Qt 5.9 | Qt WebEngine | WebEngine Demo Browser Example | searchlineedit.cpp Example File

Qt 5.9.9 Reference Documentation

# searchlineedit.cpp Example File

webenginewidgets/demobrowser/searchlineedit.cpp

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      ** This file is part of the examples of the Qt Toolkit.
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      #include "searchlineedit.h"

      #include <QtGui/QPainter>
      #include <QtGui/QMouseEvent>
      #include <QtWidgets/QMenu>
      #include <QtWidgets/QStyle>
      #include <QtWidgets/QStyleOptionFrame>

      ClearButton::ClearButton(QWidget *parent)
        : QAbstractButton(parent)
      {
      #ifndef QT_NO_CURSOR
          setCursor(Qt::ArrowCursor);
      #endif // QT_NO_CURSOR
          setToolTip(tr("Clear"));
          setVisible(false);
          setFocusPolicy(Qt::NoFocus);
      }

      void ClearButton::paintEvent(QPaintEvent *event)
      {
          Q_UNUSED(event);
          QPainter painter(this);
          int height = this->height();

          painter.setRenderHint(QPainter::Antialiasing, true);
          painter.setBrush(isDown()
                           ? palette().color(QPalette::Dark)
                           : palette().color(QPalette::Mid));
          painter.setPen(painter.brush().color());
          int size = width();
          int offset = size / 5;
          int radius = size - offset * 2;
          painter.drawEllipse(offset, offset, radius, radius);

          painter.setPen(palette().color(QPalette::Base));
          int border = offset * 2;
          painter.drawLine(border, border, width() - border, height - border);
          painter.drawLine(border, height - border, width() - border, border);
      }

      void ClearButton::textChanged(const QString &text)
      {
          setVisible(!text.isEmpty());
      }

      /*
          Search icon on the left hand side of the search widget
          When a menu is set a down arrow appears
       */
      class SearchButton : public QAbstractButton {
      public:
          SearchButton(QWidget *parent = 0);
          void paintEvent(QPaintEvent *event);
          QMenu *m_menu;

      protected:
          void mousePressEvent(QMouseEvent *event);
      };

      SearchButton::SearchButton(QWidget *parent)
        : QAbstractButton(parent),
          m_menu(0)
      {
          setObjectName(QLatin1String("SearchButton"));
      #ifndef QT_NO_CURSOR
          setCursor(Qt::ArrowCursor);
      #endif //QT_NO_CURSOR
          setFocusPolicy(Qt::NoFocus);
      }

      void SearchButton::mousePressEvent(QMouseEvent *event)
      {
          if (m_menu && event->button() == Qt::LeftButton) {
              QWidget *p = parentWidget();
              if (p) {
                  QPoint r = p->mapToGlobal(QPoint(0, p->height()));
                  m_menu->exec(QPoint(r.x() + height() / 2, r.y()));
              }
              event->accept();
          }
          QAbstractButton::mousePressEvent(event);
      }

      void SearchButton::paintEvent(QPaintEvent *event)
      {
          Q_UNUSED(event);
          QPainterPath myPath;

          int radius = (height() / 5) * 2;
          QRect circle(height() / 3 - 1, height() / 4, radius, radius);
          myPath.addEllipse(circle);

          myPath.arcMoveTo(circle, 300);
          QPointF c = myPath.currentPosition();
          int diff = height() / 7;
          myPath.lineTo(qMin(width() - 2, (int)c.x() + diff), c.y() + diff);

          QPainter painter(this);
          painter.setRenderHint(QPainter::Antialiasing, true);
          painter.setPen(QPen(Qt::darkGray, 2));
          painter.drawPath(myPath);

          if (m_menu) {
              QPainterPath dropPath;
              dropPath.arcMoveTo(circle, 320);
              QPointF c = dropPath.currentPosition();
              c = QPointF(c.x() + 3.5, c.y() + 0.5);
              dropPath.moveTo(c);
              dropPath.lineTo(c.x() + 4, c.y());
              dropPath.lineTo(c.x() + 2, c.y() + 2);
              dropPath.closeSubpath();
              painter.setPen(Qt::darkGray);
              painter.setBrush(Qt::darkGray);
              painter.setRenderHint(QPainter::Antialiasing, false);
              painter.drawPath(dropPath);
          }
          painter.end();
      }

      /*
          SearchLineEdit is an enhanced QLineEdit
          - A Search icon on the left with optional menu
          - When there is no text and doesn't have focus an "inactive text" is displayed
          - When there is text a clear button is displayed on the right hand side
       */
      SearchLineEdit::SearchLineEdit(QWidget *parent) : ExLineEdit(parent),
          m_searchButton(new SearchButton(this))
      {
          connect(lineEdit(), SIGNAL(textChanged(QString)),
                  this, SIGNAL(textChanged(QString)));
          setLeftWidget(m_searchButton);
          m_inactiveText = tr("Search");

          QSizePolicy policy = sizePolicy();
          setSizePolicy(QSizePolicy::Preferred, policy.verticalPolicy());
      }

      void SearchLineEdit::paintEvent(QPaintEvent *event)
      {
          if (lineEdit()->text().isEmpty() && !hasFocus() && !m_inactiveText.isEmpty()) {
              ExLineEdit::paintEvent(event);
              QStyleOptionFrame panel;
              initStyleOption(&panel);
              QRect r = style()->subElementRect(QStyle::SE_LineEditContents, &panel, this);
              QFontMetrics fm = fontMetrics();
              int horizontalMargin = lineEdit()->x();
              QRect lineRect(horizontalMargin + r.x(), r.y() + (r.height() - fm.height() + 1) / 2,
                             r.width() - 2 * horizontalMargin, fm.height());
              QPainter painter(this);
              painter.setPen(palette().brush(QPalette::Disabled, QPalette::Text).color());
              painter.drawText(lineRect, Qt::AlignLeft|Qt::AlignVCenter, m_inactiveText);
          } else {
              ExLineEdit::paintEvent(event);
          }
      }

      void SearchLineEdit::resizeEvent(QResizeEvent *event)
      {
          updateGeometries();
          ExLineEdit::resizeEvent(event);
      }

      void SearchLineEdit::updateGeometries()
      {
          int menuHeight = height();
          int menuWidth = menuHeight + 1;
          if (!m_searchButton->m_menu)
              menuWidth = (menuHeight / 5) * 4;
          m_searchButton->resize(QSize(menuWidth, menuHeight));
      }

      QString SearchLineEdit::inactiveText() const
      {
          return m_inactiveText;
      }

      void SearchLineEdit::setInactiveText(const QString &text)
      {
          m_inactiveText = text;
      }

      void SearchLineEdit::setMenu(QMenu *menu)
      {
          if (m_searchButton->m_menu)
              m_searchButton->m_menu->deleteLater();
          m_searchButton->m_menu = menu;
          updateGeometries();
      }

      QMenu *SearchLineEdit::menu() const
      {
          if (!m_searchButton->m_menu) {
              m_searchButton->m_menu = new QMenu(m_searchButton);
              if (isVisible())
                  (const_cast<SearchLineEdit*>(this))->updateGeometries();
          }
          return m_searchButton->m_menu;
      }