// This may look like C code, but it's really -*- C++ -*-
/*
 * Copyright (C) 2008 Emweb bvba, Kessel-Lo, Belgium.
 *
 * See the LICENSE file for terms of use.
 */
#ifndef WPAINTER_H_
#define WPAINTER_H_

#include <Wt/WBrush>
#include <Wt/WFont>
#include <Wt/WGlobal>
#include <Wt/WPainterPath>
#include <Wt/WPen>
#include <Wt/WShadow>
#include <Wt/WTransform>

namespace Wt {

class WLineF;
class WPaintDevice;
class WPainterPath;
class WPointF;
class WRectF;

/*! \defgroup painting Painting system
    \brief Classes that provide support for vector graphics

  %Wt provides a vector graphics painting system, which depending on
  the browser support, uses one of three different methods to paint
  the graphics (inline SVG, inline VML or HTML 5 &lt;canvas&gt;
  element). Vector graphics has as benefit a lower bandwidth usage
  compared to raster images, indepedent of the image size. To use the
  paint system, you need to specialize WPaintedWidget and use a
  WPainter to paint the contents of the widget inside its
  WPaintedWidget::paintEvent().

  If you want to use inline SVG (which has some benefits since it is
  widely supported and is the most complete), you will need to enable
  xhtml support in your configuration file by enabling
  send-xhtml-mimetype, see \ref config_general.
*/

/*! \class WPainter Wt/WPainter Wt/WPainter
 *  \brief Helper class for painting on a WPaintDevice
 *
 * The painter class provides a rich interface for painting on a
 * WPaintDevice. To start painting on a device, either pass the device
 * through the constructor WPainter(WPaintDevice *), or use
 * begin(WPaintDevice *). Typically, you will instantiate a %WPainter
 * from within the WPaintedWidget::paintEvent() method, but you can also
 * use a painter to paint directly to a particular paint device, for
 * example to create an SVG image.
 *
 * The painter maintains state such as the current \link setPen()
 * pen\endlink, \link setBrush() brush\endlink, \link setFont()
 * font\endlink, \link shadow() shadow\endlink, \link worldTransform()
 * transformation\endlink and clipping settings (see setClipping() and
 * setClipPath()). A particular state can be saved using save() and
 * later restored using restore().
 *
 * The painting system distinguishes between device coordinates,
 * logical coordinates, and local coordinates. The device coordinate
 * system ranges from (0, 0) in the top left corner of the device, to
 * (WPaintDevice::width(), WPaintDevice::height()) for the bottom
 * right corner. The logical coordinate system defines a coordinate
 * system that may be chosen independent of the geometry of the
 * device, which is convenient to make abstraction of the actual
 * device size. Finally, the current local coordinate system may be
 * different from the logical coordinate system because of a world
 * transformation. Initially, the local coordinate system coincides
 * with the logical coordinate system, which coincides with the device
 * coordinate system.
 *
 * By setting a viewPort() and a window(), a viewPort transformation
 * is defined which maps logical coordinates onto device
 * coordinates. By changing the world transformation (using
 * setWorldTransform(), or translate(), rotate(), scale() operations),
 * it is defined how current local coordinates map onto logical
 * coordinates.
 *
 * Although the painter has support for clipping using an arbitrary
 * \link WPainterPath path\endlink, not all devices support clipping.
 *
 * \if cpp
 * Usage example:
 * \code
 * class MyPaintedWidget : public Wt::WPaintedWidget
 * {
 * public:
 *   MyPaintedWidget(Wt::WContainerWidget *parent = 0)
 *     : Wt::WPaintedWidget(parent),
 *       foo_(100)
 *   {
 *      resize(200, 200); // provide a default size
 *   }
 *
 *   void setFoo(int foo) {
 *      foo_ = foo;
 *      update(); // trigger a repaint
 *   }
 *
 * protected:
 *   void paintEvent(Wt::WPaintedWidget *paintDevice) {
 *     Wt::WPainter painter(paintDevice);
 *     painter.drawLine(20, 20, foo_, foo_);
 *     ...
 *   }
 *
 * private:
 *   int foo_;
 * };
 * \endcode
 * \endif
 *
 * \sa WPaintedWidget::paintEvent(WPaintDevice *)
 *
 * \ingroup painting
 */
class WT_API WPainter
{
public:
  /*! \brief Enumeration for render hints
   */
  enum RenderHint {
    Antialiasing = 1, //!< Antialiasing
    LowQualityShadows = 2  //!< Use low-quality shadows (applies only to VML)
  };

