Factor logic into registry, make matches cell-based and document

src/renderer/BaseRenderLayer.ts

@@ -224,46 +224,46 @@ export abstract class BaseRenderLayer implements IRenderLayer {
   }
 
   /**
-   * Draws a character at a cell. If possible this will draw using the character
-   * atlas to reduce draw time.
+   * Draws one or more characters at a cell. If possible this will draw using
+   * the character atlas to reduce draw time.
    * @param terminal The terminal.
-   * @param char The character.
+   * @param chars The character or characters.
    * @param code The character code.
-   * @param width The width of the character.
+   * @param width The width of the characters.
    * @param x The column to draw at.
    * @param y The row to draw at.
    * @param fg The foreground color, in the format stored within the attributes.
    * @param bg The background color, in the format stored within the attributes.
    * This is used to validate whether a cached image can be used.
    * @param bold Whether the text is bold.
    */
-  protected drawChar(terminal: ITerminal, char: string, code: number, width: number, x: number, y: number, fg: number, bg: number, bold: boolean, dim: boolean, italic: boolean): void {
+  protected drawChars(terminal: ITerminal, chars: string, code: number, width: number, x: number, y: number, fg: number, bg: number, bold: boolean, dim: boolean, italic: boolean): void {
     const drawInBrightColor = terminal.options.drawBoldTextInBrightColors && bold && fg < 8;
     fg += drawInBrightColor ? 8 : 0;
     const atlasDidDraw = this._charAtlas && this._charAtlas.draw(
       this._ctx,
-      {char, code, bg, fg, bold: bold && terminal.options.enableBold, dim, italic},
+      {chars, code, bg, fg, bold: bold && terminal.options.enableBold, dim, italic},
       x * this._scaledCellWidth + this._scaledCharLeft,
       y * this._scaledCellHeight + this._scaledCharTop
     );
 
     if (!atlasDidDraw) {
-      this._drawUncachedChar(terminal, char, width, fg, x, y, bold && terminal.options.enableBold, dim, italic);
+      this._drawUncachedChars(terminal, chars, width, fg, x, y, bold && terminal.options.enableBold, dim, italic);
     }
   }
 
   /**
-   * Draws a character at a cell. The character will be clipped to
-   * ensure that it fits with the cell, including the cell to the right if it's
-   * a wide character.
+   * Draws one or more characters at one or more cells. The character(s) will be
+   * clipped to ensure that they fit with the cell(s), including the cell to the
+   * right if the last character is a wide character.
    * @param terminal The terminal.
-   * @param char The character.
+   * @param chars The character.
    * @param width The width of the character.
    * @param fg The foreground color, in the format stored within the attributes.
    * @param x The column to draw at.
    * @param y The row to draw at.
    */
-  private _drawUncachedChar(terminal: ITerminal, char: string, width: number, fg: number, x: number, y: number, bold: boolean, dim: boolean, italic: boolean): void {
+  private _drawUncachedChars(terminal: ITerminal, chars: string, width: number, fg: number, x: number, y: number, bold: boolean, dim: boolean, italic: boolean): void {
     this._ctx.save();
     this._ctx.font = this._getFont(terminal, bold, italic);
     this._ctx.textBaseline = 'top';
@@ -285,7 +285,7 @@ export abstract class BaseRenderLayer implements IRenderLayer {
     }
     // Draw the character
     this._ctx.fillText(
-        char,
+        chars,
         x * this._scaledCellWidth + this._scaledCharLeft,
         y * this._scaledCellHeight + this._scaledCharTop);
     this._ctx.restore();

