GeoJS

Class: renderer

geo.canvas. renderer

new geo.canvas.renderer(arg){geo.canvas.canvasRenderer}

canvas/canvasRenderer.js, line 17

Create a new instance of class canvasRenderer.

Name Type Description
arg object

Options for the renderer.

Name Type Description
layer geo.layer optional

Layer associated with the renderer.
canvas HTMLElement optional

Canvas element associated with the renderer.
Returns:
Type Description
geo.canvas.canvasRenderer

Extends

Members

inherited idle

Getter for the idle state. Read only.

Properties:
Name Type Description
idle boolean

true if the object is idle (onIdle would call a handler immediately).

Static Methods

staticgeo.canvas.renderer.fallback(){null}

canvas/canvasRenderer.js, line 188

If the canvas renderer is not supported, supply the name of a renderer that should be used instead. This asks for the null renderer.

Returns:
Type Description
null null for the null renderer.

staticgeo.canvas.renderer.supported(){boolean}

canvas/canvasRenderer.js, line 167

Report if the canvas renderer is supported.

Returns:
Type Description
boolean true if available.

Methods

inherited addPromise(promise){this}

object.js, line 80

Add a new promise object preventing idle event handlers from being called until it is resolved.

Name Type Description
promise Promise

A promise object.
Returns:
Type Description
this

api(){string}

canvas/canvasRenderer.js, line 48

Get API used by the renderer.

Returns:
Type Description
string 'canvas'.

inherited canvas(val){HTMLElement|this}

renderer.js, line 50

Get/set canvas for the renderer.

Name Type Description
val HTMLElement optional

If undefined, return the current canvas element, otherwise set the canvas element and mark the renderer as modified.
Returns:
Type Description
HTMLElement | this The current canvas element or the renderer instance.

clearCanvas(arg)

canvas/canvasRenderer.js, line 39

Set the clear canvas flag. If truthy, the canvas is erased at the start of the render cycle. If falsy, the old data is kept.

Name Type Description
arg boolean

Truthy to clear the canvas when rendering is started.

inherited geoIsOn(event, handler){boolean}

object.js, line 187

Report if an event handler is bound to this object.

Name Type Description
event string | Array.<string>

An event or list of events to check.
handler function optional

A function that might be bound. If undefined, this will report true if there is any handler for the specified event.
Returns:
Type Description
boolean true if any of the specified events are bound to the specified handler.

inherited geoOff(event, arg){this}

object.js, line 246

Remove handlers from one event or an array of events. If no event is provided all handlers will be removed.

Name Type Description
event string | Array.<string> optional

An event or a list of events from geo.event or defined by the user, or undefined to remove all events (in which case arg is ignored).
arg function | Array.<function()> optional nullable

A function or array of functions to remove from the events or a falsy value to remove all handlers from the events.
Returns:
Type Description
this

inherited geoOn(event, handler){this}

object.js, line 139

Bind an event handler to this object.

Name Type Description
event string

An event from geo.event or a user-defined value.
handler function

A function that is called when event is triggered. The function is passed a geo.event object.
Returns:
Type Description
this

inherited geoOnce(event, handler){function}

object.js, line 168

Bind an event handler to this object that will fire once and then deregister itself.

Name Type Description
event string

An event from geo.event or a user-defined value.
handler function

A function that is called when event is triggered. The function is passed a geo.event object.
Returns:
Type Description
function The actual bound handler. This is a wrapper around the handler that was passed to the function.

inherited geoTrigger(event, args){this}

object.js, line 207

Trigger an event (or events) on this object and call all handlers.

Name Type Description
event string | Array.<string>

An event or list of events from geo.event or defined by the user.
args object optional

Additional information to add to the geo.event object passed to the handlers.
Returns:
Type Description
this

inherited height(){number}

renderer.js, line 113

Get the height of the renderer.

Returns:
Type Description
number The height of the renderer.

inherited initialized(val){boolean|this}

renderer.js, line 81

Get/set if renderer has been initialized.

Name Type Description
val boolean optional

If undefined return the initialization state, otherwise set it.
Returns:
Type Description
boolean | this The initialization state or this renderer instance.

inherited layer(){geo.layer}

renderer.js, line 37

Get layer of the renderer.

Returns:
Type Description
geo.layer

inherited map(){geo.map|null}

renderer.js, line 65

Get the map associated with the renderer's layer.

Returns:
Type Description
geo.map | null The map associated with the renderer's layer or null if there is no layer.

inherited modified(){this}

timestamp.js, line 25

Update the timestamp to the next global timestamp value.

Returns:
Type Description
this

inherited onIdle(handler){this}

object.js, line 36

Bind a handler that will be called one time when all internal promises are resolved. If there are no outstanding promises, this is invoked synchronously.

Name Type Description
handler function

A function taking no arguments.
Returns:
Type Description
this

inherited removePromise(promise){this}

object.js, line 116

Mark a promise as no longer required to resolve before the idle state is reached.

Name Type Description
promise Promise

A promise object.
Returns:
Type Description
this

inherited timestamp(){number}

timestamp.js, line 37

Get time.

Returns:
Type Description
number The timestamp. This is 0 if the timestamp has never been modified.

inherited width(){number}

renderer.js, line 104

Get the width of the renderer.

Returns:
Type Description
number The width of the renderer.