alternate ntp: implement searchbox api for instant overlay to adopt themes

chrome/renderer/searchbox/searchbox_extension.cc

Index: chrome/renderer/searchbox/searchbox_extension.cc
diff --git a/chrome/renderer/searchbox/searchbox_extension.cc b/chrome/renderer/searchbox/searchbox_extension.cc
index c2aa8108a1ff8ac074d22f41b804859c1fcb5c3a..ce04a8cc473dd6a803490fd0e0a9052d51dbb901 100644
--- a/chrome/renderer/searchbox/searchbox_extension.cc
+++ b/chrome/renderer/searchbox/searchbox_extension.cc
@@ -4,8 +4,11 @@
 
 #include "chrome/renderer/searchbox/searchbox_extension.h"
 
+#include "base/string_number_conversions.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
+#include "chrome/browser/themes/theme_service.h"
+#include "chrome/common/extensions/extension.h"
 #include "chrome/renderer/searchbox/searchbox.h"
 #include "content/public/renderer/render_view.h"
 #include "grit/renderer_resources.h"
@@ -19,6 +22,11 @@
 
 namespace {
 
+const char kCSSBackgroundImageFormat[] =
+    "-webkit-image-set(url(chrome://theme/IDR_THEME_BACKGROUND?%s) 1x)";
+
+const char kCSSBackgroundColorFormat[] = "rgba(%d,%d,%d,%s)";
+
 // Converts a V8 value to a string16.
 string16 V8ValueToUTF16(v8::Handle<v8::Value> v) {
   v8::String::Value s(v);
@@ -30,6 +38,11 @@ v8::Handle<v8::String> UTF16ToV8String(const string16& s) {
   return v8::String::New(reinterpret_cast<const uint16_t*>(s.data()), s.size());
 }
 
+// Converts std::string to V8 String.
+v8::Handle<v8::String> UTF8ToV8String(const std::string& s) {
+  return v8::String::New(s.data(), s.size());
+}
+
 void Dispatch(WebKit::WebFrame* frame, const WebKit::WebString& script) {
   if (!frame) return;
   frame->executeScript(WebKit::WebScriptSource(script));
@@ -118,6 +131,25 @@ static const char kDispatchContextChangeEventScript[] =
     "  true;"
     "}";
 
+static const char kDispatchThemeChangeEventScript[] =
+    "if (window.chrome &&"
+    "    window.chrome.searchBox &&"
+    "    window.chrome.searchBox.onthemechange &&"
+    "    typeof window.chrome.searchBox.onthemechange == 'function') {"
+    "  window.chrome.searchBox.onthemechange();"
+    "  true;"
+    "}";
+
+static const char kDispatchThemeAreaHeightChangeEventScript[] =
+    "if (window.chrome &&"
+    "    window.chrome.searchBox &&"
+    "    window.chrome.searchBox.onthemeareaheightchange &&"
+    "    typeof window.chrome.searchBox.onthemeareaheightchange =="
+    "        'function') {"
+    "  window.chrome.searchBox.onthemeareaheightchange();"
+    "  true;"
+    "}";
+
 // ----------------------------------------------------------------------------
 
 class SearchBoxExtensionWrapper : public v8::Extension {
@@ -167,6 +199,18 @@ class SearchBoxExtensionWrapper : public v8::Extension {
   // Gets the current session context.
   static v8::Handle<v8::Value> GetContext(const v8::Arguments& args);
 
