Original change by Min-Yu Huang <minyu.huang@gmail.com> in

http://codereview.chromium.org/160347

This is the very preliminary implementation to support printing on Linux and it
has not been finished yet. For each page to be printed, we convert rendering
actions on canvas into cairo APIs and generate a PS/PDF file.

chrome/chrome.gyp:
  Include our newly added and renamed files.

chrome/browser/browser.h:
chrome/browser/browser.cc:
  Allow the user print the web page by hitting ctrl-p.

chrome/browser/gtk/standard_menus.cc:
  Show "Print" in the menu.

chrome/renderer/print_web_view_helper.cc:
chrome/renderer/print_web_view_helper.h:
chrome/renderer/print_web_view_helper_mac.cc
chrome/renderer/print_web_view_helper_win.cc
  Move the class PrepareFrameAndViewForPrint to the header file and move
platform dependent parts to their corresponding files.

chrome/renderer/print_web_view_helper_linux.cc:
  Hard-coded parameters for printing. Only print the first page now.

skia/ext/vector_canvas.cc:
skia/ext/vector_canvas.h:
skia/ext/vector_canvas_linux.cc:
skia/ext/vector_canvas_win.cc:
  Move platform dependent parts to their corresponding files.

skia/ext/vector_platform_device.h:
skia/ext/vector_platform_device_linux.cc:
skia/ext/vector_platform_device_linux.h
  We translate skia APIs into Cairo APIs here. A PDF file is also created and
saved to the disk at this moment for testing purpose (you have to run chrome
without the sandbox to save the file). There are still lots of bugs.

skia/skia.gyp:
  Include our newly added files when compiling skia package on Linux.

BUG=9847

Review URL: http://codereview.chromium.org/160673


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@22522 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 85 insertions, 0 deletions

diff --git a/chrome/renderer/print_web_view_helper_linux.cc b/chrome/renderer/print_web_view_helper_linux.cc
new file mode 100644
index 0000000..52b997d
--- /dev/null
+++ b/chrome/renderer/print_web_view_helper_linux.cc
@@ -0,0 +1,85 @@
+// 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/logging.h"
+#include "chrome/common/render_messages.h"
+#include "skia/ext/vector_canvas.h"
+#include "webkit/glue/webframe.h"
+
+
+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.
+  // For testing purpose, we hard-coded printing parameters here.
+
+  // The paper size is US Letter (8.5 in. by 11 in.).
+  // Using default margins:
+  //   Left = 0.25 in.
+  //   Right = 0.25 in.
+  //   Top = 0.25 in.
+  //   Bottom = 0.56 in.
+  const int kDPI = 72;
+  const int kWidth = (8.5-0.25-0.25) * kDPI;
+  const int kHeight = (11-0.25-0.56) * kDPI;
+  ViewMsg_Print_Params default_settings;
+  default_settings.printable_size = gfx::Size(kWidth, kHeight);
+  default_settings.dpi = kDPI;
+  default_settings.min_shrink = 1.25;
+  default_settings.max_shrink = 2.0;
+  default_settings.desired_dpi = kDPI;
+  default_settings.document_cookie = NULL;
+  default_settings.selection_only = false;
+
+  // Calculate the estimated page count.
+  PrepareFrameAndViewForPrint prep_frame_view(default_settings,
+                                              frame,
+                                              frame->GetView());
+  int expected_pages_count = prep_frame_view.GetExpectedPageCount();
+  DCHECK(expected_pages_count);
+
+  ViewMsg_PrintPage_Params page_params;
+  page_params.params = default_settings;
+
+  // TODO(myhuang): Get final printing settings via IPC.
+  // For testing purpose, we hard-coded printing settings here.
+
+  // Print the first page only.
+  expected_pages_count = 1;
+  for (int i = 0; i < expected_pages_count; ++i) {
+    page_params.page_number = i;
+    PrintPage(page_params, prep_frame_view.GetPrintCanvasSize(), frame);
+  }
+}
+
+void PrintWebViewHelper::PrintPage(const ViewMsg_PrintPage_Params& params,
+                                   const gfx::Size& canvas_size,
+                                   WebFrame* frame) {
+  // Since WebKit extends the page width depending on the magical shrink
+  // factor we make sure the canvas covers the worst case scenario
+  // (x2.0 currently).  PrintContext will then set the correct clipping region.
+  int size_x = static_cast<int>(canvas_size.width() * params.params.max_shrink);
+  int size_y = static_cast<int>(canvas_size.height() *
+      params.params.max_shrink);
+  // Calculate the dpi adjustment.
+  float shrink = static_cast<float>(canvas_size.width()) /
+      params.params.printable_size.width();
+
+  // TODO(myhuang): We now use VectorCanvas to generate a PS/PDF file for
+  // each page in printing. We might also need to create a metafile class
+  // on Linux.
+  skia::VectorCanvas canvas(size_x, size_y);
+  float webkit_shrink = frame->PrintPage(params.page_number, &canvas);
+  if (shrink <= 0) {
+    NOTREACHED() << "Printing page " << params.page_number << " failed.";
+  } else {
+    // Update the dpi adjustment with the "page shrink" calculated in webkit.
+    shrink /= webkit_shrink;
+  }
+}
+