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// Copyright (c) 2012 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/printing/print_web_view_helper.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/metrics/histogram.h"
#include "base/process_util.h"
#include "base/win/scoped_gdi_object.h"
#include "base/win/scoped_hdc.h"
#include "base/win/scoped_select_object.h"
#include "chrome/common/print_messages.h"
#include "printing/metafile.h"
#include "printing/metafile_impl.h"
#include "printing/metafile_skia_wrapper.h"
#include "printing/page_size_margins.h"
#include "printing/units.h"
#include "skia/ext/platform_device.h"
#include "skia/ext/refptr.h"
#include "skia/ext/vector_canvas.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/WebFrame.h"
#include "ui/gfx/gdi_util.h"
#include "ui/gfx/point.h"
#include "ui/gfx/rect.h"
#include "ui/gfx/size.h"
namespace printing {
using WebKit::WebFrame;
void PrintWebViewHelper::PrintPageInternal(
const PrintMsg_PrintPage_Params& params,
const gfx::Size& canvas_size,
WebFrame* frame) {
// Generate a memory-based metafile. It will use the current screen's DPI.
// Each metafile contains a single page.
scoped_ptr<NativeMetafile> metafile(new NativeMetafile);
metafile->Init();
DCHECK(metafile->context());
skia::InitializeDC(metafile->context());
int page_number = params.page_number;
// Calculate the dpi adjustment.
// Browser will render context using desired_dpi, so we need to calculate
// adjustment factor to play content on the printer DC later during the
// actual printing.
double actual_shrink = static_cast<float>(params.params.desired_dpi /
params.params.dpi);
gfx::Size page_size_in_dpi;
gfx::Rect content_area_in_dpi;
// Render page for printing.
RenderPage(params.params, page_number, frame, false, metafile.get(),
&actual_shrink, &page_size_in_dpi, &content_area_in_dpi);
// Close the device context to retrieve the compiled metafile.
if (!metafile->FinishDocument())
NOTREACHED();
if (!params.params.supports_alpha_blend && metafile->IsAlphaBlendUsed()) {
scoped_ptr<NativeMetafile> raster_metafile(
metafile->RasterizeAlphaBlend());
if (raster_metafile.get())
metafile.swap(raster_metafile);
}
// Get the size of the compiled metafile.
uint32 buf_size = metafile->GetDataSize();
DCHECK_GT(buf_size, 128u);
PrintHostMsg_DidPrintPage_Params page_params;
page_params.data_size = buf_size;
page_params.metafile_data_handle = NULL;
page_params.page_number = page_number;
page_params.document_cookie = params.params.document_cookie;
page_params.actual_shrink = actual_shrink;
page_params.page_size = page_size_in_dpi;
page_params.content_area = content_area_in_dpi;
if (!CopyMetafileDataToSharedMem(metafile.get(),
&(page_params.metafile_data_handle))) {
page_params.data_size = 0;
}
Send(new PrintHostMsg_DidPrintPage(routing_id(), page_params));
}
bool PrintWebViewHelper::RenderPreviewPage(
int page_number,
const PrintMsg_Print_Params& print_params) {
// Calculate the dpi adjustment.
double actual_shrink = static_cast<float>(print_params.desired_dpi /
print_params.dpi);
scoped_ptr<Metafile> draft_metafile;
Metafile* initial_render_metafile = print_preview_context_.metafile();
if (print_preview_context_.IsModifiable() && is_print_ready_metafile_sent_) {
draft_metafile.reset(new PreviewMetafile);
initial_render_metafile = draft_metafile.get();
}
base::TimeTicks begin_time = base::TimeTicks::Now();
RenderPage(print_params, page_number, print_preview_context_.frame(), true,
initial_render_metafile, &actual_shrink, NULL, NULL);
print_preview_context_.RenderedPreviewPage(
base::TimeTicks::Now() - begin_time);
if (draft_metafile.get()) {
draft_metafile->FinishDocument();
} else if (print_preview_context_.IsModifiable() &&
print_preview_context_.generate_draft_pages()) {
DCHECK(!draft_metafile.get());
draft_metafile.reset(
print_preview_context_.metafile()->GetMetafileForCurrentPage());
}
return PreviewPageRendered(page_number, draft_metafile.get());
}
void PrintWebViewHelper::RenderPage(
const PrintMsg_Print_Params& params, int page_number, WebFrame* frame,
bool is_preview, Metafile* metafile, double* actual_shrink,
gfx::Size* page_size_in_dpi, gfx::Rect* content_area_in_dpi) {
PageSizeMargins page_layout_in_points;
double css_scale_factor = 1.0f;
ComputePageLayoutInPointsForCss(frame, page_number, params,
ignore_css_margins_, &css_scale_factor,
&page_layout_in_points);
gfx::Size page_size;
gfx::Rect content_area;
GetPageSizeAndContentAreaFromPageLayout(page_layout_in_points, &page_size,
&content_area);
int dpi = static_cast<int>(params.dpi);
// Calculate the actual page size and content area in dpi.
