Support cancelling toast

ash/system/toast/toast_manager.cc

 // Copyright 2016 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 "ash/system/toast/toast_manager.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/threading/thread_task_runner_handle.h"
 
 namespace ash {
 
 namespace {
 
 // Minimum duration for a toast to be visible (in millisecond).
 uint64_t kMinimumDurationMs = 200;
 
 }  // anonymous namespace
 
 ToastManager::ToastManager() : weak_ptr_factory_(this) {}
 
 ToastManager::~ToastManager() {}
 
-void ToastManager::Show(const std::string& text, uint64_t duration_ms) {
-  queue_.emplace(std::make_pair(text, duration_ms));
+void ToastManager::Show(const ToastData& data) {
+  const std::string& id = data.id;
+  DCHECK(!id.empty());
+
+  if (current_toast_id_ == id) {
+    // TODO(yoshiki): Replaces the visible toast.
+    return;
+  }
+
+  auto existing_toast =
+      std::find_if(queue_.begin(), queue_.end(),
+                   [id](const ToastData& data) { return data.id == id; });
+
+  if (existing_toast == queue_.end()) {
+    queue_.emplace_back(data);
+  } else {
+    *existing_toast = data;
+  }
 
   if (queue_.size() == 1 && overlay_ == nullptr)
     ShowLatest();
 }
 
+void ToastManager::Cancel(const std::string& id) {
+  if (id == current_toast_id_) {
+    overlay_->Show(false);
+    return;
+  }
+
+  auto cancelled_toast =
+      std::find_if(queue_.begin(), queue_.end(),
+                   [id](const ToastData& data) { return data.id == id; });

[hidehiko, 2016/05/20 07:46:53]

&id

[yoshiki, 2016/05/20 08:14:55]

Done.

[hidehiko, 2016/05/20 08:52:41]

Not done?

[yoshiki, 2016/05/20 09:30:31]

I did the first one but forgot the second one (this). Done.

+  if (cancelled_toast != queue_.end())
+    queue_.erase(cancelled_toast);
+}
+
 void ToastManager::OnClosed() {
   overlay_.reset();
+  current_toast_id_.clear();
 
   // Show the next toast if available.
   if (queue_.size() != 0)

[hidehiko, 2016/05/20 07:46:53]

nit: !queue_.empty()

[yoshiki, 2016/05/20 08:14:54]

Done.

     ShowLatest();
 }
 
 void ToastManager::ShowLatest() {
   DCHECK(!overlay_);
 
-  auto data = queue_.front();
-  uint64_t duration_ms = std::max(data.second, kMinimumDurationMs);
+  const ToastData& data = queue_.front();  // Can be used until pop_front().

[hidehiko, 2016/05/20 07:46:53]

I'd recommend:

ToastData data = std::move(queue_.top());
queue_.pop_front();

[yoshiki, 2016/05/20 08:14:54]

Done.

[hidehiko, 2016/05/20 08:52:41]

I meant, getting rid of ref, so that you can pop just after this line.

[yoshiki, 2016/05/20 09:30:30]

Oh, I see. Done.

+  uint64_t duration_ms = std::max(data.duration_ms, kMinimumDurationMs);
 
-  toast_id_++;
+  current_toast_id_ = data.id;
+  serial_++;

[hidehiko, 2016/05/20 07:46:53]

Because you manage the toast UI by ID (in Cancel), serial_ looks unnecessary?

[yoshiki, 2016/05/20 08:14:55]

Same ID may come at the timing after the toast is cancelled but before the
delayed task remains. In current ARC implementation it doesn't happens, but
other user might do it. So I use the internal ID.

See the previous discussion in this codereview as well.

 
-  overlay_.reset(new ToastOverlay(this, data.first /* text */));
+  overlay_.reset(new ToastOverlay(this, data.text /* text */));

[hidehiko, 2016/05/20 07:46:53]

/* text */ looks unnecessary now.

[yoshiki, 2016/05/20 08:14:54]

Done.

   overlay_->Show(true);
 
   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
       FROM_HERE, base::Bind(&ToastManager::OnDurationPassed,
-                            weak_ptr_factory_.GetWeakPtr(), toast_id_),
+                            weak_ptr_factory_.GetWeakPtr(), serial_),
       base::TimeDelta::FromMilliseconds(duration_ms));
 
-  queue_.pop();
+  queue_.pop_front();
 }
 
-void ToastManager::OnDurationPassed(int toast_id) {
-  if (overlay_ && toast_id_ == toast_id)
+void ToastManager::OnDurationPassed(int toast_number) {
+  if (overlay_ && serial_ == toast_number)
     overlay_->Show(false);
 }
 
 }  // namespace ash