/* Copyright (c) 2006-2010 by OpenLayers Contributors (see authors.txt for
* full list of contributors). Published under the Clear BSD license.
* See http://svn.openlayers.org/trunk/openlayers/license.txt for the
* full text of the license. */
/**
* @requires OpenLayers/Handler/Drag.js
*/
/**
* Class: OpenLayers.Handler.RegularPolygon
* Handler to draw a regular polygon on the map. Polygon is displayed on mouse
* down, moves or is modified on mouse move, and is finished on mouse up.
* The handler triggers callbacks for 'done' and 'cancel'. Create a new
* instance with the <OpenLayers.Handler.RegularPolygon> constructor.
*
* Inherits from:
* - <OpenLayers.Handler>
*/
OpenLayers.Handler.RegularPolygon = OpenLayers.Class(OpenLayers.Handler.Drag, {
/**
* APIProperty: sides
* {Integer} Number of sides for the regular polygon. Needs to be greater
* than 2. Defaults to 4.
*/
sides: 4,
/**
* APIProperty: radius
* {Float} Optional radius in map units of the regular polygon. If this is
* set to some non-zero value, a polygon with a fixed radius will be
* drawn and dragged with mose movements. If this property is not
* set, dragging changes the radius of the polygon. Set to null by
* default.
*/
radius: null,
/**
* APIProperty: snapAngle
* {Float} If set to a non-zero value, the handler will snap the polygon
* rotation to multiples of the snapAngle. Value is an angle measured
* in degrees counterclockwise from the positive x-axis.
*/
snapAngle: null,
/**
* APIProperty: snapToggle
* {String} If set, snapToggle is checked on mouse events and will set
* the snap mode to the opposite of what it currently is. To disallow
* toggling between snap and non-snap mode, set freehandToggle to
* null. Acceptable toggle values are 'shiftKey', 'ctrlKey', and
* 'altKey'. Snap mode is only possible if this.snapAngle is set to a
* non-zero value.
*/
snapToggle: 'shiftKey',
/**
* Property: layerOptions
* {Object} Any optional properties to be set on the sketch layer.
*/
layerOptions: null,
/**
* APIProperty: persist
* {Boolean} Leave the feature rendered until clear is called. Default
* is false. If set to true, the feature remains rendered until
* clear is called, typically by deactivating the handler or starting
* another drawing.
*/
persist: false,
/**
* APIProperty: irregular
* {Boolean} Draw an irregular polygon instead of a regular polygon.
* Default is false. If true, the initial mouse down will represent
* one corner of the polygon bounds and with each mouse movement, the
* polygon will be stretched so the opposite corner of its bounds
* follows the mouse position. This property takes precedence over
* the radius property. If set to true, the radius property will
* be ignored.
*/
irregular: false,
/**
* Property: angle
* {Float} The angle from the origin (mouse down) to the current mouse
* position, in radians. This is measured counterclockwise from the
* positive x-axis.
*/
angle: null,
/**
* Property: fixedRadius
* {Boolean} The polygon has a fixed radius. True if a radius is set before
* drawing begins. False otherwise.
*/
fixedRadius: false,
/**
* Property: feature
* {<OpenLayers.Feature.Vector>} The currently drawn polygon feature
*/
feature: null,
/**
* Property: layer
* {<OpenLayers.Layer.Vector>} The temporary drawing layer
*/
layer: null,
/**
* Property: origin
* {<OpenLayers.Geometry.Point>} Location of the first mouse down
*/
origin: null,
/**
* Constructor: OpenLayers.Handler.RegularPolygon
* Create a new regular polygon handler.
*
* Parameters:
* control - {<OpenLayers.Control>} The control that owns this handler
* callbacks - {Object} An object with a properties whose values are
* functions. Various callbacks described below.
* options - {Object} An object with properties to be set on the handler.
* If the options.sides property is not specified, the number of sides
* will default to 4.
*
* Named callbacks:
* create - Called when a sketch is first created. Callback called with
* the creation point geometry and sketch feature.
