Added Header and Footer support using Skia

chrome/renderer/print_web_view_helper.cc

Index: chrome/renderer/print_web_view_helper.cc
diff --git a/chrome/renderer/print_web_view_helper.cc b/chrome/renderer/print_web_view_helper.cc
index c24e5830fa37b736a1bfc0426302c2fcb97326f7..90eceaa66a8b312a5b592fa9ac66e4b1f5293a0b 100644
--- a/chrome/renderer/print_web_view_helper.cc
+++ b/chrome/renderer/print_web_view_helper.cc
@@ -4,12 +4,17 @@
 
 #include "chrome/renderer/print_web_view_helper.h"
 
+#include <algorithm>
+#include <cmath>
 #include <string>
 
 #include "base/command_line.h"
+#include "base/i18n/time_formatting.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/process_util.h"
+#include "base/string_number_conversions.h"
+#include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/print_messages.h"
@@ -21,6 +26,9 @@
 #include "printing/metafile_impl.h"
 #include "printing/print_job_constants.h"
 #include "printing/units.h"
+#include "skia/ext/vector_canvas.h"
+#include "skia/ext/vector_platform_device_skia.h"
+#include "third_party/skia/include/core/SkTypeface.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebConsoleMessage.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDataSource.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDocument.h"
@@ -32,13 +40,16 @@
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebURLResponse.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
 #include "ui/base/l10n/l10n_util.h"
+#include "ui/base/text/text_elider.h"
 
 #if defined(OS_POSIX)
 #include "content/common/view_messages.h"
 #endif
 
+using base::Time;
 using printing::ConvertPixelsToPoint;
 using printing::ConvertPixelsToPointDouble;
+using printing::ConvertPointsToPixelDouble;
 using printing::ConvertUnit;
 using printing::ConvertUnitDouble;
 using WebKit::WebConsoleMessage;
@@ -88,12 +99,209 @@ bool PrintMsg_Print_Params_IsEqual(
          oldParams.params.supports_alpha_blend ==
              newParams.params.supports_alpha_blend &&
          oldParams.pages.size() == newParams.pages.size() &&
+         oldParams.params.display_header_footer ==
+             newParams.params.display_header_footer &&
          std::equal(oldParams.pages.begin(), oldParams.pages.end(),
              newParams.pages.begin());
 }
 
+// Splits the horizontal width equally into three segments with an interstice
+// between each segment. Returns the width of this segment.
+SkScalar GetSegmentWidth(PageSizeMargins& page_layout) {
+  return (page_layout.margin_left +
+      page_layout.content_width +
+      page_layout.margin_right -
+      (printing::kSettingHeaderFooterHorizontalRegions + 1) *
+      printing::kSettingHeaderFooterInterstice) /
+      printing::kSettingHeaderFooterHorizontalRegions;
+}
+
+// Given a text, the positions and the paint object, this method gets the
+// coordinates and prints the text at those co-ordinates on the canvas.
+void PrintHeaderFooterText(
+    string16 text,
+    SkPaint paint,
+    const SkRefPtr<skia::VectorCanvas>& canvas,
+    printing::HorizontalHeaderFooterPosition hor_pos,
+    printing::VerticalHeaderFooterPosition ver_pos,
+    float webkit_scale_factor,
+    PageSizeMargins& page_layout,
+    SkScalar max_text_width,
+    gfx::Font font,
+    SkScalar height_to_baseline) {
+  text = ui::ElideText(text, font, ConvertPointsToPixelDouble(max_text_width),
+                       false);
+
+  SkPoint text_location;
+  size_t text_byte_length = text.length() * sizeof(char16);
+  // Gets the (x, y) coordinate from where we want to start printing the current
+  // text depending on the alignment horizontal alignment (LEFT, RIGHT, CENTER)
+  // and vertical alignment (TOP, BOTTOM).
+  {
+    SkScalar text_width_in_points = paint.measureText(text.c_str(),
+                                                      text_byte_length);
+
+    SkScalar x = 0;
+    switch (hor_pos) {
+      case printing::LEFT: {
+        x = page_layout.margin_left * (-1) +
+            printing::kSettingHeaderFooterInterstice;
+        break;
+      }
+      case printing::RIGHT: {
+        x = (page_layout.content_width + page_layout.margin_right -
+             (printing::kSettingHeaderFooterInterstice + text_width_in_points));
+        break;
+      }
+      case printing::CENTER: {
+        SkScalar available_width = GetSegmentWidth(page_layout);
+        x = (available_width - page_layout.margin_left +
+            (available_width - text_width_in_points) / 2);
+        break;
+      }
+      default: {
+        NOTREACHED();
+      }
+    }
+
+    SkScalar y = 0;
+    switch (ver_pos) {
+      case printing::TOP: {
+        y = page_layout.margin_top * (-1) +
+            printing::kSettingHeaderFooterInterstice - height_to_baseline;
+        break;
+      }
+      case printing::BOTTOM: {
+        y = page_layout.margin_bottom + page_layout.content_height -
+            printing::kSettingHeaderFooterInterstice - height_to_baseline;
+        break;
+      }
+      default: {
+        NOTREACHED();
+      }
+    }
+
+    text_location.set(x / webkit_scale_factor, y / webkit_scale_factor);
+  }
+
+  paint.setTextSize(paint.getTextSize()/webkit_scale_factor);
+  canvas->drawText(text.c_str(), text_byte_length, text_location.x(),
+                   text_location.y(), paint);
+}
+
 }  // namespace
 
