Class Extent

Object
   |
   +--Extent

class Extent

Defined in Extent.js

Field Detail

fixedScale

Object fixedScale

height

Object height

id

Object id

lr

Object lr

model

Object model

size

Object size

ul

Object ul

width

Object width

zoomBy

Object zoomBy

Extent

Extent( model, initialRes )

A tool designed to handle geography calculations for widgets which render the model in 2D. Use of this tool requires that it's model implements get/setWindowHeight/Width methods. Encapsulates all geography and image size aspects of a geographic object displayed in a rectangular area on the screen. All coordinates are handled as points which is a 2 element array, where x is the first element and y is the second. Coordinates are either pixel and lixel (pl) relative to the top left of the extent or projection XY values (xy).

Parameters:
model - the model document that this extent represents
initialRes - (optional) if supplied the extent resolution will be set to this value

centerAt

Object centerAt(center, newres, limitExtent)

Adjust the extent so that it is centered at given XY coordinate with given resolution. Extent width and height remain fixed. Optionally check to ensure that it doesn't go beyond available extent.

Parameters:
center - projection XY coordinate to center at
newres - resolution to display at
limitExtent - ensure that the extent doesn't go beyond available bbox (TBD: not complete/tested)

Returns:
none

checkBbox

void checkBbox()

firstInit

void firstInit(extent, initialRes)

getBbox

Object getBbox()

Returns the bounding box as stored in the model

Returns:
array with the bounding box

getCenter

Object getCenter()

Returns the XY center of this extent

Returns:
array of XY for th center of the extent

getFixedScale

Object getFixedScale(res)

When given a res, it recalculates it to match the zoomlevels, when present and returns a fixed scale. When no res is given it returns the maximum resolution

Parameters:
res - optional resolution to be checked

Returns:
fixedScale the resolution to display the map with

getPL

Object getPL(xy)

Returns pixel/line coordinates for given XY projection coords

Parameters:
xy - projection XY coordinate to calculate

Returns:
point array of pxiel/line coordinates w.r.t. top left corner

getScale

Object getScale()

Returns the map scale denominator for the current extent resolution

Returns:
map scale denominator

getSize

Object getSize()

Returns the window size as stored in the model

Returns:
array with the window size

getXY

Object getXY(pl)

Returns XY coordinates for given pixel line coords w.r.t. top left corner

Parameters:
pl - pixel line in extent to calculate

Returns:
point array of XY coordinates

init

void init(extent, initialRes)

Initialization of the Extent tool, called as a loadModel event listener.

Parameters:
extent - the object being initialized
initialRes - (optional) if supplied the extent resolution will be set to this value

setBbox

void setBbox(bbox)

Recalculates a given bbox and stores a proper aspect one in the model

Parameters:
bbox - an array with a bounding box

setResolution

void setResolution(size)

Adjust the resolution so the bbox fits in the specified width and height

Parameters:
size - width, height array passed in

setScale

void setScale(scale)

Sets the model's resolution from mapScale input value. The map center remains fixed.

Parameters:
scale - map scale denominator value

setSize

void setSize(size)

Stores a given window size in the model. Can be used in the future for dynamic window resizing

Parameters:
size - an array with a window size

setZoomLevels

void setZoomLevels(enabled,zoomLevels)

zoomToBox

void zoomToBox(ul, lr)

Adjust the extent to the given bbox. Resolution is recalculated. Extent width and height remain fixed.

Parameters:
ul - upper left coordinate of bbox in XY projection coords
lr - lower right coordinate of bbox in XY projection coords