Scroller

Enumerations

enum  Elm_Scroller_Policy {
  ELM_SCROLLER_POLICY_AUTO = 0,
  ELM_SCROLLER_POLICY_ON,
  ELM_SCROLLER_POLICY_OFF
}
 Type that controls when scrollbars should appear. More...

Functions

Evas_Object * elm_scroller_add (Evas_Object *parent)
 Add a new scroller to the parent.
EINA_DEPRECATED void elm_scroller_custom_widget_base_theme_set (Evas_Object *obj, const char *widget, const char *base)
 Set custom theme elements for the scroller.
void elm_scroller_content_min_limit (Evas_Object *obj, Eina_Bool w, Eina_Bool h)
 Make the scroller minimum size limited to the minimum size of the content.
void elm_scroller_region_show (Evas_Object *obj, Evas_Coord x, Evas_Coord y, Evas_Coord w, Evas_Coord h)
 Show a specific virtual region within the scroller content object.
void elm_scroller_policy_set (Evas_Object *obj, Elm_Scroller_Policy policy_h, Elm_Scroller_Policy policy_v)
 Set the scrollbar visibility policy.
void elm_scroller_policy_get (const Evas_Object *obj, Elm_Scroller_Policy *policy_h, Elm_Scroller_Policy *policy_v)
 Gets scrollbar visibility policy.
void elm_scroller_region_get (const Evas_Object *obj, Evas_Coord *x, Evas_Coord *y, Evas_Coord *w, Evas_Coord *h)
 Get the currently visible content region.
void elm_scroller_child_size_get (const Evas_Object *obj, Evas_Coord *w, Evas_Coord *h)
 Get the size of the content object.
void elm_scroller_bounce_set (Evas_Object *obj, Eina_Bool h_bounce, Eina_Bool v_bounce)
 Set bouncing behavior.
void elm_scroller_bounce_get (const Evas_Object *obj, Eina_Bool *h_bounce, Eina_Bool *v_bounce)
 Get the bounce behaviour.
void elm_scroller_page_relative_set (Evas_Object *obj, double h_pagerel, double v_pagerel)
 Set scroll page size relative to viewport size.
void elm_scroller_page_relative_get (const Evas_Object *obj, double *h_pagerel, double *v_pagerel)
 Get a given scroller widget's scrolling page size, relative to its viewport size.
void elm_scroller_page_size_set (Evas_Object *obj, Evas_Coord h_pagesize, Evas_Coord v_pagesize)
 Set scroll page size.
void elm_scroller_page_size_get (const Evas_Object *obj, Evas_Coord *h_pagesize, Evas_Coord *v_pagesize)
 Retrieve a scroller widget's current page size.
void elm_scroller_current_page_get (const Evas_Object *obj, int *h_pagenumber, int *v_pagenumber)
 Get scroll current page number.
void elm_scroller_last_page_get (const Evas_Object *obj, int *h_pagenumber, int *v_pagenumber)
 Get scroll last page number.
void elm_scroller_page_show (Evas_Object *obj, int h_pagenumber, int v_pagenumber)
 Show a specific virtual region within the scroller content object by page number.
void elm_scroller_page_bring_in (Evas_Object *obj, int h_pagenumber, int v_pagenumber)
 Show a specific virtual region within the scroller content object by page number.
void elm_scroller_region_bring_in (Evas_Object *obj, Evas_Coord x, Evas_Coord y, Evas_Coord w, Evas_Coord h)
 Show a specific virtual region within the scroller content object.
void elm_scroller_propagate_events_set (Evas_Object *obj, Eina_Bool propagation)
 Set event propagation on a scroller.
Eina_Bool elm_scroller_propagate_events_get (const Evas_Object *obj)
 Get event propagation for a scroller.
void elm_scroller_gravity_set (Evas_Object *obj, double x, double y)
 Set scrolling gravity on a scroller.
void elm_scroller_gravity_get (const Evas_Object *obj, double *x, double *y)
 Get scrolling gravity values for a scroller.

Detailed Description

scroller_inheritance_tree.png

A scroller holds (and clips) a single object and "scrolls it around". This means that it allows the user to use a scroll bar (or a finger) to drag the viewable region around, moving through a much larger object that is contained in the scroller. The scroller will always have a small minimum size by default as it won't be limited by the contents of the scroller.

This widget inherits from the Layout one, so that all the functions acting on it also work for scroller objects.

