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 1735d90b7e661e1a46a8eebc778efd4688d310ab..1c0e29be07da96fa1c07288269a2f56d15b1e113 100644
--- a/chrome/renderer/print_web_view_helper.cc
+++ b/chrome/renderer/print_web_view_helper.cc
@@ -4,6 +4,10 @@
 
 #include "chrome/renderer/print_web_view_helper.h"
 
+#if defined(USE_SKIA)
+#include <algorithm>
+#include <cmath>
+#endif
 #include <string>
 
 #include "base/command_line.h"
@@ -36,8 +40,20 @@
 #include "content/common/view_messages.h"
 #endif
 
+#if defined(USE_SKIA)
+#include "base/i18n/time_formatting.h"
+#include "base/string_number_conversions.h"
+#include "base/time.h"
+#include "skia/ext/vector_canvas.h"
+#include "skia/ext/vector_platform_device_skia.h"
+#include "third_party/skia/include/core/SkTypeface.h"
+#include "ui/base/text/text_elider.h"
+#endif  // USE_SKIA
+
+using base::Time;
 using printing::ConvertPixelsToPoint;
 using printing::ConvertPixelsToPointDouble;
+using printing::ConvertPointsToPixelDouble;
 using printing::ConvertUnit;
 using printing::ConvertUnitDouble;
 using WebKit::WebConsoleMessage;
@@ -87,6 +103,8 @@ 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());
 }
@@ -101,8 +119,212 @@ void CalculatePrintCanvasSize(const PrintMsg_Print_Params& print_params,
                                  print_params.desired_dpi));
 }
 
+#if defined(USE_SKIA)
+// Splits the horizontal width equally into segments with an interstice
+// between each segment. Returns the width of a segment.
+SkScalar GetSegmentWidth(const PageSizeMargins& page_layout) {
+  SkScalar page_width = page_layout.margin_left +
+                        page_layout.content_width +
+                        page_layout.margin_right;
+  // Interstice is left at both ends of the page as well as between
+  // each region, so 1 is added.
+  SkScalar total_interstice_width =
+      (printing::kSettingHeaderFooterHorizontalRegions + 1) *
+      printing::kSettingHeaderFooterInterstice;
+  return (page_width - total_interstice_width) /
+             printing::kSettingHeaderFooterHorizontalRegions;
+}
+
+// Given a text, the positions, and the paint object, this method gets the
+// coordinates and prints the text at those coordinates on the canvas.
+void PrintHeaderFooterText(

[Lei Zhang, 2011/08/05 18:58:21]

nit: PrintHeaderFooterText() and PrintHeaders() have many common parameters, but
they are in a different order. Can you reorder them? Have you considered
combining some of the data into a struct instead of having 10 parameters to the
function?

[Aayush Kumar, 2011/08/08 03:19:22]

Reordered function params.
As discussed in person, decided not to create a struct since we have mostly
dis-similar items, and also, that this function is within an unnamed namespace.

