Linux native notifications: Support image notifications

chrome/browser/notifications/notification_platform_bridge_linux.cc

Index: chrome/browser/notifications/notification_platform_bridge_linux.cc
diff --git a/chrome/browser/notifications/notification_platform_bridge_linux.cc b/chrome/browser/notifications/notification_platform_bridge_linux.cc
index 6bcf7a2f34ecdf5bcddd159f33669ebb6a253429..6b42d0e158f33af7ba3313020519f059662ebbd1 100644
--- a/chrome/browser/notifications/notification_platform_bridge_linux.cc
+++ b/chrome/browser/notifications/notification_platform_bridge_linux.cc
@@ -35,6 +35,7 @@
 #include "dbus/bus.h"
 #include "dbus/message.h"
 #include "dbus/object_proxy.h"
+#include "skia/ext/image_operations.h"
 #include "ui/gfx/image/image_skia.h"
 
 namespace {
@@ -45,6 +46,10 @@ const char kFreedesktopNotificationsPath[] = "/org/freedesktop/Notifications";
 const char kDefaultButtonId[] = "default";
 const char kSettingsButtonId[] = "settings";
 
+// Max image size; specified in the FDO notification specification.
+const int kMaxImageWidth = 200;
+const int kMaxImageHeight = 100;
+
 // The values in this enumeration correspond to those of the
 // Linux.NotificationPlatformBridge.InitializationStatus histogram, so
 // the ordering should not be changed.  New error codes should be
@@ -58,6 +63,14 @@ enum class ConnectionInitializationStatusCode {
   NUM_ITEMS
 };
 
+int ClampInt(int v, int lo, int hi) {

[Lei Zhang, 2017/05/11 00:54:56]

return std::max(std::min(value, hi), low);

[Lei Zhang, 2017/05/11 00:54:56]

BTW, std::clamp() will be in C++17, so we'll have it on all supported Linux
distros in 2025. ;-) This is the same parameter order.

I'll probably find some time later to add a parameterized version of clamp() to
base, to prepare us for 2025.

[Tom (Use chromium acct), 2017/05/11 01:28:22]

Done.

+  if (v < lo)
+    return lo;
+  if (v > hi)
+    return hi;
+  return v;
+}
+
 base::string16 CreateNotificationTitle(const Notification& notification) {
   base::string16 title;
   if (notification.type() == message_center::NOTIFICATION_TYPE_PROGRESS) {
@@ -95,6 +108,29 @@ int NotificationPriorityToFdoUrgency(int priority) {
   }
 }
 
+// Constrain |image|'s size to |kMaxImageWidth|x|kMaxImageHeight|. If
+// the image does not need to be resized, or the image is empty,
+// returns |image| directly.
+gfx::Image ResizeImageToFdoMaxSize(const gfx::Image& image) {
+  if (image.IsEmpty())
+    return image;
+  int width = image.Width();
+  int height = image.Height();
+  if (width <= kMaxImageWidth && height <= kMaxImageHeight) {
+    return image;
+  } else {

[Lei Zhang, 2017/05/11 00:54:56]

No else after return.

[Tom (Use chromium acct), 2017/05/11 01:28:22]

Done.

+    const SkBitmap* image_bitmap = image.ToSkBitmap();
+    double scale = std::min(static_cast<double>(kMaxImageWidth) / width,
+                            static_cast<double>(kMaxImageHeight) / height);
+    width = ClampInt(scale * width, 1, kMaxImageWidth);
+    height = ClampInt(scale * height, 1, kMaxImageHeight);
+    return gfx::Image(
+        gfx::ImageSkia::CreateFrom1xBitmap(skia::ImageOperations::Resize(
+            *image_bitmap, skia::ImageOperations::RESIZE_LANCZOS3, width,
+            height)));
+  }
+}
+
 // Runs once the profile has been loaded in order to perform a given
 // |operation| on a notification.
 void ProfileLoadedCallback(NotificationCommon::Operation operation,
@@ -209,7 +245,9 @@ class NotificationPlatformBridgeLinuxImpl
     // non-thread-safe reference counts) to the task runner thread.
     auto notification_copy = base::MakeUnique<Notification>(notification);
     notification_copy->set_icon(DeepCopyImage(notification_copy->icon()));
-    notification_copy->set_image(gfx::Image());
+    notification_copy->set_image(body_images_supported_
+                                     ? DeepCopyImage(notification_copy->image())
+                                     : gfx::Image());
     notification_copy->set_small_image(gfx::Image());
     for (size_t i = 0; i < notification_copy->buttons().size(); i++)
       notification_copy->SetButtonIcon(i, gfx::Image());
@@ -311,6 +349,11 @@ class NotificationPlatformBridgeLinuxImpl
     CleanUp();
   }
 
+  void SetBodyImagesSupported(bool body_images_supported) {
+    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+    body_images_supported_ = body_images_supported;
+  }
+
   void PostTaskToUiThread(base::OnceClosure closure) const {
     DCHECK(task_runner_->RunsTasksOnCurrentThread());
     bool success = content::BrowserThread::PostTask(
@@ -360,6 +403,9 @@ class NotificationPlatformBridgeLinuxImpl
         capabilities_.insert(capability);
     }
     RecordMetricsForCapabilities();
+    PostTaskToUiThread(base::BindOnce(
+        &NotificationPlatformBridgeLinuxImpl::SetBodyImagesSupported, this,
+        base::ContainsKey(capabilities_, "body-images")));
 
     dbus::MethodCall get_server_information_call(kFreedesktopNotificationsName,
                                                  "GetServerInformation");
@@ -468,6 +514,18 @@ class NotificationPlatformBridgeLinuxImpl
           else
             body += title + " - " + message;
         }
+      } else if (notification->type() ==
+                     message_center::NOTIFICATION_TYPE_IMAGE &&
+                 base::ContainsKey(capabilities_, "body-images")) {
+        std::unique_ptr<ResourceFile> image_file = WriteDataToTmpFile(
+            ResizeImageToFdoMaxSize(notification->image()).As1xPNGBytes());
+        if (image_file) {
+          if (!body.empty())
+            body += "\n";
+          body +=
+              "<img src=\"" + image_file->file_path().value() + "\" alt=\"\"/>";
+          data->resource_files.push_back(std::move(image_file));
+        }
       }
     }
     writer.AppendString(body);
@@ -750,6 +808,12 @@ class NotificationPlatformBridgeLinuxImpl
   base::Optional<bool> connected_;
   std::vector<NotificationBridgeReadyCallback> on_connected_callbacks_;
 
+  // Notification servers very rarely have the 'body-images'
+  // capability, so try to avoid an image copy if possible. It is
+  // intialized to true so that the UI thread will conservatively copy
+  // the image before the GetCapabilities message completes.
+  bool body_images_supported_ = true;
+
   //////////////////////////////////////////////////////////////////////////////
   // Members used only on the task runner thread.