Improve Qt client look on hi-dpi displays

qt/Application.cc

@@ -589,6 +589,9 @@ tr_main (int    argc,
 {
   InteropHelper::initialize ();
 
+  Application::setAttribute (Qt::AA_EnableHighDpiScaling);
+  Application::setAttribute (Qt::AA_UseHighDpiPixmaps);
+
   Application app (argc, argv);
   return app.exec ();
 }

qt/CMakeLists.txt

@@ -59,6 +59,7 @@ set(${PROJECT_NAME}_SOURCES
     SessionDialog.cc
     SqueezeLabel.cc
     StatsDialog.cc
+    StyleHelper.cc
     Torrent.cc
     TorrentDelegate.cc
     TorrentDelegateMin.cc
@@ -119,6 +120,7 @@ set(${PROJECT_NAME}_HEADERS
     Speed.h
     SqueezeLabel.h
     StatsDialog.h
+    StyleHelper.h
     Torrent.h
     TorrentDelegate.h
     TorrentDelegateMin.h

qt/FaviconCache.cc

@@ -104,9 +104,7 @@ FaviconCache::findFromHost (const QString& host)
 {
   ensureCacheDirHasBeenScanned ();
 
-  const QPixmap pixmap = myPixmaps[host];
-  const QSize rightSize = getIconSize ();
-  return pixmap.isNull () || pixmap.size () == rightSize ? pixmap : pixmap.scaled (rightSize);
+  return myPixmaps[host];
 }
 
 void

qt/FilterBar.cc

@@ -147,7 +147,7 @@ FilterBar::refreshTrackers ()
       const int count = torrentsPerHost[name];
       row->setData (count, FilterBarComboBox::CountRole);
       row->setData (getCountString (count), FilterBarComboBox::CountStringRole);
-      row->setData (favicons.findFromHost (host), Qt::DecorationRole);
+      row->setData (QIcon (favicons.findFromHost (host)), Qt::DecorationRole);
     }
 
   // rows to remove
@@ -182,7 +182,7 @@ FilterBar::refreshTrackers ()
       const int count = torrentsPerHost[host];
       row->setData (count, FilterBarComboBox::CountRole);
       row->setData (getCountString (count), FilterBarComboBox::CountStringRole);
-      row->setData (favicons.findFromHost (host), Qt::DecorationRole);
+      row->setData (QIcon (favicons.findFromHost (host)), Qt::DecorationRole);
       row->setData (host, TrackerRole);
       myTrackerModel->insertRow (i, row);
       anyAdded = true;

qt/FilterBarComboBox.cc

@@ -11,6 +11,7 @@
 #include <QStylePainter>
 
 #include "FilterBarComboBox.h"
+#include "StyleHelper.h"
 #include "Utils.h"
 
 namespace
@@ -109,19 +110,12 @@ FilterBarComboBox::paintEvent (QPaintEvent * e)
       rect.adjust (2, 1, -2, -1);
 
       // draw the icon
-      QPixmap pixmap;
-      QVariant variant = modelIndex.data (Qt::DecorationRole);
-      switch (variant.type ())
-        {
-          case QVariant::Pixmap: pixmap = qvariant_cast<QPixmap> (variant); break;
-          case QVariant::Icon:   pixmap = qvariant_cast<QIcon> (variant).pixmap (iconSize ()); break;
-          default: break;
-        }
-      if (!pixmap.isNull ())
+      const QIcon icon = Utils::getIconFromIndex (modelIndex);
+      if (!icon.isNull ())
         {
           const QRect iconRect = QStyle::alignedRect(opt.direction, Qt::AlignLeft | Qt::AlignVCenter,
                                                      opt.iconSize, rect);
-          painter.drawPixmap (iconRect.topLeft (), pixmap);
+          icon.paint (&painter, iconRect, Qt::AlignCenter, StyleHelper::getIconMode (opt.state), QIcon::Off);
           Utils::narrowRect (rect, iconRect.width () + hmargin, 0, opt.direction);
         }
 

qt/FilterBarComboBoxDelegate.cc

@@ -13,6 +13,7 @@
 
 #include "FilterBarComboBox.h"
 #include "FilterBarComboBoxDelegate.h"
+#include "StyleHelper.h"
 #include "Utils.h"
 
 namespace
@@ -86,10 +87,10 @@ FilterBarComboBoxDelegate::paint (QPainter                    * painter,
       Utils::narrowRect (boundingBox, 0, countRect.width () + hmargin, option.direction);
       const QRect displayRect = boundingBox;
 
