[OpenLayers-Commits] r10828 - in trunk/openlayers: examples lib/OpenLayers/Handler tests/Handler

commits-20090109 at openlayers.org commits-20090109 at openlayers.org
Wed Oct 13 18:12:53 EDT 2010


Author: tschaub
Date: 2010-10-13 15:12:52 -0700 (Wed, 13 Oct 2010)
New Revision: 10828

Added:
   trunk/openlayers/examples/donut.html
   trunk/openlayers/examples/donut.js
Modified:
   trunk/openlayers/lib/OpenLayers/Handler/Polygon.js
   trunk/openlayers/tests/Handler/Polygon.html
Log:
Adding interior ring digitizing for polygons.  Thanks jachym for the initial work.  r=ahocevar (closes #1894)

Added: trunk/openlayers/examples/donut.html
===================================================================
--- trunk/openlayers/examples/donut.html	                        (rev 0)
+++ trunk/openlayers/examples/donut.html	2010-10-13 22:12:52 UTC (rev 10828)
@@ -0,0 +1,59 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <title>OpenLayers Polygon Hole Digitizing</title>
+        <link rel="stylesheet" href="../theme/default/style.css" type="text/css">
+        <link rel="stylesheet" href="style.css" type="text/css">
+        <style>
+            #controlToggle li {
+                list-style: none;
+            }
+            .olControlAttribution {
+                font-size: 9px;
+                bottom: 2px;
+            }
+            #output {
+                margin: 1em;
+                font-size: 0.9em;
+            }
+        </style>
+    </head>
+    <body>
+        <h1 id="title">Drawing Holes in Polygons</h1>
+        <div id="tags">
+            draw polygon hole
+        </div>         
+        <p id="shortdesc">
+            The DrawFeature control can be used to digitize donut polygons.
+        </p>
+        
+        <div id="map" class="smallmap"></div>
+        <ul id="controlToggle">
+            <li>
+                <input type="radio" name="type" value="none" id="noneToggle"
+                       onclick="toggleControl(this);" checked="checked">
+                <label for="noneToggle">navigate</label>
+            </li>
+            <li>
+                <input type="radio" name="type" value="polygon" id="polygonToggle" onclick="toggleControl(this);">
+                <label for="polygonToggle">draw polygon</label>
+            </li>
+        </ul>
+        <div id="output"></div>
+        <div id="docs">
+            <p>
+                To digitize holes in polygons, hold down the <code>Alt</code> 
+                key and draw over an existing polygon.  By default, the 
+                <code>Shift</code> key triggers freehand drawing.  Use a 
+                combination of the <code>Shift</code> and <code>Alt</code> keys
+                to digitize holes in freehand mode.
+            </p>
+            <p>
+                See the <a href="donut.js" target="_blank">
+                donut.js source</a> for details on how this is done.
+            </p>
+        </div>
+        <script src="../lib/OpenLayers.js"></script>
+        <script src="donut.js"></script>
+    </body>
+</html>

Added: trunk/openlayers/examples/donut.js
===================================================================
--- trunk/openlayers/examples/donut.js	                        (rev 0)
+++ trunk/openlayers/examples/donut.js	2010-10-13 22:12:52 UTC (rev 10828)
@@ -0,0 +1,38 @@
+var map = new OpenLayers.Map({
+    div: "map",
+    layers: [
+        new OpenLayers.Layer.OSM(),
+        new OpenLayers.Layer.Vector()
+    ],
+    center: new OpenLayers.LonLat(0, 0),
+    zoom: 1
+});
+
+var draw = new OpenLayers.Control.DrawFeature(
+    map.layers[1],
+    OpenLayers.Handler.Polygon,
+    {handlerOptions: {holeModifier: "altKey"}}
+);
+map.addControl(draw);
+
+// optionally listen for sketch events on the layer
+var output = document.getElementById("output");
+function updateOutput(event) {
+    window.setTimeout(function() {
+        output.innerHTML = event.type + " " + event.feature.id;
+    }, 100);
+}
+map.layers[1].events.on({
+    sketchmodified: updateOutput,
+    sketchcomplete: updateOutput
+})
+
+// add behavior to UI elements
+function toggleControl(element) {
+    if (element.value === "polygon" && element.checked) {
+        draw.activate();
+    } else {
+        draw.deactivate();
+    }
+}
+document.getElementById("noneToggle").checked = true;
\ No newline at end of file

