Add a tray notification UI for speech input recording in the extension API.

chrome/browser/speech/speech_input_extension_notification_ui.cc

+// Copyright (c) 2011 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/speech/speech_input_extension_notification_ui.h"
+
+#include "base/lazy_instance.h"
+#include "base/utf_string_conversions.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/status_icons/status_icon.h"
+#include "chrome/browser/status_icons/status_tray.h"
+#include "chrome/common/extensions/extension.h"
+#include "grit/chromium_strings.h"
+#include "grit/generated_resources.h"
+#include "grit/theme_resources.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/gfx/canvas_skia.h"
+#include "ui/gfx/rect.h"
+#include "ui/gfx/skbitmap_operations.h"
+
+namespace {
+
+// A lazily initialized singleton to hold all the images used by the
+// notification icon and safely destroy them on exit.
+class NotificationTrayImages {
+ public:
+  SkBitmap* mic_full() { return mic_full_; }
+  SkBitmap* mic_empty() { return mic_empty_; }
+  SkBitmap* balloon_icon() {  return balloon_icon_; }
+
+ private:
+  // Private constructor to enforce singleton.
+  friend struct base::DefaultLazyInstanceTraits<NotificationTrayImages>;
+  NotificationTrayImages();
+
+  // These bitmaps are owned by ResourceBundle and need not be destroyed.
+  SkBitmap* mic_full_; // Tray mic image with full volume.
+  SkBitmap* mic_empty_; // Tray mic image with zero volume.
+  SkBitmap* balloon_icon_; // High resolution mic for the notification balloon.
+};
+
+NotificationTrayImages::NotificationTrayImages() {
+  int icon_ids[] = {
+#if defined(OS_WIN)
+      IDR_SPEECH_INPUT_TRAY_WINDOWS_MIC_EMPTY,

[Satish, 2011/11/07 18:16:31]

any reason why we need 3 different set of IDs? could use the same ID name for
these on all 3 platforms

[Leandro Graciá Gil, 2011/11/07 19:34:42]

Done.

+      IDR_SPEECH_INPUT_TRAY_WINDOWS_MIC_FULL,
+#elif defined(OS_MACOSX)
+      IDR_SPEECH_INPUT_TRAY_MACOSX_MIC_EMPTY,
+      IDR_SPEECH_INPUT_TRAY_MACOSX_MIC_FULL,
+#else

[Satish, 2011/11/07 18:16:31]

can you make this into an explicit linux & chrome os define and perhaps handle
the #else clause properly, in case there is a new platform in future?

[Leandro Graciá Gil, 2011/11/07 19:34:42]

Done.

+      // Linux and Chrome OS icons.
+      IDR_SPEECH_INPUT_TRAY_LINUX_MIC_EMPTY,
+      IDR_SPEECH_INPUT_TRAY_LINUX_MIC_FULL,
+#endif
+  };
+
+  mic_empty_ = ResourceBundle::GetSharedInstance().GetBitmapNamed(icon_ids[0]);
+  mic_full_ = ResourceBundle::GetSharedInstance().GetBitmapNamed(icon_ids[1]);
+  balloon_icon_ = ResourceBundle::GetSharedInstance().GetBitmapNamed(
+      IDR_SPEECH_INPUT_TRAY_BALLOON_ICON);
+}
+
+base::LazyInstance<NotificationTrayImages> g_images(base::LINKER_INITIALIZED);
+
+}  // namespace
+
+SpeechInputExtensionNotificationUI::SpeechInputExtensionNotificationUI(
+    Profile* profile)
+    : profile_(profile),
+      tray_icon_(NULL) {
+  mic_image_.reset(new SkBitmap());
+  mic_image_->setConfig(SkBitmap::kARGB_8888_Config,
+                        g_images.Get().mic_empty()->width(),
+                        g_images.Get().mic_empty()->height());
+  mic_image_->allocPixels();
+
+  buffer_image_.reset(new SkBitmap());
+  buffer_image_->setConfig(SkBitmap::kARGB_8888_Config,
+                           g_images.Get().mic_empty()->width(),
+                           g_images.Get().mic_empty()->height());
+  buffer_image_->allocPixels();
+}
+
+SpeechInputExtensionNotificationUI::~SpeechInputExtensionNotificationUI() {
+}
+
+void SpeechInputExtensionNotificationUI::DrawVolume(
+    SkCanvas* canvas,
+    const SkBitmap& bitmap,
+    float volume) {
+  buffer_image_->eraseARGB(0, 0, 0, 0);
+
+  int width = mic_image_->width();
+  int height = mic_image_->height();
+  SkCanvas buffer_canvas(*buffer_image_);
+
+  buffer_canvas.save();

