The Slider object looks like a [Bar](/widgets/core/bar) supplemented with a knob. The knob can be dragged to set a value. Just like Bar, Slider can be vertical or horizontal.
-`LV_PART_MAIN` The background of the slider. Uses all the typical background style properties. `padding` makes the indicator smaller in the respective direction.
-`LV_PART_INDICATOR` The indicator that shows the current state of the slider. Also uses all the typical background style properties.
-`LV_PART_KNOB` A rectangle (or circle) drawn at the current value. Also uses all the typical background properties to describe the knob(s). By default the knob is square (with a optional corner radius) with side length equal to the smaller side of the slider. The knob can be made larger with the `padding` values. Padding values can be asymmetric too.
-`LV_SLIDER_MODE_NORMAL` A normal slider as described above
-`LV_SLIDER_SYMMETRICAL` Draw the indicator form the zero value to current value. Requires negaitve minimum range and positive maximum range.
-`LV_SLIDER_RANGE` Allows setting the start value too by `lv_bar_set_start_value(bar, new_value, LV_ANIM_ON/OFF)`. The start value has to be always smaller than the end value.
Normally, the slider can be adjusted either by dragging the knob, or by clicking on the slider bar.
In the latter case the knob moves to the point clicked and slider value changes accordingly. In some cases it is desirable to set the slider to react on dragging the knob only. This feature is enabled by adding the `LV_OBJ_FLAG_ADV_HITTEST`: `lv_obj_add_flag(slider, LV_OBJ_FLAG_ADV_HITTEST)`.
The event is sent continuously while the slider is dragged and once when released. Use `lv_slider_is_dragged` to detemine whether the Slider is still being dragged or has just been released.
