Tizen Native API  4.0
Box

box_inheritance_tree.png
box.png

A box arranges objects in a linear fashion, governed by a layout function that defines the details of this arrangement.

By default, the box will use an internal function to set the layout to a single row, either vertical or horizontal. This layout is affected by a number of parameters, such as the homogeneous flag set by elm_box_homogeneous_set(), the values given by elm_box_padding_set() and elm_box_align_set() and the hints set to each object in the box.

For this default layout, it's possible to change the orientation with elm_box_horizontal_set(). The box will start in the vertical orientation, placing its elements ordered from top to bottom. When horizontal is set, the order will go from left to right. If the box is set to be homogeneous, every object in it will be assigned the same space, that of the largest object. Padding can be used to set some spacing between the cell given to each object. The alignment of the box, set with elm_box_align_set(), determines how the bounding box of all the elements will be placed within the space given to the box widget itself.

The size hints of each object also affect how they are placed and sized within the box. evas_object_size_hint_min_set() will give the minimum size the object can have, and the box will use it as the basis for all latter calculations. Elementary widgets set their own minimum size as needed, so there's rarely any need to use it manually.

evas_object_size_hint_weight_set(), when not in homogeneous mode, is used to tell whether the object will be allocated the minimum size it needs or if the space given to it should be expanded. It's important to realize that expanding the size given to the object is not the same thing as resizing the object. It could very well end being a small widget floating in a much larger empty space. If not set, the weight for objects will normally be 0.0 for both axis, meaning the widget will not be expanded. To take as much space possible, set the weight to EVAS_HINT_EXPAND (defined to 1.0) for the desired axis to expand.

Besides how much space each object is allocated, it's possible to control how the widget will be placed within that space using evas_object_size_hint_align_set(). By default, this value will be 0.5 for both axis, meaning the object will be centered, but any value from 0.0 (left or top, for the x and y axes, respectively) to 1.0 (right or bottom) can be used. The special value EVAS_HINT_FILL, which is -1.0, means the object will be resized to fill the entire space it was allocated.

In addition, customized functions to define the layout can be set, which allow the application developer to organize the objects within the box in any number of ways.

The special elm_box_layout_transition() function can be used to switch from one layout to another, animating the motion of the children of the box.

Note:
Objects should not be added to box objects using _add() calls.

Functions

void elm_box_homogeneous_set (Elm_Box *obj, Eina_Bool homogeneous)
 Set the box to arrange its children homogeneously.
Eina_Bool elm_box_homogeneous_get (const Elm_Box *obj)
 Get whether the box is using homogeneous mode or not ($true if it's homogeneous, false otherwise)
void elm_box_align_set (Elm_Box *obj, double horizontal, double vertical)
 Set the alignment of the whole bounding box of contents.
void elm_box_align_get (const Elm_Box *obj, double *horizontal, double *vertical)
 Get the alignment of the whole bounding box of contents.
void elm_box_horizontal_set (Elm_Box *obj, Eina_Bool horizontal)
 Set the horizontal orientation.
Eina_Bool elm_box_horizontal_get (const Elm_Box *obj)
 Get the horizontal orientation ($true if the box is set to horizontal mode, false otherwise)
void elm_box_padding_set (Elm_Box *obj, Evas_Coord horizontal, Evas_Coord vertical)
 Set the space (padding) between the box's elements.
void elm_box_padding_get (const Elm_Box *obj, Evas_Coord *horizontal, Evas_Coord *vertical)
 Get the space (padding) between the box's elements.
void elm_box_layout_set (Elm_Box *obj, Evas_Object_Box_Layout cb, const void *data, Ecore_Cb free_data)
 Set the layout defining function to be used by the box.
Eina_Listelm_box_children_get (const Elm_Box *obj)
 Get a list of the objects packed into the box.
void elm_box_pack_end (Elm_Box *obj, Evas_Object *subobj)
 Add an object at the end of the pack list.
void elm_box_unpack_all (Elm_Box *obj)
 Remove all items from the box, without deleting them.
void elm_box_unpack (Elm_Box *obj, Evas_Object *subobj)
 Unpack a box item.
void elm_box_pack_after (Elm_Box *obj, Evas_Object *subobj, Evas_Object *after)
 Adds an object to the box after the indicated object.
void elm_box_pack_start (Elm_Box *obj, Evas_Object *subobj)
 Add an object to the beginning of the pack list.
void elm_box_recalculate (Elm_Box *obj)
 Force the box to recalculate its children packing.
void elm_box_pack_before (Elm_Box *obj, Evas_Object *subobj, Evas_Object *before)
 Adds an object to the box before the indicated object.
void elm_box_clear (Elm_Box *obj)
 Clear the box of all children.
void elm_box_layout_transition (Evas_Object *obj, Evas_Object_Box_Data *priv, void *data)
Elm_Box_Transitionelm_box_transition_new (const double duration, Evas_Object_Box_Layout start_layout, void *start_layout_data, Ecore_Cb start_layout_free_data, Evas_Object_Box_Layout end_layout, void *end_layout_data, Ecore_Cb end_layout_free_data, Ecore_Cb transition_end_cb, void *transition_end_data)
void elm_box_transition_free (void *data)
Evas_Objectelm_box_add (Evas_Object *parent)

