## ClutterContent

ClutterContent — Delegate for painting the content of an actor

## Functions

gboolean | clutter_content_get_preferred_size ()
void | clutter_content_invalidate ()

## Signals

void | attached | Run First
void | detached | Run First

## Types and Values

| ClutterContent
struct | ClutterContentIface

## Object Hierarchy

        GInterface
        ╰── ClutterContent

## Prerequisites

ClutterContent requires GObject.

## Known Implementations

ClutterContent is implemented by ClutterCanvas and ClutterImage.

## Description

ClutterContent is an interface to implement types responsible for painting the content of a ClutterActor.

Multiple actors can use the same ClutterContent instance, in order to share the resources associated with painting the same content.

ClutterContent is available since Clutter 1.10.

## Functions

### clutter_content_get_preferred_size ()

    gboolean
    clutter_content_get_preferred_size (ClutterContent *content,
                                        gfloat *width,
                                        gfloat *height);

Retrieves the natural size of the `content` , if any.

The natural size of a ClutterContent is defined as the size the content would have regardless of the allocation of the actor that is painting it, for instance the size of an image data.

#### Parameters

content | a ClutterContent |
width | return location for the natural width of the content. | [out]
height | return location for the natural height of the content. | [out]

#### Returns

`TRUE` if the content has a preferred size, and `FALSE` otherwise

Since 1.10

### clutter_content_invalidate ()

    void
    clutter_content_invalidate (ClutterContent *content);

Invalidates a ClutterContent.

This function should be called by ClutterContent implementations when they change the way a the content should be painted regardless of the actor state.

#### Parameters

content | a ClutterContent |

Since 1.10

## Types and Values

### ClutterContent

    typedef struct _ClutterContent ClutterContent;

The ClutterContent structure is an opaque type whose members cannot be acccessed directly.

Since 1.10

### struct ClutterContentIface

    struct ClutterContentIface {
      gboolean      (* get_preferred_size)  (ClutterContent   *content,
                                             gfloat           *width,
                                             gfloat           *height);
      void          (* paint_content)       (ClutterContent   *content,
                                             ClutterActor     *actor,
                                             ClutterPaintNode *node);

      void          (* attached)            (ClutterContent   *content,
                                             ClutterActor     *actor);
      void          (* detached)            (ClutterContent   *content,
                                             ClutterActor     *actor);

      void          (* invalidate)          (ClutterContent   *content);
    };

The ClutterContentIface structure contains only private data.

#### Members

`get_preferred_size` () | virtual function; should be overridden by subclasses of ClutterContent that have a natural size |
`paint_content` () | virtual function; called each time the content needs to paint itself |
`attached` () | virtual function; called each time a ClutterContent is attached to a ClutterActor. |
`detached` () | virtual function; called each time a ClutterContent is detached from a ClutterActor. |
`invalidate` () | virtual function; called each time a ClutterContent state is changed. |

Since 1.10

## Signal Details

### The `“attached”` signal

    void
    user_function (ClutterContent *content,
                   ClutterActor   *actor,
                   gpointer        user_data)

This signal is emitted each time a ClutterContent implementation is assigned to a ClutterActor.

#### Parameters

content | the object that emitted the signal |
actor | a ClutterActor |
user_data | user data set when the signal handler was connected. |

Flags: Run First

Since 1.10

### The `“detached”` signal

    void
    user_function (ClutterContent *content,
                   ClutterActor   *actor,
                   gpointer        user_data)

This signal is emitted each time a ClutterContent implementation is removed from a ClutterActor.

#### Parameters

content | the object that emitted the signal |
actor | a ClutterActor |
user_data | user data set when the signal handler was connected. |

Flags: Run First

Since 1.10