annot.cc

这是一个做pdf阅读器的源代码文件,是大家学习阅读器资料的很好参考

	quadding = fieldQuadLeft;
      }
      obj2.free();
      comb = 0;
      if (ff & fieldFlagComb) {
	if (fieldLookup(field, "MaxLen", &obj2)->isInt()) {
	  comb = obj2.getInt();
	}
	obj2.free();
      }
      drawText(obj1.getString(), da, fontDict,
	       ff & fieldFlagMultiline, comb, quadding, gTrue, gFalse);
    }
    obj1.free();
  } else if (ftObj.isName("Ch")) {
    //~ value/option strings can be Unicode
    if (fieldLookup(field, "Q", &obj1)->isInt()) {
      quadding = obj1.getInt();
    } else {
      quadding = fieldQuadLeft;
    }
    obj1.free();
    // combo box
    if (ff & fieldFlagCombo) {
      if (fieldLookup(field, "V", &obj1)->isString()) {
	drawText(obj1.getString(), da, fontDict,
		 gFalse, 0, quadding, gTrue, gFalse);
	//~ Acrobat draws a popup icon on the right side
      }
      obj1.free();
    // list box
    } else {
      if (field->lookup("Opt", &obj1)->isArray()) {
	nOptions = obj1.arrayGetLength();
	// get the option text
	text = (GString **)gmallocn(nOptions, sizeof(GString *));
	for (i = 0; i < nOptions; ++i) {
	  text[i] = NULL;
	  obj1.arrayGet(i, &obj2);
	  if (obj2.isString()) {
	    text[i] = obj2.getString()->copy();
	  } else if (obj2.isArray() && obj2.arrayGetLength() == 2) {
	    if (obj2.arrayGet(1, &obj3)->isString()) {
	      text[i] = obj3.getString()->copy();
	    }
	    obj3.free();
	  }
	  obj2.free();
	  if (!text[i]) {
	    text[i] = new GString();
	  }
	}
	// get the selected option(s)
	selection = (GBool *)gmallocn(nOptions, sizeof(GBool));
	//~ need to use the I field in addition to the V field
	fieldLookup(field, "V", &obj2);
	for (i = 0; i < nOptions; ++i) {
	  selection[i] = gFalse;
	  if (obj2.isString()) {
	    if (!obj2.getString()->cmp(text[i])) {
	      selection[i] = gTrue;
	    }
	  } else if (obj2.isArray()) {
	    for (j = 0; j < obj2.arrayGetLength(); ++j) {
	      if (obj2.arrayGet(j, &obj3)->isString() &&
		  !obj3.getString()->cmp(text[i])) {
		selection[i] = gTrue;
	      }
	      obj3.free();
	    }
	  }
	}
	obj2.free();
	// get the top index
	if (field->lookup("TI", &obj2)->isInt()) {
	  topIdx = obj2.getInt();
	} else {
	  topIdx = 0;
	}
	obj2.free();
	// draw the text
	drawListBox(text, selection, nOptions, topIdx, da, fontDict, quadding);
	for (i = 0; i < nOptions; ++i) {
	  delete text[i];
	}
	gfree(text);
	gfree(selection);
      }
      obj1.free();
    }
  } else if (ftObj.isName("Sig")) {
    //~unimp
  } else {
    error(-1, "Unknown field type");
  }

  if (da) {
    delete da;
  }

  // build the appearance stream dictionary
  appearDict.initDict(xref);
  appearDict.dictAdd(copyString("Length"),
		     obj1.initInt(appearBuf->getLength()));
  appearDict.dictAdd(copyString("Subtype"), obj1.initName("Form"));
  obj1.initArray(xref);
  obj1.arrayAdd(obj2.initReal(0));
  obj1.arrayAdd(obj2.initReal(0));
  obj1.arrayAdd(obj2.initReal(xMax - xMin));
  obj1.arrayAdd(obj2.initReal(yMax - yMin));
  appearDict.dictAdd(copyString("BBox"), &obj1);

  // set the resource dictionary
  if (drObj.isDict()) {
    appearDict.dictAdd(copyString("Resources"), drObj.copy(&obj1));
  }
  drObj.free();

