Added new i18n support classes

addons/i18n/src/main/java/org/vaadin/spring/i18n/support/Translatable.java

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+/*
+ * Copyright 2016 The original authors
+ *
+ * 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 org.vaadin.spring.i18n.support;
+
+import java.io.Serializable;
+import java.util.Locale;
+
+/**
+ * Interface to be implemented by all components that contain some kind of internationalized content that needs to be
+ * updated on the fly when the locale is changed.
+ * 
+ * @see TranslatableSupport
+ * @author Petter Holmström ([email protected])
+ */
+public interface Translatable extends Serializable {
+
+    /**
+     * Called when the component should update all of its translatable strings, setting locales, etc. The locale to use
+     * 
+     * @param locale the new locale to use.
+     */
+    void updateMessageStrings(Locale locale);
+}

addons/i18n/src/main/java/org/vaadin/spring/i18n/support/TranslatableSupport.java

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+/*
+ * Copyright 2016 The original authors
+ *
+ * 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 org.vaadin.spring.i18n.support;
+
+import java.util.Locale;
+
+import com.vaadin.ui.Component;
+import com.vaadin.ui.HasComponents;
+import com.vaadin.ui.UI;
+
+/**
+ * Implementation of {@link Translatable} intended to be used as a delegate by an owning {@link UI}.
+ * The {@link #updateMessageStrings(Locale)} method will traverse the entire component hierarchy of the UI and
+ * update the message strings of any components that implement the {@link Translatable} interface.
+ *
+ * @author Petter Holmström ([email protected])
+ */
+public class TranslatableSupport implements Translatable {
+
+    private final UI ui;
+
+    /**
+     * Creates a new {@code TranslatableSupport}.
+     * 
+     * @param ui the UI that owns the object.
+     */
+    public TranslatableSupport(UI ui) {
+        this.ui = ui;
+    }
+
+    @Override
+    public void updateMessageStrings(Locale locale) {
+        updateMessageStrings(locale, ui);
+    }
+
+    private void updateMessageStrings(Locale locale, Component component) {
+        if (component instanceof Translatable) {
+            ((Translatable) component).updateMessageStrings(locale);
+        }
+        if (component instanceof HasComponents) {
+            for (Component child : (HasComponents) component) {
+                updateMessageStrings(locale, child);
+            }
+        }
+    }
+
+}

addons/i18n/src/main/java/org/vaadin/spring/i18n/support/TranslatableUI.java

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+/*
+ * Copyright 2016 The original authors
+ *
+ * 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 org.vaadin.spring.i18n.support;
+
+import java.util.Locale;
+
+import com.vaadin.server.VaadinRequest;
+import com.vaadin.ui.UI;
+
+/**
+ * Base class intended to make it easier to write UIs that needs to support changing the locale on the fly.
+ * You are not required to extend this class to be able to use {@link Translatable} components. You can
+ * easily plug in the {@link TranslatableSupport} into your existing UIs.
+ * 
+ * @author Petter Holmström ([email protected])
+ */
+public abstract class TranslatableUI extends UI {
+
+    private final TranslatableSupport translatableSupport = new TranslatableSupport(this);
+
+    /**
+     * {@inheritDoc}
+     * <p>
+     * This method will also update the message strings of all {@link Translatable} components currently attached
+     * to the UI.
+     * 
+     * @see #updateMessageStrings()
+     */
+    @Override
+    public void setLocale(Locale locale) {
+        super.setLocale(locale);
+        updateMessageStrings();
+    }
+
+    /**
+     * {@inheritDoc}
+     * <p>
+     * This implementation will delegate the UI initialization to {@link #initUI(VaadinRequest)}, then update
+     * the message strings of all {@link Translatable} components.
+     * 
+     * @see #updateMessageStrings()
+     */
+    @Override
+    protected void init(VaadinRequest request) {
+        initUI(request);
+        updateMessageStrings();
+    }
+
+    /**
+     * Called by {@link #init(VaadinRequest)} to actually initialize the UI.
+     * 
+     * @param request
+     */
+    protected abstract void initUI(VaadinRequest request);
+
+    /**
+     * Returns the {@link TranslatableSupport} delegate owned by this UI.
+     */
+    protected TranslatableSupport getTranslatableSupport() {
+        return translatableSupport;
+    }
+
+    /**
+     * Updates the message strings of all {@link Translatable} components attached to this UI.
+     */
+    protected void updateMessageStrings() {
+        getTranslatableSupport().updateMessageStrings(getLocale());
+    }
+}