Introduce "shouldWriteDefaultValues" property to DesignContext.

Change-Id: I979448e5af032333a6a2f7b99b11ab16c41d7b18

21 files changed, 101 insertions, 72 deletions

diff --git a/server/src/main/java/com/vaadin/ui/AbstractColorPicker.java b/server/src/main/java/com/vaadin/ui/AbstractColorPicker.java
index a537df0b21..b950361798 100644
--- a/server/src/main/java/com/vaadin/ui/AbstractColorPicker.java
+++ b/server/src/main/java/com/vaadin/ui/AbstractColorPicker.java
@@ -514,12 +514,14 @@ public abstract class AbstractColorPicker extends AbstractField<Color> {
 
         Attributes attribute = design.attributes();
         DesignAttributeHandler.writeAttribute("color", attribute,
-                getValue().getCSS(), Color.WHITE.getCSS(), String.class);
+                getValue().getCSS(), Color.WHITE.getCSS(), String.class,
+                designContext);
         DesignAttributeHandler.writeAttribute("popup-style", attribute,
                 popupStyle == PopupStyle.POPUP_NORMAL ? "normal" : "simple",
-                "normal", String.class);
+                "normal", String.class, designContext);
         DesignAttributeHandler.writeAttribute("position", attribute,
-                positionX + "," + positionY, "0,0", String.class);
+                positionX + "," + positionY, "0,0", String.class,
+                designContext);
     }
 
     @Override
diff --git a/server/src/main/java/com/vaadin/ui/AbstractComponent.java b/server/src/main/java/com/vaadin/ui/AbstractComponent.java
index 0681612996..94fa738dd3 100644
--- a/server/src/main/java/com/vaadin/ui/AbstractComponent.java
+++ b/server/src/main/java/com/vaadin/ui/AbstractComponent.java
@@ -1240,7 +1240,8 @@ public abstract class AbstractComponent extends AbstractClientConnector
         Attributes attr = design.attributes();
         // handle default attributes
         for (String attribute : getDefaultAttributes()) {
-            DesignAttributeHandler.writeAttribute(this, attribute, attr, def);
+            DesignAttributeHandler.writeAttribute(this, attribute, attr, def,
+                    designContext);
         }
         // handle locale
         if (getLocale() != null && (getParent() == null
@@ -1261,7 +1262,8 @@ public abstract class AbstractComponent extends AbstractClientConnector
         if (this instanceof Focusable) {
             DesignAttributeHandler.writeAttribute("tabindex", attr,
                     ((Focusable) this).getTabIndex(),
-                    ((Focusable) def).getTabIndex(), Integer.class);
+                    ((Focusable) def).getTabIndex(), Integer.class,
+                    designContext);
         }
         // handle custom attributes
         Map<String, String> customAttributes = designContext
diff --git a/server/src/main/java/com/vaadin/ui/AbstractEmbedded.java b/server/src/main/java/com/vaadin/ui/AbstractEmbedded.java
index 978e82d468..a91332f948 100644
--- a/server/src/main/java/com/vaadin/ui/AbstractEmbedded.java
+++ b/server/src/main/java/com/vaadin/ui/AbstractEmbedded.java
@@ -100,7 +100,8 @@ public abstract class AbstractEmbedded extends AbstractComponent {
         super.writeDesign(design, designContext);
         AbstractEmbedded def = designContext.getDefaultInstance(this);
         DesignAttributeHandler.writeAttribute("alt", design.attributes(),
-                getAlternateText(), def.getAlternateText(), String.class);
+                getAlternateText(), def.getAlternateText(), String.class,
+                designContext);
     }
 
     @Override
diff --git a/server/src/main/java/com/vaadin/ui/AbstractField.java b/server/src/main/java/com/vaadin/ui/AbstractField.java
index c87a72e430..4add30183e 100644
--- a/server/src/main/java/com/vaadin/ui/AbstractField.java
+++ b/server/src/main/java/com/vaadin/ui/AbstractField.java
@@ -121,7 +121,8 @@ public abstract class AbstractField<T> extends AbstractComponent
         AbstractField<T> def = designContext.getDefaultInstance(this);
         Attributes attr = design.attributes();
         DesignAttributeHandler.writeAttribute("readonly", attr,
-                super.isReadOnly(), def.isReadOnly(), Boolean.class);
+                super.isReadOnly(), def.isReadOnly(), Boolean.class,
+                designContext);
     }
 
