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65 lines
2.2 KiB
Markdown
65 lines
2.2 KiB
Markdown
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```eval_rst
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.. include:: /header.rst
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:github_url: |github_link_base|/widgets/bar.md
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```
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# Bar (lv_bar)
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## Overview
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The bar object has a background and an indicator on it. The width of the indicator is set according to the current value of the bar.
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Vertical bars can be created if the width of the object is smaller than its height.
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Not only end, but the start value of the bar can be set which changes the start position of the indicator.
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## Parts and Styles
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The Bar's main part is called `LV_BAR_PART_BG` and it uses the typical background style properties.
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`LV_BAR_PART_INDIC` is a virtual part which also uses all the typical background properties.
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By default the indicator maximal size is the same as the background's size but setting positive padding values in `LV_BAR_PART_BG` will make the indicator smaller. (negative values will make it larger)
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If the *value* style property is used on the indicator the alignment will be calculated based on the current size of the indicator.
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For example a center aligned value is always shown in the middle of the indicator regardless it's current size.
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## Usage
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### Value and range
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A new value can be set by `lv_bar_set_value(bar, new_value, LV_ANIM_ON/OFF)`.
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The value is interpreted in a range (minimum and maximum values) which can be modified with `lv_bar_set_range(bar, min, max)`.
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The default range is 1..100.
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The new value in `lv_bar_set_value` can be set with or without an animation depending on the last parameter (`LV_ANIM_ON/OFF`).
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The time of the animation can be adjusted by `lv_bar_set_anim_time(bar, 100)`. The time is in milliseconds unit.
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It's also possible to set the start value of the bar using `lv_bar_set_start_value(bar, new_value, LV_ANIM_ON/OFF)`
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### Modes
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The bar can be drawn symmetrical to zero (drawn from zero, left to right), if it's enabled with `lv_bar_set_type(bar, LV_BAR_TYPE_SYMMETRICAL)`.
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## Events
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Only the [Generic events](../overview/event.html#generic-events) are sent by the object type.
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Learn more about [Events](/overview/event).
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## Keys
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No *Keys* are processed by the object type.
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Learn more about [Keys](/overview/indev).
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## Example
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```eval_rst
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.. include:: /lv_examples/src/lv_ex_widgets/lv_ex_bar/index.rst
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```
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## API
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```eval_rst
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.. doxygenfile:: lv_bar.h
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:project: lvgl
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```
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