lyx_mirror/src/frontends/screen.h

// -*- C++ -*-
/**
 * \file screen.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 SCREEN_H
#define SCREEN_H

class LyXText;
class CursorSlice;
class WorkArea;
class BufferView;

/**
 * LyXScreen - document rendering management
 *
 * This class is used to manage the on-screen rendering inside the
 * work area; it is responsible for deciding which LyXText rows
 * need re-drawing.
 *
 * This class will arrange for LyXText to paint onto a pixmap
 * provided by the WorkArea widget.
 *
 * The blinking cursor is also handled here.
 */
class LyXScreen {
public:
	LyXScreen();

	virtual ~LyXScreen();

	/// redraw the screen, without using existing pixmap
	virtual void redraw(BufferView & bv);

	/**
	 * fitCursor - fit the cursor onto the work area
	 * @param bv the bufferview
	 * @return true if a change was necessary
	 *
	 * Scrolls the screen so that the cursor is visible
	 */
	virtual bool fitCursor(BufferView *);

	/// hide the visible cursor, if it is visible
	void hideCursor();

	/// show the cursor if it is not visible
	void showCursor(BufferView & bv);

	/// toggle the cursor's visibility
	void toggleCursor(BufferView & bv);

protected:
	/// cause the display of the given area of the work area
	virtual void expose(int x, int y, int w, int h) = 0;

	/// get the work area
	virtual WorkArea & workarea() const = 0;

	/// types of cursor in work area
	enum Cursor_Shape {
		/// normal I-beam
		BAR_SHAPE,
		/// L-shape for locked insets of a different language
		L_SHAPE,
		/// reverse L-shape for RTL text
		REVERSED_L_SHAPE
	};

	/// paint the cursor and store the background
	virtual void showCursor(int x, int y, int h, Cursor_Shape shape) = 0;

	/// hide the cursor
	virtual void removeCursor() = 0;

private:
	/// grey out (no buffer)
	void greyOut();

	/// is the cursor currently displayed
	bool cursor_visible_;

	/// is the screen displaying text or the splash screen?
	bool greyed_out_;
};

#endif // SCREEN_H