+void PrintHeaderAndFooter(skia::VectorPlatformDeviceSkia* device,
+                          const SkRefPtr<skia::VectorCanvas>& canvas,
+                          int page_number, int total_pages,
+                          float webkit_scale_factor,
+                          PageSizeMargins& page_layout,
+                          const DictionaryValue* header_footer_info) {
+  // Set the drawing area to draw in the margins.
+  device->setDrawingArea(SkPDFDevice::kMargin_DrawingArea);
+
+  // Setting up styles for the headers and footers text.
+  SkPaint paint;
+  paint.setColor(SK_ColorBLACK);
+  paint.setTextEncoding(SkPaint::kUTF16_TextEncoding);
+  paint.setTextSize(printing::kSettingHeaderFooterFontSize);
+  gfx::Font font(UTF8ToUTF16(printing::kSettingHeaderFooterFontName),
+                 ceil(ConvertPointsToPixelDouble(
+                    printing::kSettingHeaderFooterFontSize)));
+  paint.setTypeface(SkTypeface::CreateFromName(
+      UTF16ToUTF8(font.GetFontName()).c_str(),
+      SkTypeface::kNormal));
+
+  // Ensuring we have enough space to print above and below the page to print
+  // headers.
+  string16 date = base::TimeFormatShortDateNumeric(Time::Now());
+  string16 title;
+  if (!header_footer_info->GetString(printing::kSettingHeaderFooterTitle,
+                                     &title)) {
+    NOTREACHED();
+  }
+
+  SkRect header_bounds;
+  string16 header_text = date + title;
+  paint.measureText(header_text.c_str(), header_text.length() * sizeof(char16),
+                    &header_bounds, 0);
+  SkScalar text_height = printing::kSettingHeaderFooterInterstice +
+      header_bounds.height();
+
+  if (text_height > page_layout.margin_top)
+    return;
+
+  // Ensuring we have enough space to print above and below the page to print
+  // footers.
+  string16 page_on_page_total = base::IntToString16(page_number) +
+                                UTF8ToUTF16("/") +
+                                base::IntToString16(total_pages);
+  std::string url;
+  if (!header_footer_info->GetString(printing::kSettingHeaderFooterURL,
+                                     &url)) {
+    NOTREACHED();
+  }
+
+  SkRect footer_bounds;
+  string16 footer_text = page_on_page_total + UTF8ToUTF16(url);
+  paint.measureText(footer_text.c_str(), footer_text.length() * sizeof(char16),
+                    &footer_bounds, 0);
+  text_height = printing::kSettingHeaderFooterInterstice +
+      footer_bounds.height();
+
+  if (text_height > page_layout.margin_bottom)
+    return;
+
+  SkScalar segment_width = GetSegmentWidth(page_layout);
+  // Printing the Date.
+  PrintHeaderFooterText(date, paint, canvas, printing::LEFT, printing::TOP,
+                        webkit_scale_factor, page_layout, segment_width,
+                        font, header_bounds.top());
+
+  // Printing the title.
+  SkScalar date_width = paint.measureText(date.c_str(),
+                                          date.length() * sizeof(char16));
+  // Calculating the available title width. If the date string is not long
+  // enough, then, we increase the available space we have for the title.
+  // Assumes there is no header text to RIGHT of title.
+  SkScalar max_title_width = std::min(2 * segment_width,
