src/Gui/IconLoader.h

   1 /* Copyright (C) 2006 - 2012 Jan Kundrát <jkt@flaska.net>
   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 #ifndef TROJITA_GUI_ICONLOADER_H
  24 #define TROJITA_GUI_ICONLOADER_H
  25
  26 #include <QIcon>
  27
  28 namespace Gui
  29 {
  30
  31 /** @short Wrapper around the QIcon::fromTheme with sane fallback
  32  *
  33  * The issue with the QIcon::fromTheme is that it does not realy work on non-X11
  34  * platforms, unless you ship your own theme index and specify your theme name.
  35  * In Trojitá, we do not really want to hardcode anything, because the
  36  * preference is to use whatever is available from the current theme, but *also*
  37  * provide an icon as a fallback. And that is exactly why this function is here.
  38  *
  39  * It is implemented inline in order to prevent a dependency from the Imap lib
  40  * into the Gui lib.
  41  * */
  42 inline QIcon loadIcon(const QString &name)
  43 {
  44     // A QIcon(QString) constructor creates non-null QIcons, even though the resulting icon will
  45     // not ever return a valid and usable pixmap. This means that we have to actually look at the
  46     // icon's pixmap to find out what to return.
  47     // If we do not do that, the GUI shows empty pixmaps instead of a text fallback, which is
  48     // clearly suboptimal.
  49     QIcon res = QIcon::fromTheme(name, QIcon(QString::fromUtf8(":/icons/%1").arg(name)));
  50     if (res.pixmap(QSize(16, 16)).isNull()) {
  51         return QIcon();
  52     } else {
  53         return res;
  54     }
  55 }
  56
  57 }
  58
  59 #endif // TROJITA_GUI_ICONLOADER_H