This widget aims to position objects in a grid layout while actually
creating and rendering only the visible ones, using the same idea as the
Genlist
: the user defines a class for
each item, specifying functions that will be called at object creation,
deletion, etc. When those items are selected by the user, a callback
function is issued. Users may interact with a gengrid via the mouse (by
clicking on items to select them and clicking on the grid’s viewport and
swiping to pan the whole view) or via the keyboard, navigating through
item with the arrow keys.
This widget supports the scrollable interface.
If you wish to control the scolling behaviour using these functions,
inherit both the widget class and the
Scrollable
class
using multiple inheritance, for example:
class ScrollableGenlist(Genlist, Scrollable):
def __init__(self, canvas, *args, **kwargs):
Genlist.__init__(self, canvas)
Gengrid may layout its items in one of two possible layouts:
horizontal or
vertical.
When in “horizontal mode”, items will be placed in columns, from top to bottom and, when the space for a column is filled, another one is started on the right, thus expanding the grid horizontally, making for horizontal scrolling. When in “vertical mode” , though, items will be placed in rows, from left to right and, when the space for a row is filled, another one is started below, thus expanding the grid vertically (and making for vertical scrolling).
An item in a gengrid can have 0 or more texts (they can be regular text
or textblock Evas objects - that’s up to the style to determine), 0 or
more contents (which are simply objects swallowed into the gengrid
item’s theming Edje object) and 0 or more boolean states, which
have the behavior left to the user to define. The Edje part names for
each of these properties will be looked up, in the theme file for the
gengrid, under the Edje (string) data items named "texts"
,
"contents"
and "states"
, respectively. For each of those
properties, if more than one part is provided, they must have names
listed separated by spaces in the data fields. For the default gengrid
item theme, we have one text part ("elm.text"
), two content
parts ("elm.swalllow.icon"
and "elm.swallow.end"
) and no
state parts.
A gengrid item may be at one of several styles. Elementary provides one
by default - “default”, but this can be extended by system or
application custom themes/overlays/extensions (see
Theme
for more details).
In order to have the ability to add and delete items on the fly, gengrid
implements a class (callback) system where the application provides a
structure with information about that type of item (gengrid may contain
multiple different items with different classes, states and styles).
Gengrid will call the functions in this struct (methods) when an item is
“realized” (i.e., created dynamically, while the user is scrolling the
grid). All objects will simply be deleted when no longer needed with
delete()
. The GengridItemClass
class contains the
following attributes and methods:
item_style
- This is a constant string and simply defines the name
of the item style. It must be specified and the default should be
default
.
func.text_get
- This function is called when an item object is
actually created. The data
parameter will point to the same data
passed to item_append()
and related item creation
functions. The obj
parameter is the gengrid object itself, while
the part
one is the name string of one of the existing text parts
in the Edje group implementing the item’s theme.
See GengridItemClass.text_get()
.
func.content_get
- This function is called when an item object is
actually created. The data
parameter will point to the same data
passed to GengridItem.append_to()
and related item creation
functions. The obj
parameter is the gengrid object itself, while
the part
one is the name string of one of the existing (content)
swallow parts in the Edje group implementing the item’s theme. It must
return None,
when no content is desired, or a valid object handle,
otherwise. The object will be deleted by the gengrid on its deletion
or when the item is “unrealized”. See GengridItemClass.content_get()
.
func.state_get
- This function is called when an item object is
actually created. The data
parameter will point to the same data
passed to GengridItem.append_to()
and related item creation
functions. The obj
parameter is the gengrid object itself, while
the part
one is the name string of one of the state parts in the
Edje group implementing the item’s theme. Return False
for
false/off or True
for true/on. Gengrids will emit a signal to
its theming Edje object with "elm,state,xxx,active"
and "elm"
as “emission” and “source” arguments, respectively, when the state is
true (the default is false), where xxx
is the name of the (state)
part. See GengridItemClass.state_get()
.
func.del
- This is called when
efl.elementary.object_item.ObjectItem.delete()
is called on
an item or clear()
is called on the gengrid. This is
intended for use when gengrid items are deleted, so any data attached
to the item (e.g. its data parameter on creation) can be deleted. See
GengridItemClass.delete()
.
