a spinner object (elm_spinner_add()) to be used to select
 * the color of our background. In its callback it's possible to see the call
 * to elm_bg_color_set(), which will change the color of this background.
 * This color is used by the background to fill areas where the image doesn't
 * cover (in this case, where we have an image background). The spinner is
 * also packed into the @c hbox :
 *
 * @skip elm_spinner_add
 * @until evas_object_show
 *
 * Then we just have to pack the @c hbox inside the @c box, set some size
 * hints, and show our window:
 *
 * @skip pack_end
 * @until }
 *
 * Now to see this code in action, open elementary_test, and go to the "Bg
 * Options" test. It should demonstrate what was implemented here.
 */

/**
 * @page actionslider_example_page Actionslider usage
 * @dontinclude actionslider_example_01.c
 *
 * For this example we are going to assume knowledge of evas smart callbacks
 * and some basic evas object functions. Elementary is not meant to be used
 * without evas, if you're not yet familiar with evas it probably is worth
 * checking that out.
 *
 * And now to the example, when using Elementary we start by including
 * Elementary.h:
 * @skipline #include
 *
 * Next we define some callbacks, they all share the same signature because
 * they are all to be used with evas_object_smart_callback_add().
 * The first one just prints the selected label(in two different ways):
 * @until }
 *
 * This next callback is a little more interesting, it makes the selected
 * label magnetic(except if it's the center label):
 * @until }
 *
 * This callback enables or disables the magnetic propertty of the center
 * label:
 * @until }
 *
 * And finally a callback to stop the main loop when the window is closed:
 * @until }
 *
 * To be able to create our actionsliders we need to do some setup, but this
 * isn't really relevant here, so if you want to know about that go @ref
 * Win "here".
 *
 * With all that boring stuff out of the way we can proceed to creating some
 * actionsliders.@n
 * All actionsliders are created the same way:
 * @skipline actionslider_add
 * Next we must choose where the indicator starts, and for this one we choose
 * the right, and set the right as magnetic:
 * @skipline indicator_pos_set
 * @until magnet_pos_set
 *
 * We then set the labels for the left and right, passing NULL as an argument
 * to any of the labels makes that position have no label.
 * @until Stop
 *
 * Furthermore we mark both left and right as enabled positions, if we didn't
 * do this all three positions would be enabled:
 * @until RIGHT
 *
 * Having the the enabled positions we now add a smart callback to change
 * which position is magnetic, so that only the last selected position is
 * magnetic:
 * @until NULL
 *
 * And finally we set our printing callback and show the actionslider:
 * @until object_show
 * @skip pack_end
 *
 * For our next actionslider we are going to do much as we did for the
 * previous except we are going to have the center as the magnet(and not
 * change it):
 * @skipline actionslider_add
 * @skipline indicator_pos_set
 * @until object_show
 *
 * And another actionslider, in this one the indicator starts on the left.
 * It has labels only in the center and right, and both bositions are
 * magnetic. Because the left doesn't have a label and is not magnetic once
 * the indicator leaves it can't return:
 * @skipline actionslider_add
 * @skipline indicator_pos_set
 * @until object_show
 * @note The greyed out area is a @ref Styles "style".
 *
 * And now an actionslider with a label in the indicator, and whose magnet
 * properties change based on what was last selected:
 * @skipline actionslider_add
 * @skipline indicator_pos_set
 * @until object_show
 * @note The greyed out area is a @ref Styles "style".
 *
 * We are almost done, this next one is just an actionslider with all
 * positions magnetized and having every possible label:
 * @skipline actionslider_add
 * @skipline indicator_pos_set
 * @until object_show
 *
 * And for our last actionslider we have one that turns the magnetic property
 * on and off:
 * @skipline actionslider_add
 * @skipline indicator_pos_set
 * @until object_show
 *
 * The example will look like this:
 * @image html screenshots/actionslider_01.png
 * @image latex screenshots/actionslider_01.eps
 *
 * See the full source code @ref actionslider_example_01 "here"
 */

