fix(linux): support themed icons

Author: ReenigneArcher

.github/workflows/ci.yml

@@ -64,10 +64,12 @@ jobs:
         run: |
           sudo apt-get update
           sudo apt-get install -y \
+            adwaita-icon-theme \
             build-essential \
             cmake \
             imagemagick \
             ninja-build \
+            qt5-gtk-platformtheme \
             qtbase5-dev \
             xvfb
 
@@ -219,6 +221,8 @@ jobs:
         # TODO: tests randomly hang on Linux, https://github.com/LizardByte/tray/issues/45
         timeout-minutes: 3
         working-directory: build/tests
+        env:
+          QT_QPA_PLATFORMTHEME: gtk3
         run: ./test_tray --gtest_color=yes --gtest_output=xml:test_results.xml
 
       - name: Upload screenshots

src/tray_linux.cpp

@@ -146,7 +146,10 @@ extern "C" {
       return;
     }
 
-    g_tray_icon->setIcon(QIcon(QString::fromUtf8(tray->icon)));
+    const QString icon_str = QString::fromUtf8(tray->icon);
+    g_tray_icon->setIcon(
+      QFileInfo(icon_str).exists() ? QIcon(icon_str) : QIcon::fromTheme(icon_str)
+    );
 
     if (tray->tooltip != nullptr) {
       g_tray_icon->setToolTip(QString::fromUtf8(tray->tooltip));
@@ -168,7 +171,8 @@ extern "C" {
       const char *icon_path = tray->notification_icon != nullptr ? tray->notification_icon : tray->icon;
       QString icon;
       if (icon_path != nullptr) {
-        icon = QUrl::fromLocalFile(QFileInfo(QString::fromUtf8(icon_path)).absoluteFilePath()).toString();
+        QFileInfo fi(QString::fromUtf8(icon_path));
+        icon = fi.exists() ? QUrl::fromLocalFile(fi.absoluteFilePath()).toString() : QString::fromUtf8(icon_path);
       }
       QVariantMap hints;
       if (!icon.isEmpty()) {

tests/unit/test_tray.cpp

@@ -29,6 +29,7 @@
 #if TRAY_QT
 constexpr const char *TRAY_ICON1 = "icon.png";
 constexpr const char *TRAY_ICON2 = "icon.png";
+constexpr const char *TRAY_ICON_THEMED = "dialog-information";
 #elif TRAY_APPKIT
 constexpr const char *TRAY_ICON1 = "icon.png";
 constexpr const char *TRAY_ICON2 = "icon.png";
@@ -596,3 +597,36 @@ TEST_F(TrayTest, TestTrayShowMenu) {
 TEST_F(TrayTest, TestTrayExit) {
   tray_exit();
 }
+
+#if defined(TRAY_QT)
+
+TEST_F(TrayTest, TestTrayIconThemed) {
+  testTray.icon = TRAY_ICON_THEMED;
+  int result = tray_init(&testTray);
+  trayRunning = (result == 0);
+  ASSERT_EQ(result, 0);
+  WaitForTrayReady();
+  EXPECT_TRUE(captureScreenshot("tray_icon_themed"));
+  testTray.icon = TRAY_ICON1;
+}
+
+TEST_F(TrayTest, TestNotificationWithThemedIcon) {
+  int initResult = tray_init(&testTray);
+  trayRunning = (initResult == 0);
+  ASSERT_EQ(initResult, 0);
+
+  testTray.notification_title = "Test Notification";
+  testTray.notification_text = "This is a test notification message";
+  testTray.notification_icon = TRAY_ICON_THEMED;
+  tray_update(&testTray);
+
+  WaitForTrayReady();
+  EXPECT_TRUE(captureScreenshot("tray_notification_themed_icon"));
+
+  testTray.notification_title = nullptr;
+  testTray.notification_text = nullptr;
+  testTray.notification_icon = nullptr;
+  tray_update(&testTray);
+}
+
+#endif  // TRAY_QT