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# 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
     ** met:
     **   * Redistributions of source code must retain the above copyright
     **     notice, this list of conditions and the following disclaimer.
     **   * Redistributions in binary form must reproduce the above copyright
     **     notice, this list of conditions and the following disclaimer in
     **     the documentation and/or other materials provided with the
     **     distribution.
     **   * Neither the name of The Qt Company Ltd nor the names of its
     **     contributors may be used to endorse or promote products derived
     **     from this software without specific prior written permission.
     **
     **
     ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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     ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
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     ****************************************************************************/

     #include <QtGui>

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

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

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

         settings = 0;
         refreshTimer.setInterval(2000);
         autoRefresh = false;

         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, SIGNAL(timeout()), this, SLOT(maybeRefresh()));
     }

     void SettingsTree::setSettingsObject(QSettings *settings)
     {
         delete this->settings;
         this->settings = settings;
         clear();

         if (settings) {
             settings->setParent(this);
             refresh();
             if (autoRefresh)
                 refreshTimer.start();
         } else {
             refreshTimer.stop();
         }
     }

     QSize SettingsTree::sizeHint() const
     {
         return QSize(800, 600);
     }

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

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

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

     void SettingsTree::refresh()
     {
         if (!settings)
             return;

         disconnect(this, SIGNAL(itemChanged(QTreeWidgetItem*,int)),
                    this, SLOT(updateSetting(QTreeWidgetItem*)));

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

         connect(this, SIGNAL(itemChanged(QTreeWidgetItem*,int)),
                 this, SLOT(updateSetting(QTreeWidgetItem*)));
     }

     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) + "/");
             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, "");
                 child->setText(2, "");
                 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 (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);
     }