+    string16 text,
+    SkPaint paint,
+    skia::VectorCanvas* canvas,
+    printing::HorizontalHeaderFooterPosition horizontal_position,
+    printing::VerticalHeaderFooterPosition vertical_position,
+    float webkit_scale_factor,
+    const PageSizeMargins& page_layout,
+    SkScalar max_text_width,
+    const gfx::Font& font,
+    SkScalar offset_to_baseline) {
+  text = ui::ElideText(text, font, ConvertPointsToPixelDouble(max_text_width),
+                       false);
+
+  size_t text_byte_length = text.length() * sizeof(char16);
+  // Get the (x, y) coordinate from where printing of the current text should
+  // start depending on the 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 (horizontal_position) {
+    case printing::LEFT:
+      x = printing::kSettingHeaderFooterInterstice - page_layout.margin_left;
+      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 (vertical_position) {
+    case printing::TOP:
+      y = printing::kSettingHeaderFooterInterstice -
+          page_layout.margin_top - offset_to_baseline;
+      break;
+    case printing::BOTTOM:
+      y = page_layout.margin_bottom + page_layout.content_height -
+          printing::kSettingHeaderFooterInterstice - offset_to_baseline;
+      break;
+    default:
+      NOTREACHED();
+  }
+
+  x = x / webkit_scale_factor;
+  y = y / webkit_scale_factor;
+  paint.setTextSize(paint.getTextSize() / webkit_scale_factor);
+  canvas->drawText(text.c_str(), text_byte_length, x, y, paint);
+}
+
+// Prints the headers onto the |canvas| if there is enough space to print them.
+void PrintHeaders(skia::VectorCanvas* canvas,
+                  const DictionaryValue& header_footer_info,
+                  SkPaint paint,
+                  const PageSizeMargins& page_layout,
+                  float webkit_scale_factor,
+                  const gfx::Font& font) {
+  string16 date = base::TimeFormatShortDateNumeric(Time::Now());
+  string16 title;
+  if (!header_footer_info.GetString(printing::kSettingHeaderFooterTitle,
+                                    &title)) {
+    NOTREACHED();
+  }
+  string16 header_text = date + title;
+
+  SkRect header_bounds;
+  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;
+
+  SkScalar segment_width = GetSegmentWidth(page_layout);
+  PrintHeaderFooterText(date, paint, canvas, printing::LEFT, printing::TOP,
+                        webkit_scale_factor, page_layout, segment_width, font,
+                        header_bounds.top());
+
+  // Calculate the available title width. If the date string is not long
+  // enough, increase the available space for the title.
+  // Assumes there is no header text to RIGHT of title.
+  SkScalar date_width = paint.measureText(date.c_str(),
+                                          date.length() * sizeof(char16));
+  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());
+}
+
+// Prints the footers onto the |canvas| if there is enough space to print them.
+void PrintFooters(skia::VectorCanvas* canvas,
+                  const DictionaryValue& header_footer_info,
+                  SkPaint paint,
+                  const PageSizeMargins& page_layout,
+                  float webkit_scale_factor,
+                  const gfx::Font& font,
+                  int page_number,
+                  int total_pages) {
+  string16 page_of_total_pages = base::IntToString16(page_number) +
+                                 UTF8ToUTF16("/") +
+                                 base::IntToString16(total_pages);
+  std::string url;
+  if (!header_footer_info.GetString(printing::kSettingHeaderFooterURL,
+                                    &url)) {
+    NOTREACHED();
+  }
+  string16 footer_text = page_of_total_pages + UTF8ToUTF16(url);
+
+  SkRect footer_bounds;
+  paint.measureText(footer_text.c_str(), footer_text.length() * sizeof(char16),
+                    &footer_bounds, 0);
+  SkScalar text_height =
+      printing::kSettingHeaderFooterInterstice + footer_bounds.height();
+  if (text_height > page_layout.margin_bottom)
+    return;
+
+  SkScalar segment_width = GetSegmentWidth(page_layout);
+  PrintHeaderFooterText(page_of_total_pages, paint, canvas, printing::RIGHT,
+                        printing::BOTTOM, webkit_scale_factor, page_layout,
+                        segment_width, font, footer_bounds.bottom());
+
+  // Calculate the available URL width. Increase the available URL width
+  // if the |page_of_total_pages| string isn't long enough.
+  // Assumes no footer text being printed in the CENTER.
+  SkScalar page_width = paint.measureText(
+      page_of_total_pages.c_str(),
+      page_of_total_pages.length() * sizeof(char16));
+  SkScalar max_url_width =
+      (page_layout.content_width + page_layout.margin_left +
+      page_layout.margin_right) * 3 / 4;
+  max_url_width = std::min(max_url_width,
+                           2 * (segment_width - page_width) + segment_width);
+  GURL gurl(url);
+  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());
+}
+#endif  // USE_SKIA
+
 }  // namespace
 
+#if defined(USE_SKIA)
+// static - Not anonymous so that platform implementations can use it.
+void PrintWebViewHelper::PrintHeaderAndFooter(
+    SkDevice* device,
+    skia::VectorCanvas* canvas,
+    int page_number,
+    int total_pages,
+    float webkit_scale_factor,
+    const PageSizeMargins& page_layout,
+    const DictionaryValue& header_footer_info) {
+  static_cast<skia::VectorPlatformDeviceSkia*>(device)->setDrawingArea(
+      SkPDFDevice::kMargin_DrawingArea);
+
+  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));
+
+  PrintHeaders(canvas, header_footer_info, paint, page_layout,
+               webkit_scale_factor, font);
+  PrintFooters(canvas, header_footer_info, paint, page_layout,
+               webkit_scale_factor, font, page_number, total_pages);
+
+  static_cast<skia::VectorPlatformDeviceSkia*>(device)->setDrawingArea(
+      SkPDFDevice::kContent_DrawingArea);
+}
+#endif  // USE_SKIA
+
 PrepareFrameAndViewForPrint::PrepareFrameAndViewForPrint(
     const PrintMsg_Print_Params& print_params,
     WebFrame* frame,
@@ -765,7 +987,7 @@ bool PrintWebViewHelper::UpdatePrintSettings(
   PrintMsg_PrintPages_Params settings;
 
   Send(new PrintHostMsg_UpdatePrintSettings(routing_id(),
-      print_pages_params_->params.document_cookie, job_settings, &settings));
+       print_pages_params_->params.document_cookie, job_settings, &settings));
 
   if (settings.params.dpi < kMinDpi || !settings.params.document_cookie)
     return false;
@@ -774,6 +996,26 @@ bool PrintWebViewHelper::UpdatePrintSettings(
     return false;
 
   print_pages_params_.reset(new PrintMsg_PrintPages_Params(settings));
+  // Getting Header and Footer settings.
+  bool display_header_footer = false;
+  if (!job_settings.GetBoolean(printing::kSettingHeaderFooterEnabled,
+                               &display_header_footer)) {
+    NOTREACHED();
+  }
+  print_pages_params_->params.display_header_footer = display_header_footer;
+
+  if (display_header_footer) {
+    string16 title;
+    std::string url;
+    if (!job_settings.GetString(printing::kSettingHeaderFooterTitle, &title) ||
+        !job_settings.GetString(printing::kSettingHeaderFooterURL, &url)) {
+      NOTREACHED();
+    }
+    header_footer_info_.reset(new DictionaryValue());
+    header_footer_info_->SetString(printing::kSettingHeaderFooterURL, url);
+    header_footer_info_->SetString(printing::kSettingHeaderFooterTitle, title);
+  }
+
   Send(new PrintHostMsg_DidGetDocumentCookie(routing_id(),
                                              settings.params.document_cookie));
   return true;