drawparams.cpp

LINUX 下以 QT/KDE 写的 SVN 客户端

  int h = _fontHeight;
  bool rotate = dp->rotated();
  int width   = (rotate ? r.height() : r.width()) -4;
  int height  = (rotate ? r.width() : r.height());
  int lines   = height / h;

  // stop if we have no space available
  if (lines<1) return false;

  // calculate free space in first line (<unused>)
  int pos = dp->position(f);
  if (pos == DrawParams::Default) {
    switch(f%4) {
    case 0: pos = DrawParams::TopLeft; break;
    case 1: pos = DrawParams::TopRight; break;
    case 2: pos = DrawParams::BottomRight; break;
    case 3: pos = DrawParams::BottomLeft; break;
    }
  }

  int unused = 0;
  bool isBottom = false;
  bool isCenter = false;
  bool isRight = false;
  int* used = 0;
  switch(pos) {
  case DrawParams::TopLeft:
    used = &_usedTopLeft;
    if (_usedTopLeft == 0) {
      if (_usedTopCenter)
        unused = (width - _usedTopCenter)/2;
      else
        unused = width - _usedTopRight;
    }
    break;

  case DrawParams::TopCenter:
    isCenter = true;
    used = &_usedTopCenter;
    if (_usedTopCenter == 0) {
      if (_usedTopLeft > _usedTopRight)
        unused = width - 2 * _usedTopLeft;
      else
        unused = width - 2 * _usedTopRight;
    }
    break;

  case DrawParams::TopRight:
    isRight = true;
    used = &_usedTopRight;
    if (_usedTopRight == 0) {
      if (_usedTopCenter)
        unused = (width - _usedTopCenter)/2;
      else
        unused = width - _usedTopLeft;
    }
    break;

  case DrawParams::BottomLeft:
    isBottom = true;
    used = &_usedBottomLeft;
    if (_usedBottomLeft == 0) {
      if (_usedBottomCenter)
        unused = (width - _usedBottomCenter)/2;
      else
        unused = width - _usedBottomRight;
    }
    break;

  case DrawParams::BottomCenter:
    isCenter = true;
    isBottom = true;
    used = &_usedBottomCenter;
    if (_usedBottomCenter == 0) {
      if (_usedBottomLeft > _usedBottomRight)
        unused = width - 2 * _usedBottomLeft;
      else
        unused = width - 2 * _usedBottomRight;
    }
    break;

  case DrawParams::BottomRight:
    isRight = true;
    isBottom = true;
    used = &_usedBottomRight;
    if (_usedBottomRight == 0) {
      if (_usedBottomCenter)
        unused = (width - _usedBottomCenter)/2;
      else
        unused = width - _usedBottomLeft;
    }
    break;
  }

  if (isBottom) {
    if ((_usedTopLeft >0) ||
        (_usedTopCenter >0) ||
        (_usedTopRight >0))
      lines--;
  }
  else if (!isBottom) {
    if ((_usedBottomLeft >0) ||
        (_usedBottomCenter >0) ||
        (_usedBottomRight >0))
      lines--;
  }
  if (lines<1) return false;


  int y = isBottom ? height - h : 0;

  if (unused < 0) unused = 0;
  if (unused == 0) {
    // no space available in last line at this position
    y = isBottom ? (y-h) : (y+h);
    lines--;

    if (lines<1) return false;

    // new line: reset used space
    if (isBottom)
      _usedBottomLeft = _usedBottomCenter = _usedBottomRight = 0;
    else
      _usedTopLeft = _usedTopCenter = _usedTopRight = 0;

    unused = width;
  }

  // stop as soon as possible when there's no space for "..."
  static int dotW = 0;
  if (!dotW) dotW = _fm->width("...");
  if (width < dotW) return false;

  // get text and pixmap now, only if we need to, because it is possible
  // that they are calculated on demand (and this can take some time)
  QString name = dp->text(f);
  if (name.isEmpty()) return 0;
  QPixmap pix = dp->pixmap(f);

  // check if pixmap can be drawn
  int pixW = pix.width();
  int pixH = pix.height();
  int pixY = 0;
  bool pixDrawn = true;
  if (pixW>0) {
    pixW += 2; // X distance from pix
    if ((width < pixW + dotW) || (height < pixH)) {
      // don't draw
      pixW = 0;
    }
    else
      pixDrawn = false;
  }

  // width of text and pixmap to be drawn
  int w = pixW + _fm->width(name);

  if (0) kdDebug(90100) << "  For '" << name << "': Unused " << unused
		   << ", StrW " << w << ", Width " << width << endl;

  // if we have limited space at 1st line:
  // use it only if whole name does fit in last line...
  if ((unused < width) && (w > unused)) {
    y = isBottom ? (y-h) : (y+h);
    lines--;

    if (lines<1) return false;

