Renamed

proximity-event/jquery.proximity.js

@@ -0,0 +1,145 @@
+/**
+ * Proximity event for jQuery
+ * ---
+ * @author James Padolsey (http://james.padolsey.com)
+ * @version 0.1
+ * @updated 28-JUL-09
+ * ---
+ * @info http://github.com/jamespadolsey/jQuery-plugins/proximity-event/
+ */
+
+(function($){
+
+    var elems = $([]),
+        doc = $(document);
+
+    $.event.special.proximity = {
+
+        defaults: {
+            max: 100,
+            min: 0,
+            throttle: 0,
+            fireOutOfBounds: 1
+        },
+
+        setup: function(data) {
+
+            if (!elems[0])
+                doc.mousemove(handle);
+
+            elems = elems.add(this);
+
+        },
+
+        add: function(o) {
+
+            var handler = o.handler,
+                data = $.extend({}, $.event.special.proximity.defaults, o.data),
+                lastCall = 0,
+                nFiredOutOfBounds = 0,
+                hoc = $(this);
+
+            o.handler = function(e, pageX, pageY) {
+
+                var max = data.max,
+                    min = data.min,
+                    throttle = data.throttle,
+                    date = +new Date,
+                    distance,
+                    proximity,
+                    inBounds,
+                    fireOutOfBounds = data.fireOutOfBounds;
+
+                if (throttle && lastCall + throttle > date) {
+                    return;
+                }
+
+                lastCall = date;
+
+                distance = calcDistance(hoc, pageX, pageY);
+                inBounds = distance < max && distance > min;
+
+                if (fireOutOfBounds || inBounds) {
+
+                    if (inBounds) {
+                        nFiredOutOfBounds = 0;
+                    } else {
+
+                        // If fireOutOfBounds is a number then keep incrementing a
+                        // counter to determine how many times the handler's been
+                        // called out of bounds. Note: the counter is reset whenever
+                        // the cursor goes back inBounds...
+
+                        if (typeof fireOutOfBounds === 'number' && nFiredOutOfBounds > fireOutOfBounds) {
+                            return;
+                        }
+                        ++nFiredOutOfBounds;
+                    }
+
+                    proximity = e.proximity = 1 - (
+                        distance < max ? distance < min ? 0 : distance / max : 1
+                    );
+
+                    e.distance = distance;
+                    e.pageX = pageX;
+                    e.pageY = pageY;
+                    e.data = data;
+
+                    return handler.call(this, e, proximity, distance);
+
+                }
+
+            };
+
+        },
+
+        teardown: function(){
+
+            elems = elems.not(this);
+
+            if (!elems[0])
+                doc.unbind('mousemove', handle);
+
+        }
+
+    };
+
+    function calcDistance(el, x, y) {
+
+        // Calculate the distance from the closest edge of the element
+        // to the cursor's current position
+
+        var left, right, top, bottom, offset,
+            cX, cY, dX, dY,
+            distance = 0;
+
+        offset = el.offset();
+        left = offset.left;
+        top = offset.top;
+        right = left + el.outerWidth();
+        bottom = top + el.outerHeight();
+
+        cX = x > right ? right : x > left ? x : left;
+        cY = y > bottom ? bottom : y > top ? y : top;
+
+        dX = Math.abs( cX - x );
+        dY = Math.abs( cY - y );
+
+        return Math.sqrt( dX * dX + dY * dY );
+
+    }
+
+    function handle(e) {
+
+        var x = e.pageX,
+            y = e.pageY,
+            i = -1,
+            fly = $([]);
+
+        while (fly[0] = elems[++i]) {
+            fly.triggerHandler('proximity', [x,y]);
+        }
+
+    }
+
+}(jQuery));