This widget emits the following signals, besides the ones sent from

  • "edge,left" - the left edge of the content has been reached
  • "edge,right" - the right edge of the content has been reached
  • "edge,top" - the top edge of the content has been reached
  • "edge,bottom" - the bottom edge of the content has been reached
  • "scroll" - the content has been scrolled (moved)
  • "scroll,anim,start" - scrolling animation has started
  • "scroll,anim,stop" - scrolling animation has stopped
  • "scroll,drag,start" - dragging the contents around has started
  • "scroll,drag,stop" - dragging the contents around has stopped

This widget implements the The Elementary Scrollable Interface interface. Its (non-deprecated) API functions, except for elm_scroller_add(), which gives basic scroller objects, are meant to be a basis for all other scrollable widgets (i.e. widgets implementing The Elementary Scrollable Interface). So, they will work both on pristine scroller widgets and on other "specialized" scrollable widgets.

Note:
The "scroll,anim,*" and "scroll,drag,*" signals are only emitted by user intervention.
When Elementary is under its default profile and theme (meant for touch interfaces), scroll bars will not be draggable -- their function is merely to indicate how much has been scrolled.
When Elementary is under its desktop/standard profile and theme, the thumb scroll (a.k.a. finger scroll) won't work.

Default content parts of the scroller widget that you can use are:

  • "default" - Content of the scroller

In Scroller example you'll find an example on how to use most of this API.


Enumeration Type Documentation

Type that controls when scrollbars should appear.

See also:
elm_scroller_policy_set()
Enumerator:
ELM_SCROLLER_POLICY_AUTO 

Show scrollbars as needed.

ELM_SCROLLER_POLICY_ON 

Always show scrollbars.

ELM_SCROLLER_POLICY_OFF 

Never show scrollbars.


Function Documentation

Evas_Object* elm_scroller_add ( Evas_Object *  parent)

Add a new scroller to the parent.

Parameters:
parentThe parent object
Returns:
The new object or NULL if it cannot be created
void elm_scroller_bounce_get ( const Evas_Object *  obj,
Eina_Bool *  h_bounce,
Eina_Bool *  v_bounce 
)

Get the bounce behaviour.

Parameters:
objThe Scroller object
h_bounceWill the scroller bounce horizontally or not
v_bounceWill the scroller bounce vertically or not
See also:
elm_scroller_bounce_set()
void elm_scroller_bounce_set ( Evas_Object *  obj,
Eina_Bool  h_bounce,
Eina_Bool  v_bounce 
)

Set bouncing behavior.

Parameters:
objThe scroller object
h_bounceAllow bounce horizontally
v_bounceAllow bounce vertically

When scrolling, the scroller may "bounce" when reaching an edge of the content object. This is a visual way to indicate the end has been reached. This is enabled by default for both axis. This API will set if it is enabled for the given axis with the boolean parameters for each axis.

void elm_scroller_child_size_get ( const Evas_Object *  obj,
Evas_Coord *  w,
Evas_Coord *  h 
)

Get the size of the content object.

Parameters:
objThe scroller object
wWidth of the content object.
hHeight of the content object.

This gets the size of the content object of the scroller.

void elm_scroller_content_min_limit ( Evas_Object *  obj,
Eina_Bool  w,
Eina_Bool  h 
)

Make the scroller minimum size limited to the minimum size of the content.

Parameters:
objThe scroller object
wEnable limiting minimum size horizontally
hEnable limiting minimum size vertically

By default the scroller will be as small as its design allows, irrespective of its content. This will make the scroller minimum size the right size horizontally and/or vertically to perfectly fit its content in that direction.

void elm_scroller_current_page_get ( const Evas_Object *  obj,
int *  h_pagenumber,
int *  v_pagenumber 
)

Get scroll current page number.

Parameters:
objThe scroller object
h_pagenumberThe horizontal page number
v_pagenumberThe vertical page number

The page number starts from 0. 0 is the first page. Current page means the page which meets the top-left of the viewport. If there are two or more pages in the viewport, it returns the number of the page which meets the top-left of the viewport.

See also:
elm_scroller_last_page_get()
elm_scroller_page_show()
elm_scroller_page_bring_in()
EINA_DEPRECATED void elm_scroller_custom_widget_base_theme_set ( Evas_Object *  obj,
const char *  widget,
const char *  base 
)

Set custom theme elements for the scroller.

