Share code between strategies.

src/core/basecheckstrategy.js

@@ -0,0 +1,38 @@
+/**
+ * @constructor
+ */
+webfont.BaseCheckStrategy = function(sizingElementCreator, activeCallback,
+    inactiveCallback, fontSizer, fontFamily, fontDescription, opt_fontTestString) {
+  this.sizingElementCreator_ = sizingElementCreator;
+  this.activeCallback_ = activeCallback;
+  this.inactiveCallback_ = inactiveCallback;
+  this.fontSizer_ = fontSizer;
+  this.fontFamily_ = fontFamily;
+  this.fontDescription_ = fontDescription;
+  this.fontTestString_ = opt_fontTestString
+      || webfont.FontWatchRunner.DEFAULT_TEST_STRING;
+};
+
+webfont.BaseCheckStrategy.prototype.setUp = function() {
+  this.originalSizeA_ = this.getStackSize_(webfont.FontWatchRunner.SANS_STACK);
+  this.originalSizeB_ = this.getStackSize_(webfont.FontWatchRunner.SERIF_STACK);
+  this.requestedFontA_ = this.sizingElementCreator_.createSizingElement(
+      this.fontFamily_, webfont.FontWatchRunner.SANS_STACK,
+      this.fontDescription_, this.fontTestString_);
+  this.requestedFontB_ = this.sizingElementCreator_.createSizingElement(
+      this.fontFamily_, webfont.FontWatchRunner.SERIF_STACK,
+      this.fontDescription_, this.fontTestString_);
+};
+
+webfont.BaseCheckStrategy.prototype.tearDown = function() {
+  this.sizingElementCreator_.deleteSizingElement(this.requestedFontA_);
+  this.sizingElementCreator_.deleteSizingElement(this.requestedFontB_);
+};
+
+webfont.BaseCheckStrategy.prototype.getStackSize_ = function(stack) {
+  var stackElement = this.sizingElementCreator_.createSizingElement('',
+      stack, this.fontDescription_, this.fontTestString_);
+  var size = this.fontSizer_.getWidth(stackElement);
+  this.sizingElementCreator_.deleteSizingElement(stackElement);
+  return size;
+};

src/core/defaultcheckstrategy.js

@@ -3,32 +3,16 @@
  */
 webfont.DefaultCheckStrategy = function(sizingElementCreator, activeCallback,
     inactiveCallback, fontSizer, fontFamily, fontDescription, opt_fontTestString) {
-  this.sizingElementCreator_ = sizingElementCreator;
-  this.activeCallback_ = activeCallback;
-  this.inactiveCallback_ = inactiveCallback;
-  this.fontSizer_ = fontSizer;
-  this.fontFamily_ = fontFamily;
-  this.fontDescription_ = fontDescription;
-  this.fontTestString_ = opt_fontTestString
-      || webfont.FontWatchRunner.DEFAULT_TEST_STRING;
+  webfont.DefaultCheckStrategy.superCtor_.call(this, sizingElementCreator,
+      activeCallback, inactiveCallback, fontSizer, fontFamily, fontDescription,
+      opt_fontTestString);
 };
+webfont.extendsClass(webfont.BaseCheckStrategy, webfont.DefaultCheckStrategy);
 
 webfont.DefaultCheckStrategy.prototype.setUp = function() {
-  this.originalSizeA_ = this.getStackSize_(webfont.FontWatchRunner.SANS_STACK);
-  this.originalSizeB_ = this.getStackSize_(webfont.FontWatchRunner.SERIF_STACK);
+  webfont.DefaultCheckStrategy.super_.setUp.call(this);
   this.lastObservedSizeA_ = this.originalSizeA_;
   this.lastObservedSizeB_ = this.originalSizeB_;
-  this.requestedFontA_ = this.sizingElementCreator_.createSizingElement(
-      this.fontFamily_, webfont.FontWatchRunner.SANS_STACK,
-      this.fontDescription_, this.fontTestString_);
-  this.requestedFontB_ = this.sizingElementCreator_.createSizingElement(
-      this.fontFamily_, webfont.FontWatchRunner.SERIF_STACK,
-      this.fontDescription_, this.fontTestString_);
-};
-
-webfont.DefaultCheckStrategy.prototype.tearDown = function() {
-  this.sizingElementCreator_.deleteSizingElement(this.requestedFontA_);
-  this.sizingElementCreator_.deleteSizingElement(this.requestedFontB_);
 };
 