  // build the appearance stream
  appearStream = new MemStream(appearBuf->getCString(), 0,
			       appearBuf->getLength(), &appearDict);
  appearance.free();
  appearance.initStream(appearStream);

  if (fontDict) {
    delete fontDict;
  }
  ftObj.free();
  mkObj.free();
}

// Set the current fill or stroke color, based on <a> (which should
// have 1, 3, or 4 elements).  If <adjust> is +1, color is brightened;
// if <adjust> is -1, color is darkened; otherwise color is not
// modified.
void Annot::setColor(Array *a, GBool fill, int adjust) {
  Object obj1;
  double color[4];
  int nComps, i;

  nComps = a->getLength();
  if (nComps > 4) {
    nComps = 4;
  }
  for (i = 0; i < nComps && i < 4; ++i) {
    if (a->get(i, &obj1)->isNum()) {
      color[i] = obj1.getNum();
    } else {
      color[i] = 0;
    }
    obj1.free();
  }
  if (nComps == 4) {
    adjust = -adjust;
  }
  if (adjust > 0) {
    for (i = 0; i < nComps; ++i) {
      color[i] = 0.5 * color[i] + 0.5;
    }
  } else if (adjust < 0) {
    for (i = 0; i < nComps; ++i) {
      color[i] = 0.5 * color[i];
    }
  }
  if (nComps == 4) {
    appearBuf->appendf("{0:.2f} {1:.2f} {2:.2f} {3:.2f} {4:c}\n",
		       color[0], color[1], color[2], color[3],
		       fill ? 'k' : 'K');
  } else if (nComps == 3) {
    appearBuf->appendf("{0:.2f} {1:.2f} {2:.2f} {3:s}\n",
		       color[0], color[1], color[2],
		       fill ? "rg" : "RG");
  } else {
    appearBuf->appendf("{0:.2f} {1:c}\n",
		       color[0],
		       fill ? 'g' : 'G');
  }
}

// Draw the variable text or caption for a field.
void Annot::drawText(GString *text, GString *da, GfxFontDict *fontDict,
		     GBool multiline, int comb, int quadding,
		     GBool txField, GBool forceZapfDingbats) {
  GList *daToks;
  GString *tok;
  GfxFont *font;
  double fontSize, fontSize2, border, x, xPrev, y, w, w2, wMax;
  int tfPos, tmPos, i, j, k, c;

  //~ if there is no MK entry, this should use the existing content stream,
  //~ and only replace the marked content portion of it
  //~ (this is only relevant for Tx fields)

  // parse the default appearance string
  tfPos = tmPos = -1;
  if (da) {
    daToks = new GList();
    i = 0;
    while (i < da->getLength()) {
      while (i < da->getLength() && Lexer::isSpace(da->getChar(i))) {
	++i;
      }
      if (i < da->getLength()) {
	for (j = i + 1;
	     j < da->getLength() && !Lexer::isSpace(da->getChar(j));
	     ++j) ;
	daToks->append(new GString(da, i, j - i));
	i = j;
      }
    }
    for (i = 2; i < daToks->getLength(); ++i) {
      if (i >= 2 && !((GString *)daToks->get(i))->cmp("Tf")) {
	tfPos = i - 2;
      } else if (i >= 6 && !((GString *)daToks->get(i))->cmp("Tm")) {
	tmPos = i - 6;
      }
    }
  } else {
    daToks = NULL;
  }

  // force ZapfDingbats
  //~ this should create the font if needed (?)
  if (forceZapfDingbats) {
    if (tfPos >= 0) {
      tok = (GString *)daToks->get(tfPos);
      if (tok->cmp("/ZaDb")) {
	tok->clear();
	tok->append("/ZaDb");
      }
    }
  }

  // get the font and font size
  font = NULL;
  fontSize = 0;
  if (tfPos >= 0) {
    tok = (GString *)daToks->get(tfPos);
    if (tok->getLength() >= 1 && tok->getChar(0) == '/') {
      if (!fontDict || !(font = fontDict->lookup(tok->getCString() + 1))) {
	error(-1, "Unknown font in field's DA string");
      }
    } else {
      error(-1, "Invalid font name in 'Tf' operator in field's DA string");
    }
    tok = (GString *)daToks->get(tfPos + 1);
    fontSize = atof(tok->getCString());
  } else {
    error(-1, "Missing 'Tf' operator in field's DA string");
  }