  /*! \brief Default constructor.
   *
   * Before painting, you must invoke begin(WPaintDevice *) on a paint device.
   *
   * \sa WPainter(WPaintDevice *)
   */
  WPainter();

  /*! \brief Creates a painter on a given paint device.
   */
  WPainter(WPaintDevice *device);

  /*! \brief Destructor.
   */
  ~WPainter();

  /*! \brief Begins painting on a paint device.
   *
   * Starts painting on a paint device. The paint device is
   * automatically cleared to become entirely transparent.
   *
   * \sa end(), isActive()
   */
  bool begin(WPaintDevice *device);

  /*! \brief Returns whether this painter is active on a paint device.
   *
   * \sa begin(WPaintDevice *), end()
   */
  bool isActive() const;

  /*! \brief Ends painting.
   *
   * \if cpp
   * This method is called automatically from the destructor.
   * \endif
   */
  bool end();

  /*! \brief Returns the device on which this painter is active (or 0 if not active).
   *
   * \sa begin(WPaintDevice *), WPainter(WPaintDevice *), isActive()
   */
  WPaintDevice *device() const { return device_; }

  /*! \brief Sets a render hint.
   *
   * Renderers may ignore particular hints for which they have no
   * support.
   */
  void setRenderHint(RenderHint hint, bool on = true);

  /*! \brief Returns the current render hints.
   *
   * Returns the logical OR of render hints currently set.
   *
   * \sa setRenderHint(RenderHint, bool).
   */
  int renderHints() const { return s().renderHints_; }

  /*! \brief Draws an arc.
   *
   * Draws an arc using the current pen, and fills using the current brush.
   *
   * The arc is defined as a segment from an ellipse, which fits in
   * the <i>rectangle</i>. The segment starts at \p startAngle, and
   * spans an angle given by \p spanAngle. These angles have as
   * unit 1/16th of a degree, and are measured counter-clockwise
   * starting from the 3 o'clock position.
   *
   * \sa drawEllipse(const WRectF&), drawChord(const WRectF&, int, int)
   * \sa drawArc(double, double, double, double, int, int)
   */
  void drawArc(const WRectF& rectangle, int startAngle, int spanAngle);

  /*! \brief Draws an arc.
   *
   * This is an overloaded method for convenience.
   *
   * \sa drawArc(const WRectF&, int, int)
   */
  void drawArc(double x, double y, double width, double height,
	       int startAngle, int spanAngle);

  /*! \brief Draws a chord.
   *
   * Draws an arc using the current pen, and connects start and end
   * point with a line. The area is filled using the current brush.
   *
   * The arc is defined as a segment from an ellipse, which fits in
   * the <i>rectangle</i>. The segment starts at \p startAngle, and
   * spans an angle given by \p spanAngle. These angles have as
   * unit 1/16th of a degree, and are measured counter-clockwise
   * starting at 3 o'clock.
   *
   * \sa drawEllipse(const WRectF&), drawArc(const WRectF&, int, int)
   * \sa drawChord(double, double, double, double, int, int)
   */
  void drawChord(const WRectF& rectangle, int startAngle, int spanAngle);

  /*! \brief Draws a chord.
   *
   * This is an overloaded method for convenience.
   *
   * \sa drawChord(const WRectF&, int, int)
   */
  void drawChord(double x, double y, double width, double height,
		 int startAngle, int spanAngle);

