lyx_mirror/src/frontends/Painter.h

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// -*- C++ -*-
/**
* \file Painter.h
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author unknown
* \author John Levon
*
* Full author contact details are available in file CREDITS.
*/
#ifndef PAINTER_H
#define PAINTER_H
#include "support/docstring.h"
namespace lyx {
class Color_color;
class Font;
namespace graphics { class Image; }
namespace frontend {
/**
* Painter - A painter class to encapsulate all graphics parameters and operations
*
* Every graphics operation in LyX should be made by this class. The
* painter is used for drawing on the WorkArea, and is passed around
* during draw operations.
*
* It hides low level windows system parameters so insets and other
* clients don't have to worry about them and we can control graphics and
* GUI toolkit dependent drawing functions inside this single class.
*
* The intention for a toolkit is that it uses these methods to paint
* onto a backing pixmap. Only when expose events arrive via the event
* queue (perhaps generated via Screen::expose), does the copy onto
* the actual WorkArea widget take place. Paints are wrapped in (possibly
* recursive) calls to start() and end() to facilitate the backing pixmap
* management.
*
* Note that the methods return *this for convenience.
*
* Caution: All char_type and docstring arguments of the text drawing
* methods of this class are no UCS4 chars or strings if the font is a
* symbol font. They simply denote the code points of the font instead.
* You have to keep this in mind when you implement the methods in a
* frontend. You must not pass these parameters to a unicode conversion
* function in particular.
*/
class Painter {
public:
Painter(): drawing_enabled_(true) {}
/// possible line widths
enum line_width {
line_thin, //< thin line
line_thick //< thick line
};
/// possible line styles
enum line_style {
line_solid, //< solid line
line_onoffdash //< dashes with spaces
};
/// possible character styles of preedit string.
/// This is used for CJK input method support.
enum preedit_style {
preedit_default, //< when unselecting, no cursor and dashed underline.
preedit_selecting, //< when selecting.
preedit_cursor //< with cursor.
};
virtual ~Painter() {}
/// draw a line from point to point
virtual void line(
int x1, int y1,
int x2, int y2,
Color_color,
line_style = line_solid,
line_width = line_thin) = 0;
/**
* lines - draw a set of lines
* @param xp array of points' x co-ords
* @param yp array of points' y co-ords
* @param np size of the points array
*/
virtual void lines(
int const * xp,
int const * yp,
int np,
Color_color,
line_style = line_solid,
line_width = line_thin) = 0;
/// draw a rectangle
virtual void rectangle(
int x, int y,
int w, int h,
Color_color,
line_style = line_solid,
line_width = line_thin) = 0;
/// draw a filled rectangle
virtual void fillRectangle(
int x, int y,
int w, int h,
Color_color) = 0;
/// draw an arc
virtual void arc(
int x, int y,
unsigned int w, unsigned int h,
int a1, int a2,
Color_color) = 0;
/// draw a pixel
virtual void point(
int x, int y,
Color_color) = 0;
/// draw a filled rectangle with the shape of a 3D button
virtual void button(int x, int y,
int w, int h, bool mouseHover);
/// draw an image from the image cache
virtual void image(int x, int y,
int w, int h,
graphics::Image const & image) = 0;
/// draw a string at position x, y (y is the baseline)
/**
* \return the width of the drawn text.
*/
virtual int text(int x, int y,
docstring const & str, Font const & f) = 0;
void setDrawingEnabled(bool drawing_enabled = true)
{ drawing_enabled_ = drawing_enabled; }
/// draw a char at position x, y (y is the baseline)
/**
* \return the width of the drawn text.
*/
virtual int text(int x, int y, char_type c, Font const & f) = 0;
/**
* Draw a string and enclose it inside a rectangle. If
* back color is specified, the background is cleared with
* the given color. If frame is specified, a thin frame is drawn
* around the text with the given color.
*/
void rectText(int x, int baseline,
docstring const & str,
Font const & font,
Color_color back,
Color_color frame);
/// draw a string and enclose it inside a button frame
void buttonText(int x, int baseline, docstring const & s,
Font const & font, bool mouseHover);
/// draw a character of a preedit string for cjk support.
int preeditText(int x, int y,
char_type c, Font const & f, preedit_style style);
protected:
/// check the font, and if set, draw an underline
void underline(Font const & f,
int x, int y, int width);
/// check the font, and if set, draw an dashed underline
void dashedUnderline(Font const & f,
int x, int y, int width);
/// draw a bevelled button border
void buttonFrame(int x, int y, int w, int h);
/// Indicate wether real screen drawing shall be done or not.
bool isDrawingEnabled() const { return drawing_enabled_; }
private:
///
bool drawing_enabled_;
};
} // namespace frontend
} // namespace lyx
#endif // PAINTER_H