SearchLineEdit.cpp

/*
 * Copyright 2011-2012 TeleMidia/PUC-Rio.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library.  If not, see
 * <http://www.gnu.org/licenses/>.
 */
#include "SearchLineEdit.h"
#include <QToolButton>
#include <QStyle>

#include <QDebug>

SearchLineEdit::SearchLineEdit(QWidget *parent) :
  QLineEdit(parent)
{
  // Create the search button and set its icon, cursor, and stylesheet
  this->mSearchButton = new QToolButton(this);
  this->mSearchButton->setFixedSize(18, 18);
  this->mSearchButton->setCursor(Qt::ArrowCursor);
  this->mSearchButton->setStyleSheet(this->buttonStyleSheetForCurrentState());

  // Update the search button when the text changes
  QObject::connect(this, SIGNAL(textChanged(QString)),
                   SLOT(updateSearchButton(QString)));

  // Some stylesheet and size corrections for the text box
  this->setPlaceholderText(tr("Search"));
  this->setStyleSheet(this->styleSheetForCurrentState());

  int frameWidth = this->style()->pixelMetric(QStyle::PM_DefaultFrameWidth);
  QSize minSizeHint = this->minimumSizeHint();
  this->setMinimumSize(
        qMax(minSizeHint.width(),
             this->mSearchButton->sizeHint().width() + frameWidth * 2 + 2),
        qMax(minSizeHint.height(),
             this->mSearchButton->sizeHint().height() + frameWidth * 2 + 2));
}

void SearchLineEdit::resizeEvent(QResizeEvent *event)
{
  Q_UNUSED(event);
  QSize size = this->mSearchButton->sizeHint();
  int frameWidth = this->style()->pixelMetric(QStyle::PM_DefaultFrameWidth);
  this->mSearchButton->move(
        this->rect().right() - frameWidth - size.width() - 2,
        (this->rect().bottom() + 2 - size.height()) / 2);
}

void SearchLineEdit::updateSearchButton(const QString &text)
{
  if (!text.isEmpty())
  {
    // We have some text in the box - set the button to clear the text
    QObject::connect(this->mSearchButton, SIGNAL(clicked()), SLOT(clear()));
  }
  else
  {
    // The text box is empty - make the icon do nothing when clicked
    QObject::disconnect(this->mSearchButton, SIGNAL(clicked()),
                        this, SLOT(clear()));
  }

  this->setStyleSheet(this->styleSheetForCurrentState());
  this->mSearchButton->setStyleSheet(this->buttonStyleSheetForCurrentState());
}

QString SearchLineEdit::styleSheetForCurrentState() const
{
  int frameWidth = this->style()->pixelMetric(QStyle::PM_DefaultFrameWidth);

  QString style;
  style += "QLineEdit {";
  if (this->text().isEmpty())
  {
    style += "font-family: 'MS Sans Serif';";
    style += "font-style: italic;";
    style += "font-size: 12px;";
  }

  style += "padding-left: 3px;";
  style += QString("padding-right: %1px;").arg(
        this->mSearchButton->sizeHint().width() + frameWidth + 1);

  style += "border-width: 3px;";
  style += "border-image: url(:/images/esf-border.png) 3 3 3 3 stretch;";
  style += "background-color: rgba(255, 255, 255, 204);";
  style += "}";
  style += "QLineEdit:hover, QLineEdit:focus {";
  style += "background-color: rgba(255, 255, 255, 255);";
  style += "}";
  return style;
}

QString SearchLineEdit::buttonStyleSheetForCurrentState() const
{
  QString style;
  style += "QToolButton {";
  style += "border: none; margin: 0; padding: 0;";
  style += QString("background-image: url(:/images/esf-%1.png);").
      arg(this->text().isEmpty() ? "search" : "clear");

  style += "}";

  if (!this->text().isEmpty())
  {
    style += "QToolButton:hover { "
        "background-image: url(:/images/esf-clear-hover.png); "
        "}";
    style += "QToolButton:pressed { "
        "background-image: url(:/images/esf-clear-active.png); "
        "}";
  }

  return style;
}

void SearchLineEdit::keyPressEvent(QKeyEvent *event)
{
  if(event->key() == Qt::Key_Escape)
  {
    emit escPressed();
  }
  else if(event->key() == Qt::Key_Return)
  {
    if(event->modifiers() & Qt::ShiftModifier)
    {
      emit shiftReturnPressed();
    }
    else
    {
      emit returnPressed();
    }
  }
  else
  {
    QLineEdit::keyPressEvent(event);
  }
}