+  // Gets the background info of the theme currently adopted by browser.
+  // Call only when overlay is showing NTP page.
+  static v8::Handle<v8::Value> GetThemeBackgroundInfo(
+      const v8::Arguments& args);
+
+  // Gets the theme area height that the entire theme background image should
+  // fill up.
+  // Call only when overlay is showing NTP page and GetThemeBackgroundInfo
+  // returns a non-empty image_url and an image_vertical_alignment that is not
+  // "top".
+  static v8::Handle<v8::Value> GetThemeAreaHeight(const v8::Arguments& args);
+
   // Navigates the window to a URL represented by either a URL string or a
   // restricted ID.
   static v8::Handle<v8::Value> NavigateContentWindow(const v8::Arguments& args);
@@ -222,6 +266,10 @@ v8::Handle<v8::FunctionTemplate> SearchBoxExtensionWrapper::GetNativeFunction(
     return v8::FunctionTemplate::New(GetAutocompleteResults);
   if (name->Equals(v8::String::New("GetContext")))
     return v8::FunctionTemplate::New(GetContext);
+  if (name->Equals(v8::String::New("GetThemeBackgroundInfo")))
+    return v8::FunctionTemplate::New(GetThemeBackgroundInfo);
+  if (name->Equals(v8::String::New("GetThemeAreaHeight")))
+    return v8::FunctionTemplate::New(GetThemeAreaHeight);
   if (name->Equals(v8::String::New("NavigateContentWindow")))
     return v8::FunctionTemplate::New(NavigateContentWindow);
   if (name->Equals(v8::String::New("SetSuggestions")))
@@ -367,6 +415,95 @@ v8::Handle<v8::Value> SearchBoxExtensionWrapper::GetContext(
   return context;
 }
 
+v8::Handle<v8::Value> SearchBoxExtensionWrapper::GetThemeBackgroundInfo(
+    const v8::Arguments& args) {
+  content::RenderView* render_view = GetRenderView();
+  if (!render_view) return v8::Undefined();
+
+  const ThemeBackgroundInfo& theme_info =
+      SearchBox::Get(render_view)->GetThemeBackgroundInfo();
+  v8::Handle<v8::Object> info = v8::Object::New();
+
+  // The theme background color is in RGBA format "rgba(R,G,B,A)" where R, G and
+  // B are between 0 and 255 inclusive, and A is a double between 0 and 1
+  // inclusive.
+  // This is the CSS "background-color" format.
+  // Value is always valid.
+  info->Set(v8::String::New("colorRgba"), UTF8ToV8String(
+      // Convert the alpha using DoubleToString because StringPrintf will use
+      // locale specific formatters (e.g., use , instead of . in German).
+      base::StringPrintf(
+          kCSSBackgroundColorFormat,
+          theme_info.color_r,
+          theme_info.color_g,
+          theme_info.color_b,
+          base::DoubleToString(theme_info.color_a / 255.0).c_str())));

[palmer, 2012/11/19 22:23:20]

Seems strange to convert this to a string. Can you change
kCSSBackgroundColorFormat to have %f instead of %s, and then just do
theme_info.color_a / 255.0 (without calling DoubleToString)?

[kuan, 2012/11/20 00:12:44]

the comment just above base::StringPrintf explains why DoubleToString is used.

[palmer, 2012/11/20 19:55:30]

But I had thought that %f followed the same locale rules? According to the
printf(3) man page, it does (if you use e.g. %'.f), but maybe base::StringPrintf
doesn't follow that convention.

I think it's OK, since at this point the potentially-untrustworthy input is just
a float.

+
+  // The theme background image url is of format
+  // "-webkit-image-set(url(chrome://theme/IDR_THEME_BACKGROUND?<theme_id>) 1x)"
+  // where <theme_id> is the id that identifies the theme.
+  // This is the CSS "background-image" format.
+  // Value is only valid if there's a custom theme background image.
+  std::string image_url;
+  if (extensions::Extension::IdIsValid(theme_info.theme_id)) {
+    image_url = base::StringPrintf(kCSSBackgroundImageFormat,
+                                   theme_info.theme_id.c_str());

[palmer, 2012/11/19 22:23:20]

Where does this get validated to ensure that it is truly theme ID-shaped?

Your calling code creates it correctly by calling GetThemeID, but attackers are
not necesarily constrained to sending only real theme IDs.

