LPS-115484 As a developer I can declare theme's customizable CSS variables

modules/apps/frontend-css/frontend-css-variables-api/bnd.bnd

@@ -1,4 +1,6 @@
 Bundle-Name: Liferay Frontend CSS Variables API
 Bundle-SymbolicName: com.liferay.frontend.css.variables.api
 Bundle-Version: 1.0.0
-Export-Package: com.liferay.frontend.css.variables
+Export-Package:\
+	com.liferay.frontend.css.variables,\
+	com.liferay.frontend.css.variables.theme

modules/apps/frontend-css/frontend-css-variables-api/src/main/java/com/liferay/frontend/css/variables/CSSVariableDescription.java

@@ -0,0 +1,26 @@
+/**
+ * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 2.1 of the License, or (at your option)
+ * any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
+ * details.
+ */
+
+package com.liferay.frontend.css.variables;
+
+/**
+ * @author Iván Zaera Avellón
+ */
+public interface CSSVariableDescription {
+
+	public CSSVariableType getCSSVariableType();
+
+	public String getName();
+
+}

modules/apps/frontend-css/frontend-css-variables-api/src/main/java/com/liferay/frontend/css/variables/CSSVariableType.java

@@ -0,0 +1,24 @@
+/**
+ * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 2.1 of the License, or (at your option)
+ * any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
+ * details.
+ */
+
+package com.liferay.frontend.css.variables;
+
+/**
+ * @author Iván Zaera Avellón
+ */
+public enum CSSVariableType {
+
+	COLOR, STRING
+
+}

modules/apps/frontend-css/frontend-css-variables-api/src/main/java/com/liferay/frontend/css/variables/theme/ThemeCSSVariableDescriptionsRegistry.java

@@ -0,0 +1,30 @@
+/**
+ * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 2.1 of the License, or (at your option)
+ * any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
+ * details.
+ */
+
+package com.liferay.frontend.css.variables.theme;
+
+import com.liferay.frontend.css.variables.CSSVariableDescription;
+import com.liferay.portal.kernel.model.Theme;
+
+import java.util.Map;
+
+/**
+ * @author Iván Zaera Avellón
+ */
+public interface ThemeCSSVariableDescriptionsRegistry {
+
+	public Map<String, CSSVariableDescription> getCSSVariableDescriptions(
+		Theme theme);
+
+}

modules/apps/frontend-css/frontend-css-variables-api/src/main/resources/com/liferay/frontend/css/variables/theme/packageinfo

@@ -0,0 +1 @@
+version 1.0.0

modules/apps/frontend-css/frontend-css-variables-web/build.gradle

@@ -11,5 +11,6 @@ dependencies {
 	compileOnly project(":core:osgi-service-tracker-collections")
 	compileOnly project(":core:petra:petra-string")
 
+	testCompile group: "com.liferay.portal", name: "com.liferay.portal.impl", version: "default"
 	testCompile group: "junit", name: "junit", version: "4.12"
 }

modules/apps/frontend-css/frontend-css-variables-web/src/main/java/com/liferay/frontend/css/variables/web/internal/CSSVariableDescriptionImpl.java

@@ -0,0 +1,45 @@
+/**
+ * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 2.1 of the License, or (at your option)
+ * any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
+ * details.
+ */
+
+package com.liferay.frontend.css.variables.web.internal;
+
+import com.liferay.frontend.css.variables.CSSVariableDescription;
+import com.liferay.frontend.css.variables.CSSVariableType;
+
+/**
+ * @author Iván Zaera Avellón
+ */
+public class CSSVariableDescriptionImpl implements CSSVariableDescription {
+
+	public CSSVariableDescriptionImpl(
+		CSSVariableType cssVariableType, String name) {
+
+		_cssVariableType = cssVariableType;
+		_name = name;
+	}
+
+	@Override
+	public CSSVariableType getCSSVariableType() {
+		return _cssVariableType;
+	}
+
+	@Override
+	public String getName() {
+		return _name;
+	}
+
+	private final CSSVariableType _cssVariableType;
+	private final String _name;
+
+}

modules/apps/frontend-css/frontend-css-variables-web/src/main/java/com/liferay/frontend/css/variables/web/internal/theme/ThemeBundleInspector.java

