libchamplain Reference Manual: ChamplainView

## ChamplainView ChamplainView — A ClutterActor to display maps |

## Functions

ClutterActor * | champlain_view_new ()
void | champlain_view_center_on ()
void | champlain_view_go_to ()
void | champlain_view_stop_go_to ()
void | champlain_view_zoom_in ()
void | champlain_view_zoom_out ()
void | champlain_view_set_zoom_level ()
void | champlain_view_set_min_zoom_level ()
void | champlain_view_set_max_zoom_level ()
void | champlain_view_set_world ()
ChamplainBoundingBox * | champlain_view_get_world ()
void | champlain_view_ensure_visible ()
void | champlain_view_ensure_layers_visible ()
void | champlain_view_set_map_source ()
void | champlain_view_add_overlay_source ()
void | champlain_view_remove_overlay_source ()
GList * | champlain_view_get_overlay_sources ()
void | champlain_view_set_deceleration ()
void | champlain_view_set_kinetic_mode ()
void | champlain_view_set_keep_center_on_resize ()
void | champlain_view_set_zoom_on_double_click ()
void | champlain_view_set_animate_zoom ()
void | champlain_view_set_background_pattern ()
void | champlain_view_add_layer ()
void | champlain_view_remove_layer ()
guint | champlain_view_get_zoom_level ()
guint | champlain_view_get_min_zoom_level ()
guint | champlain_view_get_max_zoom_level ()
ChamplainMapSource * | champlain_view_get_map_source ()
gdouble | champlain_view_get_deceleration ()
gboolean | champlain_view_get_kinetic_mode ()
gboolean | champlain_view_get_keep_center_on_resize ()
gboolean | champlain_view_get_zoom_on_double_click ()
gboolean | champlain_view_get_animate_zoom ()
ClutterContent * | champlain_view_get_background_pattern ()
void | champlain_view_reload_tiles ()
cairo_surface_t * | champlain_view_to_surface ()
gdouble | champlain_view_x_to_longitude ()
gdouble | champlain_view_y_to_latitude ()
gdouble | champlain_view_longitude_to_x ()
gdouble | champlain_view_latitude_to_y ()
void | champlain_view_get_viewport_origin ()
void | champlain_view_bin_layout_add ()
ChamplainLicense * | champlain_view_get_license_actor ()
gdouble | champlain_view_get_center_latitude ()
gdouble | champlain_view_get_center_longitude ()
ChamplainBoundingBox * | champlain_view_get_bounding_box ()
ChamplainBoundingBox * | champlain_view_get_bounding_box_for_zoom_level ()
ChamplainState | champlain_view_get_state ()

## Properties

gboolean | animate-zoom | Read / Write
ClutterActor * | background-pattern | Read / Write
gdouble | deceleration | Read / Write
guint | goto-animation-duration | Read / Write
ClutterAnimationMode | goto-animation-mode | Read / Write
gboolean | keep-center-on-resize | Read / Write
gboolean | kinetic-mode | Read / Write
gdouble | latitude | Read / Write
gdouble | longitude | Read / Write
ChamplainMapSource * | map-source | Read / Write
guint | max-zoom-level | Read / Write
guint | min-zoom-level | Read / Write
ChamplainState | state | Read
ChamplainBoundingBox * | world | Read / Write
guint | zoom-level | Read / Write
gboolean | zoom-on-double-click | Read / Write

## Signals

void | animation-completed | Has Details
void | layer-relocated | Run Last

## Types and Values

struct | ChamplainView

## Object Hierarchy

        GObject
        ╰── GInitiallyUnowned
            ╰── ClutterActor
                ╰── ChamplainView

## Implemented Interfaces

ChamplainView implements ClutterContainer, ClutterScriptable, ClutterAnimatable and AtkImplementorIface.

## Description

The ChamplainView is a ClutterActor to display maps. It supports two modes of scrolling:

- Push: the normal behavior where the maps don't move after the user stopped scrolling;

- Kinetic: the iPhone-like behavior where the maps decelerate after the user stopped scrolling.

You can use the same ChamplainView to display many types of maps. In Champlain they are called map sources. You can change the map-source property at anytime to replace the current displayed map.

