Do not scroll to the capture area when it's completely visible in the…

… current view port

lib/browser/client-scripts/gemini.js

@@ -31,12 +31,21 @@ function prepareScreenshotUnsafe(selectors, opts) {
         return rect;
     }
 
-    window.scrollTo(rect.left, rect.top);
-
     var viewportHeight = window.innerHeight || document.documentElement.clientHeight,
+        viewportWidth = window.innerWidth || document.documentElement.clientWidth,
         documentHeight = document.documentElement.scrollHeight,
         documentWidth = document.documentElement.scrollWidth,
-        coverage;
+        coverage,
+        viewPort = new Rect({
+            left: util.getScrollLeft(),
+            top: util.getScrollTop(),
+            width: viewportWidth,
+            height: viewportHeight
+        });
+
+    if (!viewPort.rectInside(rect)) {
+        window.scrollTo(rect.left, rect.top);
+    }
 
     if (opts.coverage) {
         coverage = require('./gemini.coverage').collectCoverage(rect);

lib/browser/client-scripts/rect.js

@@ -48,7 +48,7 @@ Rect.prototype = {
     },
 
     rectInside: function(rect) {
-        return util.every(this._keyPoints(), function(point) {
+        return util.every(rect._keyPoints(), function(point) {
             return this.pointInside(point[0], point[1]);
         }, this);
     },

test/rect.test.js

@@ -0,0 +1,67 @@
+'use strict';
+
+var assert = require('chai').assert,
+    Rect = require('../lib/browser/client-scripts/rect').Rect;
+
+describe('Rect', function() {
+    describe('constructor', function() {
+        it('should create instance using width/height properties', function() {
+            assert.doesNotThrow(function() {
+                return new Rect({
+                    top: 10,
+                    left: 20,
+                    width: 100,
+                    height: 100
+                });
+            });
+        });
+
+        it('should create instance using bottom/right properties', function() {
+            assert.doesNotThrow(function() {
+                return new Rect({
+                    top: 10,
+                    left: 20,
+                    bottom: 100,
+                    right: 100
+                });
+            });
+        });
+
+        it('should fail when there are no bottom/right or width/height properties', function() {
+            assert.throws(function() {
+                return new Rect({top: 10, left: 20});
+            });
+        });
+    });
+
+    describe('rectInside', function() {
+        var rect = new Rect({
+            top: 10,
+            left: 20,
+            width: 100,
+            height: 100
+        });
+
+        it('should return true when rect is inside', function() {
+            assert.isTrue(rect.rectInside(
+                new Rect({
+                    top: rect.top + 10,
+                    left: rect.left + 10,
+                    width: rect.width - 50,
+                    height: rect.height - 50
+                })
+            ));
+        });
+
+        it('should return false when rect is not inside', function() {
+            assert.isFalse(rect.rectInside(
+                new Rect({
+                    top: rect.top - 5,
+                    left: rect.left - 5,
+                    width: rect.width,
+                    height: rect.width
+                })
+            ));
+        });
+    });
+});