lv_event.h

API reference for lv_event.h

Summary

Functions

misc/lv_event.h:262function

lv_event_desc_set_external_data

Set external data and its destructor for an event descriptor. This allows associating custom data with an event callback that will be automatically cleaned up when the event descriptor is removed or destroyed.

void lv_event_desc_set_external_data(lv_event_dsc_t *dsc, void *data, void(*free_cb)(void *data))

Name	Type	Description
`dsc`	`lv_event_dsc_t *`	pointer to an event descriptor (from lv_obj_add_event_cb)
`data`	`void *`	pointer to the external data to associate with the event descriptor
`free_cb`	`void()(void data)`	function pointer to a destructor that will be called to clean up the external data. The destructor will receive the data pointer as its parameter.

Enums

misc/lv_event.h:34enum

lv_event_code_t

Type of event being sent to Widget

Name	Value	Description
`LV_EVENT_ALL`	`0`
`LV_EVENT_PRESSED`		Input device events Widget has been pressed
`LV_EVENT_PRESSING`		Widget is being pressed (sent continuously while pressing)
`LV_EVENT_PRESS_LOST`		Widget is still being pressed but slid cursor/finger off Widget
`LV_EVENT_SHORT_CLICKED`		Widget was pressed for a short period of time, then released. Not sent if scrolled.
`LV_EVENT_SINGLE_CLICKED`		Sent for first short click within a small distance and short time
`LV_EVENT_DOUBLE_CLICKED`		Sent for second short click within small distance and short time
`LV_EVENT_TRIPLE_CLICKED`		Sent for third short click within small distance and short time
`LV_EVENT_LONG_PRESSED`		Object has been pressed for at least `long_press_time`. Not sent if scrolled.
`LV_EVENT_LONG_PRESSED_REPEAT`		Sent after `long_press_time` in every `long_press_repeat_time` ms. Not sent if scrolled.
`LV_EVENT_CLICKED`		Sent on release if not scrolled (regardless to long press)
`LV_EVENT_RELEASED`		Sent in every cases when Widget has been released
`LV_EVENT_SCROLL_BEGIN`		Scrolling begins. The event parameter is a pointer to the animation of the scroll. Can be modified
`LV_EVENT_SCROLL_THROW_BEGIN`
`LV_EVENT_SCROLL_END`		Scrolling ends
`LV_EVENT_SCROLL`		Scrolling
`LV_EVENT_GESTURE`		A gesture is detected. Get gesture with `lv_indev_get_gesture_dir(lv_indev_active());`
`LV_EVENT_KEY`		A key is sent to Widget. Get key with `lv_indev_get_key(lv_indev_active());`
`LV_EVENT_ROTARY`		An encoder or wheel was rotated. Get rotation count with `lv_event_get_rotary_diff(e);`
`LV_EVENT_FOCUSED`		Widget received focus
`LV_EVENT_DEFOCUSED`		Widget's focus has been lost
`LV_EVENT_LEAVE`		Widget's focus has been lost but is still selected
`LV_EVENT_HIT_TEST`		Perform advanced hit-testing
`LV_EVENT_INDEV_RESET`		Indev has been reset
`LV_EVENT_HOVER_OVER`		Indev hover over object
`LV_EVENT_HOVER_LEAVE`		Indev hover leave object
`LV_EVENT_COVER_CHECK`		Drawing events Check if Widget fully covers an area. The event parameter is `lv_cover_check_info_t *`.
`LV_EVENT_REFR_EXT_DRAW_SIZE`		Get required extra draw area around Widget (e.g. for shadow). The event parameter is `int32_t *` to store the size.
`LV_EVENT_DRAW_MAIN_BEGIN`		Starting the main drawing phase
`LV_EVENT_DRAW_MAIN`		Perform the main drawing
`LV_EVENT_DRAW_MAIN_END`		Finishing the main drawing phase
`LV_EVENT_DRAW_POST_BEGIN`		Starting the post draw phase (when all children are drawn)
`LV_EVENT_DRAW_POST`		Perform the post draw phase (when all children are drawn)
`LV_EVENT_DRAW_POST_END`		Finishing the post draw phase (when all children are drawn)
`LV_EVENT_DRAW_TASK_ADDED`		Adding a draw task. The `LV_OBJ_FLAG_SEND_DRAW_TASK_EVENTS` flag needs to be set
`LV_EVENT_VALUE_CHANGED`		Special events Widget's value has changed (i.e. slider moved)
`LV_EVENT_INSERT`		Text has been inserted into Widget. The event data is `char *` being inserted.
`LV_EVENT_REFRESH`		Notify Widget to refresh something on it (for user)
`LV_EVENT_READY`		A process has finished
`LV_EVENT_CANCEL`		A process has been cancelled
`LV_EVENT_STATE_CHANGED`		The state of the widget changed
`LV_EVENT_CREATE`		Other events Object is being created
`LV_EVENT_DELETE`		Object is being deleted
`LV_EVENT_CHILD_CHANGED`		Child was removed, added, or its size, position were changed
`LV_EVENT_CHILD_CREATED`		Child was created, always bubbles up to all parents
`LV_EVENT_CHILD_DELETED`		Child was deleted, always bubbles up to all parents
`LV_EVENT_SCREEN_UNLOAD_START`		A screen unload started, fired immediately when scr_load is called
`LV_EVENT_SCREEN_LOAD_START`		A screen load started, fired when the screen change delay is expired
`LV_EVENT_SCREEN_LOADED`		A screen was loaded
`LV_EVENT_SCREEN_UNLOADED`		A screen was unloaded
`LV_EVENT_SIZE_CHANGED`		Object coordinates/size have changed
`LV_EVENT_STYLE_CHANGED`		Object's style has changed
`LV_EVENT_LAYOUT_CHANGED`		A child's position position has changed due to a layout recalculation
`LV_EVENT_GET_SELF_SIZE`		Get internal size of a widget
`LV_EVENT_INVALIDATE_AREA`		Events of optional LVGL components An area is invalidated (marked for redraw). `lv_event_get_param(e)` returns a pointer to an `lv_area_t` object with the coordinates of the area to be invalidated. The area can be freely modified if needed to adapt it a special requirement of the display. Usually needed with monochrome displays to invalidate `N x 8` rows or columns in one pass.
`LV_EVENT_RESOLUTION_CHANGED`		Sent when the resolution changes due to `lv_display_set_resolution()` or `lv_display_set_rotation()`.
`LV_EVENT_COLOR_FORMAT_CHANGED`		Sent as a result of any call to `lv_display_set_color_format()`.
`LV_EVENT_REFR_REQUEST`		Sent when something happened that requires redraw.
`LV_EVENT_REFR_START`		Sent before a refreshing cycle starts. Sent even if there is nothing to redraw.
`LV_EVENT_REFR_READY`		Sent when refreshing has been completed (after rendering and calling flush callback). Sent even if no redraw happened.
`LV_EVENT_RENDER_START`		Sent just before rendering begins.
`LV_EVENT_RENDER_READY`		Sent after rendering has been completed.
`LV_EVENT_FLUSH_START`		Sent before flush callback is called.
`LV_EVENT_FLUSH_FINISH`		Sent after flush callback call has returned.
`LV_EVENT_FLUSH_WAIT_START`		Sent before flush wait callback is called.
`LV_EVENT_FLUSH_WAIT_FINISH`		Sent after flush wait callback call has returned.
`LV_EVENT_SYNC_START`		Sent before sync callback is called.
`LV_EVENT_SYNC_FINISH`		Sent after sync callback call has returned.
`LV_EVENT_SYNC_WAIT_START`		Sent before sync wait callback is called.
`LV_EVENT_SYNC_WAIT_FINISH`		Sent after sync wait callback call has returned.
`LV_EVENT_UPDATE_LAYOUT_COMPLETED`		Sent after layout update completes
`LV_EVENT_VSYNC`
`LV_EVENT_VSYNC_REQUEST`
`LV_EVENT_TRANSLATION_LANGUAGE_CHANGED`		Sent when the translation language changed.
`LV_EVENT_LAST`
`LV_EVENT_PREPROCESS`	`0x8000`	Number of default events
`LV_EVENT_MARKED_DELETING`	`0x10000`	This is a flag that can be set with an event so it's processed before the class default event processing