Typedefs

typedef struct _Elm_Box_Transition Elm_Box_Transition

Typedef Documentation

Opaque handler containing the parameters to perform an animated transition of the layout the box uses.

See also:
elm_box_transition_new()
elm_box_layout_set()
elm_box_layout_transition()

Function Documentation

Add a new box to the parent

By default, the box will be in vertical mode and non-homogeneous.

Parameters:
parentThe parent object
Returns:
The new object or NULL if it cannot be created
Since :
2.3
void elm_box_align_get ( const Elm_Box *  obj,
double *  horizontal,
double *  vertical 
)

Get the alignment of the whole bounding box of contents.

See also elm_box_align_set.

Since :
2.3
Parameters:
[in]objThe object.
[out]horizontalThe horizontal alignment of elements
[out]verticalThe vertical alignment of elements
void elm_box_align_set ( Elm_Box *  obj,
double  horizontal,
double  vertical 
)

Set the alignment of the whole bounding box of contents.

Sets how the bounding box containing all the elements of the box, after their sizes and position has been calculated, will be aligned within the space given for the whole box widget.

Since :
2.3
Parameters:
[in]objThe object.
[in]horizontalThe horizontal alignment of elements
[in]verticalThe vertical alignment of elements
Eina_List* elm_box_children_get ( const Elm_Box *  obj)

Get a list of the objects packed into the box.

Returns a new list with a pointer to Evas_Object in its nodes. The order of the list corresponds to the packing order the box uses.

You must free this list with eina_list_free() once you are done with it.

Since :
2.3
Parameters:
[in]objThe object.
void elm_box_clear ( Elm_Box *  obj)

Clear the box of all children.

Remove all the elements contained by the box, deleting the respective objects.

See also elm_box_unpack, elm_box_unpack_all.

Since :
2.3
Parameters:
[in]objThe object.
Eina_Bool elm_box_homogeneous_get ( const Elm_Box *  obj)

Get whether the box is using homogeneous mode or not ($true if it's homogeneous, false otherwise)

Since :
2.3
Parameters:
[in]objThe object.
Returns:
The homogeneous flag
void elm_box_homogeneous_set ( Elm_Box *  obj,
Eina_Bool  homogeneous 
)

Set the box to arrange its children homogeneously.

If enabled, homogeneous layout makes all items the same size, according to the size of the largest of its children.

Note:
This flag is ignored if a custom layout function is set.
Since :
2.3
Parameters:
[in]objThe object.
[in]homogeneousThe homogeneous flag
Eina_Bool elm_box_horizontal_get ( const Elm_Box *  obj)

Get the horizontal orientation ($true if the box is set to horizontal mode, false otherwise)

Since :
2.3
Parameters:
[in]objThe object.
Returns:
The horizontal flag
void elm_box_horizontal_set ( Elm_Box *  obj,
Eina_Bool  horizontal 
)

Set the horizontal orientation.

By default, box object arranges their contents vertically from top to bottom. By calling this function with horizontal as true, the box will become horizontal, arranging contents from left to right.

Note:
This flag is ignored if a custom layout function is set.
Since :
2.3
Parameters:
[in]objThe object.
[in]horizontalThe horizontal flag
void elm_box_layout_set ( Elm_Box *  obj,
Evas_Object_Box_Layout  cb,
const void *  data,
Ecore_Cb  free_data 
)

Set the layout defining function to be used by the box.

