--- a/labs/openlayers/lib/OpenLayers/Handler/RegularPolygon.js +++ b/labs/openlayers/lib/OpenLayers/Handler/RegularPolygon.js @@ -1,1 +1,422 @@ - +/* 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" +}); +