lv_obj_scroll.h

Enums

enum lv_scrollbar_mode_t

Scrollbar modes: shows when should the scrollbars be visible

Values:

enumerator LV_SCROLLBAR_MODE_OFF: Never show scrollbars

enumerator LV_SCROLLBAR_MODE_ON: Always show scrollbars

enumerator LV_SCROLLBAR_MODE_ACTIVE: Show scroll bars when object is being scrolled

enumerator LV_SCROLLBAR_MODE_AUTO: Show scroll bars when the content is large enough to be scrolled

enum lv_scroll_snap_t

Scroll span align options. Tells where to align the snappable children when scroll stops.

Values:

enumerator LV_SCROLL_SNAP_NONE: Do not align, leave where it is

enumerator LV_SCROLL_SNAP_START: Align to the left/top

enumerator LV_SCROLL_SNAP_END: Align to the right/bottom

enumerator LV_SCROLL_SNAP_CENTER: Align to the center

Functions

void lv_obj_set_scrollbar_mode(lv_obj_t *obj, lv_scrollbar_mode_t mode)

Set how the scrollbars should behave.

参数:

obj -- pointer to an object
mode -- LV_SCROLL_MODE_ON/OFF/AUTO/ACTIVE

void lv_obj_set_scroll_dir(lv_obj_t *obj, lv_dir_t dir)

Set the object in which directions can be scrolled

参数:

obj -- pointer to an object
dir -- the allow scroll directions. An element or OR-ed values of lv_dir_t

void lv_obj_set_scroll_snap_x(lv_obj_t *obj, lv_scroll_snap_t align)

Set where to snap the children when scrolling ends horizontally

参数:

obj -- pointer to an object
align -- the snap align to set from lv_scroll_snap_t

void lv_obj_set_scroll_snap_y(lv_obj_t *obj, lv_scroll_snap_t align)

Set where to snap the children when scrolling ends vertically

参数:

obj -- pointer to an object
align -- the snap align to set from lv_scroll_snap_t

lv_scrollbar_mode_t lv_obj_get_scrollbar_mode(const lv_obj_t *obj)

Get the current scroll mode (when to hide the scrollbars)

参数:: obj -- pointer to an object
返回:: the current scroll mode from lv_scrollbar_mode_t

lv_dir_t lv_obj_get_scroll_dir(const lv_obj_t *obj)

Get the object in which directions can be scrolled

参数:

obj -- pointer to an object
dir -- the allow scroll directions. An element or OR-ed values of lv_dir_t

lv_scroll_snap_t lv_obj_get_scroll_snap_x(const lv_obj_t *obj)

Get where to snap the children when scrolling ends horizontally

参数:: obj -- pointer to an object
返回:: the current snap align from lv_scroll_snap_t

lv_scroll_snap_t lv_obj_get_scroll_snap_y(const lv_obj_t *obj)

Get where to snap the children when scrolling ends vertically

参数:: obj -- pointer to an object
返回:: the current snap align from lv_scroll_snap_t

int32_t lv_obj_get_scroll_x(const lv_obj_t *obj)

Get current X scroll position.

参数:: obj -- pointer to an object
返回:: the current scroll position from the left edge. If the object is not scrolled return 0 If scrolled return > 0 If scrolled in (elastic scroll) return < 0

int32_t lv_obj_get_scroll_y(const lv_obj_t *obj)

Get current Y scroll position.

参数:: obj -- pointer to an object
返回:: the current scroll position from the top edge. If the object is not scrolled return 0 If scrolled return > 0 If scrolled inside return < 0

int32_t lv_obj_get_scroll_top(lv_obj_t *obj)

Return the height of the area above the object. That is the number of pixels the object can be scrolled down. Normally positive but can be negative when scrolled inside.

参数:: obj -- pointer to an object
返回:: the scrollable area above the object in pixels

int32_t lv_obj_get_scroll_bottom(lv_obj_t *obj)

Return the height of the area below the object. That is the number of pixels the object can be scrolled down. Normally positive but can be negative when scrolled inside.

参数:: obj -- pointer to an object
返回:: the scrollable area below the object in pixels

int32_t lv_obj_get_scroll_left(lv_obj_t *obj)

Return the width of the area on the left the object. That is the number of pixels the object can be scrolled down. Normally positive but can be negative when scrolled inside.

参数:: obj -- pointer to an object
返回:: the scrollable area on the left the object in pixels

int32_t lv_obj_get_scroll_right(lv_obj_t *obj)

Return the width of the area on the right the object. That is the number of pixels the object can be scrolled down. Normally positive but can be negative when scrolled inside.

