Added Header and Footer support using Skia

chrome/renderer/print_web_view_helper_linux.cc

 // Copyright (c) 2011 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/print_web_view_helper.h"
 
 #include "base/file_descriptor_posix.h"
+#include "base/i18n/time_formatting.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram.h"
+#include "base/string_number_conversions.h"
+#include "base/time.h"
+#include "base/utf_string_conversions.h"
 #include "chrome/common/print_messages.h"
 #include "content/common/view_messages.h"
 #include "printing/metafile.h"
 #include "printing/metafile_impl.h"
 #include "printing/metafile_skia_wrapper.h"
 #include "skia/ext/vector_canvas.h"
+#include "skia/ext/vector_platform_device_skia.h"
+#include "third_party/skia/include/core/SkColor.h"
+#include "third_party/skia/include/core/SkDraw.h"
 #include "third_party/skia/include/core/SkRefCnt.h"
+#include "third_party/skia/include/core/SkTypeface.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
+#include "ui/base/text/text_elider.h"
 #include "ui/gfx/point.h"
 
 #if !defined(OS_CHROMEOS)
 #include "base/process_util.h"
 #endif  // !defined(OS_CHROMEOS)
 
+using base::Time;
 using WebKit::WebFrame;
 using WebKit::WebNode;
 
 bool PrintWebViewHelper::CreatePreviewDocument(
     const PrintMsg_PrintPages_Params& params, WebKit::WebFrame* frame,
     WebKit::WebNode* node) {
   if (!PreviewPageRendered(-1))
     return false;
 
   printing::PreviewMetafile metafile;
@@ skipping 122 matching lines @@
     return false;
   if (is_preview) {
     Send(new PrintHostMsg_DidGetPreviewPageCount(routing_id(), *page_count));
   } else {
 #if !defined(OS_CHROMEOS)
     Send(new PrintHostMsg_DidGetPrintedPagesCount(routing_id(),
                                                   printParams.document_cookie,
                                                   *page_count));
 #endif
   }
+  int total_pages = *page_count;
 
   base::TimeTicks begin_time = base::TimeTicks::Now();
   base::TimeTicks page_begin_time = begin_time;
 
   PrintMsg_PrintPage_Params page_params;
   page_params.params = printParams;
   const gfx::Size& canvas_size = prep_frame_view.GetPrintCanvasSize();
   if (params.pages.empty()) {
     for (int i = 0; i < *page_count; ++i) {
       page_params.page_number = i;
-      PrintPageInternal(page_params, canvas_size, frame, metafile);
+      PrintPageInternal(page_params, canvas_size, frame, metafile, is_preview,
+          total_pages);
       if (is_preview) {
         page_begin_time = ReportPreviewPageRenderTime(page_begin_time);
         if (!PreviewPageRendered(i))
           return false;
       }
     }
   } else {
     for (size_t i = 0; i < params.pages.size(); ++i) {
       page_params.page_number = params.pages[i];
-      PrintPageInternal(page_params, canvas_size, frame, metafile);
+      PrintPageInternal(page_params, canvas_size, frame, metafile, is_preview,
+          total_pages);
       if (is_preview) {
         page_begin_time = ReportPreviewPageRenderTime(page_begin_time);
         if (!PreviewPageRendered(params.pages[i]))
           return false;
       }
     }
   }
 
   base::TimeDelta render_time = base::TimeTicks::Now() - begin_time;
 
   prep_frame_view.FinishPrinting();
   metafile->FinishDocument();
 
   if (is_preview) {
     ReportTotalPreviewGenerationTime(params.pages.size(), *page_count,
                                      render_time,
                                      base::TimeTicks::Now() - begin_time);
   }
   return true;
 }
 
+
+size_t GetString16ByteLength(string16 text) {
+  return text.length()*sizeof(char16);
+}
+
+SkScalar PrintWebViewHelper::GetHorizontalCoordinate(
+    string16 text,
+    SkPaint paint,
+    HorizontalHeaderFooterPosition pos,
+    SkScalar margin_left_in_points,
+    SkScalar margin_right_in_points,
+    SkScalar content_width_in_points) {
+  SkScalar text_width_in_points = paint.measureText(text.c_str(),
+      GetString16ByteLength(text));
+
+  switch (pos) {
+    case LEFT:
+        return margin_left_in_points*(-1) + header_footer_interstice;
+    case RIGHT:
+        return ((content_width_in_points+margin_right_in_points) -
+                (header_footer_interstice + text_width_in_points));
+    case CENTER:
+        SkScalar available_width = (margin_left_in_points +
+                                    margin_right_in_points +
+                                    content_width_in_points -
+                                    4*header_footer_interstice)/3;
+        return (available_width - margin_left_in_points +
+                  (available_width - text_width_in_points)/2);
+  }
+  NOTREACHED();
+  return 0;
+}
+
+SkScalar PrintWebViewHelper::GetVerticalCoordinate(
+    SkPaint paint,
+    VerticalHeaderFooterPosition pos,
+    SkScalar margin_top_in_points,
+    SkScalar margin_bottom_in_points,
+    SkScalar content_height_in_points) {
+  if (pos == TOP) {
+    return margin_top_in_points*(-0.5);
+  } else if (pos == BOTTOM) {
+    return margin_top_in_points+content_height_in_points;
+  } else {
+    NOTREACHED();
+    return 0;
+  }
+}
+
+void PrintWebViewHelper::PrintHeaderFooterText(
+    string16 text,
+    SkPaint paint,
+    const SkRefPtr<skia::VectorCanvas>& canvas,
+    SkScalar margin_left_in_points,
+    SkScalar margin_right_in_points,
+    SkScalar content_width_in_points,
+    SkScalar margin_top_in_points,
+    SkScalar margin_bottom_in_points,
+    SkScalar content_height_in_points,
+    HorizontalHeaderFooterPosition hor_pos,
+    VerticalHeaderFooterPosition ver_pos) {
+  SkScalar x_cord = GetHorizontalCoordinate(text, paint, hor_pos,
+                                            margin_left_in_points,
+                                            margin_right_in_points,
+                                            content_width_in_points);
+  SkScalar y_cord = GetVerticalCoordinate(paint, ver_pos, margin_top_in_points,
+                                          margin_bottom_in_points,
+                                          content_height_in_points);
+  size_t byte_length = GetString16ByteLength(text);
+
+  canvas->drawText(text.c_str(), byte_length, x_cord, y_cord, paint);
+}
+
 void PrintWebViewHelper::PrintPageInternal(
     const PrintMsg_PrintPage_Params& params,
     const gfx::Size& canvas_size,
     WebFrame* frame,
-    printing::Metafile* metafile) {
+    printing::Metafile* metafile,
+    bool is_preview,
+    int total_pages) {
+  // TODO(aayushkumar): Make these variables private variables of the class.
   double content_width_in_points;
   double content_height_in_points;
   double margin_top_in_points;
   double margin_right_in_points;
   double margin_bottom_in_points;
   double margin_left_in_points;
   GetPageSizeAndMarginsInPoints(frame,
                                 params.page_number,
                                 params.params,
                                 &content_width_in_points,
@@ skipping 14 matching lines @@
   SkDevice* device = metafile->StartPageForVectorCanvas(
       page_size, content_area, 1.0f);
   if (!device)
     return;
 