     @Override
diff --git a/server/src/main/java/com/vaadin/ui/AbstractLayout.java b/server/src/main/java/com/vaadin/ui/AbstractLayout.java
index 3c31e59e2c..a4b4f06bf7 100644
--- a/server/src/main/java/com/vaadin/ui/AbstractLayout.java
+++ b/server/src/main/java/com/vaadin/ui/AbstractLayout.java
@@ -102,24 +102,25 @@ public abstract class AbstractLayout extends AbstractComponentContainer
             MarginInfo defMargin, DesignContext context) {
         if (margin.hasAll()) {
             DesignAttributeHandler.writeAttribute("margin", design.attributes(),
-                    margin.hasAll(), defMargin.hasAll(), boolean.class);
+                    margin.hasAll(), defMargin.hasAll(), boolean.class,
+                    context);
         } else {
 
             DesignAttributeHandler.writeAttribute("margin-left",
                     design.attributes(), margin.hasLeft(), defMargin.hasLeft(),
-                    boolean.class);
+                    boolean.class, context);
 
             DesignAttributeHandler.writeAttribute("margin-right",
                     design.attributes(), margin.hasRight(),
-                    defMargin.hasRight(), boolean.class);
+                    defMargin.hasRight(), boolean.class, context);
 
             DesignAttributeHandler.writeAttribute("margin-top",
                     design.attributes(), margin.hasTop(), defMargin.hasTop(),
-                    boolean.class);
+                    boolean.class, context);
 
             DesignAttributeHandler.writeAttribute("margin-bottom",
                     design.attributes(), margin.hasBottom(),
-                    defMargin.hasBottom(), boolean.class);
+                    defMargin.hasBottom(), boolean.class, context);
         }
     }
 }
diff --git a/server/src/main/java/com/vaadin/ui/AbstractMedia.java b/server/src/main/java/com/vaadin/ui/AbstractMedia.java
index f56f6a7f27..a992554d67 100644
--- a/server/src/main/java/com/vaadin/ui/AbstractMedia.java
+++ b/server/src/main/java/com/vaadin/ui/AbstractMedia.java
@@ -275,7 +275,7 @@ public abstract class AbstractMedia extends AbstractComponent {
         for (Resource r : getSources()) {
             Attributes attr = design.appendElement("source").attributes();
             DesignAttributeHandler.writeAttribute("href", attr, r, null,
-                    Resource.class);
+                    Resource.class, designContext);
         }
     }
 
diff --git a/server/src/main/java/com/vaadin/ui/AbstractTextField.java b/server/src/main/java/com/vaadin/ui/AbstractTextField.java
index ee2ccc6604..714f4b8e64 100644
--- a/server/src/main/java/com/vaadin/ui/AbstractTextField.java
+++ b/server/src/main/java/com/vaadin/ui/AbstractTextField.java
@@ -285,7 +285,7 @@ public abstract class AbstractTextField extends AbstractField<String>
                 .getDefaultInstance(this);
         Attributes attr = design.attributes();
         DesignAttributeHandler.writeAttribute("maxlength", attr, getMaxLength(),
-                def.getMaxLength(), Integer.class);
+                def.getMaxLength(), Integer.class, designContext);
     }
 
     @Override
diff --git a/server/src/main/java/com/vaadin/ui/Button.java b/server/src/main/java/com/vaadin/ui/Button.java
index 499713ffbd..86321f357c 100644
--- a/server/src/main/java/com/vaadin/ui/Button.java
+++ b/server/src/main/java/com/vaadin/ui/Button.java
@@ -637,11 +637,11 @@ public class Button extends AbstractFocusable
         // icon-alt
         DesignAttributeHandler.writeAttribute("icon-alt", attr,
                 getIconAlternateText(), def.getIconAlternateText(),
-                String.class);
+                String.class, designContext);
         // click-shortcut
         if (clickShortcut != null) {
             DesignAttributeHandler.writeAttribute("click-shortcut", attr,
-                    clickShortcut, null, ShortcutAction.class);
+                    clickShortcut, null, ShortcutAction.class, designContext);
         }
     }
 }
diff --git a/server/src/main/java/com/vaadin/ui/CheckBox.java b/server/src/main/java/com/vaadin/ui/CheckBox.java
index 02d7b0db8b..9a6394863e 100644
--- a/server/src/main/java/com/vaadin/ui/CheckBox.java
+++ b/server/src/main/java/com/vaadin/ui/CheckBox.java
@@ -218,7 +218,7 @@ public class CheckBox extends AbstractField<Boolean>
         CheckBox def = (CheckBox) designContext.getDefaultInstance(this);
         Attributes attr = design.attributes();
         DesignAttributeHandler.writeAttribute("checked", attr, getValue(),
-                def.getValue(), Boolean.class);
+                def.getValue(), Boolean.class, designContext);
     }
 