Whenever anything changes that requires the box in obj to recalculate the size and position of its elements, the function cb will be called to determine what the layout of the children will be.

Once a custom function is set, everything about the children layout is defined by it. The flags set by elm_box_horizontal_set and elm_box_homogeneous_set no longer have any meaning, and the values given by elm_box_padding_set and elm_box_align_set are up to this layout function to decide if they are used and how. These last two will be found in the priv parameter, of type Evas_Object_Box_Data, passed to cb. The Evas_Object the function receives is not the Elementary widget, but the internal Evas Box it uses, so none of the functions described here can be used on it.

Any of the layout functions in Evas can be used here, as well as the special elm_box_layout_transition.

The final data argument received by cb is the same data passed here, and the free_data function will be called to free it whenever the box is destroyed or another layout function is set.

Setting cb to null will revert back to the default layout function.

See also elm_box_layout_transition.

Since :
2.3
Parameters:
[in]objThe object.
[in]cbThe callback function used for layout
[in]dataData that will be passed to layout function
[in]free_dataFunction called to free data
void elm_box_layout_transition ( Evas_Object obj,
Evas_Object_Box_Data priv,
void *  data 
)

Special layout function that animates the transition from one layout to another

Normally, when switching the layout function for a box, this will be reflected immediately on screen on the next render, but it's also possible to do this through an animated transition.

This is done by creating an Elm_Box_Transition and setting the box layout to this function.

For example:

 Elm_Box_Transition *t = elm_box_transition_new(1.0,
                            evas_object_box_layout_vertical, // start
                            NULL, // data for initial layout
                            NULL, // free function for initial data
                            evas_object_box_layout_horizontal, // end
                            NULL, // data for final layout
                            NULL, // free function for final data
                            anim_end, // will be called when animation ends
                            NULL); // data for anim_end function\
 elm_box_layout_set(box, elm_box_layout_transition, t,
                    elm_box_transition_free);
Note:
This function can only be used with elm_box_layout_set(). Calling it directly will not have the expected results.
See also:
elm_box_transition_new
elm_box_transition_free
elm_box_layout_set
Since :
2.3
void elm_box_pack_after ( Elm_Box *  obj,
Evas_Object subobj,
Evas_Object after 
)

Adds an object to the box after the indicated object.

This will add the subobj to the box indicated after the object indicated with after. If after is not already in the box, results are undefined. After means either to the right of the indicated object or below it depending on orientation.

See also elm_box_pack_start, elm_box_pack_end, elm_box_pack_before, elm_box_unpack, elm_box_unpack_all, elm_box_clear.

Since :
2.3
Parameters:
[in]objThe object.
[in]subobjThe object to add to the box
[in]afterThe object after which to add it
void elm_box_pack_before ( Elm_Box *  obj,
Evas_Object subobj,
Evas_Object before 
)

Adds an object to the box before the indicated object.

This will add the subobj to the box indicated before the object indicated with before. If before is not already in the box, results are undefined. Before means either to the left of the indicated object or above it depending on orientation.

See also elm_box_pack_start, elm_box_pack_end, elm_box_pack_after, elm_box_unpack, elm_box_unpack_all, elm_box_clear.

Since :
2.3
Parameters:
[in]objThe object.
[in]subobjThe object to add to the box
[in]beforeThe object before which to add it
void elm_box_pack_end ( Elm_Box *  obj,
Evas_Object subobj 
)

Add an object at the end of the pack list.

Pack subobj into the box obj, placing it last in the list of children objects. The actual position the object will get on screen depends on the layout used. If no custom layout is set, it will be at the bottom or right, depending if the box is vertical or horizontal, respectively.

See also elm_box_pack_start, elm_box_pack_before, elm_box_pack_after, elm_box_unpack, elm_box_unpack_all, elm_box_clear.

Since :
2.3
Parameters:
[in]objThe object.
[in]subobjThe object to add to the box
void elm_box_pack_start ( Elm_Box *  obj,
Evas_Object subobj 
)

Add an object to the beginning of the pack list.

Pack subobj into the box obj, placing it first in the list of children objects. The actual position the object will get on screen depends on the layout used. If no custom layout is set, it will be at the top or left, depending if the box is vertical or horizontal, respectively.

