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85 lines
1.9 KiB
ReStructuredText
85 lines
1.9 KiB
ReStructuredText
.. _lv_line:
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==============
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Line (lv_line)
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==============
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Overview
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********
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The Line object is capable of drawing straight lines between a set of
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points.
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.. _lv_line_parts_and_styles:
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Parts and Styles
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****************
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- :cpp:enumerator:`LV_PART_MAIN` uses all the typical background properties and line style properties.
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.. _lv_line_usage:
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Usage
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*****
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Set points
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----------
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The points have to be stored in an :cpp:struct:`lv_point_precise_t` array and passed to
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the object by the :cpp:expr:`lv_line_set_points(lines, point_array, point_cnt)`
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function.
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Their coordinates can either be specified as raw pixel coordinates
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(e.g. ``{5, 10}``), or as a percentage of the line's bounding box using
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:cpp:expr:`lv_pct(x)`. In the latter case, the line's width/height may need to
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be set explicitly using ``lv_obj_set_width/height``, as percentage
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values do not automatically expand the bounding box.
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Auto-size
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---------
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By default, the Line's width and height are set to :c:macro:`LV_SIZE_CONTENT`.
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This means it will automatically set its size to fit all the points. If
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the size is set explicitly, parts on the line may not be visible.
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Invert y
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--------
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By default, the *y == 0* point is in the top of the object. It might be
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counter-intuitive in some cases so the y coordinates can be inverted
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with :cpp:expr:`lv_line_set_y_invert(line, true)`. In this case, *y == 0* will
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be the bottom of the object. *y invert* is disabled by default.
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.. _lv_line_events:
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Events
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******
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Only the `Generic events <../overview/event.html#generic-events>`__ are
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sent by the object type.
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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_line_keys:
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Keys
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****
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No *Keys* are processed by the object type.
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Learn more about :ref:`indev_keys`.
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.. _lv_line_example:
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Example
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*******
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.. include:: ../examples/widgets/line/index.rst
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.. _lv_line_api:
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API
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***
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