src/tasklist_progress_cell_delegate.cpp - QPixmapCache - waterstone/TaskList_Demo

src/tasklist_progress_cell_delegate.cpp
177 строк5 KB
Peter Sakhno
Try QPixmapCache in TaskListProgressCellDelegate::paint
22 янв 2026, 11:43
22 янв 2026, 11:433d0c513
#include "tasklist_progress_cell_delegate.h"

#include <QPainter>
#include <QPixmapCache>
#include <QGuiApplication>

#include "tasklist_ranges.h"

namespace {
#if 0
  static const QString kPixmapKeyTemplate{ "TaskListProgressCellDelegate,%1,%2,%3,%4,%5,%6,%7" };
#else
  static const QString kPixmapKeyTemplate{ "TaskListProgressCellDelegate_%1_%2_%3_%4_%5_%6_%7" };
#endif // 0

  QRectF squared(const QRectF& rect)
  {
    if (rect.width() > rect.height())
    {
      qreal diff = rect.width() - rect.height();
      return rect.adjusted(diff / 2, 0, -diff / 2, 0);
    }
    else
    {
      qreal diff = rect.height() - rect.width();
      return rect.adjusted(0, diff / 2, 0, -diff / 2);
    }
  }

}


QSize	TaskListProgressCellDelegate::sizeHint(const QStyleOptionViewItem& option,
  const QModelIndex& index) const
{
  auto hint = QStyledItemDelegate::sizeHint(option, index);
  if (hint.width() < kMinSize.width())
    hint.setWidth(kMinSize.width());
  if (hint.height() < kMinSize.height())
    hint.setHeight(kMinSize.height());
  return hint;
}

void TaskListProgressCellDelegate::paint(QPainter* painter,
  const QStyleOptionViewItem& option, const QModelIndex& index) const
{
  QStyledItemDelegate::paint(painter, option, index);

  const auto var = index.data(Qt::UserRole);
  if (var.userType() != QMetaType::Int)
    return;

  int progress = var.toInt();
  if (!ProgressRange::valid(progress) and !AnimationRange::valid(progress))
    return;

  auto bounds = squared(option.rect.adjusted(kPenWidth, kPenWidth, -kPenWidth, -kPenWidth));
#if 0
  bounds.moveCenter(option.rect.center());
#endif // 0

  QPalette::ColorGroup group = QPalette::Inactive;
  QPalette::ColorRole role = QPalette::Text;
  int back_alpha = 20;
  static const int fore_alpha = 255;
  if (option.state & QStyle::State_Active and
    option.state & QStyle::State_Selected)
  {
    group = QPalette::Active;
    role = QPalette::HighlightedText;
    back_alpha = 50;
  }
  QColor color = QGuiApplication::palette().color(group, role);

  QString back_key = kPixmapKeyTemplate.
    arg("back").
    arg(0).
    arg(kPenWidth).
    arg(back_alpha).
    arg(color.rgb()).
    arg(bounds.width()).
    arg(bounds.height());

  QPixmap back_pixmap;
  if (!QPixmapCache::find(back_key, &back_pixmap))
  {
    auto generate_pixmap = [&]() -> QPixmap {
      QPixmap pixmap = QPixmap{ bounds.size().toSize() };
      pixmap.fill(Qt::transparent);

      QPainter painter(&pixmap);
      painter.setRenderHint(QPainter::Antialiasing, true);

      color.setAlpha(back_alpha);
      painter.setPen(QPen(color, kPenWidth, Qt::SolidLine, Qt::FlatCap));
      painter.drawArc(
        {
          {kPenWidth/2.0, kPenWidth/2.0},
          bounds.size() - QSize{kPenWidth, kPenWidth}
        },
        0, 360 * 16);

      return pixmap;
    };

    back_pixmap = generate_pixmap();
    QPixmapCache::insert(back_key, back_pixmap);
  }

  // Draw pixmap at center of item
  painter->drawPixmap(bounds.toRect(), back_pixmap);

  QString fore_key = kPixmapKeyTemplate.
    arg("fore").
    arg(progress).
    arg(kPenWidth).
    arg(fore_alpha).
    arg(color.rgb()).
    arg(bounds.width()).
    arg(bounds.height());

  QPixmap fore_pixmap;
  if (!QPixmapCache::find(fore_key, &fore_pixmap))
  {
    auto generate_pixmap = [&]() -> QPixmap
    {
      QPixmap pixmap = QPixmap{ bounds.size().toSize() };
      pixmap.fill(Qt::transparent);

      QPainter painter(&pixmap);
      painter.setRenderHint(QPainter::Antialiasing, true);

      const QRectF rc{
          {kPenWidth / 2.0, kPenWidth / 2.0},
          bounds.size() - QSize{kPenWidth, kPenWidth}
      };

      color.setAlpha(fore_alpha);
      painter.setPen(QPen(color, kPenWidth, Qt::SolidLine, Qt::FlatCap));
      if (ProgressRange::valid(progress)) {
        painter.drawArc(rc, 90 * 16,
          -((progress * 360 / ProgressRange::max()) * 16 + 90));
      }
      else if (AnimationRange::valid(progress)) {
        painter.drawArc(rc, -(progress - AnimationRange::min() - 90) * 16,
          -45 * 16);
      }

      return pixmap;
    };

    fore_pixmap = generate_pixmap();
    QPixmapCache::insert(fore_key, fore_pixmap);
  }

  // Draw pixmap at center of item
  painter->drawPixmap(bounds.toRect(), fore_pixmap);

#if 0
  painter->setRenderHint(QPainter::Antialiasing);

  color.setAlpha(back_alpha);
  painter->setPen(QPen(color, kPenWidth, Qt::SolidLine, Qt::FlatCap));
  painter->drawArc(bounds, 0, 360 * 16);

  color.setAlpha(fore_alpha);
  painter->setPen(QPen(color, kPenWidth, Qt::SolidLine, Qt::FlatCap));
  if (ProgressRange::valid(progress)) {
    painter->drawArc(bounds, 90 * 16,
      -((progress * 360 / ProgressRange::max()) * 16 + 90));
  }
  else if (AnimationRange::valid(progress)) {
    painter->drawArc(bounds, -(progress - AnimationRange::min() - 90) * 16,
      -45 * 16);
  }
#endif // 0
}