[Satish, 2011/11/07 18:16:31]

since this is a scoped canvas and gets destroyed on return, is a .save() and
.restore() required?

[Leandro Graciá Gil, 2011/11/07 19:34:42]

Done.

+  const int kVolumeSteps = 6;

[Satish, 2011/11/07 18:16:31]

move this to an anonymous namespace constant

[Leandro Graciá Gil, 2011/11/07 19:34:42]

Done.

+  SkScalar clip_top =
+      (((1.0f - volume) * (height * (kVolumeSteps + 1))) - height) /
+      kVolumeSteps;
+  buffer_canvas.clipRect(SkRect::MakeLTRB(0, clip_top,
+      SkIntToScalar(width), SkIntToScalar(height)));
+  buffer_canvas.drawBitmap(bitmap, 0, 0);
+  buffer_canvas.restore();
+
+  canvas->drawBitmap(*buffer_image_.get(), 0, 0);
+}
+
+void SpeechInputExtensionNotificationUI::SetVUMeterVolume(float volume) {
+  if (!tray_icon_)
+    return;
+
+  mic_image_->eraseARGB(0, 0, 0, 0);
+  SkCanvas canvas(*mic_image_);
+
+  // Draw the empty volume image first and the current volume image on top.
+  canvas.drawBitmap(*g_images.Get().mic_empty(), 0, 0);
+  DrawVolume(&canvas, *g_images.Get().mic_full(), volume);
+
+  tray_icon_->SetImage(*mic_image_.get());
+}
+
+void SpeechInputExtensionNotificationUI::Show(const Extension* extension,
+                                              bool show_balloon) {
+  if (StatusTray* status_tray = g_browser_process->status_tray()) {
+    DCHECK(!tray_icon_);
+    tray_icon_ = status_tray->CreateStatusIcon();
+    DCHECK(tray_icon_);
+    VLOG(1) << "Tray icon added.";
+
+    SetVUMeterVolume(0.0f);
+    tray_icon_->SetToolTip(l10n_util::GetStringFUTF16(
+        IDS_SPEECH_INPUT_TRAY_TOOLTIP,
+        UTF8ToUTF16(extension->name()),
+        l10n_util::GetStringUTF16(IDS_PRODUCT_NAME)));
+  } else {
+    VLOG(1) << "This platform doesn't support notification icons.";
+    return;
+  }
+
+  if (show_balloon)
+    ShowNotificationBalloon(extension);
+}
+
+void SpeechInputExtensionNotificationUI::Hide() {
+  if (StatusTray* status_tray = g_browser_process->status_tray()) {
+    DCHECK(tray_icon_);
+    status_tray->RemoveStatusIcon(tray_icon_);
+    tray_icon_ = NULL;
+    VLOG(1) << "Tray icon removed.";
+  }
+}
+
+void SpeechInputExtensionNotificationUI::ShowNotificationBalloon(
+    const Extension* extension) {
+  string16 title = l10n_util::GetStringUTF16(
+      IDS_SPEECH_INPUT_TRAY_BALLOON_TITLE);
+  string16 message = l10n_util::GetStringFUTF16(
+          IDS_SPEECH_INPUT_TRAY_BALLOON_BODY,
+          UTF8ToUTF16(extension->name()),
+          l10n_util::GetStringUTF16(IDS_PRODUCT_NAME));
+
+  tray_icon_->DisplayBalloon(*g_images.Get().balloon_icon(), title, message);
+}