[kuan, 2012/11/20 00:12:44]

in the line just above StringPrintf, i call IdIsValid which validates the
theme_id.
ThemeService uses the id() of the theme extension as the theme id, so i use
Extension::IdIsValid to validate the theme id.

[palmer, 2012/11/20 19:55:30]

Sorry, my bad. :)

+  }
+  info->Set(v8::String::New("imageUrl"), UTF8ToV8String(image_url));
+
+  // The theme background image horizontal alignment is one of "left", "right",
+  // "center".
+  // This is the horizontal component of the CSS "background-position" format.
+  // Value is only valid if |image_url| is not empty.
+  std::string alignment = ThemeService::kAlignmentCenter;
+  if (!image_url.empty()) {
+    if (theme_info.image_alignment & ThemeService::ALIGN_LEFT)
+      alignment = ThemeService::kAlignmentLeft;
+    else if (theme_info.image_alignment & ThemeService::ALIGN_RIGHT)
+      alignment = ThemeService::kAlignmentRight;
+  }
+  info->Set(v8::String::New("imageHorizontalAlignment"),
+            UTF8ToV8String(alignment));
+
+  // The theme background image vertical alignment is one of "top", "bottom",
+  // "center".
+  // This is the vertical component of the CSS "background-position" format.
+  // Value is only valid if |image_url| is not empty.
+  alignment = alignment = ThemeService::kAlignmentCenter;
+  if (!image_url.empty()) {
+    if (theme_info.image_alignment & ThemeService::ALIGN_TOP)
+      alignment = ThemeService::kAlignmentTop;
+    else if (theme_info.image_alignment & ThemeService::ALIGN_BOTTOM)
+      alignment = ThemeService::kAlignmentBottom;
+  }
+  info->Set(v8::String::New("imageVerticalAlignment"),
+            UTF8ToV8String(alignment));
+
+  // The tiling of the theme background image is one of "no-repeat", "repeat-x",
+  // "repeat-y", "repeat".
+  // This is the CSS "background-repeat" format.
+  // Value is only valid if |image_url| is not empty.
+  std::string tiling = ThemeService::kTilingNoRepeat;
+  if (!image_url.empty())
+    tiling = ThemeService::TilingToString(theme_info.image_tiling);
+  info->Set(v8::String::New("imageTiling"), UTF8ToV8String(tiling));
+
+  // The theme background image height is only valid if |imageUrl| is valid.
+  info->Set(v8::String::New("imageHeight"),
+            v8::Int32::New(image_url.empty() ? 0 : theme_info.image_height));
+
+  return info;
+}
+
+
+v8::Handle<v8::Value> SearchBoxExtensionWrapper::GetThemeAreaHeight(
+    const v8::Arguments& args) {
+  content::RenderView* render_view = GetRenderView();
+  if (!render_view) return v8::Undefined();
+
+  return v8::Int32::New(SearchBox::Get(render_view)->GetThemeAreaHeight());
+}
+
 // static
 v8::Handle<v8::Value> SearchBoxExtensionWrapper::NavigateContentWindow(
     const v8::Arguments& args) {
@@ -601,6 +738,17 @@ void SearchBoxExtension::DispatchContextChange(WebKit::WebFrame* frame) {
 }
 
 // static
+void SearchBoxExtension::DispatchThemeChange(WebKit::WebFrame* frame) {
+  Dispatch(frame, kDispatchThemeChangeEventScript);
+}
+
+// static
+void SearchBoxExtension::DispatchThemeAreaHeightChange(
+    WebKit::WebFrame* frame) {
+  Dispatch(frame, kDispatchThemeAreaHeightChangeEventScript);
+}
+
+// static
 v8::Extension* SearchBoxExtension::Get() {
   return new SearchBoxExtensionWrapper(ResourceBundle::GetSharedInstance().
       GetRawDataResource(IDR_SEARCHBOX_API));