/**
 * @page elm_animator_example_page_01 Animator usage
 * @dontinclude animator_example_01.c
 *
 * For this example we will be using a bit of evas, you could animate a
 * elementary widget in much the same way, but to keep things simple we use
 * an evas_object_rectangle.
 *
 * As every other example we start with our include and a simple callback to
 * exit the app when the window is closed:
 * @skipline #include
 * @until }
 *
 * This next callback is the one that actually creates our animation, it
 * changes the size, position and color of a rectangle given to it in @a
 * data:
 * @until }
 *
 * Next we have a callback that prints a string, nothing special:
 * @until }
 *
 * This next callback is a little more interesting, it has a state variable
 * to know if the animation is currently paused or running, and it toogles
 * the state of the animation accordingly:
 * @until }
 * @until }
 * @until }
 *
 * Finally we have a callback to stop the animation:
 * @until }
 *
 * As with every example we need to do a bit of setup before we can actually
 * use an animation, but for the purposes of this example that's not relevant
 * so let's just skip to the good stuff, creating an animator:
 * @skipline animator_add
 * @note Since elm_animator is not a widget we can give it a NULL parent.
 *
 * Now that we have an elm_animator we set it's duration to 1 second:
 * @line duration_set
 *
 * We would also like our animation to be reversible, so:
 * @line reverse_set
 *
 * We also set our animation to repeat as many times as possible, which will
 * mean that _end_cb will only be called after UINT_MAX * 2 seconds(UINT_MAX
 * for the animation running forward and UNIT_MAX for the animation running
 * backwards):
 * @line repeat_set
 *
 * To add some fun to our animation we will use the IN_OUT curve style:
 * @line curve_style
 *
 * To actually animate anything we need an operation callback:
 * @line operation_callback
 *
 * Even though we set our animation to repeat for a very long time we are
 * going to set a end callback to it:
 * @line completion_callback
 * @note Notice that stoping the animation with the stop button will not make
 * _end_cb be called.
 *
 * Now that we have fully set up our animator we can tell it to start
 * animating:
 * @line animate
 *
 * There's a bit more of code that doesn't really matter to use so we skip
 * right down to our last interesting point:
 * @skipline animator_del
 * @note Because we created our animator with no parent we need to delete it
 * ourselves.
 *
 * The example should look like this:
 * @image html screenshots/animator_example_01.png
 * @image latex screenshots/animator_example_01.eps
 * @n
 * @image html screenshots/animator_example_02.png
 * @image latex screenshots/animator_example_02.eps
 * @n
 * @image html screenshots/animator_example_03.png
 * @image latex screenshots/animator_example_03.eps
 *
 * The full source code for this example can be found @ref
 * animator_example_01_c "here"
 */

/**
 * @page transit_example_03_c elm_transit - Combined effects and options.
 *
 * This example shows how to apply the following transition effects:
 * @li translation
 * @li color
 * @li rotation
 * @li wipe
 * @li zoom
 * @li resizing
 *
 * It allows you to apply more than one effect at once, and also allows to
 * set properties like event_enabled, auto_reverse, repeat_times and
 * tween_mode.
 *
 * @include transit_example_03.c
 */

/**
 * @page transit_example_04_c elm_transit - Combined effects over two objects.
 *
 * This example shows how to apply the transition effects:
 * @li flip
 * @li resizable_flip
 * @li fade
 * @li blend
 * over two objects. This kind of transition effect is used to make one
 * object disappear and another one appear on its place.
 *
 * You can mix more than one effect of this type on the same objects, and the
 * transition will apply both.
 *
 * @include transit_example_04.c
 */