   // The printPage method take a reference to the canvas we pass down, so it
   // can't be a stack object.
   SkRefPtr<skia::VectorCanvas> canvas = new skia::VectorCanvas(device);
   canvas->unref();  // SkRefPtr and new both took a reference.
   printing::MetafileSkiaWrapper::SetMetafileOnCanvas(canvas.get(), metafile);
+
+  // TODO(aayushkumar): Have a seperate function for printing Headers and Footer

[kmadhusu, 2011/07/13 18:47:53]

Implement this TODO.

[Aayush Kumar, 2011/07/13 21:52:16]

Done.

+  // that will hopefully be in common for all platforms.
+  if (is_preview && params.params.header_footer) {
+    // Set the drawing area to draw in the margins.
+    ((skia::VectorPlatformDeviceSkia* )device)->
+        setDrawingArea(SkPDFDevice::kMargin_DrawingArea);
+
+    // Setting up styles for the headers and footers text.
+    SkPaint paint;
+    paint.setColor(SK_ColorBLACK);
+    paint.setTextSize(SkIntToScalar(8));
+    paint.setTypeface(SkTypeface::CreateFromName(NULL, SkTypeface::kNormal));
+    paint.setTextEncoding(SkPaint::kUTF16_TextEncoding);
+
+    // Printing the Date
+    Time now = Time::Now();
+    string16 date = base::TimeFormatShortDateNumeric(now);
+    PrintHeaderFooterText(date, paint, canvas, margin_left_in_points,
+                          margin_right_in_points, content_width_in_points,
+                          margin_top_in_points, margin_bottom_in_points,
+                          content_height_in_points, LEFT, TOP);
+
+    // Printing the title
+    string16 title;
+    if (!header_footer_info_->GetString("title", &title))
+      NOTREACHED();
+
+    SkScalar maxTitleSize = (margin_left_in_points +
+                             content_width_in_points +
+                             margin_right_in_points)/3;
+    title = ui::ElideText(title, paint, maxTitleSize, false);
+    PrintHeaderFooterText(title, paint, canvas, margin_left_in_points,
+                          margin_right_in_points, content_width_in_points,
+                          margin_top_in_points, margin_bottom_in_points,
+                          content_height_in_points, CENTER, TOP);
+
+    // Printing the URL
+    std::string url;
+    if (!header_footer_info_->GetString("url", &url))
+      NOTREACHED();
+    GURL gurl(url);
+    string16 url_elided = ui::ElideUrl(gurl, paint, maxTitleSize,
+                                       std::string());
+    PrintHeaderFooterText(url_elided, paint, canvas, margin_left_in_points,
+                          margin_right_in_points, content_width_in_points,
+                          margin_top_in_points, margin_bottom_in_points,
+                          content_height_in_points, LEFT, BOTTOM);
+
+    // Printing the page numbers at the bottom right corner of page.
+    string16 page_on_page_total = base::IntToString16(params.page_number+1) +
+                               UTF8ToUTF16("/") +

[kmadhusu, 2011/07/13 18:47:53]

nit: Fix indentation.

[Aayush Kumar, 2011/07/13 21:52:16]

Done.

+                               base::IntToString16(total_pages);
+    PrintHeaderFooterText(page_on_page_total, paint, canvas,
+                          margin_left_in_points, margin_right_in_points,
+                          content_width_in_points, margin_top_in_points,
+                          margin_bottom_in_points, content_height_in_points,
+                          RIGHT, BOTTOM);
+
+   // Restore the drawing area to draw in the content area.
+    ((skia::VectorPlatformDeviceSkia* )device)->
+        setDrawingArea(SkPDFDevice::kContent_DrawingArea);
+  }
+
   frame->printPage(params.page_number, canvas.get());
 
   // TODO(myhuang): We should render the header and the footer.
 
   // Done printing. Close the device context to retrieve the compiled metafile.
   if (!metafile->FinishPage())
     NOTREACHED() << "metafile failed";
 }