Parameters:
objThe scroller object
widgetThe widget name to use (default is "scroller")
baseThe base name to use (default is "base")
Deprecated:
Use elm_layout_theme_set() instead.

References ELM_LAYOUT_DATA.

void elm_scroller_gravity_get ( const Evas_Object *  obj,
double *  x,
double *  y 
)

Get scrolling gravity values for a scroller.

Parameters:
objThe scroller object
xThe scrolling horizontal gravity
yThe scrolling vertical gravity

This gets gravity values for a scroller.

See also:
elm_scroller_gravity_set()
void elm_scroller_gravity_set ( Evas_Object *  obj,
double  x,
double  y 
)

Set scrolling gravity on a scroller.

Parameters:
objThe scroller object
xThe scrolling horizontal gravity
yThe scrolling vertical gravity

The gravity, defines how the scroller will adjust its view when the size of the scroller contents increase.

The scroller will adjust the view to glue itself as follows.

x=0.0, for showing the left most region of the content. x=1.0, for showing the right most region of the content. y=0.0, for showing the bottom most region of the content. y=1.0, for showing the top most region of the content.

Default values for x and y are 0.0

void elm_scroller_last_page_get ( const Evas_Object *  obj,
int *  h_pagenumber,
int *  v_pagenumber 
)

Get scroll last page number.

Parameters:
objThe scroller object
h_pagenumberThe horizontal page number
v_pagenumberThe vertical page number

The page number starts from 0. 0 is the first page. This returns the last page number among the pages.

See also:
elm_scroller_current_page_get()
elm_scroller_page_show()
elm_scroller_page_bring_in()
void elm_scroller_page_bring_in ( Evas_Object *  obj,
int  h_pagenumber,
int  v_pagenumber 
)

Show a specific virtual region within the scroller content object by page number.

Parameters:
objThe scroller object
h_pagenumberThe horizontal page number
v_pagenumberThe vertical page number

0, 0 of the indicated page is located at the top-left of the viewport. This will slide to the page with animation.

Example of usage:

 sc = elm_scroller_add(win);
 elm_object_content_set(sc, content);
 elm_scroller_page_relative_set(sc, 1, 0);
 elm_scroller_last_page_get(sc, &h_page, &v_page);
 elm_scroller_page_bring_in(sc, h_page, v_page);
See also:
elm_scroller_page_show()
void elm_scroller_page_relative_get ( const Evas_Object *  obj,
double *  h_pagerel,
double *  v_pagerel 
)

Get a given scroller widget's scrolling page size, relative to its viewport size.

Parameters:
objThe scroller object
h_pagerelPointer to a variable where to store the horizontal page (relative) size
v_pagerelPointer to a variable where to store the vertical page (relative) size
See also:
elm_scroller_page_relative_set() for more details
Since:
1.7
void elm_scroller_page_relative_set ( Evas_Object *  obj,
double  h_pagerel,
double  v_pagerel 
)

Set scroll page size relative to viewport size.

Parameters:
objThe scroller object
h_pagerelThe horizontal page relative size
v_pagerelThe vertical page relative size

The scroller is capable of limiting scrolling by the user to "pages". That is to jump by and only show a "whole page" at a time as if the continuous area of the scroller content is split into page sized pieces. This sets the size of a page relative to the viewport of the scroller. 1.0 is "1 viewport" is size (horizontally or vertically). 0.0 turns it off in that axis. This is mutually exclusive with page size (see elm_scroller_page_size_set() for more information). Likewise 0.5 is "half a viewport". Sane usable values are normally between 0.0 and 1.0 including 1.0. If you only want 1 axis to be page "limited", use 0.0 for the other axis.

void elm_scroller_page_show ( Evas_Object *  obj,
int  h_pagenumber,
int  v_pagenumber 
)

Show a specific virtual region within the scroller content object by page number.

Parameters:
objThe scroller object
h_pagenumberThe horizontal page number
v_pagenumberThe vertical page number

0, 0 of the indicated page is located at the top-left of the viewport. This will jump to the page directly without animation.

Example of usage:

 sc = elm_scroller_add(win);
 elm_object_content_set(sc, content);
 elm_scroller_page_relative_set(sc, 1, 0);
 elm_scroller_current_page_get(sc, &h_page, &v_page);
 elm_scroller_page_show(sc, h_page + 1, v_page);
See also:
elm_scroller_page_bring_in()
void elm_scroller_page_size_get ( const Evas_Object *  obj,
Evas_Coord *  h_pagesize,
Evas_Coord *  v_pagesize 
)

Retrieve a scroller widget's current page size.