  /*! \brief Draws an ellipse.
   *
   * Draws an ellipse using the current pen and fills it using the
   * current brush.
   *
   * The ellipse is defined as being bounded by the \p rectangle.
   *
   * \sa drawArc(const WRectF&, int, int)
   * \sa drawEllipse(double, double, double, double)
   */
  void drawEllipse(const WRectF& rectangle);

  /*! \brief Draws an ellipse.
   *
   * This is an overloaded method for convenience.
   *
   * \sa drawEllipse(const WRectF&)
   */
  void drawEllipse(double x, double y, double width, double height);

  /*! \brief An image that can be rendered on a WPainter.
   *
   * The image is specified in terms of a URL, and the width and
   * height.
   *
   * \sa drawImage()
   */
  class WT_API Image {
  public:
    /*! \brief Creates an image.
     *
     * Create an image which is located at the <i>uri</i>, and which has
     * dimensions <i>width</i> x <i>height</i>.
     */
    Image(const std::string& uri, int width, int height);

    /*! \brief Creates an image.
     *
     * Create an image which is located at <i>uri</i> which is available on
     * the local filesystem as <i>file</i>. The image dimensions are
     * retrieved from the file.
     */
    Image(const std::string& uri, const std::string& file);

    /*! \brief Returns the uri.
     */
    std::string uri() const { return uri_; }

    /*! \brief Returns the image width.
     */
    int width() const { return width_; }

    /*! \brief Returns the image height.
     */
    int height() const { return height_; }

  private:
    std::string uri_;
    int width_, height_;
  };

  /*! \brief Draws an image.
   *
   * Draws the \p image so that the top left corner corresponds to
   * \p point.
   *
   * This is an overloaded method provided for convenience.
   */
  void drawImage(const WPointF& point, const Image& image);

  /*! \brief Draws part of an image.
   *
   * Draws the \p sourceRect rectangle from an image to the
   * location \p point.
   *
   * This is an overloaded method provided for convenience.
   */
  void drawImage(const WPointF& point, const Image& image,
		 const WRectF& sourceRect);

  /*! \brief Draws an image inside a rectangle.
   *
   * Draws the <i>image</i> inside \p rect (If necessary, the image
   * is scaled to fit into the rectangle).
   *
   * This is an overloaded method provided for convenience.
   */
  void drawImage(const WRectF& rect, const Image& image);

  /*! \brief Draws part of an image inside a rectangle.
   *
   * Draws the \p sourceRect rectangle from an image inside
   * \p rect (If necessary, the image is scaled to fit into the
   * rectangle).
   */
  void drawImage(const WRectF& rect, const Image& image,
		 const WRectF& sourceRect);

  /*! \brief Draws part of an image.
   *
   * Draws the \p sourceRect rectangle with top left corner
   * (<i>sx</i>, <i>sy</i>) and size <i>sw</i> x \p sh from an
   * image to the location (<i>x</i>, \p y).
   */
  void drawImage(double x, double y, const Image& image,
		 double sx = 0, double sy = 0, double sw = -1, double sh = -1);

  /*! \brief Draws a line.
   *
   * Draws a line using the current pen.
   *
   * \sa drawLine(const WPointF&, const WPointF&),
   *     drawLine(double, double, double, double)
   */  
  void drawLine(const WLineF& line);

  /*! \brief Draws a line.
   *
   * Draws a line defined by two points.
   *
   * \sa drawLine(const WLineF&),
   *     drawLine(double, double, double, double)
   */  
  void drawLine(const WPointF& p1, const WPointF& p2);

  /*! \brief Draws a line.
   *
   * Draws a line defined by two points.
   *
   * \sa drawLine(const WLineF&),
   *     drawLine(const WPointF&, const WPointF&)
   */  
  void drawLine(double x1, double y1, double x2, double y2);

  /*! \brief Draws an array of lines.
   *
   * Draws the \p lineCount first lines from the given array of lines.
   */  
  void drawLines(const WT_ARRAY WLineF *lines, int lineCount);

