void CONSOLE::printn( const char ch, size_t count )
{
for( size_t i = 0; i < count; ++i )
{
write_char_to_console( ch, this );
}
if( this->visible )
{
video_display( this->buffer + this->top_row * this->buffer_width );
video_move_cursor( this->cursor_column, this->cursor_row - this->top_row );
}
}
void CONSOLE::printf( const char* format, ... )
{
va_list ap;
va_start( ap, format );
format_string_varg( CONSOLE::write_char_to_console, this, format, ap );
va_end( ap );
if( this->visible )
{
video_display( this->buffer + this->top_row * this->buffer_width );
video_move_cursor( this->cursor_column, this->cursor_row - this->top_row );
}
}
/**************************************************************************
* Write blanks to the entire buffer of the selected console.
* console - The address of the selected console.
**************************************************************************/
void video_clrscr( console_t *console ) {
u32int flags;
disable_and_save_interrupts(flags);
memset16((u16int *)(console->vid_buffer ), BLANK, crt_width*crt_height*2);
console->cursor_x = 0;
console->cursor_y = 0;
// Update the cursor position only for current console.
if( console==get_console_addr(0) )
video_move_cursor( console->cursor_x, console->cursor_y);
restore_interrupts(flags);
}
/**************************************************************************
* Put a character to the next space in the specified console.
// console - The address of the selected console.
// c - The ASCII code of the character to print.
* **************************************************************************/
void video_put_char( u08int c, console_t *console) {
u32int flags;
disable_and_save_interrupts(flags);
switch (c) {
case '\n': //New line
(console->cursor_y) += 1; //Move down a line
(console->cursor_x) = 0; //And back to the start of the line
break;
case '\r': // Handle carriage return
(console->cursor_x) = 0; //And back to the start of the line
break;
case '\b': //handle a backspaced request.
if(console->cursor_x == 0){ // If we are at the beginning of a line
if(console->cursor_y == 0) { //first check whether we are at the top left of screen
return;
}
//move the cursor to the end of the last line
(console->cursor_y) -= 1;
console->cursor_x = crt_width;
} else {
//If we are in the middle of a line just move the cursor back
(console->cursor_x) += 1;
// and "erase" what is there by over writing it with a space.
video_place_char(console->cursor_x, console->cursor_y, ' ', console);
}
break;
case '\t':
// Handle a tab by moving the cursor 8 spaces and then truncating it back to a division of 8
// a simple example is to snap 13 to 4 spaces we take 13 (1101) and & it with (4-1)->'s complement -> (~3) 1100
// so 1101 & 1100 = 1100 (12)
console->cursor_x = (console->cursor_x + 8) & ~(8-1);
break;
case '\a': // CTRL+G => system beep! //
//Implement a system beep
return;
break;
default: {
video_place_char(console->cursor_x, console->cursor_y, c, console);
(console->cursor_x) += 1;
break;
}
}
// Check if we need to insert a new line because we have reached the end
// of the screen.
if (console->cursor_x >= crt_width) {
(console->cursor_x) = 0;
(console->cursor_y) += 1;
}
// Check if cursor is at the bottom of the screen.
// Scroll the screen if needed.
video_scroll_console(console);
// Update the cursor position only for current console.
if( console == get_console_addr(0) ) {
video_move_cursor(console->cursor_x, console->cursor_y);
}
restore_interrupts(flags);
}