/**
 * @page transit_example_01_explained elm_transit - Basic transit usage.
 * @dontinclude transit_example_01.c
 *
 * The full code for this example can be found at @ref transit_example_01_c.
 *
 * This example shows the simplest way of creating a transition and applying
 * it to an object. Similarly to every other elementary example, we create a
 * window, set its title, size, autodel property, and setup a callback to
 * exit the program when finished:
 *
 * @skip on_done
 * @until evas_object_resize
 *
 * We also add a resizeable white background to use behind our animation:
 *
 * @skip bg_add
 * @until evas_object_show
 *
 * And then we add a button that we will use to demonstrate the effects of
 * our animation:
 *
 * @skip button_add
 * @until evas_object_show(win)
 *
 * Notice that we are not adding the button with elm_win_resize_object_add()
 * because we don't want the window to control the size of the button. We
 * will use the transition to change the button size, so it could conflict
 * with something else trying to control that size.
 *
 * Now, the simplest code possible to create the resize animation:
 *
 * @skip transit_add
 * @until transit_go
 *
 * As you can see, this code is very easy to understand. First, we create the
 * transition itself with elm_transit_add(). Then we add the button to this
 * transition with elm_transit_object_add(), which means that the transition
 * will operate over this button. The effect that we want now is changing the
 * object size from 100x50 to 300x150, and can be achieved by adding the
 * resize effect with elm_transit_effect_resizing_add().
 *
 * Finally, we set the transition time to 5 seconds and start the transition
 * with elm_transit_go(). If we wanted more effects applied to this
 * button, we could add them to the same transition. See the
 * @ref transit_example_03_c to watch many transitions being applied to an
 * object.
 */

/**
 * @page transit_example_02_explained elm_transit - Chained transitions.
 * @dontinclude transit_example_02.c
 *
 * The full code for this example can be found at @ref transit_example_02_c.
 *
 * This example shows how to implement a chain of transitions. This chain is
 * used to start a transition just after another transition ended. Similarly
 * to every other elementary example, we create a window, set its title,
 * size, autodel property, and setup a callback to exit the program when
 * finished:
 *
 * @skip on_done
 * @until evas_object_resize
 *
 * We also add a resizeable white background to use behind our animation:
 *
 * @skip bg_add
 * @until evas_object_show
 *
 * This example will have a chain of 4 transitions, each of them applied to
 * one button. Thus we create 4 different buttons:
 *
 * @skip button_add
 * @until evas_object_show(bt4)
 *
 * Now we create a simple translation transition that will be started as soon
 * as the program loads. It will be our first transition, and the other
 * transitions will be started just after this transition ends:
 *
 * @skip transit_add
 * @until transit_go
 *
 * The code displayed until now has nothing different from what you have
 * already seen in @ref transit_example_01_explained, but now comes the new
 * part: instead of creating a second transition that will start later using
 * a timer, we create the it normally, and use
 * elm_transit_chain_transit_add() instead of elm_transit_go. Since we are
 * adding it in a chain after the first transition, it will start as soon as
 * the first transition ends:
 *
 * @skip transit_add
 * @until transit_chain_transit_add
 *
 * Finally we add the 2 other transitions to the chain, and run our program.
 * It will make one transition start after the other finish, and there is the
 * transition chain.
 */