  /*! \brief Draws an array of lines.
   *
   * Draws \p lineCount lines, where each line is specified using
   * a begin and end point that are read from an array. Thus, the
   * <i>pointPairs</i> array must have at least 2*\p lineCount
   * points.
   */
  void drawLines(const WT_ARRAY WPointF *pointPairs, int lineCount);

  /*! \brief Draws an array of lines.
   *
   * Draws the lines given in the vector.
   */  
  void drawLines(const std::vector<WLineF>& lines);

  /*! \brief Draws an array of lines.
   *
   * Draws a number of lines that are specified by pairs of begin- and
   * endpoints. The vector should hold a number of points that is a
   * multiple of two.
   */  
  void drawLines(const std::vector<WPointF>& pointPairs);

  /*! \brief Draws a (complex) path.
   *
   * Draws and fills the given path using the current pen and brush.
   *
   * \sa strokePath(const WPainterPath&, const WPen&),
   *     fillPath(const WPainterPath&, const WBrush&)
   */  
  void drawPath(const WPainterPath& path);

  /*! \brief Draws a pie.
   *
   * Draws an arc using the current pen, and connects start and end
   * point with the center of the corresponding ellipse. The area is
   * filled using the current brush.
   *
   * The arc is defined as a segment from an ellipse, which fits in
   * the <i>rectangle</i>. The segment starts at \p startAngle, and
   * spans an angle given by \p spanAngle. These angles have as
   * unit 1/16th of a degree, and are measured counter-clockwise
   * starting at 3 o'clock.
   *
   * \sa drawEllipse(const WRectF&), drawArc(const WRectF&, int, int)
   * \sa drawPie(double, double, double, double, int, int)
   */
  void drawPie(const WRectF& rectangle, int startAngle, int spanAngle);

  /*! \brief Draws a pie.
   *
   * This is an overloaded method for convenience.
   *
   * \sa drawPie(const WRectF&, int, int)
   */
  void drawPie(double x, double y, double width, double height,
	       int startAngle, int spanAngle);

  /*! \brief Draws a point.
   *
   * Draws a single point using the current pen.
   *
   * \sa drawPoint(double, double)
   */
  void drawPoint(const WPointF& position);

  /*! \brief Draws a point.
   *
   * This is an overloaded method for convenience.
   *
   * \sa drawPoint(const WPointF&)
   */
  void drawPoint(double x, double y);

  /*! \brief Draws a number of points.
   *
   * Draws the \p pointCount first points from the given array of points.
   *
   * \sa drawPoint(const WPointF&)
   */
  void drawPoints(const WT_ARRAY WPointF *points, int pointCount);

  /*! \brief Draws a polygon.
   *
   * Draws a polygon that is specified by a list of points, using the
   * current pen. The polygon is closed by connecting the last point
   * with the first point, and filled using the current brush.
   *
   * \sa drawPath(const WPainterPath&), drawPolyline()
   */
  void drawPolygon(const WT_ARRAY WPointF *points, int pointCount
		   /*, FillRule fillRule */);

  /*! \brief Draws a polyline.
   *
   * Draws a polyline that is specified by a list of points, using the
   * current pen.
   *
   * \sa drawPath(const WPainterPath&), drawPolygon()
   */
  void drawPolyline(const WT_ARRAY WPointF *points, int pointCount);

  /*! \brief Draws a rectangle.
   *
   * Draws and fills a rectangle using the current pen and brush.
   *
   * \sa drawRect(double, double, double, double)
   */
  void drawRect(const WRectF& rectangle);

  /*! \brief Draws a rectangle.
   *
   * This is an overloaded method for convenience.
   *
   * \sa drawRect(const WRectF&)
   */
  void drawRect(double x, double y, double width, double height);

  /*! \brief Draws a number of rectangles.
   *
   * Draws and fills the \p rectCount first rectangles from the
   * given array, using the current pen and brush.
   *
   * \sa drawRect(const WRectF&)
   */
  void drawRects(const WT_ARRAY WRectF *rectangles, int rectCount);

