English (en-ca)
2005-01-07
$id: $
Doc_Builder
DM Solutions Group Inc.
chameleon@lists.maptools.org
Christopher R. Thorne
DM Solutions Group Inc.
chameleon@lists.maptools.org
Paul Spencer
DM Solutions Group Inc.
chameleon@lists.maptools.org
Extent
TBD
Label Widget
2.0
2005-01-10
TECHRELEASE
Paul Spencer
DM Solutions Group Inc.
chameleon@lists.maptools.org
The Extent widget is used to display one of the extents of the map currently displayed in the application, in the geographic coordinates of the map.
The MapServer file (*.map) and/or the OGC Context file (*.cml) must have a defined projection. To obtain a valid projection, you should use EPSG projection codes. It is important to define the projection so that the extent values of the map have valid units (e.g., decimal degrees, meters, etc.), so that map becomes geospatially significant within the application map view.
In a Chameleon mapping application, the map view is interactive by nature. The Extent widget helps dynamically update the extents of the map to reflect the current map view. The extents may also change dynamically when there is a change in projection.
The Extent widget displays one of the coordinates (minimum X, minimum Y, maximum X, or maximum Y) of the rectangle that describes the visible area of the map. The extents are displayed in the units of the current projection.
There are four possible extent labels for a map. These extent labels could be placed all together near the MapUnits, ProjectionLabel, and other information widgets, or in pairs at two opposite corners (i.e., Min-X, Min-Y (lower left corner) vs. Max-X, Max-Y (upper right corner)).
<CWC2 TYPE="Extent"
ENABLED="[TRUE|FALSE]"
FORMINDEX="[0 < integer]"
VISIBLE="[TRUE|FALSE]"
<!-- Extent Attributes -->
EXTENT ="[MINX|MINY|MAXX|MAXY]"
WIDGETCLASS ="[string]"
TEXTFIELDSIZE ="[integer]" />
The basic widget definition below outputs the current minimum Y extent - the bottom most horizontal line coordinate value found in the current map view.
<cwc2 type="Extent"
extent="miny" />
The example below shows how a descriptive label, along with label styling, can be added to the Min-X value. In this case, the label is "Left:", which represents the far left vertical grid line coordinate of the current map view.
<cwc2 type="Extent"
label="Left: "
visible="true"
extent="minx"
labelposition="8"
labelvalign="middle"
labelclass="label"
widgetclass="inputBox"/>
Hawaii Demo
http://www.mapsherpa.com/hawaii2/
The Hawaii Demo uses the latest 1.99 Chameleon version.
Base
Label
EXTENT
string
Required
MINX
MINY
MAXX
MAXY
The extent to display.
WIDGETCLASS
string
Widget Only
CWCExtentWidgetClass
The CSS class to control the style of the extent text.
TEXTFIELDSIZE
integer
Widget Only
20
pixels
0
2147483647
The size (in characters) to make the extent widget in JSAPI mode.
sid
unknown
string
Private
Private
string
false
unknown
JSAPI function calls for this widget are outlined here.
string
false