From 24eb8fe144a9304271195f661bd0ea6ee38455d7 Mon Sep 17 00:00:00 2001
From: crschmidt <crschmidt@crschmidt.net>
Date: Sat, 20 May 2006 22:18:44 +0000
Subject: [PATCH] Implement Drag-to-Zoom for ticket #30.

git-svn-id: http://svn.openlayers.org/trunk/openlayers@216 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf
---
 lib/OpenLayers/Control/MouseDefaults.js | 60 ++++++++++++++++++++-----
 lib/OpenLayers/Map.js                   |  4 +-
 2 files changed, 52 insertions(+), 12 deletions(-)

diff --git a/lib/OpenLayers/Control/MouseDefaults.js b/lib/OpenLayers/Control/MouseDefaults.js
index e9babfd971..7ea639e488 100644
--- a/lib/OpenLayers/Control/MouseDefaults.js
+++ b/lib/OpenLayers/Control/MouseDefaults.js
@@ -11,7 +11,7 @@ OpenLayers.Control.MouseDefaults.prototype =
         this.map.events.register( "mousedown", this.map, this.defaultMouseDown );
         this.map.events.register( "mouseup", this.map, this.defaultMouseUp );
         this.map.events.register( "mousemove", this.map, this.defaultMouseMove );
-        this.map.events.register( "mouseout", this.map, this.defaultMouseUp );
+        //this.map.events.register( "mouseout", this.map, this.defaultMouseUp );
     },
     
     /**
@@ -27,7 +27,18 @@ OpenLayers.Control.MouseDefaults.prototype =
     */
     defaultMouseDown: function (evt) {
         this.mouseDragStart = evt.xy.copyOf();
-        this.div.style.cursor = "move";
+        if (evt.shiftKey) {
+            this.div.style.cursor = "crosshair";
+            this.zoomBox = OpenLayers.Util.createDiv('zoomBox');
+            this.zoomBox.style.border = '1px solid red';
+            this.zoomBox.style.position="absolute";
+            this.zoomBox.style.zIndex=1000;
+            this.zoomBox.style.top=this.mouseDragStart.y;
+            this.zoomBox.style.left=this.mouseDragStart.x;
+            this.viewPortDiv.appendChild(this.zoomBox);
+        } else {
+            this.div.style.cursor = "move";
+        }
         Event.stop(evt);
     },
 
@@ -36,14 +47,27 @@ OpenLayers.Control.MouseDefaults.prototype =
     */
     defaultMouseMove: function (evt) {
         if (this.mouseDragStart != null) {
-            var deltaX = this.mouseDragStart.x - evt.xy.x;
-            var deltaY = this.mouseDragStart.y - evt.xy.y
-            var size = this.getSize();
-            var newXY = new OpenLayers.Pixel(size.w / 2 + deltaX,
-                                             size.h / 2 + deltaY);
-            var newCenter = this.getLonLatFromPixel( newXY ); 
-            this.setCenter(newCenter);
-            this.mouseDragStart = evt.xy.copyOf();
+            if (this.zoomBox) {
+                var deltaX = Math.abs(this.mouseDragStart.x - evt.xy.x);
+                var deltaY = Math.abs(this.mouseDragStart.y - evt.xy.y);
+                this.zoomBox.style.width = deltaX+"px";
+                this.zoomBox.style.height = deltaY+"px";
+                if (evt.xy.x < this.mouseDragStart.x) {
+                    this.zoomBox.style.left = evt.xy.x+"px";
+                }
+                if (evt.xy.y < this.mouseDragStart.y) {
+                    this.zoomBox.style.top = evt.xy.y+"px";
+                }
+            } else {
+                var deltaX = this.mouseDragStart.x - evt.xy.x;
+                var deltaY = this.mouseDragStart.y - evt.xy.y;
+                var size = this.getSize();
+                var newXY = new OpenLayers.Pixel(size.w / 2 + deltaX,
+                                                 size.h / 2 + deltaY);
+                var newCenter = this.getLonLatFromPixel( newXY ); 
+                this.setCenter(newCenter);
+                this.mouseDragStart = evt.xy.copyOf();
+            }
         }
     },
 
@@ -51,6 +75,22 @@ OpenLayers.Control.MouseDefaults.prototype =
     * @param {Event} evt
     */
     defaultMouseUp: function (evt) {
+        if (this.zoomBox) {
+            var start = this.getLonLatFromPixel( this.mouseDragStart ); 
+            var end = this.getLonLatFromPixel( evt.xy );
+            var top = (start.lat > end.lat ? start.lat : end.lat);
+            var bottom = (start.lat < end.lat ? start.lat : end.lat);
+            var left = (start.lon < end.lon ? start.lon : end.lon);
+            var right = (start.lon > end.lon ? start.lon : end.lon);
+            var bounds = new OpenLayers.Bounds(left, bottom, right, top);
+            var zoom = this.getZoomForExtent(bounds);
+            this.setCenter(new OpenLayers.LonLat(
+              (start.lon + end.lon) / 2,
+              (start.lat + end.lat) / 2
+             ), zoom);
+            this.viewPortDiv.removeChild(document.getElementById("zoomBox"));
+            this.zoomBox = null;
+        }
         this.mouseDragStart = null;
         this.div.style.cursor = "default";
     }
diff --git a/lib/OpenLayers/Map.js b/lib/OpenLayers/Map.js
index b16c195e49..d254f1e3aa 100644
--- a/lib/OpenLayers/Map.js
+++ b/lib/OpenLayers/Map.js
@@ -220,8 +220,8 @@ OpenLayers.Map.prototype = {
     */
     getZoomForExtent: function (bounds) {
         var size = this.getSize();
-        var deg_per_pixel = bounds.getWidth() / size.w;
-        var zoom = Math.log(deg_per_pixel / this.maxResolution) / Math.log(2);
+        var deg_per_pixel = (bounds.getWidth() > bounds.getHeight() ? bounds.getWidth() / size.w : bounds.getHeight() / size.h);
+        var zoom = -( Math.log(deg_per_pixel / this.maxResolution) / Math.log(2) );
         return Math.floor(Math.max(zoom, 0)); 
     },