  /*! \brief Draws a number of rectangles.
   *
   * Draws and fills a list of rectangles using the current pen and
   * brush.
   *
   * \sa drawRect(const WRectF&)
   */
  void drawRects(const std::vector<WRectF>& rectangles);
  
  /*! \brief Draws text.
   *
   * Draws text using inside the rectangle, using the current font. The
   * text is aligned inside the rectangle following alignment
   * indications given in \p flags. The text is drawn using the
   * current transformation, pen color (pen()) and font settings
   * (font()).
   *
   * Flags is the logical OR of a horizontal and vertical
   * alignment. Horizontal alignment may be one of AlignLeft,
   * AlignCenter, or AlignRight. Vertical alignment is one of
   * AlignTop, AlignMiddle or AlignBottom.
   *
   * \note HtmlCanvas: on older browsers implementing Html5 canvas,
   * text will be rendered horizontally (unaffected by rotation and
   * unaffected by the scaling component of the transformation
   * matrix). In that case, text is overlayed on top of painted shapes
   * (in DOM div's), and is not covered by shapes that are painted
   * after the text. Use the SVG and VML renderers
   * (WPaintedWidget::inlineSvgVml) for the most accurate font
   * rendering. Native HTML5 text rendering is supported on Firefox3+,
   * Chrome2+ and Safari4+.
   */
  void drawText(const WRectF& rectangle, WFlags<AlignmentFlag> flags,
		const WString& text);

  /*! \brief Draws text.
   *
   * This is an overloaded method for convenience.
   *
   * \sa drawText(const WRectF&, WFlags<AlignmentFlag>, const WString&)
   */
  void drawText(double x, double y, double width, double height,
		WFlags<AlignmentFlag> flags, const WString& text);

  /*! \brief Fills a (complex) path.
   *
   * Like drawPath(const WPainterPath&), but does not stroke the path,
   * and fills the path with the given \p brush.
   *
   * \sa drawPath(const WPainterPath&), strokePath(const WPainterPath&, const WPen&)
   */
  void fillPath(const WPainterPath& path, const WBrush& brush);

  /*! \brief Fills a rectangle.
   *
   * Like drawRect(const WRectF&), but does not stroke the rect, and
   * fills the rect with the given \p brush.
   *
   * \sa drawRect(const WRectF&)
   */
  void fillRect(const WRectF& rectangle, const WBrush& brush);

  /*! \brief Fills a rectangle.
   *
   * This is an overloaded method for convenience.
   *
   * \sa fillRect(const WRectF&, const WBrush&)
   */
  void fillRect(double x, double y, double width, double height,
		const WBrush& brush);

  /*! \brief Strokes a path.
   *
   * Like drawPath(const WPainterPath&), but does not fill the path,
   * and strokes the path with the given \p pen.
   *
   * \sa drawPath(const WPainterPath&), fillPath(const WPainterPath&, const WBrush&)
   */
  void strokePath(const WPainterPath& path, const WPen& pen);

  /*! \brief Sets a shadow effect.
   *
   * The shadow effect is applied to all things drawn (paths, text and images).
   *
   * \note With the VML backend (IE), the shadow is not applied to images,
   *       and the shadow color is always black; only the opacity (alpha)
   *       channel is taken into account.
   * \sa LowQualityShadows render hint
   */
  void setShadow(const WShadow& shadow);

  /*! \brief Returns the current shadow effect.
   *
   * \sa setShadow()
   */
  const WShadow& shadow() const { return s().currentShadow_; }

  /*! \brief Sets the fill style.
   *
   * Changes the fills style for subsequent draw operations.
   *
   * \sa brush(), setPen(const WPen&)
   */
  void setBrush(const WBrush& brush);

  /*! \brief Sets the font.
   *
   * Changes the font for subsequent text rendering. Note that only
   * font sizes that are defined as an explicit size (see
   * WFont::FixedSize) will render correctly in all devices (SVG, VML,
   * and HtmlCanvas).
   *
   * \sa font(), drawText()
   */
  void setFont(const WFont& font);

