Allow secondary tiles to be unpinned.

chrome/browser/ui/metro_pin_tab_helper.cc

Index: chrome/browser/ui/metro_pin_tab_helper.cc
diff --git a/chrome/browser/ui/metro_pin_tab_helper.cc b/chrome/browser/ui/metro_pin_tab_helper.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0a16543cdfdffc42f1b389fe0db7a5a0e9988daf
--- /dev/null
+++ b/chrome/browser/ui/metro_pin_tab_helper.cc
@@ -0,0 +1,74 @@
+// Copyright (c) 2012 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 "chrome/browser/ui/metro_pin_tab_helper.h"
+
+#include "base/logging.h"
+#include "base/utf_string_conversions.h"
+#include "content/public/browser/web_contents.h"
+
+#if defined(OS_WIN)
+#include "base/win/metro.h"
+#endif
+
+MetroPinTabHelper::MetroPinTabHelper(content::WebContents* web_contents)
+    : content::WebContentsObserver(web_contents),
+      is_pinned_(false) {}
+
+MetroPinTabHelper::~MetroPinTabHelper() {}
+
+void MetroPinTabHelper::TogglePinnedToStartScreen() {
+#if defined(OS_WIN)
+  HMODULE metro_module = base::win::GetMetroModule();
+  if (metro_module) {
+    typedef void (*MetroTogglePinnedToStartScreen)(const string16&,
+        const string16&);
+    MetroTogglePinnedToStartScreen metro_toggle_pinned_to_start_screen =
+        reinterpret_cast<MetroTogglePinnedToStartScreen>(
+            ::GetProcAddress(metro_module, "MetroTogglePinnedToStartScreen"));
+    if (!metro_toggle_pinned_to_start_screen) {
+      NOTREACHED();
+      return;
+    }
+
+    GURL url = web_contents()->GetURL();
+    string16 title = web_contents()->GetTitle();
+    VLOG(1) << __FUNCTION__ << " calling pin with title: " << title
+            << " and url " << UTF8ToUTF16(url.spec());
+    metro_toggle_pinned_to_start_screen(title, UTF8ToUTF16(url.spec()));
+    // TODO(benwells): This will update the state incorrectly if the user
+    // cancels. To fix this some sort of callback needs to be introduced as
+    // the pinning happens on another thread.
+    is_pinned_ = !is_pinned_;
+    return;
+  }
+#endif
+}
+
+void MetroPinTabHelper::DidNavigateMainFrame(
+    const content::LoadCommittedDetails& /*details*/,
+    const content::FrameNavigateParams& /*params*/) {
+  UpdatePinnedStateForCurrentURL();
+}
+
+void MetroPinTabHelper::UpdatePinnedStateForCurrentURL() {
+#if defined(OS_WIN)
+  HMODULE metro_module = base::win::GetMetroModule();
+  if (metro_module) {
+    typedef BOOL (*MetroIsPinnedToStartScreen)(const string16&);
+    MetroIsPinnedToStartScreen metro_is_pinned_to_start_screen =
+        reinterpret_cast<MetroIsPinnedToStartScreen>(
+            ::GetProcAddress(metro_module, "MetroIsPinnedToStartScreen"));
+    if (!metro_is_pinned_to_start_screen) {
+      NOTREACHED();
+      return;
+    }
+
+    GURL url = web_contents()->GetURL();
+    is_pinned_ = metro_is_pinned_to_start_screen(UTF8ToUTF16(url.spec())) != 0;
+    VLOG(1) << __FUNCTION__ << " with url " << UTF8ToUTF16(url.spec())
+            << " result: " << is_pinned_;
+  }
+#endif
+}