 }
diff --git a/server/src/main/java/com/vaadin/ui/GridLayout.java b/server/src/main/java/com/vaadin/ui/GridLayout.java
index 40b8575c36..08ca2cb2b3 100644
--- a/server/src/main/java/com/vaadin/ui/GridLayout.java
+++ b/server/src/main/java/com/vaadin/ui/GridLayout.java
@@ -27,7 +27,6 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
-import java.util.Objects;
 import java.util.Set;
 
 import org.jsoup.nodes.Attributes;
@@ -1453,7 +1452,7 @@ public class GridLayout extends AbstractLayout
 
             // Row Expand
             DesignAttributeHandler.writeAttribute("expand", row.attributes(),
-                    (int) getRowExpandRatio(i), 0, int.class);
+                    (int) getRowExpandRatio(i), 0, int.class, designContext);
 
             int colspan = 1;
             Element col;
diff --git a/server/src/main/java/com/vaadin/ui/Link.java b/server/src/main/java/com/vaadin/ui/Link.java
index 24c1433968..b80e8cd206 100644
--- a/server/src/main/java/com/vaadin/ui/Link.java
+++ b/server/src/main/java/com/vaadin/ui/Link.java
@@ -226,9 +226,11 @@ public class Link extends AbstractComponent {
         super.writeDesign(design, designContext);
         Link def = designContext.getDefaultInstance(this);
         DesignAttributeHandler.writeAttribute("target", design.attributes(),
-                getTargetName(), def.getTargetName(), String.class);
+                getTargetName(), def.getTargetName(), String.class,
+                designContext);
         DesignAttributeHandler.writeAttribute("href", design.attributes(),
-                getResource(), def.getResource(), Resource.class);
+                getResource(), def.getResource(), Resource.class,
+                designContext);
     }
 
     @Override
diff --git a/server/src/main/java/com/vaadin/ui/MenuBar.java b/server/src/main/java/com/vaadin/ui/MenuBar.java
index 24f2dd89b3..884c3d4eb3 100644
--- a/server/src/main/java/com/vaadin/ui/MenuBar.java
+++ b/server/src/main/java/com/vaadin/ui/MenuBar.java
@@ -947,13 +947,14 @@ public class MenuBar extends AbstractComponent
     public void writeDesign(Element design, DesignContext designContext) {
         super.writeDesign(design, designContext);
         for (MenuItem item : getItems()) {
-            design.appendChild(createMenuElement(item));
+            design.appendChild(createMenuElement(item, designContext));
         }
 
         // in many cases there seems to be an empty more menu item
         if (getMoreMenuItem() != null
                 && !getMoreMenuItem().getText().isEmpty()) {
-            Element moreMenu = createMenuElement(getMoreMenuItem());
+            Element moreMenu = createMenuElement(getMoreMenuItem(),
+                    designContext);
             moreMenu.attr("more", true);
             design.appendChild(moreMenu);
         }
@@ -963,34 +964,35 @@ public class MenuBar extends AbstractComponent
         }
     }
 
-    protected Element createMenuElement(MenuItem item) {
+    protected Element createMenuElement(MenuItem item, DesignContext context) {
         Element menuElement = new Element(Tag.valueOf("menu"), "");
         // Defaults
         MenuItem def = new MenuItem("", null, null);
 
         Attributes attr = menuElement.attributes();
         DesignAttributeHandler.writeAttribute("icon", attr, item.getIcon(),
-                def.getIcon(), Resource.class);
+                def.getIcon(), Resource.class, context);
         DesignAttributeHandler.writeAttribute("disabled", attr,
-                !item.isEnabled(), !def.isEnabled(), boolean.class);
+                !item.isEnabled(), !def.isEnabled(), boolean.class, context);
         DesignAttributeHandler.writeAttribute("visible", attr, item.isVisible(),
-                def.isVisible(), boolean.class);
+                def.isVisible(), boolean.class, context);
         DesignAttributeHandler.writeAttribute("separator", attr,
-                item.isSeparator(), def.isSeparator(), boolean.class);
+                item.isSeparator(), def.isSeparator(), boolean.class, context);
         DesignAttributeHandler.writeAttribute("checkable", attr,
-                item.isCheckable(), def.isCheckable(), boolean.class);
+                item.isCheckable(), def.isCheckable(), boolean.class, context);
         DesignAttributeHandler.writeAttribute("checked", attr, item.isChecked(),
-                def.isChecked(), boolean.class);
+                def.isChecked(), boolean.class, context);
         DesignAttributeHandler.writeAttribute("description", attr,
-                item.getDescription(), def.getDescription(), String.class);
+                item.getDescription(), def.getDescription(), String.class,
+                context);
         DesignAttributeHandler.writeAttribute("style-name", attr,
-                item.getStyleName(), def.getStyleName(), String.class);
+                item.getStyleName(), def.getStyleName(), String.class, context);
 