参数:: obj -- pointer to an object
返回:: the scrollable area on the right the object in pixels

void lv_obj_get_scroll_end(lv_obj_t *obj, lv_point_t *end)

Get the X and Y coordinates where the scrolling will end for this object if a scrolling animation is in progress. If no scrolling animation, give the current x or y scroll position.

参数:

obj -- pointer to an object
end -- pointer to store the result

void lv_obj_scroll_by(lv_obj_t *obj, int32_t x, int32_t y, lv_anim_enable_t anim_en)

Scroll by a given amount of pixels

备注

> 0 value means scroll right/bottom (show the more content on the right/bottom)

备注

e.g. dy = -20 means scroll down 20 px

参数:

obj -- pointer to an object to scroll
x -- pixels to scroll horizontally
y -- pixels to scroll vertically
anim_en -- LV_ANIM_ON: scroll with animation; LV_ANIM_OFF: scroll immediately

void lv_obj_scroll_by_bounded(lv_obj_t *obj, int32_t dx, int32_t dy, lv_anim_enable_t anim_en)

Scroll by a given amount of pixels. dx and dy will be limited internally to allow scrolling only on the content area.

备注

e.g. dy = -20 means scroll down 20 px

参数:

obj -- pointer to an object to scroll
dx -- pixels to scroll horizontally
dy -- pixels to scroll vertically
anim_en -- LV_ANIM_ON: scroll with animation; LV_ANIM_OFF: scroll immediately

void lv_obj_scroll_to(lv_obj_t *obj, int32_t x, int32_t y, lv_anim_enable_t anim_en)

Scroll to a given coordinate on an object. x and y will be limited internally to allow scrolling only on the content area.

参数:

obj -- pointer to an object to scroll
x -- pixels to scroll horizontally
y -- pixels to scroll vertically
anim_en -- LV_ANIM_ON: scroll with animation; LV_ANIM_OFF: scroll immediately

void lv_obj_scroll_to_x(lv_obj_t *obj, int32_t x, lv_anim_enable_t anim_en)

Scroll to a given X coordinate on an object. x will be limited internally to allow scrolling only on the content area.

参数:

obj -- pointer to an object to scroll
x -- pixels to scroll horizontally
anim_en -- LV_ANIM_ON: scroll with animation; LV_ANIM_OFF: scroll immediately

void lv_obj_scroll_to_y(lv_obj_t *obj, int32_t y, lv_anim_enable_t anim_en)

Scroll to a given Y coordinate on an object y will be limited internally to allow scrolling only on the content area.

参数:

obj -- pointer to an object to scroll
y -- pixels to scroll vertically
anim_en -- LV_ANIM_ON: scroll with animation; LV_ANIM_OFF: scroll immediately

void lv_obj_scroll_to_view(lv_obj_t *obj, lv_anim_enable_t anim_en)

Scroll to an object until it becomes visible on its parent

参数:

obj -- pointer to an object to scroll into view
anim_en -- LV_ANIM_ON: scroll with animation; LV_ANIM_OFF: scroll immediately

void lv_obj_scroll_to_view_recursive(lv_obj_t *obj, lv_anim_enable_t anim_en)

Scroll to an object until it becomes visible on its parent. Do the same on the parent's parent, and so on. Therefore the object will be scrolled into view even it has nested scrollable parents

参数:

obj -- pointer to an object to scroll into view
anim_en -- LV_ANIM_ON: scroll with animation; LV_ANIM_OFF: scroll immediately

bool lv_obj_is_scrolling(const lv_obj_t *obj)

Tell whether an object is being scrolled or not at this moment

参数:: obj -- pointer to an object
返回:: true: obj is being scrolled

void lv_obj_update_snap(lv_obj_t *obj, lv_anim_enable_t anim_en)

Check the children of obj and scroll obj to fulfill the scroll_snap settings

参数:

obj -- an object whose children needs to checked and snapped
anim_en -- LV_ANIM_ON/OFF

void lv_obj_get_scrollbar_area(lv_obj_t *obj, lv_area_t *hor, lv_area_t *ver)

Get the area of the scrollbars

参数:

obj -- pointer to an object
hor -- pointer to store the area of the horizontal scrollbar
ver -- pointer to store the area of the vertical scrollbar

void lv_obj_scrollbar_invalidate(lv_obj_t *obj)

Invalidate the area of the scrollbars

参数:: obj -- pointer to an object

void lv_obj_readjust_scroll(lv_obj_t *obj, lv_anim_enable_t anim_en)

Checks if the content is scrolled "in" and adjusts it to a normal position.

参数:

obj -- pointer to an object
anim_en -- LV_ANIM_ON/OFF