1
Files
lecture-operating-system-de…/c_os/devices/BufferedCGA.cc
2022-05-09 16:19:59 +02:00

76 lines
2.2 KiB
C++
Executable File

#include "BufferedCGA.h"
// Can't initialize in constructor as memory management already needs working CGA for output
// NOTE: This has to be called when memorymanagement is active
void BufferedCGA::init() {
this->scrollback_buffer = new ScrollbackBuffer(COLUMNS, ROWS, 5);
this->initialized = true;
this->print("\nInitialized scrollback buffer with 5 pages\n\n", 45);
}
void BufferedCGA::displaypage() {
if (this->current_page == 0) {
// Use pagebuffer
this->scrollback_buffer->copy_page_from_pagebuffer((cga_page_t*)CGA_START);
} else {
// Use scrollback
this->scrollback_buffer->copy_page_from_buffer((cga_line_t*)CGA_START, this->current_page - 1);
}
}
void BufferedCGA::print(char* string, int n, unsigned char attrib) {
if (this->current_page != 0) {
// Display newest content from buffer when new prints happen
this->current_page = 0;
this->displaypage();
}
CGA::print(string, n, attrib);
}
void BufferedCGA::scrollup() {
if (this->initialized) {
this->scrollback_buffer->line_to_buffer((cga_line_t*)CGA_START);
} else {
this->print("ScrollbackBuffer not initialized\n\n", 34);
}
CGA::scrollup();
}
void BufferedCGA::clear() {
CGA::clear();
this->current_page = 0;
if (this->initialized) {
this->scrollback_buffer->clear();
} else {
this->print("ScrollbackBuffer not initialized\n\n", 34);
}
}
unsigned int BufferedCGA::scroll_page_backward() {
// If this is the first scrollback we have to save the current screen content
if (this->current_page == 0) {
this->scrollback_buffer->copy_page_to_pagebuffer((cga_page_t*)CGA_START);
}
// current_page can be equal to scrollback_buffer->pages
// as we have a separate pagebuffer for the current screen content
if (this->current_page < this->scrollback_buffer->pages) {
this->current_page = this->current_page + 1;
}
this->displaypage();
return this->current_page;
}
unsigned int BufferedCGA::scroll_page_forward() {
if (this->current_page > 0) {
this->current_page = this->current_page - 1;
}
this->displaypage();
return this->current_page;
}