If the user wants to have multiple items selected at the same time,
multi_select
will permit it. If the gengrid is
single-selection only (the default), then selected_item
will return the selected item or None
, if none is selected. If the
gengrid is under multi-selection, then selected_items
will return a list (that is only valid as long as no items are modified
(added, deleted, selected or unselected) of child items on a gengrid.
If an item changes (internal (boolean) state, text or content changes),
then use update()
to have gengrid update the item with
the new state. A gengrid will re-“realize” the item, thus calling the
functions in the GengridItemClass
set for that item.
To programmatically (un)select an item or get the selected state, use
GengridItem.selected
. To make an item disabled (unable to be
selected and appear differently) or get the disabled state
use GengridItem.disabled
.
Grid cells will only have their selection smart callbacks called when
firstly getting selected. Any further clicks will do nothing, unless you
enable the “always select mode”, with select_mode
as
ELM_OBJECT_SELECT_MODE_ALWAYS
, thus making every click to issue
selection callbacks. select_mode
as
ELM_OBJECT_SELECT_MODE_NONE
will turn off the ability to select items
entirely in the widget and they will neither appear selected nor call
the selection smart callbacks.
Remember that you can create new styles and add your own theme
augmentation per application with
Theme.extension_add
. If you
absolutely must have a specific style that overrides any theme the user
or system sets up you can use
Theme.extension_add
to add such
a file.
activated
- The user has double-clicked or pressed
(enter|return|spacebar) on an item. The event_info
parameter
is the gengrid item that was activated.
clicked,double
- The user has double-clicked an item.
The event_info
parameter is the gengrid item that was double-clicked.
clicked,right
- The user has right-clicked an item. The
event_info
parameter is the item that was right-clicked. (since: 1.13)
longpressed
- This is called when the item is pressed for a certain
amount of time. By default it’s 1 second.
selected
- The user has made an item selected. The
event_info
parameter is the gengrid item that was selected.
unselected
- The user has made an item unselected. The
event_info
parameter is the gengrid item that was unselected.
realized
- This is called when the item in the gengrid
has its implementing Evas object instantiated, de facto.
event_info
is the gengrid item that was created.
unrealized
- This is called when the implementing Evas
object for this item is deleted. event_info
is the gengrid
item that was deleted.
changed
- Called when an item is added, removed, resized
or moved and when the gengrid is resized or gets “horizontal”
property changes.
scroll,anim,start
- This is called when scrolling animation has
started.
scroll,anim,stop
- This is called when scrolling animation has
stopped.
drag,start,up
- Called when the item in the gengrid has
been dragged (not scrolled) up.
drag,start,down
- Called when the item in the gengrid has
been dragged (not scrolled) down.
drag,start,left
- Called when the item in the gengrid has
been dragged (not scrolled) left.
drag,start,right
- Called when the item in the gengrid has
been dragged (not scrolled) right.
drag,stop
- Called when the item in the gengrid has
stopped being dragged.
drag
- Called when the item in the gengrid is being
dragged.
scroll
- called when the content has been scrolled
(moved).
scroll,drag,start
- called when dragging the content has
started.
scroll,drag,stop
- called when dragging the content has
stopped.
edge,top
- This is called when the gengrid is scrolled until
the top edge.
edge,bottom
- This is called when the gengrid is scrolled
until the bottom edge.
edge,left
- This is called when the gengrid is scrolled
until the left edge.
edge,right
- This is called when the gengrid is scrolled
until the right edge.
moved
- This is called when a gengrid item is moved by a user
interaction in a reorder mode. The event_info
parameter is the item that
was moved.
index,update
- This is called when a gengrid item index is changed.
