chrome/blink: Add functionality for in-product help for media elements.

third_party/WebKit/Source/core/dom/MediaIPHManager.cpp

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/dom/MediaIPHManager.h"
+
+#include "core/dom/Document.h"
+#include "core/html/HTMLMediaElement.h"
+#include "platform/heap/GarbageCollected.h"
+
+namespace blink {
+// static
+MediaIPHManager* MediaIPHManager::Create(
+    std::unique_ptr<WebMediaIPH> media_iph) {
+  return new MediaIPHManager(std::move(media_iph));
+}
+
+MediaIPHManager::MediaIPHManager(std::unique_ptr<WebMediaIPH> media_iph)
+    : media_iph_(std::move(media_iph)) {
+  media_iph_->BindToClient(this);
+}
+
+MediaIPHManager::~MediaIPHManager() = default;
+
+DEFINE_TRACE(MediaIPHManager) {
+  visitor->Trace(active_element_);
+}
+
+bool MediaIPHManager::IPHTriggerObservedOnElement(HTMLMediaElement& element) {
+  if (state_ != IPHState::kNotShowing)
+    return false;
+
+  active_element_ = &element;
+  state_ = IPHState::kShowing;
+  return true;
+}
+
+void MediaIPHManager::LayoutUpdated() {
+  if (state_ != IPHState::kShowing)
+    return;
+
+  // If the element was removed or the download button was removed, hide the
+  // IPH widget.
+  IntRect button_rect;
+  if (!active_element_ ||
+      !active_element_->GetMediaControls()->GetDownloadButtonRect(
+          button_rect)) {
+    // Request hide and wait for an ack from the browser.
+    state_ = IPHState::kHideRequested;
+    media_iph_->HideMediaDownloadIPH();
+    return;
+  }
+
+  media_iph_->ShowMediaDownloadIPH(button_rect);
+}
+
+void MediaIPHManager::DidHideMediaIPHWidget() {
+  if (state_ == IPHState::kNotShowing)
+    return;
+
+  state_ = IPHState::kNotShowing;
+  if (active_element_)
+    active_element_->GetMediaControls()->IPHDisabled();
+  active_element_ = nullptr;
+}
+
+}  // namespace blink