The maps are downloaded from Internet from open maps sources (like OpenStreetMap). Maps are divided in tiles for each zoom level. When a tile is requested, ChamplainView will first check if it is in cache (in the user's cache dir under champlain). If an error occurs during download, an error tile will be displayed.

The button-press-event and button-release-event signals are emitted each time a mouse button is pressed and released on the `view` .

## Functions

### champlain_view_new ()

    ClutterActor *
    champlain_view_new (void);

Creates an instance of ChamplainView.

#### Returns

a new ChamplainView ready to be used as a ClutterActor.

Since 0.4

### champlain_view_center_on ()

    void
    champlain_view_center_on (ChamplainView *view,
                              gdouble latitude,
                              gdouble longitude);

Centers the map on these coordinates.

#### Parameters

view | a ChamplainView |
latitude | the longitude to center the map at |
longitude | the longitude to center the map at |

Since 0.1

### champlain_view_go_to ()

    void
    champlain_view_go_to (ChamplainView *view,
                          gdouble latitude,
                          gdouble longitude);

Move from the current position to these coordinates. All tiles in the intermediate view WILL be loaded!

#### Parameters

view | a ChamplainView |
latitude | the longitude to center the map at |
longitude | the longitude to center the map at |

Since 0.4

### champlain_view_stop_go_to ()

    void
    champlain_view_stop_go_to (ChamplainView *view);

Stop the go to animation. The view will stay where it was when the animation was stopped.

#### Parameters

view | a ChamplainView |

Since 0.4

### champlain_view_zoom_in ()

    void
    champlain_view_zoom_in (ChamplainView *view);

Zoom in the map by one level.

#### Parameters

view | a ChamplainView |

Since 0.1

### champlain_view_zoom_out ()

    void
    champlain_view_zoom_out (ChamplainView *view);

Zoom out the map by one level.

#### Parameters

view | a ChamplainView |

Since 0.1

### champlain_view_set_zoom_level ()

    void
    champlain_view_set_zoom_level (ChamplainView *view,
                                   guint zoom_level);

Changes the current level of zoom

#### Parameters

view | a ChamplainView |
zoom_level | the level of zoom, a guint between 1 and 20 |

Since 0.4

### champlain_view_set_min_zoom_level ()

    void
    champlain_view_set_min_zoom_level (ChamplainView *view,
                                       guint zoom_level);

Changes the lowest allowed level of zoom

#### Parameters

view | a ChamplainView |
zoom_level | the level of zoom |

Since 0.4

### champlain_view_set_max_zoom_level ()

    void
    champlain_view_set_max_zoom_level (ChamplainView *view,
                                       guint zoom_level);

Changes the highest allowed level of zoom

#### Parameters

view | a ChamplainView |
zoom_level | the level of zoom |

Since 0.4

### champlain_view_set_world ()

    void
    champlain_view_set_world (ChamplainView *view,
                              ChamplainBoundingBox *bbox);

Set a bounding box to limit the world to. No tiles will be loaded outside of this bounding box. It will not be possible to scroll outside of this bounding box.

#### Parameters

view | a ChamplainView |
bbox | the ChamplainBoundingBox of the world. | [transfer none]

Since 0.12.11

### champlain_view_get_world ()

    ChamplainBoundingBox *
    champlain_view_get_world (ChamplainView *view);

Get the bounding box that represents the extent of the world.

#### Parameters

view | a ChamplainView |

#### Returns

a ChamplainBoundingBox that represents the current world.

[transfer none]

Since 0.12.11

### champlain_view_ensure_visible ()

    void
    champlain_view_ensure_visible (ChamplainView *view,
                                   ChamplainBoundingBox *bbox,
                                   gboolean animate);

Changes the map's zoom level and center to make sure the given area is visible

#### Parameters

view | a ChamplainView |
bbox | bounding box of the area that should be visible |
animate | TRUE to perform animation, FALSE otherwise |

Since 0.10

### champlain_view_ensure_layers_visible ()

    void
    champlain_view_ensure_layers_visible (ChamplainView *view,
                                          gboolean animate);

Changes the map's zoom level and center to make sure that the bounding boxes of all inserted layers are visible.

