third_party/WebKit/Source/core/page/PrintContext.h

/*
 * Copyright (C) 2007 Alp Toker <alp@atoker.com>
 * Copyright (C) 2007 Apple Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#ifndef PrintContext_h
#define PrintContext_h

#include "core/CoreExport.h"
#include "platform/heap/Handle.h"
#include "wtf/Forward.h"
#include "wtf/HashMap.h"
#include "wtf/Vector.h"
#include "wtf/text/WTFString.h"

namespace blink {

class Element;
class LocalFrame;
class FloatRect;
class FloatSize;
class GraphicsContext;
class IntRect;
class Node;

class CORE_EXPORT PrintContext
    : public GarbageCollectedFinalized<PrintContext> {
 public:
  explicit PrintContext(LocalFrame*);
  virtual ~PrintContext();

  LocalFrame* frame() const { return m_frame; }

  // Break up a page into rects without relayout.
  // FIXME: This means that CSS page breaks won't be on page boundary if the
  // size is different than what was passed to begin(). That's probably not
  // always desirable.
  // FIXME: Header and footer height should be applied before layout, not after.
  // FIXME: The printRect argument is only used to determine page aspect ratio,
  // it would be better to pass a FloatSize with page dimensions instead.
  virtual void computePageRects(const FloatRect& printRect,
                                float headerHeight,
                                float footerHeight,
                                float userScaleFactor,
                                float& outPageHeight);

  // Deprecated. Page size computation is already in this class, clients
  // shouldn't be copying it.
  // FIXME: Everyone passes |false| for the second paramer. We should remove the
  // second parameter.
  virtual void computePageRectsWithPageSize(const FloatSize& pageSizeInPixels);

  // These are only valid after page rects are computed.
  size_t pageCount() const { return m_pageRects.size(); }
  const IntRect& pageRect(size_t pageNumber) const {
    return m_pageRects[pageNumber];
  }
  const Vector<IntRect>& pageRects() const { return m_pageRects; }

  // Enter print mode, updating layout for new page size.
  // This function can be called multiple times to apply new print options
  // without going back to screen mode.
  virtual void begin(float width, float height = 0);

  // Return to screen mode.
  virtual void end();

  // Used by layout tests.
  static int pageNumberForElement(
      Element*,
      const FloatSize& pageSizeInPixels);  // Returns -1 if page isn't found.
  static String pageProperty(LocalFrame*,
                             const char* propertyName,
                             int pageNumber);
  static bool isPageBoxVisible(LocalFrame*, int pageNumber);
  static String pageSizeAndMarginsInPixels(LocalFrame*,
                                           int pageNumber,
                                           int width,
                                           int height,
                                           int marginTop,
                                           int marginRight,
                                           int marginBottom,
                                           int marginLeft);
  static int numberOfPages(LocalFrame*, const FloatSize& pageSizeInPixels);

  DECLARE_VIRTUAL_TRACE();

 protected:
  void outputLinkedDestinations(GraphicsContext&, const IntRect& pageRect);

  Member<LocalFrame> m_frame;
  Vector<IntRect> m_pageRects;

 private:
  void computePageRectsWithPageSizeInternal(const FloatSize& pageSizeInPixels);
  void collectLinkedDestinations(Node*);

  // Used to prevent misuses of begin() and end() (e.g., call end without
  // begin).
  bool m_isPrinting;

  HeapHashMap<String, Member<Element>> m_linkedDestinations;
  bool m_linkedDestinationsValid;
};

}  // namespace blink

#endif