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lecture-operating-system-de…/c_os/devices/CGA_Stream.h
2022-07-24 21:12:31 +02:00

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/*****************************************************************************
* *
* C G A _ S T R E A M *
* *
*---------------------------------------------------------------------------*
* Beschreibung: Die Klasse CGA_Stream ermoeglicht die Ausgabe verschied. *
* Datentypen als Zeichenketten auf dem CGA-Bildschirm eines*
* PCs. Fuer weitergehende Formatierung oder spezielle *
* Effekte stehen die Methoden der Klasse CGA zur *
* Verfuegung. *
* *
* Autor: Olaf Spinczyk, TU Dortmund *
* Aenderungen von Michael Schoettner, HHU, 06.04.20 *
*****************************************************************************/
#ifndef CGA_Stream_include_H_
#define CGA_Stream_include_H_
#include "devices/CGA.h"
#include "lib/OutStream.h"
#include "lib/Semaphore.h"
// Allow for easier stream-like color changing
class fgc {
public:
constexpr fgc(const CGA::color fg) : fg(fg) {}
const CGA::color fg;
};
class bgc {
public:
constexpr bgc(const CGA::color bg) : bg(bg) {}
const CGA::color bg;
};
constexpr const fgc white = fgc(CGA::WHITE);
constexpr const fgc black = fgc(CGA::BLACK);
constexpr const fgc green = fgc(CGA::GREEN);
constexpr const fgc red = fgc(CGA::RED);
constexpr const fgc lgrey = fgc(CGA::LIGHT_GREY);
class CGA_Stream : public OutStream, public CGA {
private:
// Allow for synchronization of output text, needed when running something in parallel to
// the PreemptiveThreadDemo for example
// NOTE: Should only be used by threads (like the demos) to not lock the system
Semaphore sem;
CGA::color color_fg;
CGA::color color_bg;
bool blink;
friend class Logger; // Give access to the color
public:
CGA_Stream(CGA_Stream& copy) = delete; // Verhindere Kopieren
CGA_Stream() : sem(1), color_fg(CGA::LIGHT_GREY), color_bg(CGA::BLACK), blink(false) {
pos = 0;
}
// ~CGA_Stream() override = default;
void lock() { sem.p(); }
void unlock() { sem.v(); }
// Methode zur Ausgabe des Pufferinhalts der Basisklasse StringBuffer.
void flush() override;
// Change stream color
template<typename T>
friend T& operator<<(T& os, const fgc& fg) {
CGA::color old_bg = os.color_bg;
os.flush();
os.color_bg = old_bg;
os.color_fg = fg.fg;
return os;
}
template<typename T>
friend T& operator<<(T& os, const bgc& bg) {
CGA::color old_fg = os.color_fg;
os.flush();
os.color_fg = old_fg;
os.color_bg = bg.bg;
return os;
}
};
#endif