Bug 666446, Part 3/18 - Create hook functions in nsLayoutUtils to coalesce some of the new code for frame-like objects and avoid code duplication. [r=roc]

layout/base/nsLayoutUtils.cpp

@@ -4292,6 +4292,102 @@ nsLayoutUtils::Shutdown()
   }
 }
 
+/* static */
+void
+nsLayoutUtils::RegisterImageRequest(nsPresContext* aPresContext,
+                                    imgIRequest* aRequest,
+                                    bool* aRequestRegistered)
+{
+  if (!aPresContext) {
+    return;
+  }
+
+  if (aRequestRegistered && *aRequestRegistered) {
+    // Our request is already registered with the refresh driver, so
+    // no need to register it again.
+    return;
+  }
+
+  if (aRequest) {
+    nsCOMPtr<imgIContainer> image;
+    aRequest->GetImage(getter_AddRefs(image));
+    if (image) {
+      if (!aPresContext->RefreshDriver()->AddImageRequest(aRequest)) {
+        NS_WARNING("Unable to add image request");
+        return;
+      }
+
+      if (aRequestRegistered) {
+        *aRequestRegistered = true;
+      }
+    }
+  }
+}
+
+/* static */
+void
+nsLayoutUtils::DeregisterImageRequest(nsPresContext* aPresContext,
+                                      imgIRequest* aRequest,
+                                      bool* aRequestRegistered)
+{
+  if (!aPresContext) {
+    return;
+  }
+
+  // Deregister our imgIRequest with the refresh driver to
+  // complete tear-down, but only if it has been registered
+  if (aRequestRegistered && !*aRequestRegistered) {
+    return;
+  }
+
+  if (aRequest) {
+    nsCOMPtr<imgIContainer> image;
+    aRequest->GetImage(getter_AddRefs(image));
+    if (image) {
+      aPresContext->RefreshDriver()->RemoveImageRequest(aRequest);
+
+      if (aRequestRegistered) {
+        *aRequestRegistered = false;
+      }
+    }
+  }
+}
+
+/* static */
+void
+nsLayoutUtils::DeregisterImageRequestIfNotAnimated(nsPresContext* aPresContext,
+                                                   imgIRequest* aRequest,
+                                                   bool* aRequestRegistered)
+{
+  if (!aPresContext) {
+    return;
+  }
+
+  if (aRequestRegistered && !*aRequestRegistered) {
+    // Image request isn't registered with the refresh driver - no need
+    // to try and deregister it.
+    return;
+  }
+
+  // Deregister the imgIRequest with the refresh driver if the
+  // image is not animated
+  nsCOMPtr<imgIContainer> imageContainer;
+  if (aRequest) {
+    aRequest->GetImage(getter_AddRefs(imageContainer));
+    bool animated;
+
+    if (!imageContainer) {
+      return;
+    }
+
+    nsresult rv = imageContainer->GetAnimated(&animated);
+    if (NS_SUCCEEDED(rv) && !animated) {
+      nsLayoutUtils::DeregisterImageRequest(aPresContext, aRequest,
+                                            aRequestRegistered);
+    }
+  }
+}
+
 nsSetAttrRunnable::nsSetAttrRunnable(nsIContent* aContent, nsIAtom* aAttrName,
                                      const nsAString& aValue)
   : mContent(aContent),

layout/base/nsLayoutUtils.h

@@ -1440,6 +1440,63 @@ public:
 
   static void Shutdown();
 
+  /**
+   * Register an imgIRequest object with a refresh driver.
+   *
+   * @param aPresContext The nsPresContext whose refresh driver we want to
+   *        register with.
+   * @param aRequest A pointer to the imgIRequest object which the client wants
+   *        to register with the refresh driver.
+   * @param aRequestRegistered A pointer to a boolean value which indicates
+   *        whether the given image request is registered. If
+   *        *aRequestRegistered is true, then this request will not be
+   *        registered again. If the request is registered by this function,
+   *        then *aRequestRegistered will be set to true upon the completion of
+   *        this function.
+   *
+   */
+  static void RegisterImageRequest(nsPresContext* aPresContext,
+                                   imgIRequest* aRequest,
+                                   bool* aRequestRegistered);
+  /**
+   * Deregister an imgIRequest object from a refresh driver.
+   *
+   * @param aPresContext The nsPresContext whose refresh driver we want to
+   *        deregister from.
+   * @param aRequest A pointer to the imgIRequest object with which the client
+   *        previously registered and now wants to deregister from the refresh
+   *        driver.
+   * @param aRequestRegistered A pointer to a boolean value which indicates
+   *        whether the given image request is registered. If
+   *        *aRequestRegistered is false, then this request will not be
+   *        deregistered. If the request is deregistered by this function,
+   *        then *aRequestRegistered will be set to false upon the completion of
+   *        this function.
+   */
+  static void DeregisterImageRequest(nsPresContext* aPresContext,
+                                     imgIRequest* aRequest,
+                                     bool* aRequestRegistered);
+  /**
+   * Deregister an imgIRequest object from a refresh driver, if the
+   * imgIRequest object represents a static (i.e. not animated) image.
+   *
+   * @param aPresContext The nsPresContext whose refresh driver we want to
+   *        deregister from.
+   * @param aRequest A pointer to the imgIRequest object with which the client
+   *        previously registered and now wants to deregister from the refresh
+   *        driver.
+   * @param aRequestRegistered A pointer to a boolean value which indicates
+   *        whether the given image request is registered. If
+   *        *aRequestRegistered is false, then this request will not be
+   *        deregistered. If the request is deregistered by this function,
+   *        then *aRequestRegistered will be set to false upon the completion of
+   *        this function.
+   */
+
+  static void DeregisterImageRequestIfNotAnimated(nsPresContext* aPresContext,
+                                                  imgIRequest* aRequest,
+                                                  bool* aRequestRegistered);
+
 #ifdef DEBUG
   /**
    * Assert that there are no duplicate continuations of the same frame