Write a string to the buffer and (if active) video memory Interprets a subset of the ANSI escape codes List of Xterm control sequences
(&mut self, s: &[u8])
| 140 | /// List of Xterm control sequences |
| 141 | /// <https://www.xfree86.org/current/ctlseqs.html> |
| 142 | pub fn write_string(&mut self, s: &[u8]) { |
| 143 | { |
| 144 | // Contains a lock on the buffer, and a pointer to the data |
| 145 | let lock_buffer = if self.active { |
| 146 | Some(self.screen.get_frame_buffer()) |
| 147 | } else { None }; |
| 148 | |
| 149 | let mut bytes = s.iter(); // Iterator over bytes |
| 150 | loop { |
| 151 | match bytes.next() { |
| 152 | Some(byte) => { |
| 153 | match byte { |
| 154 | 0x20..=0x7e => { |
| 155 | // printable ASCII byte |
| 156 | let screen_character = ScreenCharacter::new(*byte, self.color); |
| 157 | let offset = S::WIDTH * self.row + self.column; |
| 158 | // Modify this writer's buffer (in host memory) |
| 159 | self.buffer[offset] = screen_character; |
| 160 | if let Some((_, frame_buffer)) = lock_buffer { |
| 161 | // Write to VGA memory |
| 162 | unsafe { |
| 163 | frame_buffer.add(offset).write_volatile(screen_character); |
| 164 | } |
| 165 | } |
| 166 | self.column += 1; |
| 167 | if self.column == S::WIDTH { |
| 168 | self.column = 0; |
| 169 | self.row += 1; |
| 170 | if self.row == S::HEIGHT { |
| 171 | // Shift upwards |
| 172 | let mut_buffer = self.buffer.as_mut_ptr(); |
| 173 | self.scroll_up(mut_buffer); |
| 174 | if let Some((_, frame_buffer)) = lock_buffer { |
| 175 | self.scroll_up(frame_buffer); |
| 176 | } |
| 177 | self.row = S::HEIGHT - 1; |
| 178 | } |
| 179 | } |
| 180 | } |
| 181 | ////////////////////////////////////////// |
| 182 | // C0 control codes |
| 183 | 0x8 => { // Backspace |
| 184 | if self.column != 0 { |
| 185 | self.column -= 1; |
| 186 | } |
| 187 | } |
| 188 | b'\t' => { // Tab |
| 189 | // Move to next multiple of 8 |
| 190 | self.column += 8 - (self.column % 8); |
| 191 | if self.column >= S::WIDTH { |
| 192 | // Next line |
| 193 | self.row += 1; |
| 194 | if self.row == S::HEIGHT { |
| 195 | // Shift upwards |
| 196 | let mut_buffer = self.buffer.as_mut_ptr(); |
| 197 | self.scroll_up(mut_buffer); |
| 198 | if let Some((_, frame_buffer)) = lock_buffer { |
| 199 | self.scroll_up(frame_buffer); |
no test coverage detected