/*
 * This file Copyright (C) 2015 Mnemosyne LLC
 *
 * It may be used under the GNU GPL versions 2 or 3
 * or any future license endorsed by Mnemosyne LLC.
 *
 */

#include <QApplication>
#include <QStyleOptionHeader>
#include <QStylePainter>

#include "TorrentView.h"

class TorrentView::HeaderWidget: public QWidget
{
  public:
    HeaderWidget (TorrentView * parent):
      QWidget (parent),
      myText ()
    {
      setFont (qApp->font ("QMiniFont"));
    }

    void setText (const QString& text)
    {
      myText = text;
      update ();
    }

    // QWidget
    virtual QSize sizeHint () const
    {
      QStyleOptionHeader option;
      option.rect = QRect (0, 0, 100, 100);

      const QRect labelRect = style ()->subElementRect (QStyle::SE_HeaderLabel, &option, this);

      return QSize (100, fontMetrics ().height () + (option.rect.height () - labelRect.height ()));
    }

  protected:
    // QWidget
    virtual void paintEvent (QPaintEvent * /*event*/)
    {
      QStyleOptionHeader option;
      option.initFrom (this);
      option.state = QStyle::State_Enabled;
      option.position = QStyleOptionHeader::OnlyOneSection;

      QStylePainter painter (this);
      painter.drawControl (QStyle::CE_HeaderSection, option);

      option.rect = style ()->subElementRect (QStyle::SE_HeaderLabel, &option, this);
      painter.drawItemText (option.rect, Qt::AlignCenter, option.palette, true, myText, QPalette::ButtonText);
    }

    virtual void mouseDoubleClickEvent (QMouseEvent * /*event*/)
    {
      emit static_cast<TorrentView *> (parent ())->headerDoubleClicked ();
    }

  private:
    QString myText;
};

TorrentView::TorrentView (QWidget * parent):
  QListView (parent),
  myHeaderWidget (new HeaderWidget (this))
{
}

void
TorrentView::setHeaderText (const QString& text)
{
  const bool headerVisible = !text.isEmpty ();

  myHeaderWidget->setText (text);
  myHeaderWidget->setVisible (headerVisible);

  if (headerVisible)
    adjustHeaderPosition ();

  setViewportMargins (0, headerVisible ? myHeaderWidget->height () : 0, 0, 0);
}

void
TorrentView::resizeEvent (QResizeEvent * event)
{
  QListView::resizeEvent (event);

  if (myHeaderWidget->isVisible ())
    adjustHeaderPosition ();
}

void
TorrentView::adjustHeaderPosition ()
{
  QRect headerWidgetRect = contentsRect ();
  headerWidgetRect.setWidth (viewport ()->width ());
  headerWidgetRect.setHeight (myHeaderWidget->sizeHint ().height ());
  myHeaderWidget->setGeometry (headerWidgetRect);
}