| MGMap.selectPolygonMode |
|
void selectPolygonMode()
Enters the select polygon mode.
In this mode, Autodesk MapGuide allows the user to digitize a polygon and select all map features that fall within the polygon.
Note that this method does not work during a busy state. For additional information about the busy state, refer to "Handling Busy State and Map Refresh" chapter in the Autodesk MapGuide Developer's Guide.
-1 (busy)
The following example is designed to work with the Tutorial.mwf file that is included with Autodesk MapGuide Author. It invokes polygon selection mode.
Note that the user can make a polygon selection only if one or more selectable layers is visible.
function polySelect()
{
getMap().selectPolygonMode();
}
The next example checks for selectable map features before calling selectPolygonMode(). If one or more selectable layers is visible, the user can make a selection. Otherwise an alert displays.
// first function calls selectPolygonMode()
function polySelect()
{
map = getMap();
// call function that tests selectability
var test = checkSelectability();
// selectable map features?
if (test == true)
{
// ...if yes, user can make polygon selection
alert("Make a polygon selection now...");
map.selectPolygonMode();
}
else
{
// ...if no, display alert
alert("Sorry, no selectable features found!");
}
}
// second function checks map feature selectability
function checkSelectability()
{
var map = getMap();
var layers = map.getMapLayersEx();
// false means a selectable layer has not (yet) been found
var selectable = false;
// cycle through each layer in map...
for (var i = 0; i < layers.size(); i++)
{
var layer = layers.item(i);
// is the layer visible?
if ( layer.isVisible() )
{
// is it selectable?
if (layer.getSelectability())
{
// first time a visible/selectable layer is
// found, set flag to true and exit loop
selectable = true;
break;
}
}
}
return selectable;
}