#### Parameters

view | a ChamplainView |
animate | TRUE to perform animation, FALSE otherwise |

Since 0.10

### champlain_view_set_map_source ()

    void
    champlain_view_set_map_source (ChamplainView *view,
                                   ChamplainMapSource *map_source);

Changes the currently used map source. ``g_object_unref()`` will be called on the previous one.

As a side effect, changing the primary map source will also clear all secondary map sources.

#### Parameters

view | a ChamplainView |
map_source | a ChamplainMapSource |

Since 0.4

### champlain_view_add_overlay_source ()

    void
    champlain_view_add_overlay_source (ChamplainView *view,
                                       ChamplainMapSource *map_source,
                                       guint8 opacity);

Adds a new overlay map source to render tiles with the supplied opacity on top of the ordinary map source. Multiple overlay sources can be added.

#### Parameters

view | a ChamplainView |
map_source | a ChamplainMapSource |
opacity | opacity to use |

Since 0.12.5

### champlain_view_remove_overlay_source ()

    void
    champlain_view_remove_overlay_source (ChamplainView *view,
                                          ChamplainMapSource *map_source);

Removes an overlay source from ChamplainView.

#### Parameters

view | a ChamplainView |
map_source | a ChamplainMapSource |

Since 0.12.5

### champlain_view_get_overlay_sources ()

    GList *
    champlain_view_get_overlay_sources (ChamplainView *view);

Gets a list of overlay sources.

#### Parameters

view | a ChamplainView |

#### Returns

the list.

[transfer container][element-type ChamplainMapSource]

Since 0.12.5

### champlain_view_set_deceleration ()

    void
    champlain_view_set_deceleration (ChamplainView *view,
                                     gdouble rate);

The deceleration rate for the kinetic mode.

#### Parameters

view | a ChamplainView |
rate | a gdouble between 1.001 and 2.0 |

Since 0.4

### champlain_view_set_kinetic_mode ()

    void
    champlain_view_set_kinetic_mode (ChamplainView *view,
                                     gboolean kinetic);

Determines the way the view reacts to scroll events.

#### Parameters

view | a ChamplainView |
kinetic | TRUE for kinetic mode, FALSE for push mode |

Since 0.10

### champlain_view_set_keep_center_on_resize ()

    void
    champlain_view_set_keep_center_on_resize
                                   (ChamplainView *view,
                                    gboolean value);

Keep the current centered position when resizing the view.

#### Parameters

view | a ChamplainView |
value | a gboolean |

Since 0.4

### champlain_view_set_zoom_on_double_click ()

    void
    champlain_view_set_zoom_on_double_click
                                   (ChamplainView *view,
                                    gboolean value);

Should the view zoom in and recenter when the user double click on the map.

#### Parameters

view | a ChamplainView |
value | a gboolean |

Since 0.4

### champlain_view_set_animate_zoom ()

    void
    champlain_view_set_animate_zoom (ChamplainView *view,
                                     gboolean value);

Should the view animate zoom level changes.

#### Parameters

view | a ChamplainView |
value | a gboolean |

Since 0.12

### champlain_view_set_background_pattern ()

    void
    champlain_view_set_background_pattern (ChamplainView *view,
                                           ClutterContent *background);

Sets the background texture displayed behind the map. Setting the background pattern affects performence slightly - use reasonably large patterns for better performance.

#### Parameters

view | a ChamplainView |
background | The background texture |

Since 0.12.4

### champlain_view_add_layer ()

    void
    champlain_view_add_layer (ChamplainView *view,
                              ChamplainLayer *layer);

Adds a new layer to the view

#### Parameters

view | a ChamplainView |
layer | a ChamplainLayer |

Since 0.2

### champlain_view_remove_layer ()

    void
    champlain_view_remove_layer (ChamplainView *view,
                                 ChamplainLayer *layer);

Removes the given layer from the view

#### Parameters

view | a ChamplainView |
layer | a ChamplainLayer |

Since 0.4.1

### champlain_view_get_zoom_level ()

    guint
    champlain_view_get_zoom_level (ChamplainView *view);

Gets the view's current zoom level.

