fix: Placeholder linux icon in the taskbar

This will publish the main class in the package.json file, which is used by the linux installer to set the StartupWMClass property of the desktop file on linux.
This is used to set the icon on the status bar, as reported in #273

Author: shannah

cli/src/main/java/ca/weblite/jdeploy/publishing/BasePublishDriver.java

@@ -15,6 +15,9 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
+import java.util.jar.Attributes;
+import java.util.jar.JarFile;
+import java.util.jar.Manifest;
 
 @Singleton
 public class BasePublishDriver implements PublishDriverInterface {
@@ -94,6 +97,28 @@ public void prepare(
             checksums.put("installsplash.png", MD5.getMD5Checksum(installSplash));
         }
 
+        // Extract main class from JAR manifest and add to jdeploy object
+        // This will be used for the Linux StartupWMClass desktop entry
+        if (!jdeployObj.has("mainClass") && jdeployObj.has("jar")) {
+            try {
+                File mainJarFile = new File(publishJdeployBundleDir, new File(jdeployObj.getString("jar")).getName());
+                if (mainJarFile.exists()) {
+                    try (JarFile jarFile = new JarFile(mainJarFile)) {
+                        Manifest manifest = jarFile.getManifest();
+                        if (manifest != null) {
+                            String mainClass = manifest.getMainAttributes().getValue(Attributes.Name.MAIN_CLASS);
+                            if (mainClass != null && !mainClass.isEmpty()) {
+                                jdeployObj.put("mainClass", mainClass);
+                            }
+                        }
+                    }
+                }
+            } catch (Exception e) {
+                // Log but don't fail - main class is optional for Linux desktop entry
+                System.err.println("Warning: Could not extract main class from JAR manifest: " + e.getMessage());
+            }
+        }
+
         FileUtils.writeStringToFile(new File(context.getPublishDir(),"package.json"), packageJSON.toString(), "UTF-8");
 
         if (context.packagingContext.isPackageSigningEnabled()) {

installer/src/main/java/ca/weblite/jdeploy/installer/Main.java

@@ -804,6 +804,15 @@ private void install() throws IOException {
     }
 
     private void writeLinuxDesktopFile(File dest, String appTitle, File appIcon, File launcher) throws IOException {
+        // Derive StartupWMClass from the npm package name
+        String wmClass = npmPackageVersion().getMainClass();
+        if (wmClass != null) {
+            wmClass = wmClass.replaceAll("\\.", "-");
+        }
+        if (npmPackageVersion().getWmClassName() != null) {
+            wmClass = npmPackageVersion().getWmClassName();
+        }
+
         String contents = "[Desktop Entry]\n" +
                 "Version=1.0\n" +
                 "Type=Application\n" +
@@ -813,6 +822,11 @@ private void writeLinuxDesktopFile(File dest, String appTitle, File appIcon, Fil
                 "Comment=Launch {{APP_TITLE}}\n" +
                 "Terminal=false\n";
 
+        // Add StartupWMClass if we have a valid value
+        if (wmClass != null && !wmClass.isEmpty()) {
+            contents += "StartupWMClass=" + wmClass + "\n";
+        }
+
         if (appInfo().hasDocumentTypes() || appInfo().hasUrlSchemes()) {
             StringBuilder mimetypes = new StringBuilder();
             if (appInfo().hasDocumentTypes()) {

installer/src/main/java/ca/weblite/jdeploy/installer/npm/NPMPackage.java

@@ -18,8 +18,6 @@ public String getName() {
         return packageInfo.getString("name");
     }
 
-
-
     private static boolean isPrerelease(String version) {
         if (!version.contains("-")) return false;
         String lcVersion = version.toLowerCase();
@@ -135,7 +133,4 @@ public NPMPackageVersion getLatestVersion(boolean prerelease, String semVer) {
         }
         return new NPMPackageVersion(this, versionNumber, packageInfo.getJSONObject("versions").getJSONObject(versionNumber));
     }
-
-
-
 }

installer/src/main/java/ca/weblite/jdeploy/installer/npm/NPMPackageVersion.java

@@ -100,4 +100,18 @@ public String getInstallerTheme() {
     public Map<PermissionRequest, String> getPermissionRequests() {
         return new PermissionRequestService().getPermissionRequests(packageJson);
     }
+
+    public String getMainClass() {
+        if (jdeploy().has("mainClass")) {
+            return jdeploy().getString("mainClass");
+        }
+        return null;
+    }
+
+    public String getWmClassName() {
+        if (jdeploy().has("linux") && jdeploy().getJSONObject("linux").has("wmClassName")) {
+            return jdeploy().getJSONObject("linux").getString("wmClassName");
+        }
+        return null;
+    }
 }