Launching + Views

mojo/examples/image_viewer/image_viewer.cc

+// Copyright 2014 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 <algorithm>
+
+#include "base/strings/string_tokenizer.h"
+#include "mojo/public/cpp/application/application.h"
+#include "mojo/services/public/cpp/view_manager/view.h"
+#include "mojo/services/public/cpp/view_manager/view_manager.h"
+#include "mojo/services/public/cpp/view_manager/view_manager_delegate.h"
+#include "mojo/services/public/cpp/view_manager/view_manager_types.h"
+#include "mojo/services/public/cpp/view_manager/view_tree_node.h"
+#include "mojo/services/public/interfaces/launcher/launcher.mojom.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "ui/gfx/codec/png_codec.h"
+
+namespace mojo {
+namespace examples {
+
+class ImageViewer;
+
+class LaunchableConnection : public InterfaceImpl<launcher::Launchable> {
+ public:
+  explicit LaunchableConnection(ImageViewer* viewer) : viewer_(viewer) {}
+  virtual ~LaunchableConnection() {}
+
+ private:
+  // Overridden from launcher::Launchable:
+  virtual void OnLaunch(URLResponsePtr response,
+                        ScopedDataPipeConsumerHandle response_body_stream,
+                        uint32_t node_id) OVERRIDE {
+    int content_length = GetContentLength(response->headers);
+    unsigned char* data = new unsigned char[content_length];
+    unsigned char* buf = data;
+    uint32_t bytes_remaining = content_length;
+    uint32_t num_bytes = bytes_remaining;
+    while (bytes_remaining > 0) {
+      MojoResult result = ReadDataRaw(
+          response_body_stream.get(),
+          buf,
+          &num_bytes,
+          MOJO_READ_DATA_FLAG_NONE);
+      if (result == MOJO_RESULT_SHOULD_WAIT) {
+        Wait(response_body_stream.get(),
+             MOJO_WAIT_FLAG_READABLE,
+             MOJO_DEADLINE_INDEFINITE);
+      } else if (result == MOJO_RESULT_OK) {
+        buf += num_bytes;
+        num_bytes = bytes_remaining -= num_bytes;
+      } else {
+        break;
+      }
+    }
+
+    SkBitmap bitmap;
+    gfx::PNGCodec::Decode(static_cast<const unsigned char*>(data),
+                          content_length, &bitmap);

[Aaron Boodman, 2014/06/13 20:09:52]

Wow, this is a cool outcome of Mojo's design.

When I first saw this my gut reaction was "yikes! security blah blah". But then
I realized actually this whole process would be sandboxed, so it's not a
problem. Neat.

[Ben Goodger (Google), 2014/06/13 20:29:28]

Yeah it's interesting. We do this in chrome today for a few things.. e.g.
profile import is done in a sandboxed process.

+    UpdateView(node_id, bitmap);
+
+    delete[] data;
+  }
+
+  void UpdateView(view_manager::Id node_id, const SkBitmap& bitmap);
+
+  int GetContentLength(const Array<String>& headers) {
+    for (size_t i = 0; i < headers.size(); ++i) {
+      base::StringTokenizer t(headers[i], ": ;=");

[Aaron Boodman, 2014/06/13 20:09:52]

Probably right thing to do here is either reuse Blink entirely, or at least
header parsing code from net.

[Ben Goodger (Google), 2014/06/13 20:29:28]

Agreed, esp as this is the second time I've copy-pasted this in my demo apps.
Question is whether or not we want this code to depend on net via http_util...
or if we want to build out the utils in mojo/services/public/cpp/network. Filed
http://crbug.com/384530

+      while (t.GetNext()) {
+        if (!t.token_is_delim() && t.token() == "Content-Length") {
+          while (t.GetNext()) {
+            if (!t.token_is_delim())
+              return atoi(t.token().c_str());
+          }
+        }
+      }
+    }
+    return 0;
+  }
+
+  ImageViewer* viewer_;
+
+  DISALLOW_COPY_AND_ASSIGN(LaunchableConnection);
+};
+
+class ImageViewer : public Application,
+                    public view_manager::ViewManagerDelegate {
+ public:
+  ImageViewer() : content_view_(NULL) {}
+  virtual ~ImageViewer() {}
+
+  void UpdateView(view_manager::Id node_id, const SkBitmap& bitmap) {
+    bitmap_ = bitmap;
+    DrawBitmap();
+  }
+
+ private:
+  // Overridden from Application:
+  virtual void Initialize() OVERRIDE {
+    AddService<LaunchableConnection>(this);
+    view_manager::ViewManager::Create(this, this);
+  }
+
+  // Overridden from view_manager::ViewManagerDelegate:
+  virtual void OnRootAdded(view_manager::ViewManager* view_manager,
+                           view_manager::ViewTreeNode* root) OVERRIDE {
+    content_view_ = view_manager::View::Create(view_manager);
+    root->SetActiveView(content_view_);
+    content_view_->SetColor(SK_ColorRED);
+    if (!bitmap_.isNull())
+      DrawBitmap();
+  }
+
+  void DrawBitmap() {
+    if (content_view_)
+      content_view_->SetContents(bitmap_);
+  }
+
+  view_manager::View* content_view_;
+  SkBitmap bitmap_;
+
+  DISALLOW_COPY_AND_ASSIGN(ImageViewer);
+};
+
+void LaunchableConnection::UpdateView(view_manager::Id node_id,
+                                      const SkBitmap& bitmap) {
+  viewer_->UpdateView(node_id, bitmap);
+}
+
+}  // namespace examples
+
+// static
+Application* Application::Create() {
+  return new examples::ImageViewer;
+}
+
+}  // namespace mojo