Added Header and Footer support using Skia

chrome/renderer/print_web_view_helper.h

Index: chrome/renderer/print_web_view_helper.h
diff --git a/chrome/renderer/print_web_view_helper.h b/chrome/renderer/print_web_view_helper.h
index 48b7037999372703132400390e08ccf939139703..de41c474ed20ce9a7c2a884b1e08c4829f75d867 100644
--- a/chrome/renderer/print_web_view_helper.h
+++ b/chrome/renderer/print_web_view_helper.h
@@ -9,9 +9,15 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/shared_memory.h"
 #include "base/time.h"
+#include "base/utf_string_conversions.h"
+#include "base/values.h"
 #include "content/renderer/render_view_observer.h"
 #include "content/renderer/render_view_observer_tracker.h"
 #include "printing/metafile.h"
+#include "skia/ext/vector_canvas.h"
+#include "third_party/skia/include/core/SkPaint.h"
+#include "third_party/skia/include/core/SkRefCnt.h"
+#include "third_party/skia/include/core/SkScalar.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebFrameClient.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebViewClient.h"
 #include "ui/gfx/size.h"
@@ -109,7 +115,11 @@ class PrintWebViewHelper : public RenderViewObserver,
   void OnInitiatePrintPreview();
 
   // Generate a print preview using |settings|.
-  void OnPrintPreview(const base::DictionaryValue& settings);
+  // |header_footer_info| contains the necessary strings generated by the
+  // browser process to be printed as headers and footers if requested by the
+  // user.
+  void OnPrintPreview(const base::DictionaryValue& settings,
+                      const DictionaryValue& header_footer_info);
 
   // Print / preview the node under the context menu.
   void OnPrintNodeUnderContextMenu();
@@ -177,7 +187,9 @@ class PrintWebViewHelper : public RenderViewObserver,
   void PrintPageInternal(const PrintMsg_PrintPage_Params& params,
                          const gfx::Size& canvas_size,
                          WebKit::WebFrame* frame,
-                         printing::Metafile* metafile);
+                         printing::Metafile* metafile,
+                         bool is_preview,
+                         int total_pages);
 #else
   void PrintPageInternal(const PrintMsg_PrintPage_Params& params,
                          const gfx::Size& canvas_size,
@@ -225,13 +237,7 @@ class PrintWebViewHelper : public RenderViewObserver,
   void GetPageSizeAndMarginsInPoints(
       WebKit::WebFrame* frame,
       int page_index,
-      const PrintMsg_Print_Params& default_params,
-      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);
+      const PrintMsg_Print_Params& default_params);
 
   bool IsModifiable(WebKit::WebFrame* frame, WebKit::WebNode* node);
 
@@ -295,6 +301,64 @@ class PrintWebViewHelper : public RenderViewObserver,
   int preview_page_count_;
   scoped_ptr<PrintMsg_PrintPages_Params> old_print_pages_params_;
 
+  // Contains strings generated by the browser process to be printed as headers
+  // and footers if requested by the user.
+  const DictionaryValue* header_footer_info_;
+
+  // Specifies the horizontal alignment of the Headers and Footers.
+  enum HorizontalHeaderFooterPosition {
+    LEFT,
+    CENTER,
+    RIGHT
+  };
+
+  // Specifies the vertical alignment of the Headers and Footers.
+  enum VerticalHeaderFooterPosition {
+    TOP,
+    BOTTOM
+  };
+
+  // Gets the x-coordinate from where we want to start printing the current text
+  // depending on the alignment (LEFT, RIGHT, CENTER).
+  SkScalar GetHorizontalCoordinate(
+    string16 text,
+    SkPaint paint,
+    HorizontalHeaderFooterPosition pos);
+
+  // Gets the y-coordinate from where we want to start printing based on if we
+  // are printing the Header or the Footer (TOP or BOTTOM).
+  SkScalar GetVerticalCoordinate(
+    SkPaint paint,
+    VerticalHeaderFooterPosition pos);
+
+  // Interstice or gap between different Header and Footer components.
+  // Hardcoded to 0.25cm = 1/10" = 7.2 points
+  const SkScalar header_footer_interstice;
+
+  // Given a text, the positions and the paint object, this method calculates
+  // the coordinates and prints the text at those co-ordinates.
+  void PrintHeaderFooterText(
+      string16 text,
+      SkPaint paint,
+      const SkRefPtr<skia::VectorCanvas>& canvas,
+      HorizontalHeaderFooterPosition hor_pos,
+      VerticalHeaderFooterPosition ver_pos,
+      float webkit_scale_factor);
+
+  // Given the device and canvas to draw on, prints the appropriate headers
+  // and footers on to the canvas.
+  void PrintHeaderAndFooter(SkDevice *device,
+                            const SkRefPtr<skia::VectorCanvas>& canvas,
+                            int page_number, int total_pages,
+                            float webkit_scale_factor);
+
+  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;
+
   DISALLOW_COPY_AND_ASSIGN(PrintWebViewHelper);
 };