chrome/browser/thumbnails/thumbnail_list_source.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/thumbnails/thumbnail_list_source.h"
   6
   7 #include <string>
   8
   9 #include "base/base64.h"
  10 #include "base/bind.h"
  11 #include "base/logging.h"
  12 #include "base/memory/ref_counted_memory.h"
  13 #include "base/strings/string_util.h"
  14 #include "chrome/browser/history/top_sites_factory.h"
  15 #include "chrome/browser/profiles/profile.h"
  16 #include "chrome/browser/search/instant_io_context.h"
  17 #include "chrome/browser/thumbnails/thumbnail_service.h"
  18 #include "chrome/browser/thumbnails/thumbnail_service_factory.h"
  19 #include "chrome/common/url_constants.h"
  20 #include "components/history/core/browser/top_sites.h"
  21 #include "content/public/browser/browser_thread.h"
  22 #include "net/base/escape.h"
  23 #include "net/url_request/url_request.h"
  24
  25 using content::BrowserThread;
  26
  27 namespace {
  28
  29 const char kHtmlHeader[] =
  30     "<!DOCTYPE html>\n<html>\n<head>\n<title>TopSites Thumbnails</title>\n"
  31     "<meta charset=\"utf-8\">\n"
  32     "<style type=\"text/css\">\nimg.thumb {border: 1px solid black;}\n"
  33     "li {white-space: nowrap;}\n</style>\n";
  34 const char kHtmlBody[] = "</head>\n<body>\n";
  35 const char kHtmlFooter[] = "</body>\n</html>\n";
  36
  37 // If |want_thumbnails| == true, then renders elements in |mvurl_list| that have
  38 // thumbnails, with their thumbnails. Otherwise renders elements in |mvurl_list|
  39 // that have no thumbnails.
  40 void RenderMostVisitedURLList(
  41     const history::MostVisitedURLList& mvurl_list,
  42     const std::vector<std::string>& base64_encoded_pngs,
  43     bool want_thumbnails,
  44     std::vector<std::string>* out) {
  45   DCHECK_EQ(mvurl_list.size(), base64_encoded_pngs.size());
  46   bool doing_forced_urls = true;
  47   out->push_back("<div><b>Forced URLs:</b></div>\n"
  48                  "<div><ul>\n");
  49   for (size_t i = 0; i < mvurl_list.size(); ++i) {
  50     const history::MostVisitedURL& mvurl = mvurl_list[i];
  51     if (doing_forced_urls && mvurl.last_forced_time.is_null()) {
  52       out->push_back("</ul></div>\n"
  53                      "<div><b>Non-forced URLs:</b></div>\n"
  54                      "<div><ul>\n");
  55       doing_forced_urls = false;
  56     }
  57     bool has_thumbnail = !base64_encoded_pngs[i].empty();
  58     if (has_thumbnail == want_thumbnails) {
  59       out->push_back("<li>\n");
  60       out->push_back(net::EscapeForHTML(mvurl.url.spec()) + "\n");
  61       if (want_thumbnails) {
  62         out->push_back("<div><img class=\"thumb\" "
  63                        "src=\"data:image/png;base64," +
  64                        base64_encoded_pngs[i] + "\"/></div>\n");
  65       }
  66       if (!mvurl.redirects.empty()) {
  67         out->push_back("<ul>\n");
  68         history::RedirectList::const_iterator jt;
  69         for (jt = mvurl.redirects.begin();
  70              jt != mvurl.redirects.end(); ++jt) {
  71           out->push_back("<li>" + net::EscapeForHTML(jt->spec()) + "</li>\n");
  72         }
  73         out->push_back("</ul>\n");
  74       }
  75       out->push_back("</li>\n");
  76     }
  77   }
  78   out->push_back("</ul></div>\n");
  79 }
  80
  81 }  // namespace
  82
  83 ThumbnailListSource::ThumbnailListSource(Profile* profile)
  84     : thumbnail_service_(ThumbnailServiceFactory::GetForProfile(profile)),
  85       top_sites_(TopSitesFactory::GetForProfile(profile)),
  86       weak_ptr_factory_(this) {
  87 }
  88
  89 ThumbnailListSource::~ThumbnailListSource() {
  90 }
  91
  92 std::string ThumbnailListSource::GetSource() const {
  93   return chrome::kChromeUIThumbnailListHost;
  94 }
  95
  96 void ThumbnailListSource::StartDataRequest(
  97     const std::string& path,
  98     int render_process_id,
  99     int render_frame_id,
 100     const content::URLDataSource::GotDataCallback& callback) {
 101   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 102   if (!top_sites_) {
 103     callback.Run(NULL);
 104     return;
 105   }
 106
 107   top_sites_->GetMostVisitedURLs(
 108       base::Bind(&ThumbnailListSource::OnMostVisitedURLsAvailable,
 109                  weak_ptr_factory_.GetWeakPtr(), callback),
 110       true);
 111 }
 112
 113 std::string ThumbnailListSource::GetMimeType(const std::string& path) const {
 114   return "text/html";
 115 }
 116
 117 base::MessageLoop* ThumbnailListSource::MessageLoopForRequestPath(
 118     const std::string& path) const {
 119   // TopSites can be accessed from the IO thread.
 120   return thumbnail_service_.get() ?
 121       NULL : content::URLDataSource::MessageLoopForRequestPath(path);
 122 }
 123
 124 bool ThumbnailListSource::ShouldServiceRequest(
 125     const net::URLRequest* request) const {
 126   if (request->url().SchemeIs(chrome::kChromeSearchScheme))
 127     return InstantIOContext::ShouldServiceRequest(request);
 128   return URLDataSource::ShouldServiceRequest(request);
 129 }
 130
 131 bool ThumbnailListSource::ShouldReplaceExistingSource() const {
 132   return false;
 133 }
 134
 135 void ThumbnailListSource::OnMostVisitedURLsAvailable(
 136     const content::URLDataSource::GotDataCallback& callback,
 137     const history::MostVisitedURLList& mvurl_list) {
 138   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 139   const size_t num_mv = mvurl_list.size();
 140   size_t num_mv_with_thumb = 0;
 141
 142   // Encode all available thumbnails and store into |base64_encoded_pngs|.
 143   std::vector<std::string> base64_encoded_pngs(num_mv);
 144   for (size_t i = 0; i < num_mv; ++i) {
 145     scoped_refptr<base::RefCountedMemory> data;
 146     if (thumbnail_service_->GetPageThumbnail(mvurl_list[i].url, false, &data)) {
 147       base::Base64Encode(std::string(data->front_as<char>(), data->size()),
 148                          &base64_encoded_pngs[i]);
 149       ++num_mv_with_thumb;
 150     }
 151   }
 152
 153   // Render HTML to embed URLs and thumbnails.
 154   std::vector<std::string> out;
 155   out.push_back(kHtmlHeader);
 156   out.push_back(kHtmlBody);
 157   if (num_mv_with_thumb > 0) {
 158     out.push_back("<h2>TopSites URLs with Thumbnails</h2>\n");
 159     RenderMostVisitedURLList(mvurl_list, base64_encoded_pngs, true, &out);
 160   }
 161   if (num_mv_with_thumb < num_mv) {
 162     out.push_back("<h2>TopSites URLs without Thumbnails</h2>\n");
 163     RenderMostVisitedURLList(mvurl_list, base64_encoded_pngs, false, &out);
 164   }
 165   out.push_back(kHtmlFooter);
 166
 167   std::string out_html = base::JoinString(out, base::StringPiece());
 168   callback.Run(base::RefCountedString::TakeString(&out_html));
 169 }