Note that this callback is called while each item is being realized.
highlighted
- an item in the list is highlighted. This is called when
the user presses an item or keyboard selection is done so the item is
physically highlighted. The event_info
parameter is the item that was
highlighted.
unhighlighted
- an item in the list is unhighlighted. This is called
when the user releases an item or keyboard selection is moved so the item
is physically unhighlighted. The event_info
parameter is the item that
was unhighlighted.
item,focused
- When the gengrid item has received focus. (since 1.10)
item,unfocused
- When the gengrid item has lost focus. (since 1.10)
item,reorder,anim,start
- This is called when a gengrid item movement
has just started by keys in reorder mode. The parameter is the item that
is going to move. (since 1.10)
item,reorder,anim,stop
- This is called when a gengrid item movement just
stopped in reorder mode. The parameter is the item that was moved. (since 1.10)
efl.elementary.
ELM_GENGRID_ITEM_SCROLLTO_NONE
¶No scroll to
efl.elementary.
ELM_GENGRID_ITEM_SCROLLTO_IN
¶Scroll to the nearest viewport
efl.elementary.
ELM_GENGRID_ITEM_SCROLLTO_TOP
¶Scroll to the top of viewport
efl.elementary.
ELM_GENGRID_ITEM_SCROLLTO_MIDDLE
¶Scroll to the middle of viewport
efl.elementary.
ELM_GENGRID_ITEM_SCROLLTO_BOTTOM
¶Scroll to the bottom of viewport
New in version 1.17.
efl.elementary.
ELM_OBJECT_MULTI_SELECT_MODE_DEFAULT
¶Default multiple select mode
New in version 1.10.
efl.elementary.
ELM_OBJECT_MULTI_SELECT_MODE_WITH_CONTROL
¶Disallow mutiple selection when clicked without control key pressed
New in version 1.10.
efl.elementary.
ELM_OBJECT_MULTI_SELECT_MODE_MAX
¶Value unknown
New in version 1.10.
efl.elementary.
Gengrid
(Object parent, *args, **kwargs)¶parent (efl.evas.Object
) – The parent object
**kwargs – All the remaining keyword arguments are interpreted as properties of the instance
efl.elementary.
GengridItem
(GengridItemClass item_class, item_data=None, func=None, func_data=None, *args, **kwargs)¶item_class – a valid instance that defines the
behavior of this item. See GengridItemClass
.
item_data – some data that defines the model of this
item. This value will be given to methods of
item_class
such as
GengridItemClass.text_get()
. It will also be
provided to func
as its last parameter.
func –
if not None, this must be a callable to be called back when the item is selected. The function signature is:
func(item, obj, item_data)
Where item
is the handle, obj
is the Evas object
that represents this item, and item_data
is the
value given as parameter to this function.
efl.elementary.
GengridItemClass
(item_style=None, text_get_func=None, content_get_func=None, state_get_func=None, del_func=None)¶This class should be created and handled to the Gengrid itself.
It may be subclassed, in this case the methods text_get()
,
content_get()
, state_get()
and delete()
will be used.
It may also be instantiated directly, given getters to override as constructor parameters.
item_style – the string that defines the gengrid item theme to be used. The corresponding edje group will have this as suffix.
text_get_func – if provided will override the
behavior defined by text_get()
in this class. Its
purpose is to return the label string to be used by a
given part and row. This function should have the
signature:
func(obj, part, item_data) -> str
content_get_func – if provided will override the behavior
defined by content_get()
in this class. Its purpose is
to return the icon object to be used (swallowed) by a
given part and row. This function should have the
signature:
func(obj, part, item_data) -> obj
state_get_func – if provided will override the
behavior defined by state_get()
in this class. Its
purpose is to return the boolean state to be used by a
given part and row. This function should have the
signature:
func(obj, part, item_data) -> bool
del_func – if provided will override the behavior
defined by delete()
in this class. Its purpose is to be
called when item is deleted, thus finalizing resources
and similar. This function should have the signature:
func(obj, item_data)
Note
In all these signatures, ‘obj’ means Gengrid and ‘item_data’ is the value given to Gengrid item append/prepend methods, it should represent your item model as you want.