Qt 4.8: borderlayout.cpp Example File (layouts/borderlayout/borderlayout.cpp)

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# borderlayout.cpp Example File

layouts/borderlayout/borderlayout.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
     ** Contact: http://www.qt-project.org/legal
     **
     ** 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 Digia Plc and its Subsidiary(-ies) 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,
     ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
     **
     ** $QT_END_LICENSE$
     **
     ****************************************************************************/

     #include <QtGui>

     #include "borderlayout.h"

     BorderLayout::BorderLayout(QWidget *parent, int margin, int spacing)
         : QLayout(parent)
     {
         setMargin(margin);
         setSpacing(spacing);
     }

     BorderLayout::BorderLayout(int spacing)
     {
         setSpacing(spacing);
     }

     BorderLayout::~BorderLayout()
     {
         QLayoutItem *l;
         while ((l = takeAt(0)))
             delete l;
     }

     void BorderLayout::addItem(QLayoutItem *item)
     {
         add(item, West);
     }

     void BorderLayout::addWidget(QWidget *widget, Position position)
     {
         add(new QWidgetItem(widget), position);
     }

     Qt::Orientations BorderLayout::expandingDirections() const
     {
         return Qt::Horizontal | Qt::Vertical;
     }

     bool BorderLayout::hasHeightForWidth() const
     {
         return false;
     }

     int BorderLayout::count() const
     {
         return list.size();
     }

     QLayoutItem *BorderLayout::itemAt(int index) const
     {
         ItemWrapper *wrapper = list.value(index);
         if (wrapper)
             return wrapper->item;
         else
             return 0;
     }

     QSize BorderLayout::minimumSize() const
     {
         return calculateSize(MinimumSize);
     }

     void BorderLayout::setGeometry(const QRect &rect)
     {
         ItemWrapper *center = 0;
         int eastWidth = 0;
         int westWidth = 0;
         int northHeight = 0;
         int southHeight = 0;
         int centerHeight = 0;
         int i;

         QLayout::setGeometry(rect);

         for (i = 0; i < list.size(); ++i) {
             ItemWrapper *wrapper = list.at(i);
             QLayoutItem *item = wrapper->item;
             Position position = wrapper->position;

             if (position == North) {
                 item->setGeometry(QRect(rect.x(), northHeight, rect.width(),
                                         item->sizeHint().height()));

                 northHeight += item->geometry().height() + spacing();
             } else if (position == South) {
                 item->setGeometry(QRect(item->geometry().x(),
                                         item->geometry().y(), rect.width(),
                                         item->sizeHint().height()));

                 southHeight += item->geometry().height() + spacing();

                 item->setGeometry(QRect(rect.x(),
                                   rect.y() + rect.height() - southHeight + spacing(),
                                   item->geometry().width(),
                                   item->geometry().height()));
             } else if (position == Center) {
                 center = wrapper;
             }
         }

         centerHeight = rect.height() - northHeight - southHeight;

         for (i = 0; i < list.size(); ++i) {
             ItemWrapper *wrapper = list.at(i);
             QLayoutItem *item = wrapper->item;
             Position position = wrapper->position;

             if (position == West) {
                 item->setGeometry(QRect(rect.x() + westWidth, northHeight,
                                         item->sizeHint().width(), centerHeight));

                 westWidth += item->geometry().width() + spacing();
             } else if (position == East) {
                 item->setGeometry(QRect(item->geometry().x(), item->geometry().y(),
                                         item->sizeHint().width(), centerHeight));

                 eastWidth += item->geometry().width() + spacing();

                 item->setGeometry(QRect(
                                   rect.x() + rect.width() - eastWidth + spacing(),
                                   northHeight, item->geometry().width(),
                                   item->geometry().height()));
             }
         }

         if (center)
             center->item->setGeometry(QRect(westWidth, northHeight,
                                             rect.width() - eastWidth - westWidth,
                                             centerHeight));
     }

     QSize BorderLayout::sizeHint() const
     {
         return calculateSize(SizeHint);
     }

     QLayoutItem *BorderLayout::takeAt(int index)
     {
         if (index >= 0 && index < list.size()) {
             ItemWrapper *layoutStruct = list.takeAt(index);
             return layoutStruct->item;
         }
         return 0;
     }

     void BorderLayout::add(QLayoutItem *item, Position position)
     {
         list.append(new ItemWrapper(item, position));
     }

     QSize BorderLayout::calculateSize(SizeType sizeType) const
     {
         QSize totalSize;

         for (int i = 0; i < list.size(); ++i) {
             ItemWrapper *wrapper = list.at(i);
             Position position = wrapper->position;
             QSize itemSize;

             if (sizeType == MinimumSize)
                 itemSize = wrapper->item->minimumSize();
             else // (sizeType == SizeHint)
                 itemSize = wrapper->item->sizeHint();

             if (position == North || position == South || position == Center)
                 totalSize.rheight() += itemSize.height();

             if (position == West || position == East || position == Center)
                 totalSize.rwidth() += itemSize.width();
         }
         return totalSize;
     }