Step #1

Author: hebasto

src/qt/bitcoin.qrc

@@ -1,6 +1,10 @@
 <!DOCTYPE RCC><RCC version="1.0">
+    <qresource prefix="/">
+        <file>res/icon_theme/index.theme</file>
+        <file>res/icon_theme/16x16/actions/bitcoin.png</file>
+        <file>res/icon_theme/32x32/actions/bitcoin.png</file>
+    </qresource>
     <qresource prefix="/icons">
-        <file alias="bitcoin">res/icons/bitcoin.png</file>
         <file alias="address-book">res/icons/address-book.png</file>
         <file alias="send">res/icons/send.png</file>
         <file alias="connect_0">res/icons/connect0.png</file>

src/qt/bitcoingui.cpp

@@ -43,6 +43,7 @@
 #include <QApplication>
 #include <QComboBox>
 #include <QDateTime>
+#include <QDebug>
 #include <QDragEnterEvent>
 #include <QListWidget>
 #include <QMenu>
@@ -90,6 +91,8 @@ BitcoinGUI::BitcoinGUI(interfaces::Node& node, const PlatformStyle *_platformSty
 #ifdef ENABLE_WALLET
     enableWallet = WalletModel::isWalletEnabled();
 #endif // ENABLE_WALLET
+    qInfo() << m_network_style->getTrayAndWindowIcon().availableSizes();
+
     QApplication::setWindowIcon(m_network_style->getTrayAndWindowIcon());
     setWindowIcon(m_network_style->getTrayAndWindowIcon());
     updateWindowTitle();

src/qt/networkstyle.cpp

@@ -73,8 +73,16 @@ NetworkStyle::NetworkStyle(const QString &_appName, const int iconColorHueShift,
         pixmap.convertFromImage(img);
     }
 
-    appIcon             = QIcon(pixmap);
-    trayAndWindowIcon   = QIcon(pixmap.scaled(QSize(256,256)));
+    appIcon = QIcon(pixmap);
+    // trayAndWindowIcon = QIcon(pixmap.scaled(QSize(256, 256)));
+    // trayAndWindowIcon.addPixmap(pixmap.scaled(QSize(128, 128)));
+    // trayAndWindowIcon.addPixmap(pixmap.scaled(QSize(48, 48)));
+    // trayAndWindowIcon.addPixmap(pixmap.scaled(QSize(32, 32)));
+    // trayAndWindowIcon.addPixmap(pixmap.scaled(QSize(16, 16)));
+
+    QIcon::setThemeSearchPaths(QIcon::themeSearchPaths() << ":/res");
+    QIcon::setThemeName("icon_theme");
+    trayAndWindowIcon = QIcon::fromTheme("bitcoin");
 }
 
 const NetworkStyle* NetworkStyle::instantiate(const std::string& networkId)

src/qt/res/icon_theme/16x16/actions/bitcoin.png

@@ -0,0 +1,15 @@
+[Icon Theme]
+Name=bitcoin
+Comment=An original Bitcoin Core icon theme
+
+Directories=16x16/actions,32x32/actions
+
+[16x16/actions]
+Size=16
+Context=Actions
+Type=Fixed
+
+[32x32/actions]
+Size=32
+Context=Actions
+Type=Fixed