  // get the border width
  border = borderStyle->getWidth();

  // setup
  if (txField) {
    appearBuf->append("/Tx BMC\n");
  }
  appearBuf->append("q\n");
  appearBuf->append("BT\n");

  // multi-line text
  if (multiline) {
    // note: the comb flag is ignored in multiline mode

    wMax = xMax - xMin - 2 * border - 4;

    // compute font autosize
    if (fontSize == 0) {
      for (fontSize = 20; fontSize > 1; --fontSize) {
	y = yMax - yMin;
	w2 = 0;
	i = 0;
	while (i < text->getLength()) {
	  getNextLine(text, i, font, fontSize, wMax, &j, &w, &k);
	  if (w > w2) {
	    w2 = w;
	  }
	  i = k;
	  y -= fontSize;
	}
	// approximate the descender for the last line
	if (y >= 0.33 * fontSize) {
	  break;
	}
      }
      if (tfPos >= 0) {
	tok = (GString *)daToks->get(tfPos + 1);
	tok->clear();
	tok->appendf("{0:.2f}", fontSize);
      }
    }

    // starting y coordinate
    // (note: each line of text starts with a Td operator that moves
    // down a line)
    y = yMax - yMin;

    // set the font matrix
    if (tmPos >= 0) {
      tok = (GString *)daToks->get(tmPos + 4);
      tok->clear();
      tok->append('0');
      tok = (GString *)daToks->get(tmPos + 5);
      tok->clear();
      tok->appendf("{0:.2f}", y);
    }

    // write the DA string
    if (daToks) {
      for (i = 0; i < daToks->getLength(); ++i) {
	appearBuf->append((GString *)daToks->get(i))->append(' ');
      }
    }

    // write the font matrix (if not part of the DA string)
    if (tmPos < 0) {
      appearBuf->appendf("1 0 0 1 0 {0:.2f} Tm\n", y);
    }

    // write a series of lines of text
    i = 0;
    xPrev = 0;
    while (i < text->getLength()) {

      getNextLine(text, i, font, fontSize, wMax, &j, &w, &k);

      // compute text start position
      switch (quadding) {
      case fieldQuadLeft:
      default:
	x = border + 2;
	break;
      case fieldQuadCenter:
	x = (xMax - xMin - w) / 2;
	break;
      case fieldQuadRight:
	x = xMax - xMin - border - 2 - w;
	break;
      }

      // draw the line
      appearBuf->appendf("{0:.2f} {1:.2f} Td\n", x - xPrev, -fontSize);
      appearBuf->append('(');
      for (; i < j; ++i) {
	c = text->getChar(i) & 0xff;
	if (c == '(' || c == ')' || c == '\\') {
	  appearBuf->append('\\');
	  appearBuf->append(c);
	} else if (c < 0x20 || c >= 0x80) {
	  appearBuf->appendf("\\{0:03o}", c);
	} else {
	  appearBuf->append(c);
	}
      }
      appearBuf->append(") Tj\n");

      // next line
      i = k;
      xPrev = x;
    }

  // single-line text
  } else {
    //~ replace newlines with spaces? - what does Acrobat do?

    // comb formatting
    if (comb > 0) {

      // compute comb spacing
      w = (xMax - xMin - 2 * border) / comb;

      // compute font autosize
      if (fontSize == 0) {
	fontSize = yMax - yMin - 2 * border;
	if (w < fontSize) {
	  fontSize = w;
	}
	fontSize = floor(fontSize);
	if (tfPos >= 0) {
	  tok = (GString *)daToks->get(tfPos + 1);
	  tok->clear();
	  tok->appendf("{0:.2f}", fontSize);
	}
      }

