Fix native image recreated on layout even if the view is not resized

apps/tests/testRunner.ts

@@ -144,17 +144,41 @@ function log(): void {
     TKUnit.write(testsName + " COMPLETED for " + duration + " BACKSTACK DEPTH: " + topmost().backStack.length, messageType.info);
 }
 
-export var runAll = function (moduleName?: string) {
+export var runAll = function (testSelector?: string) {
     if (running) {
         // TODO: We may schedule pending run requests
         return;
     }
+    
+    var singleModuleName, singleTestName;
+    if (testSelector) {
+        var pair = testSelector.split(".");
+        singleModuleName = pair[0];
+        if (singleModuleName) {
+            if (singleModuleName.length === 0) {
+                singleModuleName = undefined;
+            } else {
+                singleModuleName = singleModuleName.toLowerCase();
+            }
+        }
+        
+        singleTestName = pair[1];
+        if (singleTestName) {
+            if (singleTestName.length === 0) {
+                singleTestName = undefined;
+            } else {
+                singleTestName = singleTestName.toLowerCase();
+            }
+        }
+    }
+    
+    console.log("TESTS: " + singleModuleName + " " + singleTestName);
 
     var totalSuccess = 0;
     var totalFailed: Array<TKUnit.TestFailure> = [];
     testsQueue.push(new TestInfo(function () { running = true; }));
     for (var name in allTests) {
-        if (moduleName && (moduleName.toLowerCase() !== name.toLowerCase())) {
+        if (singleModuleName && (singleModuleName !== name.toLowerCase())) {
             continue;
         }
 
@@ -170,8 +194,11 @@ export var runAll = function (moduleName?: string) {
             testsQueue.push(new TestInfo(test.setUpModule, test));
         }
 
-
         for (var testName in test) {
+            if (singleTestName && (singleTestName !== testName.toLowerCase())) {
+                continue;
+            }
+            
             var testFunction = test[testName];
             if ((typeof (testFunction) === "function") && (testName.substring(0, 4) == "test")) {
                 if (test.setUp) {

apps/tests/ui/view/view-tests.ios.ts

@@ -1,6 +1,12 @@
 import commonTests = require("./view-tests-common");
 import view = require("ui/core/view");
 
+import grid = require("ui/layouts/grid-layout");
+import color = require("color");
+import helper = require("../helper");
+import page = require("ui/page");
+import TKUnit = require("../../TKUnit");
+
 global.moduleMerge(commonTests, exports);
 
 export function getNativeBorderWidth(v: view.View): number {
@@ -27,4 +33,55 @@ export function checkNativeBackgroundColor(v: view.View): boolean {
 
 export function checkNativeBackgroundImage(v: view.View): boolean {
     return (<UIView>v.ios).backgroundColor !== undefined;
-}
+}
+
+export function testBackgroundInternalChangedOnceOnResize() {
+    
+    var layout = new grid.GridLayout();
+    layout.className = "myClass";
+    layout.backgroundColor = new color.Color(255, 255, 0, 0);
+    
+    var pageFactory = () => {
+        var root = new page.Page();
+        root.css = ".myClass { background-image: url('~/tests/logo.png') }";
+        root.content = layout;
+        return root;
+    }
+
+    helper.navigate(pageFactory);
+    
+    try {
+        var sizeChangedCount = 0;
+        function trackCount() {
+            var result = sizeChangedCount;
+            sizeChangedCount = 0;
+            return result;
+        }
+        
+        var base = (<any>layout.style)._applyStyleProperty;
+        (<any>layout.style)._applyStyleProperty = function(property) {
+            base.apply(layout.style, arguments);
+            if (property.name === "_backgroundInternal") {
+                ++sizeChangedCount;
+            }
+        }
+        
+        layout.requestLayout();
+        layout.layout(0, 0, 200, 200);
+        
+        TKUnit.assertEqual(trackCount(), 1, "Expected background to be re-applied at most once when the view is layed-out on 0 0 200 200.");
+        
+        layout.requestLayout();
+        layout.layout(50, 50, 250, 250);
+        
+        TKUnit.assertEqual(trackCount(), 0, "Expected background to NOT change when view is layed-out from 0 0 200 200 to 50 50 250 250.");
+        
+        layout.requestLayout();
+        layout.layout(0, 0, 250, 250);
+        
+        TKUnit.assertEqual(trackCount(), 1, "Expected background to be re-applied at most once when the view is layed-out from 50 50 250 250 to 0 0 250 250.");
+    }
+    finally {
+        helper.goBack();
+    }
+}