#### Parameters

view | a ChamplainView |

#### Returns

the view's current zoom level.

Since 0.4

### champlain_view_get_min_zoom_level ()

    guint
    champlain_view_get_min_zoom_level (ChamplainView *view);

Gets the view's minimal allowed zoom level.

#### Parameters

view | a ChamplainView |

#### Returns

the view's minimal allowed zoom level.

Since 0.4

### champlain_view_get_max_zoom_level ()

    guint
    champlain_view_get_max_zoom_level (ChamplainView *view);

Gets the view's maximum allowed zoom level.

#### Parameters

view | a ChamplainView |

#### Returns

the view's maximum allowed zoom level.

Since 0.4

### champlain_view_get_map_source ()

    ChamplainMapSource *
    champlain_view_get_map_source (ChamplainView *view);

Gets the view's current map source.

#### Parameters

view | a ChamplainView |

#### Returns

the view's current map source. If you need to keep a reference to the map source then you have to call ``g_object_ref()``.

[transfer none]

Since 0.4

### champlain_view_get_deceleration ()

    gdouble
    champlain_view_get_deceleration (ChamplainView *view);

Gets the view's deceleration rate.

#### Parameters

view | a ChamplainView |

#### Returns

the view's deceleration rate.

Since 0.4

### champlain_view_get_kinetic_mode ()

    gboolean
    champlain_view_get_kinetic_mode (ChamplainView *view);

Gets the view's scroll mode behaviour.

#### Parameters

view | a ChamplainView |

#### Returns

TRUE for kinetic mode, FALSE for push mode.

Since 0.10

### champlain_view_get_keep_center_on_resize ()

    gboolean
    champlain_view_get_keep_center_on_resize
                                   (ChamplainView *view);

Checks whether to keep the center on resize

#### Parameters

view | a ChamplainView |

#### Returns

TRUE if the view keeps the center on resize, FALSE otherwise.

Since 0.4

### champlain_view_get_zoom_on_double_click ()

    gboolean
    champlain_view_get_zoom_on_double_click
                                   (ChamplainView *view);

Checks whether the view zooms on double click.

#### Parameters

view | a ChamplainView |

#### Returns

TRUE if the view zooms on double click, FALSE otherwise.

Since 0.4

### champlain_view_get_animate_zoom ()

    gboolean
    champlain_view_get_animate_zoom (ChamplainView *view);

Checks whether the view animates zoom level changes.

#### Parameters

view | a ChamplainView |

#### Returns

TRUE if the view animates zooms, FALSE otherwise.

Since 0.12

### champlain_view_get_background_pattern ()

    ClutterContent *
    champlain_view_get_background_pattern (ChamplainView *view);

Gets the current background texture displayed behind the map.

#### Parameters

view | a ChamplainView |

#### Returns

The texture.

[transfer none]

Since 0.12.4

### champlain_view_reload_tiles ()

    void
    champlain_view_reload_tiles (ChamplainView *view);

Reloads all visible tiles.

#### Parameters

view | a ChamplainView |

Since 0.8

### champlain_view_to_surface ()

    cairo_surface_t *
    champlain_view_to_surface (ChamplainView *view,
                               gboolean include_layers);

Will generate a cairo_surface_t that represents the current view of the map. Without any markers or layers. If the current ChamplainRenderer used does not support this, this function will return `NULL`.

If `include_layers` is set to `TRUE` all layers that implement ChamplainExportable will be included in the surface.

The ChamplainView also need to be in CHAMPLAIN_STATE_DONE state.

#### Parameters

view | a ChamplainView |
include_layers | Set to `TRUE` if you want to include layers |

#### Returns

a cairo_surface_t or `NULL` on failure. Free with `cairo_surface_destroy()` when done.

[transfer full]

### champlain_view_x_to_longitude ()

    gdouble
    champlain_view_x_to_longitude (ChamplainView *view,
                                   gdouble x);

Converts the view's x coordinate to longitude.

#### Parameters

view | a ChamplainView |
x | x coordinate of the view |

#### Returns

the longitude

Since 0.10

### champlain_view_y_to_latitude ()

    gdouble
    champlain_view_y_to_latitude (ChamplainView *view,
                                  gdouble y);

Converts the view's y coordinate to latitude.