if (page_size_in_dpi) {
*page_size_in_dpi = gfx::Size(
static_cast<int>(ConvertUnitDouble(page_size.width(), kPointsPerInch,
dpi)),
static_cast<int>(ConvertUnitDouble(page_size.height(), kPointsPerInch,
dpi)));
}
if (content_area_in_dpi) {
*content_area_in_dpi = gfx::Rect(
static_cast<int>(ConvertUnitDouble(content_area.x(), kPointsPerInch,
dpi)),
static_cast<int>(ConvertUnitDouble(content_area.y(), kPointsPerInch,
dpi)),
static_cast<int>(ConvertUnitDouble(content_area.width(), kPointsPerInch,
dpi)),
static_cast<int>(ConvertUnitDouble(content_area.height(),
kPointsPerInch, dpi)));
}
if (!is_preview) {
// Since WebKit extends the page width depending on the magical scale factor
// we make sure the canvas covers the worst case scenario (x2.0 currently).
// PrintContext will then set the correct clipping region.
page_size = gfx::Size(
static_cast<int>(page_layout_in_points.content_width *
params.max_shrink),
static_cast<int>(page_layout_in_points.content_height *
params.max_shrink));
}
float webkit_page_shrink_factor = frame->getPrintPageShrink(page_number);
float scale_factor = css_scale_factor * webkit_page_shrink_factor;
gfx::Rect canvas_area =
params.display_header_footer ? gfx::Rect(page_size) : content_area;
SkDevice* device = metafile->StartPageForVectorCanvas(
page_size, canvas_area, scale_factor);
DCHECK(device);
// The printPage method may take a reference to the canvas we pass down, so it
// can't be a stack object.
skia::RefPtr<skia::VectorCanvas> canvas =
skia::AdoptRef(new skia::VectorCanvas(device));
if (is_preview) {
MetafileSkiaWrapper::SetMetafileOnCanvas(*canvas, metafile);
skia::SetIsDraftMode(*canvas, is_print_ready_metafile_sent_);
skia::SetIsPreviewMetafile(*canvas, is_preview);
}
if (params.display_header_footer) {
// |page_number| is 0-based, so 1 is added.
PrintHeaderAndFooter(canvas.get(), page_number + 1,
print_preview_context_.total_page_count(), scale_factor,
page_layout_in_points, *header_footer_info_, params);
}
float webkit_scale_factor = RenderPageContent(frame, page_number, canvas_area,
content_area, scale_factor,
canvas.get());
if (*actual_shrink <= 0 || webkit_scale_factor <= 0) {
NOTREACHED() << "Printing page " << page_number << " failed.";
} else {
// While rendering certain plugins (PDF) to metafile, we might need to
// set custom scale factor. Update |actual_shrink| with custom scale
// if it is set on canvas.
// TODO(gene): We should revisit this solution for the next versions.
// Consider creating metafile of the right size (or resizable)
// https://code.google.com/p/chromium/issues/detail?id=126037
if (!MetafileSkiaWrapper::GetCustomScaleOnCanvas(
*canvas, actual_shrink)) {
// Update the dpi adjustment with the "page |actual_shrink|" calculated in
// webkit.
*actual_shrink /= (webkit_scale_factor * css_scale_factor);
}
}
bool result = metafile->FinishPage();
DCHECK(result);
}
bool PrintWebViewHelper::CopyMetafileDataToSharedMem(
Metafile* metafile, base::SharedMemoryHandle* shared_mem_handle) {
uint32 buf_size = metafile->GetDataSize();
base::SharedMemory shared_buf;
if (buf_size >= kMetafileMaxSize) {
NOTREACHED() << "Buffer too large: " << buf_size;
return false;
}
// Allocate a shared memory buffer to hold the generated metafile data.
if (!shared_buf.CreateAndMapAnonymous(buf_size)) {
NOTREACHED() << "Buffer allocation failed";
return false;
}
// Copy the bits into shared memory.
if (!metafile->GetData(shared_buf.memory(), buf_size)) {
NOTREACHED() << "GetData() failed";
shared_buf.Unmap();
return false;
}
shared_buf.GiveToProcess(base::GetCurrentProcessHandle(), shared_mem_handle);
shared_buf.Unmap();
Send(new PrintHostMsg_DuplicateSection(routing_id(), *shared_mem_handle,
shared_mem_handle));
return true;
}
} // namespace printing
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