+                                      2 * (segment_width - date_width) +
+                                          segment_width);
+  PrintHeaderFooterText(title, paint, canvas, printing::CENTER,
+                        printing::TOP, webkit_scale_factor, page_layout,
+                        max_title_width, font, header_bounds.top());
+
+  // Printing the page numbers at the bottom right corner of page.
+  PrintHeaderFooterText(page_on_page_total, paint, canvas, printing::RIGHT,
+                        printing::BOTTOM, webkit_scale_factor,
+                        page_layout, segment_width, font,
+                        footer_bounds.bottom());
+
+  // Printing the URL.
+  GURL gurl(url);
+  SkScalar page_width = paint.measureText(
+      page_on_page_total.c_str(),
+      page_on_page_total.length() * sizeof(char16));
+
+  // Calculating the available URL width. We increase the available URL width
+  // if the |page_on_page_total| string isn't long enough.
+  // Assumes no footer text being printed in the CENTER.
+  SkScalar max_url_width = 3 * (page_layout.content_width +
+      page_layout.margin_left + page_layout.margin_right) / 4;
+  max_url_width = std::min(max_url_width,
+                           2 * (segment_width - page_width) + segment_width);
+  string16 url_elided = ui::ElideUrl(gurl, font,
+                                     ConvertPointsToPixelDouble(max_url_width),
+                                     std::string());
+  PrintHeaderFooterText(url_elided, paint, canvas, printing::LEFT,
+                        printing::BOTTOM, webkit_scale_factor,
+                        page_layout, max_url_width, font,
+                        footer_bounds.bottom());
+
+  // Restore the drawing area to draw in the content area.
+  device->setDrawingArea(SkPDFDevice::kContent_DrawingArea);
+}
+
 PrepareFrameAndViewForPrint::PrepareFrameAndViewForPrint(
     const PrintMsg_Print_Params& print_params,
     WebFrame* frame,
@@ -280,9 +488,12 @@ void PrintWebViewHelper::OnPrintForSystemDialog() {
   }
 }
 
-void PrintWebViewHelper::OnPrintPreview(const DictionaryValue& settings) {
+void PrintWebViewHelper::OnPrintPreview(
+    const DictionaryValue& settings,
+    const DictionaryValue& header_footer_info) {
   DCHECK(is_preview_);
   print_preview_context_.OnPrintPreview();
+  header_footer_info_ = header_footer_info.DeepCopy();
 
   if (!InitPrintSettings(print_preview_context_.frame(),
                          print_preview_context_.node())) {
@@ -738,6 +949,7 @@ bool PrintWebViewHelper::UpdatePrintSettingsCloud(
     return false;
   // TODO(abodenha@chromium.org) Parse page ranges from the job_settings.
   print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
+  print_pages_params_->params.display_header_footer = false;
   return true;
 }
 
@@ -755,6 +967,11 @@ bool PrintWebViewHelper::UpdatePrintSettingsLocal(
     return false;
 
   print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
+  bool header_footer;
+  if (!job_settings.GetBoolean(printing::kSettingHeaderFooter, &header_footer))
+    NOTREACHED();
+  print_pages_params_->params.display_header_footer = header_footer;
+
   Send(new PrintHostMsg_DidGetDocumentCookie(routing_id(),
                                              settings.params.document_cookie));
   return true;