* done - Called when the sketch drawing is finished. The callback will
* recieve a single argument, the sketch geometry.
* cancel - Called when the handler is deactivated while drawing. The
* cancel callback will receive a geometry.
*/
initialize: function(control, callbacks, options) {
if(!(options && options.layerOptions && options.layerOptions.styleMap)) {
this.style = OpenLayers.Util.extend(OpenLayers.Feature.Vector.style['default'], {});
}
OpenLayers.Handler.prototype.initialize.apply(this,
[control, callbacks, options]);
this.options = (options) ? options : {};
},
/**
* APIMethod: setOptions
*
* Parameters:
* newOptions - {Object}
*/
setOptions: function (newOptions) {
OpenLayers.Util.extend(this.options, newOptions);
OpenLayers.Util.extend(this, newOptions);
},
/**
* APIMethod: activate
* Turn on the handler.
*
* Return:
* {Boolean} The handler was successfully activated
*/
activate: function() {
var activated = false;
if(OpenLayers.Handler.prototype.activate.apply(this, arguments)) {
// create temporary vector layer for rendering geometry sketch
var options = OpenLayers.Util.extend({
displayInLayerSwitcher: false,
// indicate that the temp vector layer will never be out of range
// without this, resolution properties must be specified at the
// map-level for this temporary layer to init its resolutions
// correctly
calculateInRange: OpenLayers.Function.True
}, this.layerOptions);
this.layer = new OpenLayers.Layer.Vector(this.CLASS_NAME, options);
this.map.addLayer(this.layer);
activated = true;
}
return activated;
},
/**
* APIMethod: deactivate
* Turn off the handler.
*
* Return:
* {Boolean} The handler was successfully deactivated
*/
deactivate: function() {
var deactivated = false;
if(OpenLayers.Handler.Drag.prototype.deactivate.apply(this, arguments)) {
// call the cancel callback if mid-drawing
if(this.dragging) {
this.cancel();
}
// If a layer's map property is set to null, it means that that
// layer isn't added to the map. Since we ourself added the layer
// to the map in activate(), we can assume that if this.layer.map
// is null it means that the layer has been destroyed (as a result
// of map.destroy() for example.
if (this.layer.map != null) {
this.layer.destroy(false);
if (this.feature) {
this.feature.destroy();
}
}
this.layer = null;
this.feature = null;
deactivated = true;
}
return deactivated;
},
/**
* Method: down
* Start drawing a new feature
*
* Parameters:
* evt - {Event} The drag start event
*/
down: function(evt) {
this.fixedRadius = !!(this.radius);
var maploc = this.map.getLonLatFromPixel(evt.xy);
this.origin = new OpenLayers.Geometry.Point(maploc.lon, maploc.lat);
// create the new polygon
if(!this.fixedRadius || this.irregular) {
// smallest radius should not be less one pixel in map units
// VML doesn't behave well with smaller
this.radius = this.map.getResolution();
}
if(this.persist) {
this.clear();
}
this.feature = new OpenLayers.Feature.Vector();
this.createGeometry();
this.callback("create", [this.origin, this.feature]);
this.layer.addFeatures([this.feature], {silent: true});
this.layer.drawFeature(this.feature, this.style);
},
/**
* Method: move
* Respond to drag move events
*
* Parameters:
* evt - {Evt} The move event
*/
move: function(evt) {
var maploc = this.map.getLonLatFromPixel(evt.xy);
var point = new OpenLayers.Geometry.Point(maploc.lon, maploc.lat);
if(this.irregular) {
var ry = Math.sqrt(2) * Math.abs(point.y - this.origin.y) / 2;
this.radius = Math.max(this.map.getResolution() / 2, ry);
} else if(this.fixedRadius) {
this.origin = point;
} else {
this.calculateAngle(point, evt);
this.radius = Math.max(this.map.getResolution() / 2,
point.distanceTo(this.origin));
}
this.modifyGeometry();
if(this.irregular) {
var dx = point.x - this.origin.x;
var dy = point.y - this.origin.y;
var ratio;
if(dy == 0) {
ratio = dx / (this.radius * Math.sqrt(2));
} else {
ratio = dx / dy;
}
this.feature.geometry.resize(1, this.origin, ratio);
this.feature.geometry.move(dx / 2, dy / 2);
}
this.layer.drawFeature(this.feature, this.style);
},
/**
* Method: up
* Finish drawing the feature
*
* Parameters:
* evt - {Event} The mouse up event
*/
up: function(evt) {
this.finalize();
// the mouseup method of superclass doesn't call the
// "done" callback if there's been no move between
// down and up
if (this.start == this.last) {
this.callback("done", [evt.xy]);
}
},
/**
* Method: out
* Finish drawing the feature.
