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142 lines
3.8 KiB
ReStructuredText
142 lines
3.8 KiB
ReStructuredText
.. _lv_menu:
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==============
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Menu (lv_menu)
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==============
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Overview
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********
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The menu widget can be used to easily create multi-level menus. It
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handles the traversal between pages automatically.
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.. _lv_menu_parts_and_styles:
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Parts and Styles
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****************
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The menu widget is built from the following objects:
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- Main container: :cpp:type:`lv_menu_main_cont`
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- Main header: :cpp:type:`lv_menu_main_header_cont`
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- Back button: :ref:`lv_button`
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- Back button icon: :ref:`lv_image`
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- Main page: :cpp:type:`lv_menu_page`
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- Sidebar container: :cpp:type:`lv_menu_sidebar_cont`
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- Sidebar header: :cpp:type:`lv_menu_sidebar_header_cont`
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- Back button: :ref:`lv_button`
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- Back button icon: :ref:`lv_image`
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- Sidebar page: :cpp:type:`lv_menu_page`
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.. _lv_menu_usage:
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Usage
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*****
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Create a menu
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-------------
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:cpp:expr:`lv_menu_create(parent)` creates a new empty menu.
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Header mode
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-----------
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The following header modes exist:
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- :cpp:enumerator:`LV_MENU_HEADER_TOP_FIXED` Header is positioned at the top.
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- :cpp:enumerator:`LV_MENU_HEADER_TOP_UNFIXED` Header is positioned at the top and can be scrolled out of view.
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- :cpp:enumerator:`LV_MENU_HEADER_BOTTOM_FIXED` Header is positioned at the bottom.
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You can set header modes with :cpp:expr:`lv_menu_set_mode_header(menu, LV_MENU_HEADER...)`.
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Root back button mode
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---------------------
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The following root back button modes exist:
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- :cpp:enumerator:`LV_MENU_ROOT_BACK_BTN_DISABLED`
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- :cpp:enumerator:`LV_MENU_ROOT_BACK_BTN_ENABLED`
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You can set root back button modes with
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:cpp:expr:`lv_menu_set_mode_root_back_button(menu, LV_MENU_ROOT_BACK_BTN...)`.
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Create a menu page
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------------------
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:cpp:expr:`lv_menu_page_create(menu, title)` creates a new empty menu page. You
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can add any widgets to the page.
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Set a menu page in the main area
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--------------------------------
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Once a menu page has been created, you can set it to the main area with
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:cpp:expr:`lv_menu_set_page(menu, page)`. ``NULL`` to clear main and clear menu
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history.
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Set a menu page in the sidebar
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------------------------------
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Once a menu page has been created, you can set it to the sidebar with
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:cpp:expr:`lv_menu_set_sidebar_page(menu, page)`. ``NULL`` to clear sidebar.
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Linking between menu pages
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--------------------------
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For instance, you have created a button obj in the main page. When you
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click the button obj, you want it to open up a new page, use
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:cpp:expr:`lv_menu_set_load_page_event(menu, obj, new page)`.
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Create a menu container, section, separator
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-------------------------------------------
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The following objects can be created so that it is easier to style the
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menu:
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- :cpp:expr:`lv_menu_cont_create(parent page)` creates a new empty container.
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- :cpp:expr:`lv_menu_section_create(parent page)` creates a new empty section.
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- :cpp:expr:`lv_menu_separator_create(parent page)` creates a separator.
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.. _lv_menu_events:
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Events
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******
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- :cpp:enumerator:`LV_EVENT_VALUE_CHANGED` Sent when a page is shown.
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- :cpp:expr:`lv_menu_get_cur_main_page(menu)` returns a pointer to menu page
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that is currently displayed in main.
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- :cpp:expr:`lv_menu_get_cur_sidebar_page(menu)` returns a pointer to menu
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page that is currently displayed in sidebar.
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- :cpp:enumerator:`LV_EVENT_CLICKED` Sent when a back button in a header from either
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main or sidebar is clicked. :cpp:enumerator:`LV_OBJ_FLAG_EVENT_BUBBLE` is enabled
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on the buttons so you can add events to the menu itself.
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- :cpp:expr:`lv_menu_back_button_is_root(menu, button)` to check if button is root
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back button
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See the events of the :ref:`Base object <lv_obj>` too.
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Learn more about :ref:`events`.
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.. _lv_menu_keys:
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Keys
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****
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No keys are handled by the menu widget.
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Learn more about :ref:`indev_keys`.
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.. _lv_menu_example:
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Example
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*******
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.. include:: ../examples/widgets/menu/index.rst
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.. _lv_menu_api:
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API
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***
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