Used by 21 functions

lv_obj_add_screen_load_event — param trigger
lv_obj_add_screen_create_event — param trigger
lv_obj_add_play_timeline_event — param trigger
lv_obj_send_event — param event_code
lv_obj_add_event_cb — param filter
lv_obj_add_subject_increment_event — param trigger
lv_obj_add_subject_toggle_event — param trigger
lv_obj_add_subject_set_int_event — param trigger
lv_obj_add_subject_set_float_event — param trigger
lv_obj_add_subject_set_string_event — param trigger
lv_display_add_event_cb — param filter
lv_display_send_event — param code
lv_draw_unit_send_event — param code
lv_indev_add_event_cb — param filter
lv_indev_send_event — param code
lv_freetype_outline_add_event — param filter
lv_gltf_model_node_add_event_cb — param filter_list
lv_gltf_model_node_add_event_cb_with_world_position — param filter_list
lv_event_add — param filter
lv_event_code_get_name — param code
lv_event_push_and_send — param code

Structs

struct

lv_event_list_t

Member	Type	Description
`array`	`lv_array_t`
`is_traversing`	`uint8_t`	True: the list is being nested traversed
`has_marked_deleting`	`uint8_t`	True: the list has marked deleting objects when some of events are marked as deleting

Used by 8 functions

lv_event_send — param list
lv_event_add — param list
lv_event_remove_dsc — param list
lv_event_get_count — param list
lv_event_get_dsc — param list
lv_event_remove — param list
lv_event_remove_all — param list
lv_event_push_and_send — param event_list

Typedefs

misc/lv_event.h:29typedef

lv_event_cb_t

typedef void(* lv_event_cb_t) (lv_event_t *e)

Used by 13 functions

lv_obj_add_event_cb — param event_cb
lv_obj_remove_event_cb — param event_cb
lv_obj_remove_event_cb_with_user_data — param event_cb
lv_display_add_event_cb — param event_cb
lv_display_remove_event_cb_with_user_data — param event_cb
lv_display_register_vsync_event — param event_cb
lv_display_unregister_vsync_event — param event_cb
lv_indev_add_event_cb — param event_cb
lv_indev_remove_event_cb_with_user_data — param event_cb
lv_freetype_outline_add_event — param event_cb
lv_gltf_model_node_add_event_cb — param cb
lv_gltf_model_node_add_event_cb_with_world_position — param cb
lv_event_add — param cb

Dependencies

Indirect dependencies

lv_conf_kconfig.h

lv_event.h

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