    // new line: reset used space
    if (isBottom)
      _usedBottomLeft = _usedBottomCenter = _usedBottomRight = 0;
    else
      _usedTopLeft = _usedTopCenter = _usedTopRight = 0;
  }

  p->save();
  p->setPen( (qGray(dp->backColor().rgb())>100) ? Qt::black : Qt::white);
  p->setFont(dp->font());
  if (rotate) {
    //p->translate(r.x()+2, r.y()+r.height());
    p->translate(r.x(), r.y()+r.height()-2);
    p->rotate(270);
  }
  else
    p->translate(r.x()+2, r.y());


  // adjust available lines according to maxLines
  int max = dp->maxLines(f);
  if ((max > 0) && (lines>max)) lines = max;

  /* loop over name parts to break up string depending on available width.
   * every char category change is supposed a possible break,
   * with the exception Uppercase=>Lowercase.
   * It's good enough for numbers, Symbols...
   *
   * If the text is to be written at the bottom, we start with the
   * end of the string (so everything is reverted)
   */
  QString remaining;
  int origLines = lines;
  while (lines>0) {

    if (w>width && lines>1) {
      int lastBreakPos = name.length(), lastWidth = w;
      int len = name.length();
      QChar::Category caOld, ca;

      if (!isBottom) {
        // start with comparing categories of last 2 chars
        caOld = name[len-1].category();
        while (len>2) {
          len--;
          ca = name[len-1].category();
          if (ca != caOld) {
            // "Aa" has no break between...
            if (ca == QChar::Letter_Uppercase &&
                caOld == QChar::Letter_Lowercase) {
              caOld = ca;
              continue;
            }
            caOld = ca;
            lastBreakPos = len;
            w = pixW + _fm->width(name, len);
            lastWidth = w;
            if (w <= width) break;
          }
        }
        w = lastWidth;
        remaining = name.mid(lastBreakPos);
        // remove space on break point
        if (name[lastBreakPos-1].category() == QChar::Separator_Space)
          name = name.left(lastBreakPos-1);
        else
          name = name.left(lastBreakPos);
      }
      else { // bottom
        int l = len;
        caOld = name[l-len].category();
        while (len>2) {
          len--;
          ca = name[l-len].category();

          if (ca != caOld) {
            // "Aa" has no break between...
            if (caOld == QChar::Letter_Uppercase &&
                ca == QChar::Letter_Lowercase) {
              caOld = ca;
              continue;
            }
            caOld = ca;
            lastBreakPos = len;
            w = pixW + _fm->width(name.right(len));
            lastWidth = w;
            if (w <= width) break;
          }
        }
        w = lastWidth;
        remaining = name.left(l-lastBreakPos);
        // remove space on break point
        if (name[l-lastBreakPos].category() == QChar::Separator_Space)
          name = name.right(lastBreakPos-1);
        else
          name = name.right(lastBreakPos);
      }
    }
    else
      remaining = QString::null;

    /* truncate and add ... if needed */
    if (w>width) {
      int len = name.length();
      w += dotW;
      while (len>2 && (w > width)) {
        len--;
        w = pixW + _fm->width(name, len) + dotW;
      }
      // stop drawing: we cannot draw 2 chars + "..."
      if (w>width) break;

      name = name.left(len) + "...";
    }

    int x = 0;
    if (isCenter)
      x = (width - w)/2;
    else if (isRight)
      x = width - w;

    if (!pixDrawn) {
        pixY = y+(h-pixH)/2; // default: center vertically
        if (pixH > h) pixY = isBottom ? y-(pixH-h) : y;

	p->drawPixmap( x, pixY, pix);

        // for distance to next text
	pixY = isBottom ? (pixY - h - 2) : (pixY + pixH + 2);
	pixDrawn = true;
    }


    if (0) kdDebug(90100) << "  Drawing '" << name << "' at "
		     << x+pixW << "/" << y << endl;

    p->drawText( x+pixW, y,
		 width - pixW, h,
		 Qt::AlignLeft, name);
    y = isBottom ? (y-h) : (y+h);
    lines--;

    if (remaining.isEmpty()) break;
    name = remaining;
    w = pixW + _fm->width(name);
  }

  // make sure the pix stays visible
  if (pixDrawn && (pixY>0)) {
    if (isBottom && (pixY<y)) y = pixY;
    if (!isBottom && (pixY>y)) y = pixY;
  }

  if (origLines > lines) {
    // if only 1 line written, don't reset _used* vars
    if (lines - origLines >1) {
      if (isBottom)
        _usedBottomLeft = _usedBottomCenter = _usedBottomRight = 0;
      else
        _usedTopLeft = _usedTopCenter = _usedTopRight = 0;
    }

    // take back one line
    y = isBottom ? (y+h) : (y-h);
    if (used) *used = w;
  }

  // update free space
  if (!isBottom) {
    if (rotate)
      _rect.setRect(r.x()+y, r.y(), r.width()-y, r.height());
    else
      _rect.setRect(r.x(), r.y()+y, r.width(), r.height()-y);
  }
  else {
    if (rotate)
      _rect.setRect(r.x(), r.y(), y+h, r.height());
    else
      _rect.setRect(r.x(), r.y(), r.width(), y+h);
  }

  p->restore();

  return true;
}