/**
 * @page general_functions_example_page General (top-level) functions example
 * @dontinclude general_funcs_example.c
 *
 * As told in their documentation blocks, the
 * elm_app_compile_*_dir_set() family of functions have to be called
 * before elm_app_info_set():
 * @skip tell elm about
 * @until elm_app_info_set
 *
 * We are here setting the fallback paths to the compiling time target
 * paths, naturally. If you're building the example out of the
 * project's build system, we're assuming they are the canonical ones.
 *
 * After the program starts, elm_app_info_set() will actually run and
 * then you'll see an intrincasy: Elementary does the prefix lookup @b
 * twice. This is so because of the quicklaunch infrastructure in
 * Elementary (@ref Start), which will register a predefined prefix
 * for possible users of the launch schema. We're not hooking into a
 * quick launch, so this first call can't be avoided.
 *
 * If you ran this example from your "bindir" installation
 * directiory, no output will emerge from these both attempts -- it
 * will find the "magic" file there registered and set the prefixes
 * silently. Otherwise, you could get something like:
 @verbatim
 WARNING: Could not determine its installed prefix for 'ELM'
       so am falling back on the compiled in default:
         usr
       implied by the following:
         bindir    = usr/lib
         libdir    = usr/lib
         datadir   = usr/share/elementary
         localedir = usr/share/locale
       Try setting the following environment variables:
         ELM_PREFIX     - points to the base prefix of install
       or the next 4 variables
         ELM_BIN_DIR    - provide a specific binary directory
         ELM_LIB_DIR    - provide a specific library directory
         ELM_DATA_DIR   - provide a specific data directory
         ELM_LOCALE_DIR - provide a specific locale directory
 @endverbatim
 * if you also didn't change those environment variables (remember
 * they are also a valid way of communicating your prefix to the
 * binary) - this is the scenario where it fallbacks to the paths set
 * for compile time.
 *
 * Then, you can check the prefixes set on the standard output:
 * @skip prefix was set to
 * @until locale directory is
 *
 * In the fragment
 * @skip by using this policy
 * @until elm_win_autodel_set
 * we demonstrate the use of Elementary policies. The policy defining
 * under which circunstances our application should quit automatically
 * is set to when its last window is closed (this one has just one
 * window, though). This will save us from having to set a callback
 * ourselves on the window, like done in @ref bg_example_01_c "this"
 * example. Note that we need to tell the window to delete itself's
 * object on a request to destroy the canvas coming, with
 * elm_win_autodel_set().
 *
 * What follows is some boilerplate code, creating a frame with a @b
 * button, our object of interest, and, below, widgets to change the
 * button's behavior and exemplify the group of functions in question.
 *
 * @dontinclude general_funcs_example.c
 * We enabled the focus highlight object for this window, so that you
 * can keep track of the current focused object better:
 * @skip elm_win_focus_highlight_enabled_set
 * @until evas_object_show
 * Use the tab key to navigate through the focus chain.
 *
 * @dontinclude general_funcs_example.c
 * While creating the button, we exemplify how to use Elementary's
 * finger size information to scale our UI:
 * @skip fprintf(stdout, "Elementary
 * @until evas_object_show
 *
 * @dontinclude general_funcs_example.c
 * The first checkbox's callback is:
 * @skip static void
 * @until }
 * When unsetting the checkbox, we disable the button, which will get a new
 * decoration (greyed out) and stop receiving events. The focus chain
 * will also ignore it.
 *
 * Following, there are 2 more buttons whose actions are focus/unfocus
 * the top button, respectively:
 * @skip focus callback
 * @until }
 * and
 * @skip unfocus callback
 * @until }
 * Note the situations in which they won't take effect:
 * - the button is not allowed to get focus or
 * - the button is disabled
 *
 * The first restriction above you'll get by a second checkbox, whose
 * callback is:
 * @skip focus allow callback
 * @until }
 * Note that the button will still get mouse events, though.
 *
 * Next, there's a slider controlling the button's scale:
 * @skip scaling callback
 * @until }
 *
 * Experiment with it, so you understand the effect better. If you
 * change its value, it will mess with the button's original size,
 * naturally.
 *
 * The full code for this example can be found
 * @ref general_functions_example_c "here".
 */

