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73 lines
2.3 KiB
Markdown
73 lines
2.3 KiB
Markdown
2 years ago
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# Checkbox (lv_checkbox)
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## Overview
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The Checkbox object is created from a "tick box" and a label. When the Checkbox is clicked the tick box is toggled.
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## Parts and Styles
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- `LV_PART_MAIN` The is the background of the Checkbox and it uses the text and all the typical background style properties.
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`pad_column` adjusts the spacing between the tickbox and the label
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- `LV_PART_INDICATOR` The "tick box" is a square that uses all the typical background style properties.
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By default, its size is equal to the height of the main part's font. Padding properties make the tick box larger in the respective directions.
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The Checkbox is added to the default group (if it is set).
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## Usage
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### Text
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The text can be modified with the `lv_checkbox_set_text(cb, "New text")` function and will be dynamically allocated.
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To set a static text,
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use `lv_checkbox_set_static_text(cb, txt)`. This way, only a pointer to `txt` will be stored. The text then shouldn't be deallocated while the checkbox exists.
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### Check, uncheck, disable
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You can manually check, un-check, and disable the Checkbox by using the common state add/clear function:
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```c
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lv_obj_add_state(cb, LV_STATE_CHECKED); /*Make the chekbox checked*/
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lv_obj_clear_state(cb, LV_STATE_CHECKED); /*MAke the checkbox unchecked*/
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lv_obj_add_state(cb, LV_STATE_CHECKED | LV_STATE_DISABLED); /*Make the checkbox checked and disabled*/
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```
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## Events
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- `LV_EVENT_VALUE_CHANGED` Sent when the checkbox is toggled.
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- `LV_EVENT_DRAW_PART_BEGIN` and `LV_EVENT_DRAW_PART_END` are sent for the following types:
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- `LV_CHECKBOX_DRAW_PART_BOX` The tickbox of the checkbox
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- `part`: `LV_PART_INDICATOR`
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- `draw_area`: the area of the tickbox
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- `rect_dsc`
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See the events of the [Base object](/widgets/obj) too.
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Learn more about [Events](/overview/event).
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## Keys
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The following *Keys* are processed by the 'Buttons':
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- `LV_KEY_RIGHT/UP` Go to toggled state if toggling is enabled
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- `LV_KEY_LEFT/DOWN` Go to non-toggled state if toggling is enabled
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- `LV_KEY_ENTER` Clicks the checkbox and toggles it
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Note that, as usual, the state of `LV_KEY_ENTER` is translated to `LV_EVENT_PRESSED/PRESSING/RELEASED` etc.
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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:: ../../../examples/widgets/checkbox/index.rst
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```
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## API
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```eval_rst
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.. doxygenfile:: lv_checkbox.h
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:project: lvgl
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```
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