src/Gui/ColoredItemDelegate.cpp

   1 /* Copyright (C) Roland Pallai <dap78@magex.hu>
   2
   3    This file is part of the Trojita Qt IMAP e-mail client,
   4    http://trojita.flaska.net/
   5
   6    This program is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU General Public License as
   8    published by the Free Software Foundation; either version 2 of
   9    the License or (at your option) version 3 or any later version
  10    accepted by the membership of KDE e.V. (or its successor approved
  11    by the membership of KDE e.V.), which shall act as a proxy
  12    defined in Section 14 of version 3 of the license.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "ColoredItemDelegate.h"
  24
  25 namespace Gui
  26 {
  27
  28 ColoredItemDelegate::ColoredItemDelegate(QObject *parent) : QStyledItemDelegate(parent)
  29 {
  30 }
  31
  32 void ColoredItemDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const
  33 {
  34     QStyleOptionViewItem viewOption(option);
  35     QColor itemForegroundColor = index.data(Qt::ForegroundRole).value<QColor>();
  36     if (itemForegroundColor.isValid()) {
  37         // Thunderbird works like this and we like it
  38         viewOption.palette.setColor(QPalette::ColorGroup::Active, QPalette::Highlight, itemForegroundColor);
  39
  40         // We have to make sure that the text remains readable with the new Highlight color.
  41         // This covers most of the cases out there if not all. Feel free to extend if you are using a very
  42         // special theme.
  43         auto fgLightnessF = viewOption.palette.color(QPalette::ColorGroup::Active, QPalette::HighlightedText).lightnessF();
  44         auto bgLightnessF = viewOption.palette.color(QPalette::ColorGroup::Active, QPalette::Highlight).lightnessF();
  45         if (fgLightnessF > 0.75 && bgLightnessF > 0.75) {
  46             viewOption.palette.setColor(QPalette::ColorGroup::Active, QPalette::HighlightedText, Qt::black);
  47         } else
  48         if (fgLightnessF < 0.25 && bgLightnessF < 0.25) {
  49             viewOption.palette.setColor(QPalette::ColorGroup::Active, QPalette::HighlightedText, Qt::white);
  50         }
  51
  52         viewOption.palette.setColor(QPalette::ColorGroup::Inactive, QPalette::HighlightedText, itemForegroundColor);
  53     }
  54     QStyledItemDelegate::paint(painter, viewOption, index);
  55 }
  56
  57 }