Compute pageScaleFactor on page so that fixed layout page fits width of window.

chrome/renderer/chrome_render_view_observer.cc

Index: chrome/renderer/chrome_render_view_observer.cc
diff --git a/chrome/renderer/chrome_render_view_observer.cc b/chrome/renderer/chrome_render_view_observer.cc
index 55b3ddad597430a0fecc7289d7e2a316f4912cdc..360fc5518779227003505579357db58eaf6986ac 100644
--- a/chrome/renderer/chrome_render_view_observer.cc
+++ b/chrome/renderer/chrome_render_view_observer.cc
@@ -22,6 +22,7 @@
 #include "chrome/renderer/chrome_render_process_observer.h"
 #include "chrome/renderer/content_settings_observer.h"
 #include "chrome/renderer/extensions/extension_dispatcher.h"
+#include "chrome/renderer/extensions/extension_helper.h"
 #include "chrome/renderer/external_host_bindings.h"
 #include "chrome/renderer/frame_sniffer.h"
 #include "chrome/renderer/prerender/prerender_helper.h"
@@ -29,6 +30,7 @@
 #include "chrome/renderer/translate_helper.h"
 #include "chrome/renderer/webview_color_overlay.h"
 #include "content/public/common/bindings_policy.h"
+#include "content/public/common/view_type.h"
 #include "content/public/renderer/render_view.h"
 #include "content/public/renderer/content_renderer_client.h"
 #include "net/base/data_url.h"
@@ -93,6 +95,10 @@ static const size_t kMaxIndexChars = 65535;
 static const int kThumbnailWidth = 212;
 static const int kThumbnailHeight = 132;
 
+// The default layout width for pages when fixed layout is enabled.
+static const int kDefaultLayoutWidth = 980;
+static const int kDefaultLayoutHeight = 640;
+
 // Constants for UMA statistic collection.
 static const char kWWWDotGoogleDotCom[] = "www.google.com";
 static const char kMailDotGoogleDotCom[] = "mail.google.com";
@@ -372,6 +378,27 @@ void ChromeRenderViewObserver::OnSetAsInterstitial() {
 }
 
 void ChromeRenderViewObserver::Navigate(const GURL& url) {
+  ExtensionHelper* extension_helper = ExtensionHelper::Get(render_view());

[Aaron Boodman, 2012/01/20 18:49:23]

What are you trying to do here? It looks to me like ExtensionHelper exists for
all render views, so this code will run for all tab contents - web or extension.

Is that what you want?

+  bool is_tab_contents = extension_helper &&
+      extension_helper->view_type() == content::VIEW_TYPE_TAB_CONTENTS;

[darin (slow to review), 2012/01/20 19:10:20]

it seems a little hacky to be using something from the extension system for
this.  it seems like you are trying to test if the RenderView belongs to a
TabContents.  surely, there must be or could be a more direct way of determining
that via the Content API.  if not, then perhaps we should add one.  it seems
wrong to entangle the extension system here when this code really has nothing to
do with extensions.

[Fady Samuel, 2012/01/20 21:05:04]

I don't know what the answer to that question is...perhaps jam might know? I'll
ask him.

[jam, 2012/01/20 21:08:05]

code in the renderer doesn't generally know about TabContents, by design. can
you have the browser process (TabContents?) to send relevant ipcs to
enable/disable ? it also seems that this isn't chrome related, but something
that completely belongs in content (since all the other code in this cl is
there)

+  const CommandLine* cmd_line = CommandLine::ForCurrentProcess();
+  // Only use fixed layout on tab contents.
+  if (is_tab_contents && cmd_line->HasSwitch(switches::kEnableFixedLayout)) {
+    WebSize viewSize = render_view()->GetWebView()->size();

[darin (slow to review), 2012/01/20 19:10:20]

nit: view_size

[Fady Samuel, 2012/01/20 21:05:04]

Done.

+    int layoutHeight =

[darin (slow to review), 2012/01/20 19:10:20]

nit: layout_height

[Fady Samuel, 2012/01/20 21:05:04]

Done.

+        viewSize.height ?
+            viewSize.height * kDefaultLayoutWidth / viewSize.width :
+            kDefaultLayoutHeight;
+    WebSize layout_size(kDefaultLayoutWidth, layoutHeight);
+    render_view()->GetWebView()->enableFixedLayoutMode(true);
+    render_view()->GetWebView()->setFixedLayoutSize(layout_size);
+    render_view()->GetWebView()->
+        setShouldLayoutFixedElementsRelativeToFrame(true);

[darin (slow to review), 2012/01/20 19:10:20]

isn't this done through WebSettings now?

[Fady Samuel, 2012/01/20 21:05:04]

Patch hasn't landed yet. Will fix now.  But once it does, this isn't necessary,
so I've removed those lines.

+  } else {
+    render_view()->GetWebView()->enableFixedLayoutMode(false);
+    render_view()->GetWebView()->
+        setShouldLayoutFixedElementsRelativeToFrame(false);
+  }
   // Execute cache clear operations that were postponed until a navigation
   // event (including tab reload).
   if (chrome_render_process_observer_)