Qt 5.11 | Qt Widgets | Simple Anchor Layout Example | main.cpp Example File

Qt 5.11.3 Reference Documentation

# main.cpp Example File

graphicsview/simpleanchorlayout/main.cpp

      /****************************************************************************
      **
      ** Copyright (C) 2016 The Qt Company Ltd.
      ** Contact: https://www.qt.io/licensing/
      **
      ** This file is part of the examples of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:BSD$
      ** Commercial License Usage
      ** Licensees holding valid commercial Qt licenses may use this file in
      ** accordance with the commercial license agreement provided with the
      ** Software or, alternatively, in accordance with the terms contained in
      ** a written agreement between you and The Qt Company. For licensing terms
      ** and conditions see https://www.qt.io/terms-conditions. For further
      ** information use the contact form at https://www.qt.io/contact-us.
      **
      ** BSD License Usage
      ** Alternatively, 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,
      ** 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 <QtWidgets>

      class Widget : public QGraphicsWidget
      {
      public:
          Widget(const QColor &color, const QColor &textColor, const QString &caption,
                 QGraphicsItem *parent = 0)
              : QGraphicsWidget(parent)
              , caption(caption)
              , color(color)
              , textColor(textColor)
          {
          }

          void paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget * = 0) override
          {
              QFont font;
              font.setPixelSize(0.75 * qMin(boundingRect().width(), boundingRect().height()));

              painter->fillRect(boundingRect(), color);
              painter->save();
              painter->setFont(font);
              painter->setPen(textColor);
              painter->drawText(boundingRect(), Qt::AlignCenter, caption);
              painter->restore();
          }

      private:
          QString caption;
          QColor color;
          QColor textColor;
      };

      int main(int argc, char *argv[])
      {
          QApplication app(argc, argv);

          QGraphicsScene *scene = new QGraphicsScene();

          Widget *a = new Widget(Qt::blue, Qt::white, "a");
          a->setPreferredSize(100, 100);
          Widget *b = new Widget(Qt::green, Qt::black, "b");
          b->setPreferredSize(100, 100);
          Widget *c = new Widget(Qt::red, Qt::black, "c");
          c->setPreferredSize(100, 100);

          QGraphicsAnchorLayout *layout = new QGraphicsAnchorLayout();
      /*
          layout->addAnchor(a, Qt::AnchorTop, layout, Qt::AnchorTop);
          layout->addAnchor(a, Qt::AnchorLeft, layout, Qt::AnchorLeft);
      */
          layout->addCornerAnchors(a, Qt::TopLeftCorner, layout, Qt::TopLeftCorner);

          layout->addAnchor(b, Qt::AnchorLeft, a, Qt::AnchorRight);
          layout->addAnchor(b, Qt::AnchorTop, a, Qt::AnchorBottom);

          // Place a third widget below the second.
          layout->addAnchor(b, Qt::AnchorBottom, c, Qt::AnchorTop);

      /*
          layout->addAnchor(b, Qt::AnchorLeft, c, Qt::AnchorLeft);
          layout->addAnchor(b, Qt::AnchorRight, c, Qt::AnchorRight);
      */

          layout->addAnchors(b, c, Qt::Horizontal);

          // Anchor the bottom-right corner of the third widget to the bottom-right
          // corner of the layout.
          layout->addCornerAnchors(c, Qt::BottomRightCorner, layout, Qt::BottomRightCorner);

          QGraphicsWidget *w = new QGraphicsWidget(0, Qt::Window | Qt::CustomizeWindowHint | Qt::WindowTitleHint);
          w->setPos(20, 20);
          w->setMinimumSize(100, 100);
          w->setPreferredSize(320, 240);
          w->setLayout(layout);
          w->setWindowTitle(QApplication::translate("simpleanchorlayout", "QGraphicsAnchorLayout in use"));
          scene->addItem(w);

          QGraphicsView *view = new QGraphicsView();
          view->setScene(scene);
          view->setWindowTitle(QApplication::translate("simpleanchorlayout", "Simple Anchor Layout"));

          view->resize(360, 320);
          view->show();

          return app.exec();
      }