See also elm_box_pack_end, elm_box_pack_before, elm_box_pack_after, elm_box_unpack, elm_box_unpack_all, elm_box_clear.

Since :
2.3
Parameters:
[in]objThe object.
[in]subobjThe object to add to the box
void elm_box_padding_get ( const Elm_Box *  obj,
Evas_Coord horizontal,
Evas_Coord vertical 
)

Get the space (padding) between the box's elements.

See also elm_box_padding_set.

Since :
2.3
Parameters:
[in]objThe object.
[out]horizontalThe horizontal space between elements
[out]verticalThe vertical space between elements
void elm_box_padding_set ( Elm_Box *  obj,
Evas_Coord  horizontal,
Evas_Coord  vertical 
)

Set the space (padding) between the box's elements.

Extra space in pixels that will be added between a box child and its neighbors after its containing cell has been calculated. This padding is set for all elements in the box, besides any possible padding that individual elements may have through their size hints.

Since :
2.3
Parameters:
[in]objThe object.
[in]horizontalThe horizontal space between elements
[in]verticalThe vertical space between elements
void elm_box_recalculate ( Elm_Box *  obj)

Force the box to recalculate its children packing.

If any children was added or removed, box will not calculate the values immediately rather leaving it to the next main loop iteration. While this is great as it would save lots of recalculation, whenever you need to get the position of a just added item you must force recalculate before doing so.

Since :
2.3
Parameters:
[in]objThe object.
void elm_box_transition_free ( void *  data)

Free a Elm_Box_Transition instance created with elm_box_transition_new().

This function is mostly useful as the free_data parameter in elm_box_layout_set() when elm_box_layout_transition().

Parameters:
dataThe Elm_Box_Transition instance to be freed.
See also:
elm_box_transition_new
elm_box_layout_transition
Since :
2.3
Elm_Box_Transition* elm_box_transition_new ( const double  duration,
Evas_Object_Box_Layout  start_layout,
void *  start_layout_data,
Ecore_Cb  start_layout_free_data,
Evas_Object_Box_Layout  end_layout,
void *  end_layout_data,
Ecore_Cb  end_layout_free_data,
Ecore_Cb  transition_end_cb,
void *  transition_end_data 
)

Create a new Elm_Box_Transition to animate the switch of layouts

If you want to animate the change from one layout to another, you need to set the layout function of the box to elm_box_layout_transition(), passing as user data to it an instance of Elm_Box_Transition with the necessary information to perform this animation. The free function to set for the layout is elm_box_transition_free().

The parameters to create an Elm_Box_Transition sum up to how long will it be, in seconds, a layout function to describe the initial point, another for the final position of the children and one function to be called when the whole animation ends. This last function is useful to set the definitive layout for the box, usually the same as the end layout for the animation, but could be used to start another transition.

Parameters:
durationThe duration of the transition in seconds
start_layoutThe layout function that will be used to start the animation
start_layout_dataThe data to be passed the start_layout function
start_layout_free_dataFunction to free start_layout_data
end_layoutThe layout function that will be used to end the animation
end_layout_dataData param passed to end_layout
end_layout_free_dataThe data to be passed the end_layout function
end_layout_free_dataFunction to free end_layout_data
transition_end_cbCallback function called when animation ends
transition_end_dataData to be passed to transition_end_cb
Returns:
An instance of Elm_Box_Transition
See also:
elm_box_transition_new
elm_box_layout_transition
Since :
2.3
void elm_box_unpack ( Elm_Box *  obj,
Evas_Object subobj 
)

Unpack a box item.

Remove the object given by subobj from the box obj without deleting it.

See also elm_box_unpack_all, elm_box_clear.

Since :
2.3
Parameters:
[in]objThe object.
[in]subobjThe object to unpack
void elm_box_unpack_all ( Elm_Box *  obj)

Remove all items from the box, without deleting them.

Clear the box from all children, but don't delete the respective objects. If no other references of the box children exist, the objects will never be deleted, and thus the application will leak the memory. Make sure when using this function that you hold a reference to all the objects in the box obj.

See also elm_box_clear, elm_box_unpack.

Since :
2.3
Parameters:
[in]objThe object.