Modified: trunk/openlayers/lib/OpenLayers/Handler/Polygon.js
===================================================================
--- trunk/openlayers/lib/OpenLayers/Handler/Polygon.js	2010-10-13 21:25:21 UTC (rev 10827)
+++ trunk/openlayers/lib/OpenLayers/Handler/Polygon.js	2010-10-13 22:12:52 UTC (rev 10828)
@@ -20,7 +20,21 @@
  */
 OpenLayers.Handler.Polygon = OpenLayers.Class(OpenLayers.Handler.Path, {
     
+    /** 
+     * APIProperty: holeModifier
+     * {String} Key modifier to trigger hole digitizing.  Acceptable values are
+     *     "altKey", "shiftKey", or "ctrlKey".  If not set, no hole digitizing
+     *     will take place.  Default is null.
+     */
+    holeModifier: null,
+    
     /**
+     * Property: drawingHole
+     * {Boolean} Currently drawing an interior ring.
+     */
+    drawingHole: false,
+    
+    /**
      * Parameter: polygon
      * {<OpenLayers.Feature.Vector>}
      */
@@ -68,15 +82,152 @@
         this.line = new OpenLayers.Feature.Vector(
             new OpenLayers.Geometry.LinearRing([this.point.geometry])
         );
-        this.polygon = new OpenLayers.Feature.Vector(
-            new OpenLayers.Geometry.Polygon([this.line.geometry])
-        );
+        
+        // check for hole digitizing
+        var polygon;
+        if (this.holeModifier && (this.evt[this.holeModifier])) {
+            var geometry = this.point.geometry;
+            var features = this.control.layer.features;
+            var candidate;
+            // look for intersections, last drawn gets priority
+            for (var i=features.length-1; i>=0; --i) {
+                candidate = features[i].geometry;
+                if ((candidate instanceof OpenLayers.Geometry.Polygon || 
+                    candidate instanceof OpenLayers.Geometry.MultiPolygon) && 
+                    candidate.intersects(geometry)) {
+                    polygon = features[i];
+                    this.control.layer.removeFeatures([polygon], {silent: true});
+                    this.control.layer.events.registerPriority(
+                        "sketchcomplete", this, this.finalizeInteriorRing
+                    );
+                    this.control.layer.events.registerPriority(
+                        "sketchmodified", this, this.enforceTopology
+                    );
+                    polygon.geometry.addComponent(this.line.geometry);
+                    this.polygon = polygon;
+                    this.drawingHole = true;
+                    break;
+                }
+            }
+        }
+        if (!polygon) {
+            this.polygon = new OpenLayers.Feature.Vector(
+                new OpenLayers.Geometry.Polygon([this.line.geometry])
+            );
+        }
+        
         this.callback("create", [this.point.geometry, this.getSketch()]);
         this.point.geometry.clearBounds();
         this.layer.addFeatures([this.polygon, this.point], {silent: true});
     },
+    
+    /**
+     * Method: enforceTopology
+     * Simple topology enforcement for drawing interior rings.  Ensures vertices
+     *     of interior rings are contained by exterior ring.  Other topology 
+     *     rules are enforced in <finalizeInteriorRing> to allow drawing of 
+     *     rings that intersect only during the sketch (e.g. a "C" shaped ring
+     *     that nearly encloses another ring).
+     */
+    enforceTopology: function(event) {
+        var point = event.vertex;
+        var components = this.line.geometry.components;
+        // ensure that vertices of interior ring are contained by exterior ring
+        if (!this.polygon.geometry.intersects(point)) {
+            var last = components[components.length-3];
+            point.x = last.x;
+            point.y = last.y;
+        }
+    },
+    
+    /**
+     * Method: finalizeInteriorRing
+     * Enforces that new ring has some area and doesn't contain vertices of any
+     *     other rings.
+     */
+    finalizeInteriorRing: function() {
+        var ring = this.line.geometry;
+        // ensure that ring has some area
+        var modified = (ring.getArea() !== 0);
+        if (modified) {
+            // ensure that new ring doesn't intersect any other rings
+            var rings = this.polygon.geometry.components;
+            for (var i=rings.length-2; i>=0; --i) {
+                if (ring.intersects(rings[i])) {
+                    modified = false;
+                    break;
+                }
+            }
+            if (modified) {
+                // ensure that new ring doesn't contain any other rings
+                var target;
+                outer: for (var i=rings.length-2; i>0; --i) {
+                    points = rings[i].components;
+                    for (var j=0, jj=points.length; j<jj; ++j) {
+                        if (ring.containsPoint(points[j])) {
+                            modified = false;
+                            break outer;
+                        }
+                    }
+                }
+            }
+        }
+        if (modified) {
+            if (this.polygon.state !== OpenLayers.State.INSERT) {
+                this.polygon.state = OpenLayers.State.UPDATE;
+            }
+        } else {
+            this.polygon.geometry.removeComponent(ring);
+        }
+        this.restoreFeature();
+        return false;
+    },
 