*
* Parameters:
* evt - {Event} The mouse out event
*/
out: function(evt) {
this.finalize();
},
/**
* Method: createGeometry
* Create the new polygon geometry. This is called at the start of the
* drag and at any point during the drag if the number of sides
* changes.
*/
createGeometry: function() {
this.angle = Math.PI * ((1/this.sides) - (1/2));
if(this.snapAngle) {
this.angle += this.snapAngle * (Math.PI / 180);
}
this.feature.geometry = OpenLayers.Geometry.Polygon.createRegularPolygon(
this.origin, this.radius, this.sides, this.snapAngle
);
},
/**
* Method: modifyGeometry
* Modify the polygon geometry in place.
*/
modifyGeometry: function() {
var angle, point;
var ring = this.feature.geometry.components[0];
// if the number of sides ever changes, create a new geometry
if(ring.components.length != (this.sides + 1)) {
this.createGeometry();
ring = this.feature.geometry.components[0];
}
for(var i=0; i<this.sides; ++i) {
point = ring.components[i];
angle = this.angle + (i * 2 * Math.PI / this.sides);
point.x = this.origin.x + (this.radius * Math.cos(angle));
point.y = this.origin.y + (this.radius * Math.sin(angle));
point.clearBounds();
}
},
/**
* Method: calculateAngle
* Calculate the angle based on settings.
*
* Parameters:
* point - {<OpenLayers.Geometry.Point>}
* evt - {Event}
*/
calculateAngle: function(point, evt) {
var alpha = Math.atan2(point.y - this.origin.y,
point.x - this.origin.x);
if(this.snapAngle && (this.snapToggle && !evt[this.snapToggle])) {
var snapAngleRad = (Math.PI / 180) * this.snapAngle;
this.angle = Math.round(alpha / snapAngleRad) * snapAngleRad;
} else {
this.angle = alpha;
}
},
/**
* APIMethod: cancel
* Finish the geometry and call the "cancel" callback.
*/
cancel: function() {
// the polygon geometry gets cloned in the callback method
this.callback("cancel", null);
this.finalize();
},
/**
* Method: finalize
* Finish the geometry and call the "done" callback.
*/
finalize: function() {
this.origin = null;
this.radius = this.options.radius;
},
/**
* APIMethod: clear
* Clear any rendered features on the temporary layer. This is called
* when the handler is deactivated, canceled, or done (unless persist
* is true).
*/
clear: function() {
if (this.layer) {
this.layer.renderer.clear();
this.layer.destroyFeatures();
}
},
/**
* Method: callback
* Trigger the control's named callback with the given arguments
*
* Parameters:
* name - {String} The key for the callback that is one of the properties
* of the handler's callbacks object.
* args - {Array} An array of arguments with which to call the callback
* (defined by the control).
*/
callback: function (name, args) {
// override the callback method to always send the polygon geometry
if (this.callbacks[name]) {
this.callbacks[name].apply(this.control,
[this.feature.geometry.clone()]);
}
// since sketch features are added to the temporary layer
// they must be cleared here if done or cancel
if(!this.persist && (name == "done" || name == "cancel")) {
this.clear();
}
},
CLASS_NAME: "OpenLayers.Handler.RegularPolygon"
});