#### Parameters

view | a ChamplainView |
y | y coordinate of the view |

#### Returns

the latitude

Since 0.10

### champlain_view_longitude_to_x ()

    gdouble
    champlain_view_longitude_to_x (ChamplainView *view,
                                   gdouble longitude);

Converts the longitude to view's x coordinate.

#### Parameters

view | a ChamplainView |
longitude | the longitude |

#### Returns

the x coordinate

Since 0.10

### champlain_view_latitude_to_y ()

    gdouble
    champlain_view_latitude_to_y (ChamplainView *view,
                                  gdouble latitude);

Converts the latitude to view's y coordinate.

#### Parameters

view | a ChamplainView |
latitude | the latitude |

#### Returns

the y coordinate

Since 0.10

### champlain_view_get_viewport_origin ()

    void
    champlain_view_get_viewport_origin (ChamplainView *view,
                                        gint *x,
                                        gint *y);

Gets the x and y coordinate of the viewport in respect to the layer origin.

#### Parameters

view | a ChamplainView |
x | the x coordinate of the viewport. | [out]
y | the y coordinate of the viewport. | [out]

Since 0.10

### champlain_view_bin_layout_add ()

    void
    champlain_view_bin_layout_add (ChamplainView *view,
                                   ClutterActor *child,
                                   ClutterBinAlignment x_align,
                                   ClutterBinAlignment y_align);

`champlain_view_bin_layout_add` has been deprecated since version 0.12.4 and should not be used in newly-written code.

Use ClutterActorAlign and the ClutterActor API instead.

This function inserts a custom actor to the undrelying ClutterBinLayout manager. The inserted actors appear on top of the map. See `clutter_bin_layout_add()` for reference.

#### Parameters

view | a ChamplainView |
child | The child to be inserted |
x_align | x alignment |
y_align | y alignment |

Since 0.10

### champlain_view_get_license_actor ()

    ChamplainLicense *
    champlain_view_get_license_actor (ChamplainView *view);

Returns the ChamplainLicense actor which is inserted by default into the layout manager. It can be manipulated using standard ClutterActor methods (hidden and so on).

#### Parameters

view | a ChamplainView |

#### Returns

the license actor.

[transfer none]

Since 0.10

### champlain_view_get_center_latitude ()

    gdouble
    champlain_view_get_center_latitude (ChamplainView *view);

Gets the latitude of the view's center.

#### Parameters

view | a ChamplainView |

#### Returns

the latitude.

Since 0.10

### champlain_view_get_center_longitude ()

    gdouble
    champlain_view_get_center_longitude (ChamplainView *view);

Gets the longitude of the view's center.

#### Parameters

view | a ChamplainView |

#### Returns

the longitude.

Since 0.10

### champlain_view_get_bounding_box ()

    ChamplainBoundingBox *
    champlain_view_get_bounding_box (ChamplainView *view);

Gets the bounding box for view `view` at current zoom-level.

#### Parameters

view | a ChamplainView |

#### Returns

the bounding box.

[transfer full]

Since 0.12.4

### champlain_view_get_bounding_box_for_zoom_level ()

    ChamplainBoundingBox *
    champlain_view_get_bounding_box_for_zoom_level
                                   (ChamplainView *view,
                                    guint zoom_level);

Gets the bounding box for view `view` at `zoom_level` .

#### Parameters

view | a ChamplainView |
zoom_level | the level of zoom, a guint between 1 and 20 |

#### Returns

the bounding box for the view at `zoom_level` .

[transfer full]

Since 0.12.6

### champlain_view_get_state ()

    ChamplainState
    champlain_view_get_state (ChamplainView *view);

Gets the view's state.

#### Parameters

view | a ChamplainView |

#### Returns

the state.

Since 0.10

## Types and Values

### struct ChamplainView

    struct ChamplainView;

The ChamplainView structure contains only private data and should be accessed using the provided API

Since 0.1

## Property Details

### The `“animate-zoom”` property

      “animate-zoom”             gboolean

Animate zoom change when zooming in/out.