src/renderer/CharacterJoinerRegistry.test.ts

@@ -0,0 +1,278 @@
+import { assert } from 'chai';
+
+import { LineData, CharData } from '../Types';
+import { MockTerminal, MockBuffer } from '../utils/TestUtils.test';
+import { CircularList } from '../common/CircularList';
+
+import { ICharacterJoinerRegistry } from './Types';
+import { CharacterJoinerRegistry } from './CharacterJoinerRegistry';
+
+describe('CharacterJoinerRegistry', () => {
+  let registry: ICharacterJoinerRegistry;
+
+  beforeEach(() => {
+    const terminal = new MockTerminal();
+    terminal.cols = 16;
+    terminal.buffer = new MockBuffer();
+    const lines = new CircularList<LineData>(7);
+    lines.set(0, lineData('a -> b -> c -> d'));
+    lines.set(1, lineData('a -> b => c -> d'));
+    lines.set(2, [...lineData('a -> b -', 0xFFFFFFFF), ...lineData('> c -> d', 0)]);
+    lines.set(3, lineData('no joined ranges'));
+    lines.set(4, []);
+    lines.set(5, [...lineData('a', 0x11111111), ...lineData(' -> b -> c -> '), ...lineData('d', 0x22222222)]);
+    lines.set(6, [
+      ...lineData('wi'),
+      [0, '￥', 2, '￥'.charCodeAt(0)],
+      [0, '', 0, null],
+      ...lineData('deemo'),
+      [0, '\xf0\x9f\x98\x81', 1, 128513],
+      [0, ' ', 1, ' '.charCodeAt(0)],
+      ...lineData('jiabc')
+    ]);
+    (<MockBuffer>terminal.buffer).setLines(lines);
+    terminal.buffer.ydisp = 0;
+    registry = new CharacterJoinerRegistry(terminal);
+  });
+
+  it('has no joiners upon creation', () => {
+    assert.deepEqual(registry.getJoinedCharacters(0), []);
+  });
+
+  it('returns ranges matched by the registered joiners', () => {
+    registry.registerCharacterJoiner(substringJoiner('->'));
+    assert.deepEqual(
+      registry.getJoinedCharacters(0),
+      [[2, 4], [7, 9], [12, 14]]
+    );
+  });
+
+  it('processes the input using all provided joiners', () => {
+    registry.registerCharacterJoiner(substringJoiner('->'));
+    assert.deepEqual(
+      registry.getJoinedCharacters(1),
+      [[2, 4], [12, 14]]
+    );
+
+    registry.registerCharacterJoiner(substringJoiner('=>'));
+    assert.deepEqual(
+      registry.getJoinedCharacters(1),
+      [[2, 4], [7, 9], [12, 14]]
+    );
+  });
+
+  it('removes deregistered joiners from future calls', () => {
+    const joiner1 = registry.registerCharacterJoiner(substringJoiner('->'));
+    const joiner2 = registry.registerCharacterJoiner(substringJoiner('=>'));
+    assert.deepEqual(
+      registry.getJoinedCharacters(1),
+      [[2, 4], [7, 9], [12, 14]]
+    );
+
+    registry.deregisterCharacterJoiner(joiner1);
+    assert.deepEqual(
+      registry.getJoinedCharacters(1),
+      [[7, 9]]
+    );
+
+    registry.deregisterCharacterJoiner(joiner2);
+    assert.deepEqual(
+      registry.getJoinedCharacters(1),
+      []
+    );
+  });
+
+  it('doesn\'t process joins on differently-styled characters', () => {
+    registry.registerCharacterJoiner(substringJoiner('->'));
+    assert.deepEqual(
+      registry.getJoinedCharacters(2),
+      [[2, 4], [12, 14]]
+    );
+  });
+
+  it('returns an empty list of ranges if there is nothing to be joined', () => {
+    registry.registerCharacterJoiner(substringJoiner('->'));
+    assert.deepEqual(
+      registry.getJoinedCharacters(3),
+      []
+    );
+  });
+
+  it('returns an empty list of ranges if the line is empty', () => {
+    registry.registerCharacterJoiner(substringJoiner('->'));
+    assert.deepEqual(
+      registry.getJoinedCharacters(4),
+      []
+    );
+  });
+
+  it('returns false when trying to deregister a joiner that does not exist', () => {
+    registry.registerCharacterJoiner(substringJoiner('->'));
+    assert.deepEqual(registry.deregisterCharacterJoiner(123), false);
+    assert.deepEqual(
+      registry.getJoinedCharacters(0),
+      [[2, 4], [7, 9], [12, 14]]
+    );
+  });
+
+  it('doesn\'t process same-styled ranges that only have one character', () => {
+    registry.registerCharacterJoiner(substringJoiner('a'));
+    registry.registerCharacterJoiner(substringJoiner('b'));
+    registry.registerCharacterJoiner(substringJoiner('d'));
+    assert.deepEqual(
+      registry.getJoinedCharacters(5),
+      [[5, 6]]
+    );
+  });
+
+  it('handles ranges that extend all the way to the end of the line', () => {
+    registry.registerCharacterJoiner(substringJoiner('-> d'));
+    assert.deepEqual(
+      registry.getJoinedCharacters(2),
+      [[12, 16]]
+    );
+  });
+
