Implement limited paged media support for linux.

chrome/renderer/print_web_view_helper_linux.cc

 // Copyright (c) 2009 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/logging.h"
 #include "chrome/common/render_messages.h"
 #include "printing/native_metafile.h"
 #include "printing/units.h"
 #include "skia/ext/vector_canvas.h"
 #include "third_party/WebKit/WebKit/chromium/public/WebFrame.h"
+#include "third_party/WebKit/WebKit/chromium/public/WebSize.h"
 
+using printing::ConvertPixelsToPoint;
+using printing::ConvertPixelsToPointDouble;
 using printing::NativeMetafile;
 using WebKit::WebFrame;
+using WebKit::WebSize;
+
+// If frame is NULL, this function returns the default value.
+static void GetPageSizeAndMarginsInPoints(WebFrame* frame,
+                                          int page_index,
+                                          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) {
+  // TODO(myhuang): Get printing parameters via IPC
+  // using the print_web_view_helper.cc version of Print.
+  // For testing purpose, we hard-coded printing parameters here.
+
+  // The paper size is US Letter (8.5 in. by 11 in.).
+  WebSize page_size_in_pixels(8.5 * printing::kPixelsPerInch,
+                              11.0 * printing::kPixelsPerInch);
+
+  int margin_top_in_pixels = static_cast<int>(
+      NativeMetafile::kTopMarginInInch * printing::kPixelsPerInch);
+  int margin_right_in_pixels = static_cast<int>(
+      NativeMetafile::kRightMarginInInch * printing::kPixelsPerInch);
+  int margin_bottom_in_pixels = static_cast<int>(
+      NativeMetafile::kBottomMarginInInch * printing::kPixelsPerInch);
+  int margin_left_in_pixels = static_cast<int>(
+      NativeMetafile::kLeftMarginInInch * printing::kPixelsPerInch);
+
+  if (frame) {
+    frame->pageSizeAndMarginsInPixels(page_index,
+                                      page_size_in_pixels,
+                                      margin_top_in_pixels,
+                                      margin_right_in_pixels,
+                                      margin_bottom_in_pixels,
+                                      margin_left_in_pixels);
+  }
+
+  *content_width_in_points = ConvertPixelsToPoint(page_size_in_pixels.width
+                                                  - margin_left_in_pixels
+                                                  - margin_right_in_pixels);
+  *content_height_in_points = ConvertPixelsToPoint(page_size_in_pixels.height
+                                                   - margin_top_in_pixels
+                                                   - margin_bottom_in_pixels);
+
+  // Invalid page size and/or margins. We just use the default setting.
+  if (*content_width_in_points < 1.0 || *content_height_in_points < 1.0) {
+    GetPageSizeAndMarginsInPoints(NULL,
+                                  page_index,
+                                  content_width_in_points,
+                                  content_height_in_points,
+                                  margin_top_in_points,
+                                  margin_right_in_points,
+                                  margin_bottom_in_points,
+                                  margin_left_in_points);
+    return;
+  }
+
+  if (margin_top_in_points)
+    *margin_top_in_points =
+        ConvertPixelsToPointDouble(margin_top_in_pixels);
+  if (margin_right_in_points)
+    *margin_right_in_points =
+        ConvertPixelsToPointDouble(margin_right_in_pixels);
+  if (margin_bottom_in_points)
+    *margin_bottom_in_points =
+        ConvertPixelsToPointDouble(margin_bottom_in_pixels);
+  if (margin_left_in_points)
+    *margin_left_in_points =
+        ConvertPixelsToPointDouble(margin_left_in_pixels);
+}
 
 void PrintWebViewHelper::Print(WebFrame* frame, bool script_initiated) {
   // If still not finished with earlier print request simply ignore.
   if (IsPrinting())
     return;
 
-  // TODO(myhuang): Get printing parameters via IPC
-  // using the print_web_view_helper.cc version of Print.
-  // For testing purpose, we hard-coded printing parameters here.
+  double content_width, content_height;
+  GetPageSizeAndMarginsInPoints(frame, 0, &content_width, &content_height,
+                                NULL, NULL, NULL, NULL);
 
-  // The paper size is US Letter (8.5 in. by 11 in.).
-  const int kDPI = printing::kPointsPerInch;
-  const int kWidth = static_cast<int>(
-      8.5 * kDPI - NativeMetafile::kLeftMargin - NativeMetafile::kRightMargin);
-  const int kHeight = static_cast<int>(
-      11 * kDPI - NativeMetafile::kTopMargin - NativeMetafile::kBottomMargin);
   ViewMsg_Print_Params default_settings;
-  default_settings.printable_size = gfx::Size(kWidth, kHeight);
-  default_settings.dpi = kDPI;
+  default_settings.printable_size = gfx::Size(
+      static_cast<int>(content_width), static_cast<int>(content_height));
+  default_settings.dpi = printing::kPointsPerInch;
   default_settings.min_shrink = 1.25;
   default_settings.max_shrink = 2.0;
-  default_settings.desired_dpi = kDPI;
+  default_settings.desired_dpi = printing::kPointsPerInch;
   default_settings.document_cookie = 0;
   default_settings.selection_only = false;
 
   ViewMsg_PrintPages_Params print_settings;
   print_settings.params = default_settings;
 
   PrintPages(print_settings, frame);
 }
 
 void PrintWebViewHelper::PrintPages(const ViewMsg_PrintPages_Params& params,
@@ skipping 47 matching lines @@
     return;
 
   // Tell the browser we've finished writing the file.
   Send(new ViewHostMsg_TempFileForPrintingWritten(fd_in_browser));
 }
 
 void PrintWebViewHelper::PrintPage(const ViewMsg_PrintPage_Params& params,
                                    const gfx::Size& canvas_size,
                                    WebFrame* frame,
                                    printing::NativeMetafile* metafile) {
+  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,
+                                &content_width_in_points,
+                                &content_height_in_points,
+                                &margin_top_in_points,
+                                &margin_right_in_points,
+                                &margin_bottom_in_points,
+                                &margin_left_in_points);
+
   cairo_t* cairo_context =
-      metafile->StartPage(canvas_size.width(), canvas_size.height());
+      metafile->StartPage(content_width_in_points,
+                          content_height_in_points,
+                          margin_top_in_points,
+                          margin_right_in_points,
+                          margin_bottom_in_points,
+                          margin_left_in_points);
   if (!cairo_context)
     return;
 
   skia::VectorCanvas canvas(cairo_context,
                             canvas_size.width(), canvas_size.height());
   frame->printPage(params.page_number, &canvas);
 
   // TODO(myhuang): We should handle transformation for paper margins.
   // 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";
 }