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111 lines
2.6 KiB
ReStructuredText
111 lines
2.6 KiB
ReStructuredText
.. _lv_checkbox:
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======================
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Checkbox (lv_checkbox)
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======================
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Overview
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********
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The Checkbox Widget is created from a "tick box" and a label. When the
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Checkbox is clicked the tick box is toggled.
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.. _lv_checkbox_parts_and_styles:
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Parts and Styles
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****************
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- :cpp:enumerator:`LV_PART_MAIN` Background of Checkbox and it uses
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the text and the :ref:`typical background style properties <typical bg props>`.
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``pad_column`` adjusts spacing between tickbox and label
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- :cpp:enumerator:`LV_PART_INDICATOR` The "tick box" is a square that uses the
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:ref:`typical background style properties <typical bg props>`. By default, its
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size is equal to the height of the main part's font. Padding properties make the
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tick box larger in the respective directions.
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The Checkbox is added to the default group (if one is set).
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.. _lv_checkbox_usage:
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Usage
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*****
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Text
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----
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The text can be modified with
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:cpp:expr:`lv_checkbox_set_text(cb, "New text")` and will be
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dynamically allocated.
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To set static text, use :cpp:expr:`lv_checkbox_set_text_static(cb, txt)`. This
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way, only a pointer to ``txt`` will be stored. The provided text buffer must remain
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available for the life of the Checkbox.
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Check, uncheck, disable
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-----------------------
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You can programmatically check, un-check, and disable the Checkbox by using the
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common state add/clear function:
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.. code-block:: c
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lv_obj_add_state(cb, LV_STATE_CHECKED); /* Make Checkbox checked */
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lv_obj_remove_state(cb, LV_STATE_CHECKED); /* Make Checkbox unchecked */
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lv_obj_add_state(cb, LV_STATE_CHECKED | LV_STATE_DISABLED); /* Make Checkbox checked and disabled */
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To find out whether the Checkbox is checked use
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:cpp:expr:`lv_obj_has_state(cb, LV_STATE_CHECKED)`.
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.. _lv_checkbox_events:
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Events
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******
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- :cpp:enumerator:`LV_EVENT_VALUE_CHANGED` Sent when Checkbox is toggled.
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.. admonition:: Further Reading
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Learn more about :ref:`lv_obj_events` emitted by all Widgets.
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Learn more about :ref:`events`.
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.. _lv_checkbox_keys:
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Keys
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****
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The following *Keys* are processed by Checkbox:
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- ``LV_KEY_RIGHT/UP`` Go to CHECKED state if Checkbox is enabled
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- ``LV_KEY_LEFT/DOWN`` Go to non-CHECKED state if Checkbox is enabled
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- :cpp:enumerator:`LV_KEY_ENTER` Clicks the Checkbox and toggles its value.
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Note that, as usual, the state of :cpp:enumerator:`LV_KEY_ENTER` is translated to
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``LV_EVENT_PRESSED/PRESSING/RELEASED`` etc.
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.. admonition:: Further Reading
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Learn more about :ref:`indev_keys`.
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.. _lv_checkbox_example:
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Example
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*******
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.. include:: ../../examples/widgets/checkbox/index.rst
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.. _lv_checkboxapi:
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API
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***
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