CTK/Libs/Widgets/ctkTitleComboBox.cpp

/*=========================================================================

  Library:   CTK
 
  Copyright (c) Kitware Inc.

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
 
=========================================================================*/

// Qt includes
#include <QStylePainter>
#include <QApplication>
#include <QDebug>

// CTK includes
#include "ctkTitleComboBox.h"

// -------------------------------------------------------------------------
ctkTitleComboBox::ctkTitleComboBox(QWidget* _parent)
  : QComboBox(_parent)
{
  this->Title = "Select an item...";
}

// -------------------------------------------------------------------------
ctkTitleComboBox::~ctkTitleComboBox()
{
  
}

// -------------------------------------------------------------------------
void ctkTitleComboBox::setTitle(const QString& _title)
{
  this->Title = _title;
  this->SizeHint = QSize();
  this->updateGeometry();
}

// -------------------------------------------------------------------------
QString ctkTitleComboBox::title()const
{
  return this->Title;
}

// -------------------------------------------------------------------------
void ctkTitleComboBox::setIcon(const QIcon& _icon)
{
  this->Icon = _icon;
  this->SizeHint = QSize();
  this->updateGeometry();
}

// -------------------------------------------------------------------------
QIcon ctkTitleComboBox::icon()const
{
  return this->Icon;
}

// -------------------------------------------------------------------------
void ctkTitleComboBox::paintEvent(QPaintEvent*)
{
  QStylePainter painter(this);
  painter.setPen(palette().color(QPalette::Text));

  QStyleOptionComboBox opt;
  initStyleOption(&opt);

  opt.currentText = this->Title;
  opt.currentIcon = this->Icon;
  if (!this->Icon.isNull() && !this->Icon.availableSizes().empty())
    {
    QList<QSize> sizes = this->Icon.availableSizes();
    // TODO: pick the best size (based on the pixelMetric maybe)
    //int iconSize = style()->pixelMetric(QStyle::PM_SmallIconSize);
    opt.iconSize = sizes[0];
    }

  // draw the combobox frame, focusrect and selected etc.
  painter.drawComplexControl(QStyle::CC_ComboBox, opt);
  // draw the icon and text
  painter.drawControl(QStyle::CE_ComboBoxLabel, opt);
}

// -------------------------------------------------------------------------
QSize ctkTitleComboBox::minimumSizeHint() const
{
  return this->recomputeSizeHint(this->SizeHint);
}

// -------------------------------------------------------------------------
/*!
    \reimp

    This implementation caches the size hint to avoid resizing when
    the contents change dynamically. To invalidate the cached value
    change the \l sizeAdjustPolicy.
*/
QSize ctkTitleComboBox::sizeHint() const
{
  return this->recomputeSizeHint(this->SizeHint);
}

// -------------------------------------------------------------------------
QSize ctkTitleComboBox::recomputeSizeHint(QSize &sh) const
{
  if (sh.isValid()) 
    {
    return sh.expandedTo(QApplication::globalStrut());
    }
  const QFontMetrics &fm = this->fontMetrics();
  QList<QSize> iconSizes = this->Icon.availableSizes();
  if (!this->Icon.isNull() && !iconSizes.empty()) 
    {
    // TODO: pick the best size (based on the pixelMetric maybe)
    QSize _iconSize = iconSizes[0];
    sh.setWidth(qMax(sh.width(), fm.boundingRect(this->Title).width() + _iconSize.width() + 4));
    }
  else
    {
    sh.setWidth(qMax(sh.width(), fm.boundingRect(this->Title).width()));
    }

  // height
  sh.setHeight(qMax(fm.lineSpacing(), 14) + 2);
  if (!this->Icon.isNull() && !iconSizes.empty()) 
    {
    // TODO: pick the best size (based on the pixelMetric maybe)
    QSize _iconSize = iconSizes[0];
    sh.setHeight(qMax(sh.height(), _iconSize.height() + 2));
    }

  // add style and strut values
  QStyleOptionComboBox opt;
  this->initStyleOption(&opt);
  sh = this->style()->sizeFromContents(QStyle::CT_ComboBox, &opt, sh, this);

  return sh.expandedTo(QApplication::globalStrut());
}