Implements a zoom icon in the Omnibox for Views.

chrome/browser/ui/views/location_bar/zoom_bubble_view.cc

+// 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/views/location_bar/zoom_bubble_view.h"
+
+#include "base/bind.h"
+#include "base/message_loop.h"
+#include "grit/generated_resources.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/views/layout/fill_layout.h"
+
+namespace {
+
+// The number of milliseconds the bubble should stay on the screen for if it
+// will automatically close.
+const int kBubbleCloseDelay = 400;
+
+}
+
+// Singleton instance.

[Ben Goodger (Google), 2012/06/22 19:16:06]

// static

[Kyle Horimoto, 2012/06/26 21:55:53]

Done.

+ZoomBubbleView* ZoomBubbleView::zoom_bubble_ = NULL;

[Peter Kasting, 2012/06/22 20:16:20]

Using a singleton for this is wrong.  For example, if the user opens the same
page in two browser windows, then changes zoom, we'll want to show a bubble in
both windows (in part because we don't know which one the user might be looking
at; one might be obscured).  So it seems like we need at least one bubble per
browser window.

Rather than using a singleton, you should look at the content settings bubbles
or the star bubble to see how they do ownership.

Also, be very careful with auto-showing bubbles; take my example two-window case
above, and minimize one window.  Now you probably don't want to try and show a
bubble in that window (because where precisely are you going to parent it?). 
Make sure you have thought through and handled scary edge case scenarios like
this.

[Kyle Horimoto, 2012/06/26 21:55:53]

As discussed offline, the bubble is purposely not shown in any window but the
active window, so a singleton is acceptable here.

+
+// static
+void ZoomBubbleView::ShowBubble(views::View* anchor_view,
+                                int zoom_percent,
+                                bool auto_close) {
+  if (IsShowing())
+    CloseBubble();
+
+  zoom_bubble_ = new ZoomBubbleView(anchor_view, zoom_percent, auto_close);
+  views::BubbleDelegateView::CreateBubble(zoom_bubble_);
+  zoom_bubble_->Show();
+}
+
+// static
+void ZoomBubbleView::CloseBubble() {
+  if (IsShowing())
+    zoom_bubble_->Close();
+}
+
+// static
+bool ZoomBubbleView::IsShowing() {
+  return zoom_bubble_ != NULL;
+}
+
+void ZoomBubbleView::WindowClosing() {
+  DCHECK(zoom_bubble_ == this);
+  zoom_bubble_ = NULL;
+}
+
+void ZoomBubbleView::Init() {
+  SetLayoutManager(new views::FillLayout());
+  zoom_percent_label_ = new views::Label(

[Peter Kasting, 2012/06/22 20:16:20]

Nit: We don't need a member for this, since we never use it directly outside of
here.

[Kyle Horimoto, 2012/06/26 21:55:53]

Done.

+      l10n_util::GetStringFUTF16Int(IDS_ZOOM_PERCENT, zoom_percent_));
+  AddChildView(zoom_percent_label_);
+
+  if (auto_close_)

[Ben Goodger (Google), 2012/06/22 19:16:06]

braces around this one

[Kyle Horimoto, 2012/06/26 21:55:53]

Done.

+    MessageLoop::current()->PostDelayedTask(
+        FROM_HERE,
+        base::Bind(&ZoomBubbleView::Close, factory_.GetWeakPtr()),
+        kBubbleCloseDelay);
+}
+
+ZoomBubbleView::ZoomBubbleView(views::View* anchor_view,
+                               int zoom_percent,
+                               bool auto_close)
+  : BubbleDelegateView(anchor_view, views::BubbleBorder::TOP_RIGHT),

[Ben Goodger (Google), 2012/06/22 19:16:06]

4-space indent to the :

[Kyle Horimoto, 2012/06/26 21:55:53]

Done.

+    ALLOW_THIS_IN_INITIALIZER_LIST(factory_(this)),
+    zoom_percent_(zoom_percent),
+    auto_close_(auto_close),
+    zoom_percent_label_(NULL) {
+  set_use_focusless(auto_close);
+}
+
+ZoomBubbleView::~ZoomBubbleView() {
+}
+
+void ZoomBubbleView::Close() {

[Ben Goodger (Google), 2012/06/22 19:16:06]

this doesn't look to be used?

[Peter Kasting, 2012/06/22 20:16:20]

CloseBubble() above?

[Kyle Horimoto, 2012/06/26 21:55:53]

It's used in CloseBubble() above.

[Kyle Horimoto, 2012/06/26 21:55:53]

Yep.

+  GetWidget()->Close();
+}