Flags: Read / Write

Default value: TRUE

Since 0.12

### The `“background-pattern”` property

      “background-pattern”       ClutterActor *

The pattern displayed in the background of the map.

Flags: Read / Write

Since 0.12.4

### The `“deceleration”` property

      “deceleration”             gdouble

The deceleration rate for the kinetic mode. The default value is 1.1.

Flags: Read / Write

Allowed values: [1.0001,2]

Default value: 1.1

Since 0.10

### The `“goto-animation-duration”` property

      “goto-animation-duration”  guint

The duration of an animation when going to a location. A value of 0 means that the duration is calculated automatically for you.

Please note that animation of champlain_view_ensure_visible also involves a 'goto' animation.

Flags: Read / Write

Allowed values: <= G_MAXINT

Default value: 0

### The `“goto-animation-mode”` property

      “goto-animation-mode”      ClutterAnimationMode

The mode of animation when going to a location.

Please note that animation of champlain_view_ensure_visible also involves a 'goto' animation.

Flags: Read / Write

Default value: CLUTTER_EASE_IN_OUT_CIRC

### The `“keep-center-on-resize”` property

      “keep-center-on-resize”    gboolean

Keep the current centered position when resizing the view.

Flags: Read / Write

Default value: TRUE

Since 0.2.7

### The `“kinetic-mode”` property

      “kinetic-mode”             gboolean

Determines whether the view should use kinetic mode.

Flags: Read / Write

Default value: FALSE

Since 0.10

### The `“latitude”` property

      “latitude”                 gdouble

The latitude coordonate of the map

Flags: Read / Write

Allowed values: [-90,90]

Default value: 0

Since 0.1

### The `“longitude”` property

      “longitude”                gdouble

The longitude coordonate of the map

Flags: Read / Write

Allowed values: [-180,180]

Default value: 0

Since 0.1

### The `“map-source”` property

      “map-source”               ChamplainMapSource *

The ChamplainMapSource being displayed

Flags: Read / Write

Since 0.2

### The `“max-zoom-level”` property

      “max-zoom-level”           guint

The highest allowed level of zoom of the content.

Flags: Read / Write

Allowed values: <= 20

Default value: 20

Since 0.4

### The `“min-zoom-level”` property

      “min-zoom-level”           guint

The lowest allowed level of zoom of the content.

Flags: Read / Write

Allowed values: <= 20

Default value: 0

Since 0.4

### The `“state”` property

      “state”                    ChamplainState

The view's global state. Useful to inform using if the view is busy loading tiles or not.

Flags: Read

Default value: CHAMPLAIN_STATE_NONE

Since 0.4

### The `“world”` property

      “world”                    ChamplainBoundingBox *

Set a bounding box to limit the world to. No tiles will be loaded outside of this bounding box. It will not be possible to scroll outside of this bounding box.

Default world is the actual world.

Flags: Read / Write

Since 0.12.11

### The `“zoom-level”` property

      “zoom-level”               guint

The level of zoom of the content.

Flags: Read / Write

Allowed values: <= 20

Default value: 3

Since 0.1

### The `“zoom-on-double-click”` property

      “zoom-on-double-click”     gboolean

Should the view zoom in and recenter when the user double click on the map.

Flags: Read / Write

Default value: TRUE

Since 0.4

## Signal Details

### The `“animation-completed”` signal

    void
    user_function (ChamplainView *arg0,
                   gpointer       user_data)

The “animation-completed” signal is emitted when any animation in the view ends. This is a detailed signal. For example, if you want to be signaled only for go-to animation, you should connect to "animation-completed::go-to". And for zoom, connect to "animation-completed::zoom".

#### Parameters

user_data | user data set when the signal handler was connected. |

Flags: Has Details

Since 0.4

### The `“layer-relocated”` signal

    void
    user_function (ChamplainView *arg0,
                   gpointer       user_data)

Indicates that the layers have been "relocated". In practice this means that every layer should connect to this signal and redraw itself when the signal is emitted. Layer relocation happens when zooming in/out and when panning for more than MAX_INT pixels.

#### Parameters

user_data | user data set when the signal handler was connected. |

Flags: Run Last

Since 0.10