     /**
+     * APIMethod: cancel
+     * Finish the geometry and call the "cancel" callback.
+     */
+    cancel: function() {
+        if (this.drawingHole) {
+            this.polygon.geometry.removeComponent(this.line.geometry);
+            this.restoreFeature(true);
+        }
+        return OpenLayers.Handler.Path.prototype.cancel.apply(this, arguments);
+    },
+    
+    /**
+     * Method: restoreFeature
+     * Move the feature from the sketch layer to the target layer.
+     *
+     * Properties: 
+     * cancel - {Boolean} Cancel drawing.  If falsey, the "sketchcomplete" event
+     *     will be fired.
+     */
+    restoreFeature: function(cancel) {
+        this.control.layer.events.unregister(
+            "sketchcomplete", this, this.finalizeInteriorRing
+        );
+        this.control.layer.events.unregister(
+            "sketchmodified", this, this.enforceTopology
+        );
+        this.layer.removeFeatures([this.polygon], {silent: true});
+        this.control.layer.addFeatures([this.polygon], {silent: true});
+        this.drawingHole = false;
+        if (!cancel) {
+            // Re-trigger "sketchcomplete" so other listeners can do their
+            // business.  While this is somewhat sloppy (if a listener is 
+            // registered with registerPriority - not common - between the start
+            // and end of a single ring drawing - very uncommon - it will be 
+            // called twice).
+            // TODO: In 3.0, collapse sketch handlers into geometry specific
+            // drawing controls.
+            this.control.layer.events.triggerEvent(
+                "sketchcomplete", {feature : this.polygon}
+            );
+        }
+    },
+
+    /**
      * Method: destroyFeature
      * Destroy temporary geometries
      */

Modified: trunk/openlayers/tests/Handler/Polygon.html
===================================================================
--- trunk/openlayers/tests/Handler/Polygon.html	2010-10-13 21:25:21 UTC (rev 10827)
+++ trunk/openlayers/tests/Handler/Polygon.html	2010-10-13 22:12:52 UTC (rev 10828)
@@ -158,6 +158,187 @@
         map.destroy();
     }        
 
