Feature/Linux KDE Plasma Desktop environment support

README.md

@@ -13,7 +13,10 @@ It can be useful for example if you want to synchronize your GUI App's look and
 > This library is inspired by the dark-theme detection in [Intellij Idea](https://github.com/JetBrains/intellij-community).
 
 # Compatibility
-It works on **Windows 10**, **MacOS Mojave** (or later) and even on **some Linux distributions**.
+It works on **Windows 10**, **MacOS Mojave** (or later) and even on **some Linux desktop environments**:
+
+- Gnome: Fully supported and tested on Ubuntu
+- KDE Plasma: For now will only support `isDark` method, tested on Ubuntu with `kde-plasma-desktop` package
 
 # Requirements
 **Java 11 or higher**

src/main/java/com/jthemedetecor/KdeThemeDetector.java

@@ -0,0 +1,98 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *          http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *   Unless required by applicable law or agreed to in writing, software
+ *   distributed under the License is distributed on an "AS IS" BASIS,
+ *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *   See the License for the specific language governing permissions and
+ *   limitations under the License.
+ */
+
+package com.jthemedetecor;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Arrays;
+import java.util.function.Consumer;
+
+/**
+ * Used for detecting the dark theme on a Linux KDE desktop environment.
+ * Tested on Ubuntu KDE Plasma (kde-plasma-desktop).
+ *
+ * @see GnomeThemeDetector
+ */
+public class KdeThemeDetector extends OsThemeDetector {
+    private static final Logger logger = LoggerFactory.getLogger(KdeThemeDetector.class);
+    /**
+     * List of the known look and feel packages, if the user use a package that is not listed in this list
+     * then will check if the package name contains `dark` regardless of the case sensitivity
+     * */
+    private static final String[] darkLookAndFeelPackages = {
+            "org.kde.breezedark.desktop", "org.kde.oxygen", "org.kde.arc-dark",
+            "org.kde.numix-dark", "org.kde.papirus-dark", "org.kde.suru-dark"
+    };
+
+    @Override
+    public boolean isDark() {
+        try {
+            String currentLookAndFeelPackageName = getCurrentLookAndFeelPackageName();
+
+            if (Arrays.asList(darkLookAndFeelPackages).contains(currentLookAndFeelPackageName)) {
+                return true;
+            }
+
+            return currentLookAndFeelPackageName.toLowerCase().contains("dark".toLowerCase());
+
+        } catch (IOException e) {
+            logger.error("Couldn't detect Linux OS theme", e);
+            return false;
+        }
+    }
+
+    private String getCurrentLookAndFeelPackageName() throws IOException {
+        String kdeGlobalsFilePath;
+
+        // Get user's home directory
+        Path homeDir = Paths.get(System.getProperty("user.home"));
+
+        // Build the complete file path
+        kdeGlobalsFilePath = homeDir.resolve(".config/kdeglobals").toString();
+
+        // Read the file and get the value of the property LookAndFeelPackage
+        try (BufferedReader reader = new BufferedReader(new FileReader(kdeGlobalsFilePath))) {
+            String lookAndFeelPackage = null;
+            String line;
+            while ((line = reader.readLine()) != null) {
+                if (line.startsWith("LookAndFeelPackage=")) {
+                    lookAndFeelPackage = line.substring(line.indexOf("=") + 1);
+                    break;
+                }
+            }
+            return lookAndFeelPackage;
+        }
+    }
+
+    // TODO: Add support for the listeners, don't forgot to update the README.md if you did
+
+    @Override
+    public synchronized void registerListener(@NotNull Consumer<Boolean> darkThemeListener) {
+
+    }
+
+    @Override
+    public synchronized void removeListener(@Nullable Consumer<Boolean> darkThemeListener) {
+
+    }
+}

src/main/java/com/jthemedetecor/OsThemeDetector.java

@@ -62,6 +62,9 @@ private static OsThemeDetector createDetector() {
         } else if (OsInfo.isGnome()) {
             logDetection("Gnome", GnomeThemeDetector.class);
             return new GnomeThemeDetector();
+        } else if (OsInfo.isKde()) {
+            logDetection("Kde", KdeThemeDetector.class);
+            return new KdeThemeDetector();
         } else if (OsInfo.isMacOsMojaveOrLater()) {
             logDetection("MacOS", MacOSThemeDetector.class);
             return new MacOSThemeDetector();
@@ -102,7 +105,8 @@ private static void logDetection(String desktop, Class<? extends OsThemeDetector
 
     @ThreadSafe
     public static boolean isSupported() {
-        return OsInfo.isWindows10OrLater() || OsInfo.isMacOsMojaveOrLater() || OsInfo.isGnome();
+        return OsInfo.isWindows10OrLater() || OsInfo.isMacOsMojaveOrLater() || OsInfo.isGnome() ||
+                OsInfo.isKde();
     }
 
     private static final class EmptyDetector extends OsThemeDetector {

src/main/java/com/jthemedetecor/util/OsInfo.java

@@ -43,12 +43,17 @@ public static boolean isMacOsMojaveOrLater() {
         return hasTypeAndVersionOrHigher(PlatformEnum.MACOS, "10.14");
     }
 
+    @NotNull
+    public static String getCurrentLinuxDesktopEnvironmentName() {
+        return System.getenv("XDG_CURRENT_DESKTOP");
+    }
+
     public static boolean isGnome() {
-        return isLinux() && (
-                        queryResultContains("echo $XDG_CURRENT_DESKTOP", "gnome") ||
-                        queryResultContains("echo $XDG_DATA_DIRS | grep -Eo 'gnome'", "gnome") ||
-                        queryResultContains("ps -e | grep -E -i \"gnome\"", "gnome")
-        );
+        return isLinux() && getCurrentLinuxDesktopEnvironmentName().toLowerCase().contains("gnome");
+    }
+
+    public static boolean isKde() {
+        return isLinux() && getCurrentLinuxDesktopEnvironmentName().toLowerCase().contains("KDE".toLowerCase());
     }
 
     public static boolean hasType(PlatformEnum platformType) {