GeoJS

Class: imageTile

geo. imageTile

new geo.imageTile(spec)

imageTile.js, line 32

This class defines a tile that is part of a standard "image pyramid", such as an open street map tile set. Every tile is uniquely indexed by a row, column, and zoom level. The number of rows/columns at zoom level z is 2^z, the number of pixels per tile is configurable.

By default, this class assumes that images are fetched from the url, but subclasses may define additional rendering steps to produce the images before passing them off to the handlers.

Name Type Description
spec geo.imageTile.spec

The tile specification.

Extends

Type Definitions

geo.imageTile.specgeo.tile.spec

Properties:
Name Type Argument Default Description
index object

The global position of the tile.

Properties
Name Type Description
x number

The x-coordinate (the column number).
y number

The y-coordinate (the row number).
level number

The zoom level.
size object <optional>

The size of each tile.

Properties
Name Type Argument Default Description
x number <optional>
 256

Width in pixels.
y number <optional>
 256

Height in pixels.
crossDomain string <optional>
 'anonymous'

Image CORS attribute.
url object | string

A url or jQuery ajax config object.
overlap object <optional>

The size of overlap with neighboring tiles.

Properties
Name Type Default Description
x number 0
y number 0

Members

inherited bottom

Computes the global coordinates of the bottom edge.

Properties:
Name Type Description
bottom number

The global coordinates of the bottom edge.

image

Read only accessor to the Image object used by the tile. Note, this method does not guarantee that the image data is available. Use the promise interface to add asynchronous handlers.

Properties:
Name Type Description
image Image

The image object used by the tile.

inherited index

Return the index coordinates. Read only.

Properties:
Name Type Description
index object

The tile index.

Properties
Name Type Description
x number

The tile x index.
y number

The tile y index.

inherited left

Computes the global coordinates of the left edge.

Properties:
Name Type Description
left number

The global coordinates of the left edge.

inherited overlap

Return the tile overlap. Read only.

Properties:
Name Type Description
overlap object

The tile overlap.

Properties
Name Type Description
x number

The tile x overlap.
y number

The tile y overlap.

Computes the global coordinates of the right edge.

Properties:
Name Type Description
right number

The global coordinates of the right edge.

inherited size

Return the tile size. Read only.

Properties:
Name Type Description
size object

The tile size.

Properties
Name Type Description
x number

The tile width.
y number

The tile height.

inherited top

Computes the global coordinates of the top edge.

Properties:
Name Type Description
top number

The global coordinates of the top edge.

Methods

inherited bounds(index, shift){object}

tile.js, line 162

Return the bounds of the tile given an index offset and a translation.

Name Type Description
index object

The tile index containing (0, 0).
shift object

The coordinates of (0, 0) inside the tile.
Returns:
Type Description
object An object with left, top, right, bottom.

inherited catch(method){this}

tile.js, line 139

Add a method to be called with the data when the ajax fails.

Name Type Description
method function

The rejection handler.
Returns:
Type Description
this

fadeIn(duration){this}

imageTile.js, line 94

Set the opacity of the tile to 0 and gradually fade in over the given number of milliseconds. This will also resolve the embedded promise interface.

Name Type Description
duration number

The duration of the animation in ms.
Returns:
Type Description
this

fetch(){this}

imageTile.js, line 64

Initiate the image request.

Returns:
Type Description
this

inherited fetched(){boolean}

tile.js, line 104

Return whether this tile has been fetched already.

Returns:
Type Description
boolean True if the tile has been fetched.

inherited then(onSuccess, onFailure){this}

tile.js, line 116

Add a method to be called with the data when the ajax request is successfully resolved.

Name Type Description
onSuccess function nullable

The success handler.
onFailure function nullable

The failure handler.
Returns:
Type Description
this

inherited toString(){string}

tile.js, line 151

Return a unique string representation of the given tile useable as a hash key. Possibly extend later to include url information to make caches aware of the tile source.

Returns:
Type Description
string