  /*! \brief Sets the pen.
   *
   * Changes the pen used for stroking subsequent draw operations.
   *
   * \sa pen(), setBrush(const WBrush&)
   */
  void setPen(const WPen& pen);

  /*! \brief Returns the current brush.
   *
   * Returns the brush style that is currently used for filling.
   *
   * \sa setBrush(const WBrush&)
   */
  const WBrush& brush() const { return s().currentBrush_; }

  /*! \brief Returns the current font.
   *
   * Returns the font that is currently used for rendering text.
   * The default font is a 10pt sans serif font.
   *
   * \sa setFont(const WFont&)
   */
  const WFont& font() const { return s().currentFont_; }

  /*! \brief Returns the current pen.
   *
   * Returns the pen that is currently used for stroking.
   *
   * \sa setPen(const WPen&)
   */
  const WPen& pen() const { return s().currentPen_; }

  /*! \brief Enables or disables clipping.
   *
   * Enables are disables clipping for subsequent operations using the
   * current clip path set using setClipPath().
   *
   * \p Note: Clipping is not supported for the VML renderer.
   *
   * \sa hasClipping(), setClipPath(const WPainterPath&)
   */
  void setClipping(bool enable);

  /*! \brief Returns whether clipping is enabled.
   *
   * \p Note: Clipping is not supported for the VML renderer.
   *
   * \sa setClipping(bool), setClipPath(const WPainterPath&)
   */
  bool hasClipping() const { return s().clipping_; }

  /*! \brief Sets the clip path.
   *
   * Sets the path that is used for clipping subsequent drawing
   * operations. The clip path is only used when clipping is enabled
   * using setClipping(bool). The path is specified in local
   * coordinates.
   *
   * <i>Note: Only clipping with a rectangle is supported for the VML
   *    renderer (see WPainterPath::addRect()). The rectangle must,
   *    after applying the combined transformation system, be aligned
   *    with the window.</i>
   *
   * \sa clipPath(), setClipping(bool)
   */
  void setClipPath(const WPainterPath& clipPath);

  /*! \brief Returns the clip path.
   *
   * The clip path is returned as it was defined: in the local
   * coordinates at time of definition.
   *
   * \sa setClipPath(const WPainterPath&)
   */
  WPainterPath clipPath() const { return s().clipPath_; }

  /*! \brief Resets the current transformation.
   *
   * Resets the current transformation to the identity transformation
   * matrix, so that the logical coordinate system coincides with the
   * device coordinate system.
   */
  void resetTransform();

  /*! \brief Rotates the logical coordinate system.
   *
   * Rotates the logical coordinate system around its origin. The
   * \p angle is specified in degrees, and positive values are
   * clock-wise.
   *
   * \sa scale(double, double), translate(double, double), resetTransform()
   */
  void rotate(double angle);

  /*! \brief Scales the logical coordinate system.
   *
   * Scales the logical coordinate system around its origin, by a factor
   * in the X and Y directions.
   *
   * \sa rotate(double), translate(double, double), resetTransform()
   */
  void scale(double sx, double sy);

  /*! \brief Translates the origin of the logical coordinate system.
   *
   * Translates the origin of the logical coordinate system to a new
   * location relative to the current logical coordinate system.
   *
   * \sa translate(double, double), rotate(double),
   *     scale(double, double), resetTransform()
   */
  void translate(const WPointF& offset);

  /*! \brief Translates the origin of the logical coordinate system.
   *
   * Translates the origin of the logical coordinate system to a new
   * location relative to the logical coordinate system.
   *
   * \sa translate(const WPointF& offset), rotate(double),
   *     scale(double, double), resetTransform()
   */
  void translate(double dx, double dy);