/**
 * @page theme_example_01 Theme - Using extensions
 *
 * @dontinclude theme_example_01.c
 *
 * Using extensions is extremely easy, discarding the part where you have to
 * write the theme for them.
 *
 * In the following example we'll be creating two buttons, one to load or
 * unload our extension theme and one to cycle around three possible styles,
 * one of which we created.
 *
 * After including our one and only header we'll jump to the callback for
 * the buttons. First one takes care of loading or unloading our extension
 * file, relative to the default theme set (thus the @c NULL in the
 * functions first parameter).
 * @skipline Elementary.h
 * @skip static void
 * @until }
 * @until }
 * @until }
 *
 * The second button, as we said before, will just switch around different
 * styles. In this case we have three of them. The first one is our custom
 * style, named after something very unlikely to find in the default theme.
 * The other two styles are the standard and one more, anchor, which exists
 * in the default and is similar to the default, except the button vanishes
 * when the mouse is not over it.
 * @skip static void
 * @until }
 * @until }
 *
 * So what happens if the style switches to our custom one when the
 * extension is loaded? Elementary falls back to the default for the
 * widget.
 *
 * And the main function, simply enough, will create the window, set the
 * buttons and their callbacks, and just to begin with our button styled
 * we're also loading our extension at the beginning.
 * @skip int
 * @until ELM_MAIN
 *
 * In this case we wanted to easily remove extensions, but all adding an
 * extension does is tell Elementary where else it should look for themes
 * when it can't find them in the default theme. Another way to do this
 * is to set the theme search order using elm_theme_set(), but this requires
 * that the developer is careful not to override any user configuration.
 * That can be helped by adding our theme to the end of whatver is already
 * set, like in the following snippet.
 * @code
 * char buf[4096];
 * snprintf(buf, sizeof(buf), "%s:./theme_example.edj", elme_theme_get(NULL);
 * elm_theme_set(NULL, buf);
 * @endcode
 *
 * If we were using overlays instead of extensions, the same thing applies,
 * but the custom theme must be added to the front of the search path.
 *
 * In the end, we should be looking at something like this:
 * @image html screenshots/theme_example_01.png
 * @image latex screenhots/theme_example_01.eps
 *
 * That's all. Boringly simple, and the full code in one piece can be found
 * @ref theme_example_01.c "here".
 *
 * And the code for our extension is @ref theme_example.edc "here".
 *
 * @example theme_example_01.c
 * @example theme_example.edc
 */

/**
 * @page theme_example_02 Theme - Using overlays
 *
 * @dontinclude theme_example_02.c
 *
 * Overlays are like extensions in that you tell Elementary that some other
 * theme contains the styles you need for your program. The difference is that
 * they will be look in first, so they can override the default style of any
 * widget.
 *
 * There's not much to say about them that hasn't been said in our previous
 * example about @ref theme_example_01 "extensions", so going quickly through
 * the code we have a function to load or unload the theme, which will be
 * called when we click any button.
 * @skipline Elementary.h
 * @skip static void
 * @until }
 *
 * And the main function, creating the window and adding some buttons to it.
 * We load our theme as an overlay and nothing else. Notice there's no style
 * set for any button there, which means they should be using the default
 * that we override.
 * @skip int
 * @until ELM_MAIN
 *
 * That's pretty much it. The full code is @ref theme_example_02.c "here" and
 * the definition of the theme is the same as before, and can be found in
 * @ref theme_example.edc "here".
 *
 * @example theme_example_02.c
 */

/**
 * @page bg_example_01_c bg_example_01.c
 * @include bg_example_01.c
 * @example bg_example_01.c
 */

/**
 * @page bg_example_02_c bg_example_02.c
 * @include bg_example_02.c
 * @example bg_example_02.c
 */

/**
 * @page bg_example_03_c bg_example_03.c
 * @include bg_example_03.c
 * @example bg_example_03.c
 */

/**
 * @page actionslider_example_01 Actionslider example
 * @include actionslider_example_01.c
 * @example actionslider_example_01.c
 */

/**
 * @page animator_example_01_c Animator example 01
 * @include animator_example_01.c
 * @example animator_example_01.c
 */

/**
 * @page transit_example_01_c Transit example 1
 * @include transit_example_01.c
 * @example transit_example_01.c
 */

/**
 * @page transit_example_02_c Transit example 2
 * @include transit_example_02.c
 * @example transit_example_02.c
 */

/**
 * @page general_functions_example_c General (top-level) functions example
 * @include general_funcs_example.c
 * @example general_funcs_example.c
 */