Method drawLabelMaybeCached

3rdparty/qcustomplot/qcustomplot.cpp:5683–5742

! \internal Draws a single tick label with the provided \a painter, utilizing the internal label cache to significantly speed up drawing of labels that were drawn in previous calls. The tick label is always bound to an axis, the distance to the axis is controllable via \a distanceToAxis in pixels. The pixel position in the axis direction is passed in the \a position parameter. Hence f

  getTickLabelData).
*/
void QCPLabelPainterPrivate::drawLabelMaybeCached(QCPPainter *painter, const QFont &font, const QColor &color, const QPointF &pos, AnchorSide side, double rotation, const QString &text)
{
  // warning: if you change anything here, also adapt getMaxTickLabelSize() accordingly!
  if (text.isEmpty()) return;
  QSize finalSize;

  if (mParentPlot->plottingHints().testFlag(QCP::phCacheLabels) && !painter->modes().testFlag(QCPPainter::pmNoCaching)) // label caching enabled
  {
    QByteArray key = cacheKey(text, color, rotation, side);
    CachedLabel *cachedLabel = mLabelCache.take(QString::fromUtf8(key)); // attempt to take label from cache (don't use object() because we want ownership/prevent deletion during our operations, we re-insert it afterwards)
    if (!cachedLabel)  // no cached label existed, create it
    {
      LabelData labelData = getTickLabelData(font, color, rotation, side, text);
      cachedLabel = createCachedLabel(labelData);
    }
    // if label would be partly clipped by widget border on sides, don't draw it (only for outside tick labels):
    bool labelClippedByBorder = false;
    /*
    if (tickLabelSide == QCPAxis::lsOutside)
    {
      if (QCPAxis::orientation(type) == Qt::Horizontal)
        labelClippedByBorder = labelAnchor.x()+cachedLabel->offset.x()+cachedLabel->pixmap.width()/mParentPlot->bufferDevicePixelRatio() > viewportRect.right() || labelAnchor.x()+cachedLabel->offset.x() < viewportRect.left();
      else
        labelClippedByBorder = labelAnchor.y()+cachedLabel->offset.y()+cachedLabel->pixmap.height()/mParentPlot->bufferDevicePixelRatio() > viewportRect.bottom() || labelAnchor.y()+cachedLabel->offset.y() < viewportRect.top();
    }
    */
    if (!labelClippedByBorder)
    {
      painter->drawPixmap(pos+cachedLabel->offset, cachedLabel->pixmap);
      finalSize = cachedLabel->pixmap.size()/mParentPlot->bufferDevicePixelRatio(); // TODO: collect this in a member rect list?
    }
    mLabelCache.insert(QString::fromUtf8(key), cachedLabel);
  } else // label caching disabled, draw text directly on surface:
  {
    LabelData labelData = getTickLabelData(font, color, rotation, side, text);
    // if label would be partly clipped by widget border on sides, don't draw it (only for outside tick labels):
     bool labelClippedByBorder = false;
     /*
    if (tickLabelSide == QCPAxis::lsOutside)
    {
      if (QCPAxis::orientation(type) == Qt::Horizontal)
        labelClippedByBorder = finalPosition.x()+(labelData.rotatedTotalBounds.width()+labelData.rotatedTotalBounds.left()) > viewportRect.right() || finalPosition.x()+labelData.rotatedTotalBounds.left() < viewportRect.left();
      else
        labelClippedByBorder = finalPosition.y()+(labelData.rotatedTotalBounds.height()+labelData.rotatedTotalBounds.top()) > viewportRect.bottom() || finalPosition.y()+labelData.rotatedTotalBounds.top() < viewportRect.top();
    }
    */
    if (!labelClippedByBorder)
    {
      drawText(painter, pos, labelData);
      finalSize = labelData.rotatedTotalBounds.size();
    }
  }
  /*
  // expand passed tickLabelsSize if current tick label is larger:
  if (finalSize.width() > tickLabelsSize->width())
    tickLabelsSize->setWidth(finalSize.width());
  if (finalSize.height() > tickLabelsSize->height())
    tickLabelsSize->setHeight(finalSize.height());