headless: Initial headless embedder API implementation

headless/app/headless_shell.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 "base/bind.h"
+#include "base/callback.h"
+#include "base/command_line.h"
+#include "base/location.h"
+#include "base/memory/ref_counted.h"
+#include "base/numerics/safe_conversions.h"
+#include "base/strings/string_number_conversions.h"
+#include "content/public/common/content_switches.h"
+#include "headless/public/headless_browser.h"
+#include "headless/public/headless_web_contents.h"
+#include "ui/gfx/geometry/size.h"
+
+using headless::HeadlessBrowser;
+using headless::HeadlessWebContents;
+
+namespace {
+// Address where to listen to incoming DevTools connections.
+const char kDevToolsHttpServerAddress[] = "127.0.0.1";
+}
+
+// A sample application which demonstrates the use of the headless API.
+class HeadlessShell : public HeadlessWebContents::Observer {
+ public:
+  HeadlessShell() : browser_(nullptr) {}
+  ~HeadlessShell() override {
+    if (web_contents_)
+      web_contents_->RemoveObserver(this);
+  }
+
+  void OnStart(HeadlessBrowser* browser) {
+    browser_ = browser;
+    web_contents_ = browser->CreateWebContents(gfx::Size(800, 600));
+    web_contents_->AddObserver(this);
+
+    base::CommandLine::StringVector args =
+        base::CommandLine::ForCurrentProcess()->GetArgs();
+
+    const char kDefaultUrl[] = "https://google.com";

[Ryan Sleevi, 2016/02/25 22:04:36]

Any reason this couldn't just be about:blank ?

(Reasoning: It's unclear whether //headless should have anything Google specific
/ branded)

[Sami, 2016/02/26 18:49:16]

Good point, about:blank sgtm.

+    GURL url;
+    if (args.empty() || args[0].empty()) {
+      url = GURL(kDefaultUrl);
+    } else {
+      url = GURL(args[0]);
+    }
+    if (!web_contents_->OpenURL(url)) {
+      LOG(ERROR) << "Navigation failed";
+      web_contents_ = nullptr;
+      browser_->Shutdown();
+    }
+  }
+
+  void ShutdownIfNeeded() {
+    const base::CommandLine& command_line =
+        *base::CommandLine::ForCurrentProcess();
+    if (!command_line.HasSwitch(switches::kRemoteDebuggingPort)) {
+      web_contents_ = nullptr;
+      browser_->Shutdown();
+    }
+  }
+
+  // HeadlessWebContents::Observer implementation:
+  void DocumentOnLoadCompletedInMainFrame() override {
+    LOG(INFO) << "Document load completed";
+    ShutdownIfNeeded();
+  }
+
+ private:
+  HeadlessBrowser* browser_;  // Not owned.
+  scoped_ptr<HeadlessWebContents> web_contents_;
+
+  DISALLOW_COPY_AND_ASSIGN(HeadlessShell);
+};
+
+int main(int argc, const char** argv) {
+  HeadlessShell shell;
+  HeadlessBrowser::Options::Builder builder(argc, argv);
+
+  // Enable devtools if requested.
+  base::CommandLine command_line(argc, argv);
+  if (command_line.HasSwitch(switches::kRemoteDebuggingPort)) {
+    int parsed_port;
+    std::string port_str =
+        command_line.GetSwitchValueASCII(switches::kRemoteDebuggingPort);
+    if (base::StringToInt(port_str, &parsed_port) &&
+        base::IsValueInRangeForNumericType<uint16_t>(parsed_port)) {
+      builder.EnableDevToolsServer(kDevToolsHttpServerAddress,
+                                   base::checked_cast<uint16_t>(parsed_port));
+    }
+  }
+
+  return HeadlessBrowserMain(
+      builder.Build(),
+      base::Bind(&HeadlessShell::OnStart, base::Unretained(&shell)));
+}