+  it('handles adjacent ranges', () => {
+    registry.registerCharacterJoiner(substringJoiner('->'));
+    registry.registerCharacterJoiner(substringJoiner('> c '));
+    assert.deepEqual(
+      registry.getJoinedCharacters(2),
+      [[2, 4], [8, 12], [12, 14]]
+    );
+  });
+
+  it('handles fullwidth characters in the middle of ranges', () => {
+    registry.registerCharacterJoiner(substringJoiner('wi￥de'));
+    assert.deepEqual(
+      registry.getJoinedCharacters(6),
+      [[0, 6]]
+    );
+  });
+
+  it('handles fullwidth characters at the end of ranges', () => {
+    registry.registerCharacterJoiner(substringJoiner('wi￥'));
+    assert.deepEqual(
+      registry.getJoinedCharacters(6),
+      [[0, 4]]
+    );
+  });
+
+  it('handles emojis in the middle of ranges', () => {
+    registry.registerCharacterJoiner(substringJoiner('emo\xf0\x9f\x98\x81 ji'));
+    assert.deepEqual(
+      registry.getJoinedCharacters(6),
+      [[6, 13]]
+    );
+  });
+
+  it('handles emojis at the end of ranges', () => {
+    registry.registerCharacterJoiner(substringJoiner('emo\xf0\x9f\x98\x81 '));
+    assert.deepEqual(
+      registry.getJoinedCharacters(6),
+      [[6, 11]]
+    );
+  });
+
+  it('handles ranges after wide and emoji characters', () => {
+    registry.registerCharacterJoiner(substringJoiner('abc'));
+    assert.deepEqual(
+      registry.getJoinedCharacters(6),
+      [[13, 16]]
+    );
+  });
+
+  describe('range merging', () => {
+    it('inserts a new range before the existing ones', () => {
+      registry.registerCharacterJoiner(() => [[1, 2], [2, 3]]);
+      registry.registerCharacterJoiner(() => [[0, 1]]);
+      assert.deepEqual(
+        registry.getJoinedCharacters(0),
+        [[0, 1], [1, 2], [2, 3]]
+      );
+    });
+
+    it('inserts in between two ranges', () => {
+      registry.registerCharacterJoiner(() => [[0, 2], [4, 6]]);
+      registry.registerCharacterJoiner(() => [[2, 4]]);
+      assert.deepEqual(
+        registry.getJoinedCharacters(0),
+        [[0, 2], [2, 4], [4, 6]]
+      );
+    });
+
+    it('inserts after the last range', () => {
+      registry.registerCharacterJoiner(() => [[0, 2], [4, 6]]);
+      registry.registerCharacterJoiner(() => [[6, 8]]);
+      assert.deepEqual(
+        registry.getJoinedCharacters(0),
+        [[0, 2], [4, 6], [6, 8]]
+      );
+    });
+
+    it('extends the beginning of a range', () => {
+      registry.registerCharacterJoiner(() => [[0, 2], [4, 6]]);
+      registry.registerCharacterJoiner(() => [[3, 5]]);
+      assert.deepEqual(
+        registry.getJoinedCharacters(0),
+        [[0, 2], [3, 6]]
+      );
+    });
+
+    it('extends the end of a range', () => {
+      registry.registerCharacterJoiner(() => [[0, 2], [4, 6]]);
+      registry.registerCharacterJoiner(() => [[1, 4]]);
+      assert.deepEqual(
+        registry.getJoinedCharacters(0),
+        [[0, 4], [4, 6]]
+      );
+    });
+
+    it('extends the last range', () => {
+      registry.registerCharacterJoiner(() => [[0, 2], [4, 6]]);
+      registry.registerCharacterJoiner(() => [[5, 7]]);
+      assert.deepEqual(
+        registry.getJoinedCharacters(0),
+        [[0, 2], [4, 7]]
+      );
+    });
+
+    it('connects two ranges', () => {
+      registry.registerCharacterJoiner(() => [[0, 2], [4, 6]]);
+      registry.registerCharacterJoiner(() => [[1, 5]]);
+      assert.deepEqual(
+        registry.getJoinedCharacters(0),
+        [[0, 6]]
+      );
+    });
+
+    it('connects more than two ranges', () => {
+      registry.registerCharacterJoiner(() => [[0, 2], [4, 6], [8, 10], [12, 14]]);
+      registry.registerCharacterJoiner(() => [[1, 10]]);
+      assert.deepEqual(
+        registry.getJoinedCharacters(0),
+        [[0, 10], [12, 14]]
+      );
+    });
+  });
+});
+
+function lineData(line: string, attr: number = 0): LineData {
+  return line.split('').map<CharData>(char => [attr, char, 1, char.charCodeAt(0)]);
+}
+
+function substringJoiner(substring: string): (sequence: string) => [number, number][] {
+  return (sequence: string): [number, number][] => {
+    const ranges: [number, number][] = [];
+    let searchIndex = 0;
+    let matchIndex = -1;
+
+    while ((matchIndex = sequence.indexOf(substring, searchIndex)) !== -1) {
+      const matchEndIndex = matchIndex + substring.length;
+      searchIndex = matchEndIndex;
+      ranges.push([matchIndex, matchEndIndex]);
+    }
+
+    return ranges;
+  };
+}