      // compute text start position
      switch (quadding) {
      case fieldQuadLeft:
      default:
	x = border + 2;
	break;
      case fieldQuadCenter:
	x = border + 2 + 0.5 * (comb - text->getLength()) * w;
	break;
      case fieldQuadRight:
	x = border + 2 + (comb - text->getLength()) * w;
	break;
      }
      y = 0.5 * (yMax - yMin) - 0.4 * fontSize;

      // set the font matrix
      if (tmPos >= 0) {
	tok = (GString *)daToks->get(tmPos + 4);
	tok->clear();
	tok->appendf("{0:.2f}", x);
	tok = (GString *)daToks->get(tmPos + 5);
	tok->clear();
	tok->appendf("{0:.2f}", y);
      }

      // write the DA string
      if (daToks) {
	for (i = 0; i < daToks->getLength(); ++i) {
	  appearBuf->append((GString *)daToks->get(i))->append(' ');
	}
      }

      // write the font matrix (if not part of the DA string)
      if (tmPos < 0) {
	appearBuf->appendf("1 0 0 1 {0:.2f} {1:.2f} Tm\n", x, y);
      }

      // write the text string
      //~ this should center (instead of left-justify) each character within
      //~     its comb cell
      for (i = 0; i < text->getLength(); ++i) {
	if (i > 0) {
	  appearBuf->appendf("{0:.2f} 0 Td\n", w);
	}
	appearBuf->append('(');
	c = text->getChar(i) & 0xff;
	if (c == '(' || c == ')' || c == '\\') {
	  appearBuf->append('\\');
	  appearBuf->append(c);
	} else if (c < 0x20 || c >= 0x80) {
	  appearBuf->appendf("{0:.2f} 0 Td\n", w);
	} else {
	  appearBuf->append(c);
	}
	appearBuf->append(") Tj\n");
      }

    // regular (non-comb) formatting
    } else {

      // compute string width
      if (font && !font->isCIDFont()) {
	w = 0;
	for (i = 0; i < text->getLength(); ++i) {
	  w += ((Gfx8BitFont *)font)->getWidth(text->getChar(i));
	}
      } else {
	// otherwise, make a crude estimate
	w = text->getLength() * 0.5;
      }

      // compute font autosize
      if (fontSize == 0) {
	fontSize = yMax - yMin - 2 * border;
	fontSize2 = (xMax - xMin - 4 - 2 * border) / w;
	if (fontSize2 < fontSize) {
	  fontSize = fontSize2;
	}
	fontSize = floor(fontSize);
	if (tfPos >= 0) {
	  tok = (GString *)daToks->get(tfPos + 1);
	  tok->clear();
	  tok->appendf("{0:.2f}", fontSize);
	}
      }

      // compute text start position
      w *= fontSize;
      switch (quadding) {
      case fieldQuadLeft:
      default:
	x = border + 2;
	break;
      case fieldQuadCenter:
	x = (xMax - xMin - w) / 2;
	break;
      case fieldQuadRight:
	x = xMax - xMin - border - 2 - w;
	break;
      }
      y = 0.5 * (yMax - yMin) - 0.4 * fontSize;

      // set the font matrix
      if (tmPos >= 0) {
	tok = (GString *)daToks->get(tmPos + 4);
	tok->clear();
	tok->appendf("{0:.2f}", x);
	tok = (GString *)daToks->get(tmPos + 5);
	tok->clear();
	tok->appendf("{0:.2f}", y);
      }

      // write the DA string
      if (daToks) {
	for (i = 0; i < daToks->getLength(); ++i) {
	  appearBuf->append((GString *)daToks->get(i))->append(' ');
	}
      }

      // write the font matrix (if not part of the DA string)
      if (tmPos < 0) {
	appearBuf->appendf("1 0 0 1 {0:.2f} {1:.2f} Tm\n", x, y);
      }

      // write the text string
      appearBuf->append('(');
      for (i = 0; i < text->getLength(); ++i) {
	c = text->getChar(i) & 0xff;
	if (c == '(' || c == ')' || c == '\\') {
	  appearBuf->append('\\');
	  appearBuf->append(c);
	} else if (c < 0x20 || c >= 0x80) {
	  appearBuf->appendf("\\{0:03o}", c);