         menuElement.append(item.getText());
 
         if (item.hasChildren()) {
             for (MenuItem subMenu : item.getChildren()) {
-                menuElement.appendChild(createMenuElement(subMenu));
+                menuElement.appendChild(createMenuElement(subMenu, context));
             }
         }
 
diff --git a/server/src/main/java/com/vaadin/ui/PasswordField.java b/server/src/main/java/com/vaadin/ui/PasswordField.java
index 231236c01f..7a154b2b29 100644
--- a/server/src/main/java/com/vaadin/ui/PasswordField.java
+++ b/server/src/main/java/com/vaadin/ui/PasswordField.java
@@ -76,6 +76,6 @@ public class PasswordField extends TextField {
                 .getDefaultInstance(this);
         Attributes attr = design.attributes();
         DesignAttributeHandler.writeAttribute("value", attr, getValue(),
-                def.getValue(), String.class);
+                def.getValue(), String.class, designContext);
     }
 }
diff --git a/server/src/main/java/com/vaadin/ui/ProgressBar.java b/server/src/main/java/com/vaadin/ui/ProgressBar.java
index 7df0fc5f83..e5d82a62b0 100644
--- a/server/src/main/java/com/vaadin/ui/ProgressBar.java
+++ b/server/src/main/java/com/vaadin/ui/ProgressBar.java
@@ -126,7 +126,7 @@ public class ProgressBar extends AbstractComponent {
         Float defaultValue = ((ProgressBar) designContext
                 .getDefaultInstance(this)).getValue();
         DesignAttributeHandler.writeAttribute("value", design.attributes(),
-                getValue(), defaultValue, Float.class);
+                getValue(), defaultValue, Float.class, designContext);
     }
 
     /**
diff --git a/server/src/main/java/com/vaadin/ui/Slider.java b/server/src/main/java/com/vaadin/ui/Slider.java
index 397e33e7c3..3a1d77e38f 100644
--- a/server/src/main/java/com/vaadin/ui/Slider.java
+++ b/server/src/main/java/com/vaadin/ui/Slider.java
@@ -372,7 +372,7 @@ public class Slider extends AbstractField<Double> {
         }
         Slider defaultSlider = context.getDefaultInstance(this);
         DesignAttributeHandler.writeAttribute(this, "value",
-                design.attributes(), defaultSlider);
+                design.attributes(), defaultSlider, context);
     }
 
     @Override
diff --git a/server/src/main/java/com/vaadin/ui/TabSheet.java b/server/src/main/java/com/vaadin/ui/TabSheet.java
index 7a154dd752..b19acf8ddb 100644
--- a/server/src/main/java/com/vaadin/ui/TabSheet.java
+++ b/server/src/main/java/com/vaadin/ui/TabSheet.java
@@ -1556,29 +1556,32 @@ public class TabSheet extends AbstractComponentContainer
         Attributes attr = tabElement.attributes();
         // write attributes
         DesignAttributeHandler.writeAttribute("visible", attr, tab.isVisible(),
-                def.isVisible(), Boolean.class);
+                def.isVisible(), Boolean.class, designContext);
         DesignAttributeHandler.writeAttribute("closable", attr,
-                tab.isClosable(), def.isClosable(), Boolean.class);
+                tab.isClosable(), def.isClosable(), Boolean.class,
+                designContext);
         DesignAttributeHandler.writeAttribute("caption", attr, tab.getCaption(),
-                def.getCaption(), String.class);
+                def.getCaption(), String.class, designContext);
         DesignAttributeHandler.writeAttribute("enabled", attr, tab.isEnabled(),
-                def.isEnabled(), Boolean.class);
+                def.isEnabled(), Boolean.class, designContext);
         DesignAttributeHandler.writeAttribute("icon", attr, tab.getIcon(),
-                def.getIcon(), Resource.class);
+                def.getIcon(), Resource.class, designContext);
         DesignAttributeHandler.writeAttribute("icon-alt", attr,
                 tab.getIconAlternateText(), def.getIconAlternateText(),
-                String.class);
+                String.class, designContext);
         DesignAttributeHandler.writeAttribute("description", attr,
-                tab.getDescription(), def.getDescription(), String.class);
+                tab.getDescription(), def.getDescription(), String.class,
+                designContext);
         DesignAttributeHandler.writeAttribute("style-name", attr,
-                tab.getStyleName(), def.getStyleName(), String.class);
+                tab.getStyleName(), def.getStyleName(), String.class,
+                designContext);
         DesignAttributeHandler.writeAttribute("id", attr, tab.getId(),
-                def.getId(), String.class);
+                def.getId(), String.class, designContext);
         if (getSelectedTab() != null
                 && getSelectedTab().equals(tab.getComponent())) {
             // use write attribute to get consistent handling for boolean
             DesignAttributeHandler.writeAttribute("selected", attr, true, false,
-                    boolean.class);
+                    boolean.class, designContext);
         }
     }
 
