Qt 5.6 | Qt Widgets | Settings Editor Example | settingstree.cpp Example File

Qt 5.6.2 Reference Documentation

# settingstree.cpp Example File

tools/settingseditor/settingstree.cpp

      /****************************************************************************
      **
      ** Copyright (C) 2015 The Qt Company Ltd.
      ** Contact: http://www.qt.io/licensing/
      **
      ** This file is part of the examples of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:BSD$
      ** You may use this file under the terms of the BSD license as follows:
      **
      ** "Redistribution and use in source and binary forms, with or without
      ** modification, are permitted provided that the following conditions are
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      **     from this software without specific prior written permission.
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      #include <QtWidgets>

      #include "settingstree.h"
      #include "variantdelegate.h"

      SettingsTree::SettingsTree(QWidget *parent)
          : QTreeWidget(parent)
          , autoRefresh(false)
      {
          setItemDelegate(new VariantDelegate(this));

          QStringList labels;
          labels << tr("Setting") << tr("Type") << tr("Value");
          setHeaderLabels(labels);
          header()->setSectionResizeMode(0, QHeaderView::ResizeToContents);
          header()->setSectionResizeMode(1, QHeaderView::ResizeToContents);
          header()->setSectionResizeMode(2, QHeaderView::Stretch);

          refreshTimer.setInterval(2000);

          groupIcon.addPixmap(style()->standardPixmap(QStyle::SP_DirClosedIcon),
                              QIcon::Normal, QIcon::Off);
          groupIcon.addPixmap(style()->standardPixmap(QStyle::SP_DirOpenIcon),
                              QIcon::Normal, QIcon::On);
          keyIcon.addPixmap(style()->standardPixmap(QStyle::SP_FileIcon));

          connect(&refreshTimer, &QTimer::timeout, this, &SettingsTree::maybeRefresh);
      }

      SettingsTree::~SettingsTree()
      {
      }

      void SettingsTree::setSettingsObject(const SettingsPtr &newSettings)
      {
          settings = newSettings;
          clear();

          if (settings.isNull()) {
              refreshTimer.stop();
          } else {
              refresh();
              if (autoRefresh)
                  refreshTimer.start();
          }
      }

      QSize SettingsTree::sizeHint() const
      {
          const QRect availableGeometry = QApplication::desktop()->availableGeometry(this);
          return QSize(availableGeometry.width() * 2 / 3, availableGeometry.height() * 2 / 3);
      }

      void SettingsTree::setAutoRefresh(bool autoRefresh)
      {
          this->autoRefresh = autoRefresh;
          if (!settings.isNull()) {
              if (autoRefresh) {
                  maybeRefresh();
                  refreshTimer.start();
              } else {
                  refreshTimer.stop();
              }
          }
      }

      void SettingsTree::setFallbacksEnabled(bool enabled)
      {
          if (!settings.isNull()) {
              settings->setFallbacksEnabled(enabled);
              refresh();
          }
      }

      void SettingsTree::maybeRefresh()
      {
          if (state() != EditingState)
              refresh();
      }

      void SettingsTree::refresh()
      {
          if (settings.isNull())
              return;

          disconnect(this, &QTreeWidget::itemChanged,
                     this, &SettingsTree::updateSetting);

          settings->sync();
          updateChildItems(0);

          connect(this, &QTreeWidget::itemChanged,
                  this, &SettingsTree::updateSetting);
      }

      bool SettingsTree::event(QEvent *event)
      {
          if (event->type() == QEvent::WindowActivate) {
              if (isActiveWindow() && autoRefresh)
                  maybeRefresh();
          }
          return QTreeWidget::event(event);
      }

      void SettingsTree::updateSetting(QTreeWidgetItem *item)
      {
          QString key = item->text(0);
          QTreeWidgetItem *ancestor = item->parent();
          while (ancestor) {
              key.prepend(ancestor->text(0) + QLatin1Char('/'));
              ancestor = ancestor->parent();
          }

          settings->setValue(key, item->data(2, Qt::UserRole));
          if (autoRefresh)
              refresh();
      }

      void SettingsTree::updateChildItems(QTreeWidgetItem *parent)
      {
          int dividerIndex = 0;

          foreach (QString group, settings->childGroups()) {
              QTreeWidgetItem *child;
              int childIndex = findChild(parent, group, dividerIndex);
              if (childIndex != -1) {
                  child = childAt(parent, childIndex);
                  child->setText(1, QString());
                  child->setText(2, QString());
                  child->setData(2, Qt::UserRole, QVariant());
                  moveItemForward(parent, childIndex, dividerIndex);
              } else {
                  child = createItem(group, parent, dividerIndex);
              }
              child->setIcon(0, groupIcon);
              ++dividerIndex;

              settings->beginGroup(group);
              updateChildItems(child);
              settings->endGroup();
          }

          foreach (const QString &key, settings->childKeys()) {
              QTreeWidgetItem *child;
              int childIndex = findChild(parent, key, 0);

              if (childIndex == -1 || childIndex >= dividerIndex) {
                  if (childIndex != -1) {
                      child = childAt(parent, childIndex);
                      for (int i = 0; i < child->childCount(); ++i)
                          delete childAt(child, i);
                      moveItemForward(parent, childIndex, dividerIndex);
                  } else {
                      child = createItem(key, parent, dividerIndex);
                  }
                  child->setIcon(0, keyIcon);
                  ++dividerIndex;
              } else {
                  child = childAt(parent, childIndex);
              }

              QVariant value = settings->value(key);
              if (value.type() == QVariant::Invalid) {
                  child->setText(1, "Invalid");
              } else {
                  child->setText(1, value.typeName());
              }
              child->setText(2, VariantDelegate::displayText(value));
              child->setData(2, Qt::UserRole, value);
          }

          while (dividerIndex < childCount(parent))
              delete childAt(parent, dividerIndex);
      }

      QTreeWidgetItem *SettingsTree::createItem(const QString &text,
                                                QTreeWidgetItem *parent, int index)
      {
          QTreeWidgetItem *after = 0;
          if (index != 0)
              after = childAt(parent, index - 1);

          QTreeWidgetItem *item;
          if (parent)
              item = new QTreeWidgetItem(parent, after);
          else
              item = new QTreeWidgetItem(this, after);

          item->setText(0, text);
          item->setFlags(item->flags() | Qt::ItemIsEditable);
          return item;
      }

      QTreeWidgetItem *SettingsTree::childAt(QTreeWidgetItem *parent, int index)
      {
          if (parent)
              return parent->child(index);
          else
              return topLevelItem(index);
      }

      int SettingsTree::childCount(QTreeWidgetItem *parent)
      {
          if (parent)
              return parent->childCount();
          else
              return topLevelItemCount();
      }

      int SettingsTree::findChild(QTreeWidgetItem *parent, const QString &text,
                                  int startIndex)
      {
          for (int i = startIndex; i < childCount(parent); ++i) {
              if (childAt(parent, i)->text(0) == text)
                  return i;
          }
          return -1;
      }

      void SettingsTree::moveItemForward(QTreeWidgetItem *parent, int oldIndex,
                                         int newIndex)
      {
          for (int i = 0; i < oldIndex - newIndex; ++i)
              delete childAt(parent, newIndex);
      }