Support truecolor

src/Buffer.ts

@@ -2,8 +2,13 @@
  * @license MIT
  */
 
-import { ITerminal } from './Interfaces';
+import { ITerminal, IBuffer } from './Interfaces';
 import { CircularList } from './utils/CircularList';
+import { LineData } from './Types';
+import { TextStyle } from './TextStyle';
+
+export const CHAR_DATA_CHAR_INDEX = 0;
+export const CHAR_DATA_WIDTH_INDEX = 1;
 
 /**
  * This class represents a terminal buffer (an internal state of the terminal), where the
@@ -12,8 +17,13 @@ import { CircularList } from './utils/CircularList';
  *   - cursor position
  *   - scroll position
  */
-export class Buffer {
-  public lines: CircularList<[number, string, number][]>;
+export class Buffer implements IBuffer {
+  public lines: CircularList<LineData>;
+  public textStyles: TextStyle[];
+
+  private _currentTextStyle: TextStyle;
+  // linesIndexOffset usage should be encapsulated
+  private _linesIndexOffset: number;
 
   public savedY: number;
   public savedX: number;
@@ -36,7 +46,90 @@ export class Buffer {
     public scrollTop: number = 0,
     public tabs: any = {},
   ) {
-    this.lines = new CircularList<[number, string, number][]>(this.terminal.scrollback);
+    this.lines = new CircularList<LineData>(this.terminal.scrollback);
+    this.textStyles = [];
+    this._linesIndexOffset = 0;
     this.scrollBottom = this.terminal.rows - 1;
+
+    // TODO: Listen to line's trim and adjust char attributes
+    this.lines.on('trim', (amount: number) => this._onTrim(amount));
+  }
+
+  /**
+   * Starts a new character attributes at the cursor.
+   */
+  public startTextStyle(flags: number, fgColor: number, bgColor: number): void {
+    // TODO: Move current* variables into the buffer?
+    this._currentTextStyle = new TextStyle(this.x, this.ybase + this.y + this._linesIndexOffset, null, null, [flags, fgColor, bgColor]);
+    this.textStyles.push(this._currentTextStyle);
+  }
+
+  /**
+   * Finishes the current character attributes at the cursor. Do nothing if
+   * there is not a current character attributes.
+   */
+  public finishTextStyle(): void {
+    if (!this._currentTextStyle) {
+      return;
+    }
+    this._currentTextStyle.x2 = this.x;
+    this._currentTextStyle.y2 = this._linesIndexOffset + this.ybase + this.y;
+    this._currentTextStyle = null;
+  }
+
+  private _onTrim(amount: number): void {
+    // Trim the top of charAttributes to ensure it never points at trimmed rows
+    this._linesIndexOffset += amount;
+    while (this.textStyles.length > 0 && this.textStyles[0].y1 < this._linesIndexOffset) {
+      this.textStyles.shift();
+    }
+  }
+
+  /**
+   * Translates a buffer line to a string, with optional start and end columns.
+   * Wide characters will count as two columns in the resulting string. This
+   * function is useful for getting the actual text underneath the raw selection
+   * position.
+   * @param line The line being translated.
+   * @param trimRight Whether to trim whitespace to the right.
+   * @param startCol The column to start at.
+   * @param endCol The column to end at.
+   */
+  public translateBufferLineToString(lineIndex: number, trimRight: boolean, startCol: number = 0, endCol: number = null): string {
+    // Get full line
+    let lineString = '';
+    let widthAdjustedStartCol = startCol;
+    let widthAdjustedEndCol = endCol;
+    const line = this.lines.get(lineIndex);
+    for (let i = 0; i < line.length; i++) {
+      const char = line[i];
+      lineString += char[CHAR_DATA_CHAR_INDEX];
+      // Adjust start and end cols for wide characters if they affect their
+      // column indexes
+      if (char[CHAR_DATA_WIDTH_INDEX] === 0) {
+        if (startCol >= i) {
+          widthAdjustedStartCol--;
+        }
+        if (endCol >= i) {
+          widthAdjustedEndCol--;
+        }
+      }
+    }
+
+    // Calculate the final end col by trimming whitespace on the right of the
+    // line if needed.
+    let finalEndCol = widthAdjustedEndCol || line.length;
+    if (trimRight) {
+      const rightWhitespaceIndex = lineString.search(/\s+$/);
+      if (rightWhitespaceIndex !== -1) {
+        finalEndCol = Math.min(finalEndCol, rightWhitespaceIndex);
+      }
+      // Return the empty string if only trimmed whitespace is selected
+      if (finalEndCol <= widthAdjustedStartCol) {
+        return '';
+      }
+    }
+
+    return lineString.substring(widthAdjustedStartCol, finalEndCol);
   }
 }