Support cancelling toast

ash/system/toast/toast_manager.cc

Index: ash/system/toast/toast_manager.cc
diff --git a/ash/system/toast/toast_manager.cc b/ash/system/toast/toast_manager.cc
index 86f8653be2f0e51c9499bf7b00f44397c40c6b94..a296f5210a0f49d517ab2ca3a93f081a4530da29 100644
--- a/ash/system/toast/toast_manager.cc
+++ b/ash/system/toast/toast_manager.cc
@@ -21,15 +21,45 @@ 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.

@@ -39,24 +69,25 @@ void ToastManager::OnClosed() {
 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);
 }