+    function test_rings(t) {
+        t.plan(12);
+
+        var log = [];
+        var map = new OpenLayers.Map({
+            div: "map",
+            resolutions: [1],
+            maxExtent: new OpenLayers.Bounds(-10, -10, 10, 10),
+            layers: [
+                new OpenLayers.Layer.Vector(null, {
+                    isBaseLayer: true,
+                    eventListeners: {
+                        featureadded: function(event) {
+                            log.push(event);
+                        },
+                        sketchmodified: function(event) {
+                            log.push(event);
+                        },
+                        sketchcomplete: function(event) {
+                            log.push(event);
+                        }
+                    }
+                })
+            ],
+            center: new OpenLayers.LonLat(0, 0),
+            zoom: 0
+        });
+        
+        // create control for drawing polygons with holes
+        var draw = new OpenLayers.Control.DrawFeature(
+            map.layers[0],
+            OpenLayers.Handler.Polygon,
+            {handlerOptions: {holeModifier: "altKey"}}
+        );
+        map.addControl(draw);
+        draw.activate();
+        
+        var event;
+        function trigger(type, event) {
+            map.events.triggerEvent(type, OpenLayers.Util.extend({}, event));
+        }
+        
+        // a) draw a polygon
+        log = [];
+        // start at -9, 9
+        event = {xy: new OpenLayers.Pixel(-9, 9)};
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // draw to -1, 9
+        event = {xy: new OpenLayers.Pixel(-1, 9)};
+        trigger("mousemove", event);
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // draw to -1, 1
+        event = {xy: new OpenLayers.Pixel(-1, 1)};
+        trigger("mousemove", event);
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // draw to -9, 1
+        event = {xy: new OpenLayers.Pixel(-9, 1)};
+        trigger("mousemove", event);
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // finish
+        event = {xy: new OpenLayers.Pixel(-9, 1)};
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        trigger("dblclick", event);
+        
+        // make assertions
+        t.eq(log.length, 9, "a) correct number of events");
+        t.eq(log[log.length-1].type, "featureadded", "a) featureadded event last");
+        t.eq(log[log.length-1].feature.geometry.getArea(), 64, "a) correct polygon area");
+
+        // b) draw a hole
+        log = [];
+        // start at -6, 6
+        event = {xy: new OpenLayers.Pixel(-6, 6), altKey: true};
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // draw to -3, 6
+        event = {xy: new OpenLayers.Pixel(-3, 6), altKey: true};
+        trigger("mousemove", event);
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // draw to -3, 3
+        event = {xy: new OpenLayers.Pixel(-3, 3), altKey: true};
+        trigger("mousemove", event);
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // draw to -6, 3
+        event = {xy: new OpenLayers.Pixel(-6, 3), altKey: true};
+        trigger("mousemove", event);
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // finish
+        event = {xy: new OpenLayers.Pixel(-6, 3), altKey: true};
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        trigger("dblclick", event);
+        
+        // make assertions
+        t.eq(log.length, 8, "b) correct number of events");
+        t.eq(log[log.length-1].type, "sketchcomplete", "b) sketchcomplete event last");
+        t.eq(log[log.length-1].feature.geometry.getArea(), 55, "b) correct polygon area");
+        
+
+        // c) draw a polygon that overlaps the first
+        log = [];
+        // start at -2, 2
+        event = {xy: new OpenLayers.Pixel(-2, 2)};
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // draw to 2, 2
+        event = {xy: new OpenLayers.Pixel(2, 2)};
+        trigger("mousemove", event);
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // draw to 2, -2
+        event = {xy: new OpenLayers.Pixel(2, -2)};
+        trigger("mousemove", event);
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // draw to -2, -2
+        event = {xy: new OpenLayers.Pixel(-2, -2)};
+        trigger("mousemove", event);
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // finish
+        event = {xy: new OpenLayers.Pixel(-2, -2)};
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        trigger("dblclick", event);
+        
+        // make assertions
+        t.eq(log.length, 9, "c) correct number of events");
+        t.eq(log[log.length-1].type, "featureadded", "c) featureadded event last");
+        t.eq(log[log.length-1].feature.geometry.getArea(), 16, "c) correct polygon area");
+
+        // d) draw a hole that tries to go outside the exterior ring
+        log = [];
+        // start at -1, 1
+        event = {xy: new OpenLayers.Pixel(-1, 1), altKey: true};
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // draw to 1, 1
+        event = {xy: new OpenLayers.Pixel(1, 1), altKey: true};
+        trigger("mousemove", event);
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // try to draw to -8, 8 (ouside active polygon)
+        event = {xy: new OpenLayers.Pixel(-8, 8), altKey: true};
+        trigger("mousemove", event);
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // draw to 1, -1
+        event = {xy: new OpenLayers.Pixel(1, -1), altKey: true};
+        trigger("mousemove", event);
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // draw to -1, -1
+        event = {xy: new OpenLayers.Pixel(-1, -1), altKey: true};
+        trigger("mousemove", event);
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        // finish
+        event = {xy: new OpenLayers.Pixel(-1, 1), altKey: true};
+        trigger("mousedown", event);
+        trigger("mouseup", event);
+        trigger("dblclick", event);
+        
+        // make assertions
+        t.eq(log.length, 11, "d) correct number of events");
+        t.eq(log[log.length-1].type, "sketchcomplete", "d) sketchcomplete event last");
+        t.eq(log[log.length-1].feature.geometry.getArea(), 12, "d) correct polygon area");
+        
+        
+        map.destroy();
+    }        
+
+
     function test_Handler_Polygon_destroy(t) {
         t.plan(8);
         var map = new OpenLayers.Map('map');



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