headless: Initial headless embedder API implementation

headless/public/headless_web_contents.h

Index: headless/public/headless_web_contents.h
diff --git a/headless/public/web_contents.h b/headless/public/headless_web_contents.h
similarity index 64%
rename from headless/public/web_contents.h
rename to headless/public/headless_web_contents.h
index 634cdb4ff3c5cca96e7b324c1706dde6bfb29dbf..d503e9a97e047a178494d7fa404d658d947050bd 100644
--- a/headless/public/web_contents.h
+++ b/headless/public/headless_web_contents.h
@@ -2,29 +2,31 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef HEADLESS_PUBLIC_WEB_CONTENTS_H_
-#define HEADLESS_PUBLIC_WEB_CONTENTS_H_
+#ifndef HEADLESS_PUBLIC_HEADLESS_WEB_CONTENTS_H_
+#define HEADLESS_PUBLIC_HEADLESS_WEB_CONTENTS_H_
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "headless/public/headless_export.h"
+#include "ui/gfx/geometry/size.h"
 #include "url/gurl.h"
 
 class SkBitmap;
 
 namespace content {

[pfeldman, 2016/02/09 19:49:51]

Do you envision content/ to leak into the headless API for clients? We might
want to provide a more stable headless client API in comparison to what content/
provides today.

[Sami, 2016/02/09 21:40:51]

Right, the idea is to insulate the clients from content/. Removed these.

+class NavigationController;
 class WebContents;
 }
 
 namespace headless {
-class WebFrame;
+class HeadlessWebFrame;
 
-// Class representing contents of a browser tab.
-// Should be accessed from browser main thread.
-class HEADLESS_EXPORT WebContents {
+// Class representing contents of a browser tab. Should be accessed from browser
+// main thread.
+class HEADLESS_EXPORT HeadlessWebContents {
  public:
-  virtual ~WebContents() {}
+  virtual ~HeadlessWebContents() {}
 
   class Observer {
    public:
@@ -34,7 +36,7 @@ class HEADLESS_EXPORT WebContents {
 
     virtual void OnLoadProgressChanged(double progress) = 0;
     virtual void AddMessageToConsole(const std::string& message) = 0;
-    virtual bool ShouldSuppressDialogs(WebContents* source) = 0;
+    virtual bool ShouldSuppressDialogs(HeadlessWebContents* source) = 0;
     virtual void OnModalAlertDialog(const std::string& message) = 0;

[pfeldman, 2016/02/09 19:49:51]

How is this one accepted programmatically? That's what we have for web driver:
http://chromedevtools.github.io/debugger-protocol-viewer/Page/#method-handleJ...

[Sami, 2016/02/09 21:40:51]

This one was accepted automatically (unlike the two below), but I agree that a
more powerful interface would be better. Now removed.

     virtual bool OnModalConfirmDialog(const std::string& message) = 0;
     virtual std::string OnModalPromptDialog(
@@ -42,9 +44,17 @@ class HEADLESS_EXPORT WebContents {
         const std::string& default_value) = 0;
 
    protected:
-    explicit Observer(WebContents* web_contents);
+    // Use this constructor when the observer's lifetime matches that of the
+    // HeadlessWebContents.
+    explicit Observer(HeadlessWebContents* web_contents);
+
+    // This constructor creates a detached observer. Use Observe() to attach it
+    // to a HeadlessWebContents instance.
+    Observer();
     virtual ~Observer();
 
+    void Observe(HeadlessWebContents* web_contents);
+
    private:
     class ObserverImpl;
     scoped_ptr<ObserverImpl> observer_;
@@ -66,34 +76,34 @@ class HEADLESS_EXPORT WebContents {
   virtual Settings* GetSettings() = 0;
   virtual const Settings* GetSettings() const = 0;
 
-  virtual NavigationController* GetController() = 0;
-  virtual const NavigationController* GetController() const = 0;
+  virtual content::NavigationController* GetController() = 0;
+  virtual const content::NavigationController* GetController() const = 0;
 
   virtual std::string GetTitle() const = 0;
   virtual const GURL& GetVisibleURL() const = 0;
   virtual const GURL& GetLastCommittedURL() const = 0;
   virtual bool IsLoading() const = 0;
 
-  virtual bool SetViewportSize(const gfx::Size& size) const = 0;
+  virtual void SetViewportSize(const gfx::Size& size) = 0;

[pfeldman, 2016/02/09 19:49:51]

Looks at how much more powerful the emulation one is:
http://chromedevtools.github.io/debugger-protocol-viewer/Emulation/#method-se...

emulation is now hot in the web driver / continuous integration scenarios.

[Sami, 2016/02/09 21:40:51]

Yep, let's try to use that one.

 
   // Returns main frame for web page. Note that the returned interface should
   // only be used on the renderer main thread.
-  virtual WebFrame* GetMainFrame() = 0;
+  virtual HeadlessWebFrame* GetMainFrame() = 0;
 
   // Requests browser tab to navigate to given url.
   virtual void OpenURL(const GURL& url) = 0;

[pfeldman, 2016/02/09 19:49:51]

http://chromedevtools.github.io/debugger-protocol-viewer/Page/#method-navigate

[Sami, 2016/02/09 21:40:51]

Ditto. However I still wanted to keep this one around for now so you can
actually do something with the headless shell and we can test that it works.
Let's replace it with a real client API later.

 
+  // Renders an image of the web contents.
   using ScreenshotCallback = base::Callback<void(scoped_ptr<SkBitmap>)>;

[pfeldman, 2016/02/09 19:49:51]

http://chromedevtools.github.io/debugger-protocol-viewer/Page/#method-capture...

[Sami, 2016/02/09 21:40:51]

Removed for now.

-  // Requests an image of web contents.
-  virtual void GetScreenshot(const ScreenshotCallback& callback) = 0;
+  virtual void TakeScreenshot(const ScreenshotCallback& callback) = 0;
 
  protected:
-  virtual content::WebContents* web_contents() = 0;
+  HeadlessWebContents() {}
 
  private:
-  DISALLOW_COPY_AND_ASSIGN(WebContents);
+  DISALLOW_COPY_AND_ASSIGN(HeadlessWebContents);
 };
 
 }  // namespace headless
 
-#endif  // HEADLESS_PUBLIC_WEB_CONTENTS_H_
+#endif  // HEADLESS_PUBLIC_HEADLESS_WEB_CONTENTS_H_