 webfont.DefaultCheckStrategy.prototype.isLoaded = function() {
@@ -55,11 +39,3 @@ webfont.DefaultCheckStrategy.prototype.getTimeoutCallback = function() {
       this.inactiveCallback_(this.fontFamily_, this.fontDescription_);
   });
 };
-
-webfont.DefaultCheckStrategy.prototype.getStackSize_ = function(stack) {
-  var stackElement = this.sizingElementCreator_.createSizingElement('',
-      stack, this.fontDescription_, this.fontTestString_);
-  var size = this.fontSizer_.getWidth(stackElement);
-  this.sizingElementCreator_.deleteSizingElement(stackElement);
-  return size;
-};

src/core/lastresortwebkitcheckstrategy.js

@@ -3,31 +3,16 @@
  */
 webfont.LastResortWebKitCheckStrategy = function(sizingElementCreator, activeCallback,
     inactiveCallback, fontSizer, fontFamily, fontDescription, opt_fontTestString) {
-  this.sizingElementCreator_ = sizingElementCreator;
-  this.activeCallback_ = activeCallback;
-  this.inactiveCallback_ = inactiveCallback;
-  this.fontSizer_ = fontSizer;
-  this.fontFamily_ = fontFamily;
-  this.fontDescription_ = fontDescription;
-  this.fontTestString_ = opt_fontTestString
-      || webfont.FontWatchRunner.DEFAULT_TEST_STRING;
+  webfont.LastResortWebKitCheckStrategy.superCtor_.call(this,
+      sizingElementCreator, activeCallback, inactiveCallback, fontSizer,
+      fontFamily, fontDescription, opt_fontTestString);
 };
+webfont.extendsClass(webfont.BaseCheckStrategy,
+    webfont.LastResortWebKitCheckStrategy);
 
 webfont.LastResortWebKitCheckStrategy.prototype.setUp = function() {
-  this.originalSizeA_ = this.getStackSize_(webfont.FontWatchRunner.SANS_STACK);
-  this.originalSizeB_ = this.getStackSize_(webfont.FontWatchRunner.SERIF_STACK);
+  webfont.LastResortWebKitCheckStrategy.super_.setUp.call(this);
   this.webKitLastResortFontSizes_ = this.setUpWebKitLastResortFontSizes_();
-  this.requestedFontA_ = this.sizingElementCreator_.createSizingElement(
-      this.fontFamily_, webfont.FontWatchRunner.SANS_STACK,
-      this.fontDescription_, this.fontTestString_);
-  this.requestedFontB_ = this.sizingElementCreator_.createSizingElement(
-      this.fontFamily_, webfont.FontWatchRunner.SERIF_STACK,
-      this.fontDescription_, this.fontTestString_);
-};
-
-webfont.LastResortWebKitCheckStrategy.prototype.tearDown = function() {
-  this.sizingElementCreator_.deleteSizingElement(this.requestedFontA_);
-  this.sizingElementCreator_.deleteSizingElement(this.requestedFontB_);
 };
 
 webfont.LastResortWebKitCheckStrategy.prototype.isLoaded = function() {
@@ -48,14 +33,6 @@ webfont.LastResortWebKitCheckStrategy.prototype.getTimeoutCallback = function()
   return this.getActiveCallback();
 };
 
-webfont.LastResortWebKitCheckStrategy.prototype.getStackSize_ = function(stack) {
-  var stackElement = this.sizingElementCreator_.createSizingElement('',
-      stack, this.fontDescription_, this.fontTestString_);
-  var size = this.fontSizer_.getWidth(stackElement);
-  this.sizingElementCreator_.deleteSizingElement(stackElement);
-  return size;
-};
-
 /**
  * While loading a web font webkit applies a last resort fallback font to the
  * element on which the web font is applied.

src/core/namespace.js

@@ -14,3 +14,17 @@ webfont.bind = function(context, func, opt_args) {
     return func.apply(context, args);
   };
 };
+
+webfont.extendsClass = function(baseClass, subClass) {
+
+  // Avoid polluting the baseClass prototype object with methods from the
+  // subClass
+  /** @constructor */
+  function baseExtendClass() {};
+  baseExtendClass.prototype = baseClass.prototype;
+  subClass.prototype = new baseExtendClass();
+
+  subClass.prototype.constructor = subClass;
+  subClass.superCtor_ = baseClass;
+  subClass.super_ = baseClass.prototype;
+};

src/modules.yml

@@ -6,6 +6,7 @@ core:
   - core/eventdispatcher.js
   - core/fontmoduleloader.js
   - core/sizingelementcreator.js
+  - core/basecheckstrategy.js
   - core/defaultcheckstrategy.js
   - core/lastresortwebkitcheckstrategy.js
   - core/fontwatcher.js