+      const QIcon icon = Utils::getIconFromIndex (index);
+
       drawBackground (painter, option, index);
-      QStyleOptionViewItem option2 = option;
-      option2.decorationSize = myCombo->iconSize ();
-      drawDecoration (painter, option, decorationRect, decoration (option2,index.data (Qt::DecorationRole)));
+      icon.paint (painter, decorationRect, Qt::AlignCenter, StyleHelper::getIconMode (option.state), QIcon::Off);
       drawDisplay (painter, option, displayRect, index.data (Qt::DisplayRole).toString ());
       drawDisplay (painter, disabledOption, countRect, index.data (FilterBarComboBox::CountStringRole).toString ());
       drawFocus (painter, option, displayRect|countRect);
@@ -113,7 +114,7 @@ FilterBarComboBoxDelegate::sizeHint (const QStyleOptionViewItem & option,
       QSize size = QItemDelegate::sizeHint (option, index);
       size.setHeight (qMax (size.height (), myCombo->iconSize ().height () + 6));
       size.rwidth () += s->pixelMetric (QStyle::PM_FocusFrameHMargin, 0, myCombo);
-      size.rwidth () += rect (option,index,FilterBarComboBox::CountStringRole).width ();
+      size.rwidth () += rect (option, index, FilterBarComboBox::CountStringRole).width ();
       size.rwidth () += hmargin * 4;
       return size;
     }

qt/StyleHelper.cc

@@ -0,0 +1,19 @@
+/*
+ * This file Copyright (C) 2017 Mnemosyne LLC
+ *
+ * It may be used under the GNU GPL versions 2 or 3
+ * or any future license endorsed by Mnemosyne LLC.
+ *
+ */
+
+#include "StyleHelper.h"
+
+QIcon::Mode
+StyleHelper::getIconMode (QStyle::State state)
+{
+  if ((state & QStyle::State_Enabled) == 0)
+    return QIcon::Disabled;
+  if ((state & QStyle::State_Selected) != 0)
+    return QIcon::Selected;
+  return QIcon::Normal;
+}

qt/StyleHelper.h

@@ -0,0 +1,18 @@
+/*
+ * This file Copyright (C) 2017 Mnemosyne LLC
+ *
+ * It may be used under the GNU GPL versions 2 or 3
+ * or any future license endorsed by Mnemosyne LLC.
+ *
+ */
+
+#pragma once
+
+#include <QIcon>
+#include <QStyle>
+
+class StyleHelper
+{
+  public:
+    static QIcon::Mode getIconMode (QStyle::State state);
+};

qt/TrackerModel.cc

@@ -40,7 +40,7 @@ TrackerModel::data (const QModelIndex& index, int role) const
             break;
 
           case Qt::DecorationRole:
-            var = trackerInfo.st.getFavicon ();
+            var = QIcon (trackerInfo.st.getFavicon ());
             break;
 
           case TrackerRole:

qt/Utils.cc

@@ -181,6 +181,23 @@ Utils::guessMimeIcon (const QString& filename)
   return fallback;
 }
 
+QIcon
+Utils::getIconFromIndex (const QModelIndex& index)
+{
+  const QVariant variant = index.data (Qt::DecorationRole);
+  switch (variant.type ())
+    {
+      case QVariant::Icon:
+        return qvariant_cast<QIcon> (variant);
+
+      case QVariant::Pixmap:
+        return QIcon (qvariant_cast<QPixmap> (variant));
+
+      default:
+        return QIcon ();
+    }
+}
+
 bool
 Utils::isValidUtf8 (const char * s)
 {

qt/Utils.h

@@ -18,11 +18,14 @@ class QAbstractItemView;
 class QColor;
 class QHeaderView;
 class QIcon;
+class QModelIndex;
 
 class Utils
 {
   public:
     static QIcon guessMimeIcon (const QString& filename);
+    static QIcon getIconFromIndex (const QModelIndex& index);
+
     // Test if string is UTF-8 or not
     static bool isValidUtf8 (const char * s);
 

qt/qtr.pro

@@ -105,6 +105,7 @@ SOURCES += AboutDialog.cc \
            SessionDialog.cc \
            SqueezeLabel.cc \
            StatsDialog.cc \
+           StyleHelper.cc \
            Torrent.cc \
            TorrentDelegate.cc \
            TorrentDelegateMin.cc \