alternate ntp: implement Show/HideBars API to reduce jank when showing/hiding bars

chrome/renderer/searchbox/searchbox_extension.cc

 // Copyright 2012 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 "chrome/renderer/searchbox/searchbox_extension.h"
 
 #include "base/i18n/rtl.h"
 #include "base/stringprintf.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/utf_string_conversions.h"
@@ skipping 221 matching lines @@
     "if (window.chrome &&"
     "    window.chrome.embeddedSearch &&"
     "    window.chrome.embeddedSearch.newTabPage &&"
     "    window.chrome.embeddedSearch.newTabPage.onmostvisitedchange &&"
     "    typeof window.chrome.embeddedSearch.newTabPage.onmostvisitedchange =="
     "         'function') {"
     "  window.chrome.embeddedSearch.newTabPage.onmostvisitedchange();"
     "  true;"
     "}";
 
+static const char kDispatchBarsHiddenEventScript[] =
+    "if (window.chrome &&"
+    "    window.chrome.searchBox &&"
+    "    window.chrome.searchBox.onbarshidden &&"
+    "    typeof window.chrome.searchBox.onbarshidden == 'function') {"
+    "  window.chrome.searchBox.onbarshidden();"
+    "  true;"
+    "}";
+
 // ----------------------------------------------------------------------------
 
 class SearchBoxExtensionWrapper : public v8::Extension {
  public:
   explicit SearchBoxExtensionWrapper(const base::StringPiece& code);
 
   // Allows v8's javascript code to call the native functions defined
   // in this class for window.chrome.
   virtual v8::Handle<v8::FunctionTemplate> GetNativeFunction(
       v8::Handle<v8::String> name) OVERRIDE;
@@ skipping 106 matching lines @@
       const v8::Arguments& args);
 
   // Undoes the deletion of all Most Visited itens.
   static v8::Handle<v8::Value> UndoAllMostVisitedDeletions(
       const v8::Arguments& args);
 
   // Undoes the deletion of a Most Visited item.
   static v8::Handle<v8::Value> UndoMostVisitedDeletion(
       const v8::Arguments& args);
 
+  // Shows any attached bars.
+  static v8::Handle<v8::Value> ShowBars(const v8::Arguments& args);
+
+  // Hides any attached bars.  When the bars are hidden, the "onbarshidden"
+  // event is fired to notify the page.
+  static v8::Handle<v8::Value> HideBars(const v8::Arguments& args);
+
  private:
   DISALLOW_COPY_AND_ASSIGN(SearchBoxExtensionWrapper);
 };
 
 SearchBoxExtensionWrapper::SearchBoxExtensionWrapper(
     const base::StringPiece& code)
     : v8::Extension(kSearchBoxExtensionName, code.data(), 0, 0, code.size()) {
 }
 
 v8::Handle<v8::FunctionTemplate> SearchBoxExtensionWrapper::GetNativeFunction(
@@ skipping 55 matching lines @@
   if (name->Equals(v8::String::New("FocusOmnibox")))
     return v8::FunctionTemplate::New(FocusOmnibox);
   if (name->Equals(v8::String::New("StartCapturingKeyStrokes")))
     return v8::FunctionTemplate::New(StartCapturingKeyStrokes);
   if (name->Equals(v8::String::New("StopCapturingKeyStrokes")))
     return v8::FunctionTemplate::New(StopCapturingKeyStrokes);
   if (name->Equals(v8::String::New("UndoAllMostVisitedDeletions")))
     return v8::FunctionTemplate::New(UndoAllMostVisitedDeletions);
   if (name->Equals(v8::String::New("UndoMostVisitedDeletion")))
     return v8::FunctionTemplate::New(UndoMostVisitedDeletion);
+  if (name->Equals(v8::String::New("ShowBars")))
+    return v8::FunctionTemplate::New(ShowBars);
+  if (name->Equals(v8::String::New("HideBars")))
+    return v8::FunctionTemplate::New(HideBars);
   return v8::Handle<v8::FunctionTemplate>();
 }
 
 // static
 content::RenderView* SearchBoxExtensionWrapper::GetRenderView() {
   WebKit::WebFrame* webframe = WebKit::WebFrame::frameForCurrentContext();
   if (!webframe) return NULL;
 
   WebKit::WebView* webview = webframe->view();
   if (!webview) return NULL;  // can happen during closing
@@ skipping 639 matching lines @@
 
 // static
 bool SearchBoxExtension::PageSupportsInstant(WebKit::WebFrame* frame) {
   if (!frame) return false;
   v8::HandleScope handle_scope;
   v8::Handle<v8::Value> v = frame->executeScriptAndReturnValue(
       WebKit::WebScriptSource(kSupportsInstantScript));
   return !v.IsEmpty() && v->BooleanValue();
 }
 
+v8::Handle<v8::Value> SearchBoxExtensionWrapper::ShowBars(
+    const v8::Arguments& args) {
+  content::RenderView* render_view = GetRenderView();
+  if (!render_view) return v8::Undefined();
+
+  DVLOG(1) << render_view << " ShowBars";
+  SearchBox::Get(render_view)->ShowBars();
+  return v8::Undefined();
+}
+
+// static
+v8::Handle<v8::Value> SearchBoxExtensionWrapper::HideBars(
+    const v8::Arguments& args) {
+  content::RenderView* render_view = GetRenderView();
+  if (!render_view) return v8::Undefined();
+
+  DVLOG(1) << render_view << " HideBars";
+  SearchBox::Get(render_view)->HideBars();
+  return v8::Undefined();
+}
+
 // static
 void SearchBoxExtension::DispatchChange(WebKit::WebFrame* frame) {
   Dispatch(frame, kDispatchChangeEventScript);
 }
 
 // static
 void SearchBoxExtension::DispatchSubmit(WebKit::WebFrame* frame) {
   Dispatch(frame, kDispatchSubmitEventScript);
 }
 
@@ skipping 44 matching lines @@
 // static
 void SearchBoxExtension::DispatchThemeChange(WebKit::WebFrame* frame) {
   Dispatch(frame, kDispatchThemeChangeEventScript);
 }
 
 // static
 void SearchBoxExtension::DispatchMostVisitedChanged(
     WebKit::WebFrame* frame) {
   Dispatch(frame, kDispatchMostVisitedChangedScript);
 }
+
+void SearchBoxExtension::DispatchBarsHidden(WebKit::WebFrame* frame) {
+  Dispatch(frame, kDispatchBarsHiddenEventScript);
+}
+
 }  // namespace extensions_v8