@@ -0,0 +1,172 @@
+/**
+ * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
+ *
+ * This library is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 2.1 of the License, or (at your option)
+ * any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
+ * details.
+ */
+
+package com.liferay.frontend.css.variables.web.internal.theme;
+
+import com.liferay.frontend.css.variables.CSSVariableDescription;
+import com.liferay.frontend.css.variables.CSSVariableType;
+import com.liferay.frontend.css.variables.web.internal.CSSVariableDescriptionImpl;
+import com.liferay.petra.string.StringBundler;
+import com.liferay.portal.kernel.json.JSONArray;
+import com.liferay.portal.kernel.json.JSONException;
+import com.liferay.portal.kernel.json.JSONFactory;
+import com.liferay.portal.kernel.json.JSONObject;
+import com.liferay.portal.kernel.util.LocaleUtil;
+import com.liferay.portal.kernel.util.StringUtil;
+import com.liferay.portal.kernel.util.Validator;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import java.net.URL;
+
+import java.util.Dictionary;
+import java.util.HashMap;
+import java.util.Locale;
+import java.util.Map;
+
+import org.osgi.framework.Bundle;
+
+/**
+ * @author Iván Zaera Avellón
+ */
+public class ThemeBundleInspector {
+
+	public static boolean isTheme(Bundle bundle) {
+		boolean theme = false;
+
+		URL url = bundle.getResource("WEB-INF/liferay-look-and-feel.xml");
+
+		if (url != null) {
+			try (InputStream inputStream = url.openStream()) {
+				String xml = StringUtil.read(inputStream);
+
+				if (xml.contains("</theme>")) {
+					theme = true;
+				}
+			}
+			catch (IOException ioException) {
+				throw new RuntimeException(ioException);
+			}
+		}
+
+		return theme;
+	}
+
+	/**
+	 * @throws IllegalArgumentException if the bundle is not a theme bundle
+	 */
+	public ThemeBundleInspector(Bundle bundle, JSONFactory jsonFactory)
+		throws IllegalArgumentException {
+
+		_bundle = bundle;
+		_jsonFactory = jsonFactory;
+
+		if (!isTheme(bundle)) {
+			throw new IllegalArgumentException(
+				StringBundler.concat(
+					"Bundle ", _bundle.getSymbolicName(), " is not a theme"));
+		}
+	}
+
+	public Map<String, CSSVariableDescription> getCSSVariableDescriptions()
+		throws JSONException {
+
+		JSONObject jsonObject = _parseJSONObject(_getTokensPath());
+
+		if (jsonObject == null) {
+			return null;
+		}
+
+		JSONArray variablesJSONArray = jsonObject.getJSONArray("variables");
+
+		if (variablesJSONArray == null) {
+			return null;
+		}
+
+		Map<String, CSSVariableDescription> cssVariableDescriptions =
+			new HashMap<>();
+
+		for (int i = 0; i < variablesJSONArray.length(); i++) {
+			JSONObject cssVariableDefinitionJSONObject =
+				variablesJSONArray.getJSONObject(i);
+
+			String name = cssVariableDefinitionJSONObject.getString("name");
+
+			cssVariableDescriptions.put(
+				name,
+				new CSSVariableDescriptionImpl(
+					_getCSSVariableType(cssVariableDefinitionJSONObject),
+					name));
+		}
+
+		if (cssVariableDescriptions.isEmpty()) {
+			return null;
+		}
+
+		return cssVariableDescriptions;
+	}
+
+	public String getSymbolicName() {
+		return _bundle.getSymbolicName();
+	}
+
+	private CSSVariableType _getCSSVariableType(JSONObject jsonObject) {
+		String type = jsonObject.getString("type");
+
+		if (type.equals("color")) {
+			return CSSVariableType.COLOR;
+		}
+
+		return CSSVariableType.STRING;
+	}
+
+	private String _getTokensPath() {
+		Locale defaultLocale = LocaleUtil.getDefault();
+
+		Dictionary<String, String> headers = _bundle.getHeaders(
+			defaultLocale.toString());
+
+		String tokensPath = headers.get("Tokens-Path");
+
+		if (Validator.isNull(tokensPath)) {
+			tokensPath = "WEB-INF/tokens.json";
+		}
+
+		if (tokensPath.charAt(0) == '/') {
+			tokensPath = tokensPath.substring(1);
+		}
+
+		return tokensPath;
+	}
+
+	private JSONObject _parseJSONObject(String fileName) throws JSONException {
+		URL resource = _bundle.getResource(fileName);
+
+		if (resource == null) {
+			return null;
+		}
+
+		try (InputStream is = resource.openStream()) {
+			return _jsonFactory.createJSONObject(StringUtil.read(is));
+		}
+		catch (IOException ioException) {
+			throw new JSONException("Unable to parse " + fileName, ioException);
+		}
+	}
+
+	private final Bundle _bundle;
+	private final JSONFactory _jsonFactory;
+
+}