Parameters:
objThe scroller object
h_pagesizeWhere to store its horizontal page size
v_pagesizeWhere to store its vertical page size
See also:
elm_scroller_page_size_set() for more details
elm_scroller_page_relative_set()
Since:
1.7
void elm_scroller_page_size_set ( Evas_Object *  obj,
Evas_Coord  h_pagesize,
Evas_Coord  v_pagesize 
)

Set scroll page size.

Parameters:
objThe scroller object
h_pagesizeThe horizontal page size
v_pagesizeThe vertical page size

This sets the page size to an absolute fixed value, with 0 turning it off for that axis.

See also:
elm_scroller_page_relative_set()
elm_scroller_page_size_get()
void elm_scroller_policy_get ( const Evas_Object *  obj,
Elm_Scroller_Policy policy_h,
Elm_Scroller_Policy policy_v 
)

Gets scrollbar visibility policy.

Parameters:
objThe scroller object
policy_hHorizontal scrollbar policy
policy_vVertical scrollbar policy
See also:
elm_scroller_policy_set()
void elm_scroller_policy_set ( Evas_Object *  obj,
Elm_Scroller_Policy  policy_h,
Elm_Scroller_Policy  policy_v 
)

Set the scrollbar visibility policy.

Parameters:
objThe scroller object
policy_hHorizontal scrollbar policy
policy_vVertical scrollbar policy

This sets the scrollbar visibility policy for the given scroller. ELM_SCROLLER_POLICY_AUTO means the scrollbar is made visible if it is needed, and otherwise kept hidden. ELM_SCROLLER_POLICY_ON turns it on all the time, and ELM_SCROLLER_POLICY_OFF always keeps it off. This applies respectively for the horizontal and vertical scrollbars.

Eina_Bool elm_scroller_propagate_events_get ( const Evas_Object *  obj)

Get event propagation for a scroller.

Parameters:
objThe scroller object
Returns:
The propagation state

This gets the event propagation for a scroller.

See also:
elm_scroller_propagate_events_set()
void elm_scroller_propagate_events_set ( Evas_Object *  obj,
Eina_Bool  propagation 
)

Set event propagation on a scroller.

Parameters:
objThe scroller object
propagationIf propagation is enabled or not

This enables or disables event propagation from the scroller content to the scroller and its parent. By default event propagation is enabled.

void elm_scroller_region_bring_in ( Evas_Object *  obj,
Evas_Coord  x,
Evas_Coord  y,
Evas_Coord  w,
Evas_Coord  h 
)

Show a specific virtual region within the scroller content object.

Parameters:
objThe scroller object
xX coordinate of the region
yY coordinate of the region
wWidth of the region
hHeight of the region

This will ensure all (or part if it does not fit) of the designated region in the virtual content object (0, 0 starting at the top-left of the virtual content object) is shown within the scroller. Unlike elm_scroller_region_show(), this allow the scroller to "smoothly slide" to this location (if configuration in general calls for transitions). It may not jump immediately to the new location and make take a while and show other content along the way.

See also:
elm_scroller_region_show()
void elm_scroller_region_get ( const Evas_Object *  obj,
Evas_Coord *  x,
Evas_Coord *  y,
Evas_Coord *  w,
Evas_Coord *  h 
)

Get the currently visible content region.

Parameters:
objThe scroller object
xX coordinate of the region
yY coordinate of the region
wWidth of the region
hHeight of the region

This gets the current region in the content object that is visible through the scroller. The region co-ordinates are returned in the x, y, w, h values pointed to.

Note:
All coordinates are relative to the content.
See also:
elm_scroller_region_show()
void elm_scroller_region_show ( Evas_Object *  obj,
Evas_Coord  x,
Evas_Coord  y,
Evas_Coord  w,
Evas_Coord  h 
)

Show a specific virtual region within the scroller content object.

Parameters:
objThe scroller object
xX coordinate of the region
yY coordinate of the region
wWidth of the region
hHeight of the region

This will ensure all (or part if it does not fit) of the designated region in the virtual content object (0, 0 starting at the top-left of the virtual content object) is shown within the scroller.