  /*! \brief Sets a transformation for the logical coordinate system.
   *
   * Sets a new transformation which transforms logical coordinates to
   * device coordinates. When \p combine is \c true, the
   * transformation is combined with the current world transformation
   * matrix.
   *
   * \sa worldTransform()
   * \sa rotate(double), scale(double, double), translate(double, double)
   * \sa resetTransform()
   */
  void setWorldTransform(const WTransform& matrix, bool combine = false);

  /*! \brief Returns the current world transformation matrix.
   *
   * \sa setWorldTransform()
   */
  const WTransform& worldTransform() const { return s().worldTransform_; }

  /*! \brief Saves the current state.
   *
   * A copy of the current state is saved on a stack. This state will
   * may later be restored by popping this state from the stack using
   * restore().
   *
   * The state that is saved is the current \link setPen()
   * pen\endlink, \link setBrush() brush\endlink, \link setFont()
   * font\endlink, \link shadow() shadow\endlink, \link
   * worldTransform() transformation\endlink and clipping settings
   * (see setClipping() and setClipPath()).
   *
   * \sa restore()
   */
  void save();

  /*! \brief Returns the last save state.
   *
   * Pops the last saved state from the state stack.
   *
   * \sa save()
   */
  void restore();

  /*! \brief Sets the viewport.
   *
   * Selects the part of the device that will correspond to the logical
   * coordinate system.
   *
   * By default, the viewport spans the entire device: it is the
   * rectangle (0, 0) to (device->width(), device->height()). The
   * window defines how the viewport is mapped to logical coordinates.
   *
   * \sa viewPort(), setWindow(const WRectF&)
   */
  void setViewPort(const WRectF& viewPort);

  /*! \brief Sets the viewport.
   *
   * This is an overloaded method for convenience.
   *
   * \sa setViewPort(const WRectF&)
   */
  void setViewPort(double x, double y, double width, double height);

  /*! \brief Returns the viewport.
   *
   * \sa setViewPort(const WRectF&)
   */
  WRectF viewPort() const { return viewPort_; }

  /*! \brief Sets the window.
   *
   * Defines the viewport rectangle in logical coordinates, and thus how
   * logical coordinates map onto the viewPort.
   *
   * By default, is (0, 0) to (device->width(), device->height()). Thus,
   * the default window and viewport leave logical coordinates identical
   * to device coordinates.
   *
   * \sa window(), setViewPort(const WRectF&)
   */
  void setWindow(const WRectF& window);

  /*! \brief Sets the window.
   *
   * This is an overloaded method for convenience.
   *
   * \sa setWindow(const WRectF&)
   */
  void setWindow(double x, double y, double width, double height);

  /*! \brief Returns the current window.
   *
   * \sa setViewPort(const WRectF&)
   */
  WRectF window() const { return window_; }

  /*! \brief Returns the combined transformation matrix.
   *
   * Returns the transformation matrix that maps coordinates to device
   * coordinates. It is the combination of the current world
   * transformation (which defines the transformation within the
   * logical coordinate system) and the window/viewport transformation
   * (which transforms logical coordinates to device coordinates).
   *
   * \sa setWorldTransform(), setViewPort(), setWindow()
   */
  WTransform combinedTransform() const;

  const WTransform& clipPathTransform() const;

  WLength normalizedPenWidth(const WLength& penWidth, bool correctCosmetic)
    const;

private:
  WPaintDevice *device_;
  WRectF        viewPort_, window_;
  WTransform    viewTransform_;

  struct State {
    WTransform    worldTransform_;
    WBrush        currentBrush_;
    WFont         currentFont_;
    WPen          currentPen_;
    WShadow       currentShadow_;
    int           renderHints_;
    WPainterPath  clipPath_;
    WTransform    clipPathTransform_;
    bool          clipping_;

    State();

#ifdef WT_TARGET_JAVA
    State clone();
#endif
  };

  std::vector<State> stateStack_;

  State& s() { return stateStack_.back(); }
  const State& s() const { return stateStack_.back(); }

  void recalculateViewTransform();
};

}

/*! @} */

#endif // WPAINTER_H_
