showText()

in src/display/canvas.js [1877:2078]

• 179 lines of code
• 41 McCabe index (conditional complexity)

  showText(glyphs) {
    const current = this.current;
    const font = current.font;
    if (font.isType3Font) {
      return this.showType3Text(glyphs);
    }

    const fontSize = current.fontSize;
    if (fontSize === 0) {
      return undefined;
    }

    const ctx = this.ctx;
    const fontSizeScale = current.fontSizeScale;
    const charSpacing = current.charSpacing;
    const wordSpacing = current.wordSpacing;
    const fontDirection = current.fontDirection;
    const textHScale = current.textHScale * fontDirection;
    const glyphsLength = glyphs.length;
    const vertical = font.vertical;
    const spacingDir = vertical ? 1 : -1;
    const defaultVMetrics = font.defaultVMetrics;
    const widthAdvanceScale = fontSize * current.fontMatrix[0];

    const simpleFillText =
      current.textRenderingMode === TextRenderingMode.FILL &&
      !font.disableFontFace &&
      !current.patternFill;

    ctx.save();
    if (current.textMatrix) {
      ctx.transform(...current.textMatrix);
    }
    ctx.translate(current.x, current.y + current.textRise);

    if (fontDirection > 0) {
      ctx.scale(textHScale, -1);
    } else {
      ctx.scale(textHScale, 1);
    }

    let patternFillTransform, patternStrokeTransform;
    if (current.patternFill) {
      ctx.save();
      const pattern = current.fillColor.getPattern(
        ctx,
        this,
        getCurrentTransformInverse(ctx),
        PathType.FILL
      );
      patternFillTransform = getCurrentTransform(ctx);
      ctx.restore();
      ctx.fillStyle = pattern;
    }

    if (current.patternStroke) {
      ctx.save();
      const pattern = current.strokeColor.getPattern(
        ctx,
        this,
        getCurrentTransformInverse(ctx),
        PathType.STROKE
      );
      patternStrokeTransform = getCurrentTransform(ctx);
      ctx.restore();
      ctx.strokeStyle = pattern;
    }

    let lineWidth = current.lineWidth;
    const scale = current.textMatrixScale;
    if (scale === 0 || lineWidth === 0) {
      const fillStrokeMode =
        current.textRenderingMode & TextRenderingMode.FILL_STROKE_MASK;
      if (
        fillStrokeMode === TextRenderingMode.STROKE ||
        fillStrokeMode === TextRenderingMode.FILL_STROKE
      ) {
        lineWidth = this.getSinglePixelWidth();
      }
    } else {
      lineWidth /= scale;
    }

    if (fontSizeScale !== 1.0) {
      ctx.scale(fontSizeScale, fontSizeScale);
      lineWidth /= fontSizeScale;
    }

    ctx.lineWidth = lineWidth;

    if (font.isInvalidPDFjsFont) {
      const chars = [];
      let width = 0;
      for (const glyph of glyphs) {
        chars.push(glyph.unicode);
        width += glyph.width;
      }
      ctx.fillText(chars.join(""), 0, 0);
      current.x += width * widthAdvanceScale * textHScale;
      ctx.restore();
      this.compose();

      return undefined;
    }

    let x = 0,
      i;
    for (i = 0; i < glyphsLength; ++i) {
      const glyph = glyphs[i];
      if (typeof glyph === "number") {
        x += (spacingDir * glyph * fontSize) / 1000;
        continue;
      }

      let restoreNeeded = false;
      const spacing = (glyph.isSpace ? wordSpacing : 0) + charSpacing;
      const character = glyph.fontChar;
      const accent = glyph.accent;
      let scaledX, scaledY;
      let width = glyph.width;
      if (vertical) {
        const vmetric = glyph.vmetric || defaultVMetrics;
        const vx =
          -(glyph.vmetric ? vmetric[1] : width * 0.5) * widthAdvanceScale;
        const vy = vmetric[2] * widthAdvanceScale;

        width = vmetric ? -vmetric[0] : width;
        scaledX = vx / fontSizeScale;
        scaledY = (x + vy) / fontSizeScale;
      } else {
        scaledX = x / fontSizeScale;
        scaledY = 0;
      }

      if (font.remeasure && width > 0) {
        // Some standard fonts may not have the exact width: rescale per
        // character if measured width is greater than expected glyph width
        // and subpixel-aa is enabled, otherwise just center the glyph.
        const measuredWidth =
          ((ctx.measureText(character).width * 1000) / fontSize) *
          fontSizeScale;
        if (width < measuredWidth && this.isFontSubpixelAAEnabled) {
          const characterScaleX = width / measuredWidth;
          restoreNeeded = true;
          ctx.save();
          ctx.scale(characterScaleX, 1);
          scaledX /= characterScaleX;
        } else if (width !== measuredWidth) {
          scaledX +=
            (((width - measuredWidth) / 2000) * fontSize) / fontSizeScale;
        }
      }

      // Only attempt to draw the glyph if it is actually in the embedded font
      // file or if there isn't a font file so the fallback font is shown.
      if (this.contentVisible && (glyph.isInFont || font.missingFile)) {
        if (simpleFillText && !accent) {
          // common case
          ctx.fillText(character, scaledX, scaledY);
        } else {
          this.paintChar(
            character,
            scaledX,
            scaledY,
            patternFillTransform,
            patternStrokeTransform
          );
          if (accent) {
            const scaledAccentX =
              scaledX + (fontSize * accent.offset.x) / fontSizeScale;
            const scaledAccentY =
              scaledY - (fontSize * accent.offset.y) / fontSizeScale;
            this.paintChar(
              accent.fontChar,
              scaledAccentX,
              scaledAccentY,
              patternFillTransform,
              patternStrokeTransform
            );
          }
        }
      }

      const charWidth = vertical
        ? width * widthAdvanceScale - spacing * fontDirection
        : width * widthAdvanceScale + spacing * fontDirection;
      x += charWidth;

      if (restoreNeeded) {
        ctx.restore();
      }
    }
    if (vertical) {
      current.y -= x;
    } else {
      current.x += x * textHScale;
    }
    ctx.restore();
    this.compose();

    return undefined;
  }