diff --git a/server/src/main/java/com/vaadin/ui/TextField.java b/server/src/main/java/com/vaadin/ui/TextField.java
index c01650fb60..b6eec11795 100644
--- a/server/src/main/java/com/vaadin/ui/TextField.java
+++ b/server/src/main/java/com/vaadin/ui/TextField.java
@@ -87,6 +87,6 @@ public class TextField extends AbstractTextField {
                 .getDefaultInstance(this);
         Attributes attr = design.attributes();
         DesignAttributeHandler.writeAttribute("value", attr, getValue(),
-                def.getValue(), String.class);
+                def.getValue(), String.class, designContext);
     }
 }
diff --git a/server/src/main/java/com/vaadin/ui/Video.java b/server/src/main/java/com/vaadin/ui/Video.java
index a9c3f3e729..af0ef618a4 100644
--- a/server/src/main/java/com/vaadin/ui/Video.java
+++ b/server/src/main/java/com/vaadin/ui/Video.java
@@ -118,7 +118,7 @@ public class Video extends AbstractMedia {
         if (getPoster() != null) {
             Attributes attr = design.appendElement("poster").attributes();
             DesignAttributeHandler.writeAttribute("href", attr, getPoster(),
-                    null, Resource.class);
+                    null, Resource.class, designContext);
         }
     }
 
diff --git a/server/src/main/java/com/vaadin/ui/Window.java b/server/src/main/java/com/vaadin/ui/Window.java
index 82acf0ee6f..df06e54457 100644
--- a/server/src/main/java/com/vaadin/ui/Window.java
+++ b/server/src/main/java/com/vaadin/ui/Window.java
@@ -1406,7 +1406,7 @@ public class Window extends Panel
         }
 
         DesignAttributeHandler.writeAttribute("position", design.attributes(),
-                getPosition(), def.getPosition(), String.class);
+                getPosition(), def.getPosition(), String.class, context);
 
         // Process keyboard shortcuts
         if (closeShortcuts.size() == 1 && hasCloseShortcut(KeyCode.ESCAPE)) {
@@ -1425,7 +1425,8 @@ public class Window extends Panel
 
             // Write everything except the last "," to the design
             DesignAttributeHandler.writeAttribute("close-shortcut",
-                    design.attributes(), attrString.trim(), null, String.class);
+                    design.attributes(), attrString.trim(), null, String.class,
+                    context);
         }
 
         for (Component c : getAssistiveDescription()) {
diff --git a/server/src/main/java/com/vaadin/ui/declarative/DesignAttributeHandler.java b/server/src/main/java/com/vaadin/ui/declarative/DesignAttributeHandler.java
index 4d655e0cbf..2eea59a046 100644
--- a/server/src/main/java/com/vaadin/ui/declarative/DesignAttributeHandler.java
+++ b/server/src/main/java/com/vaadin/ui/declarative/DesignAttributeHandler.java
@@ -56,25 +56,10 @@ public class DesignAttributeHandler implements Serializable {
         return Logger.getLogger(DesignAttributeHandler.class.getName());
     }
 
-    private static Map<Class<?>, AttributeCacheEntry> cache = new ConcurrentHashMap<>();
+    private final static Map<Class<?>, AttributeCacheEntry> cache = new ConcurrentHashMap<>();
 
     // translates string <-> object
-    private static DesignFormatter FORMATTER = new DesignFormatter();
-
-    private static boolean writeDefaultValues = false;
-
-    /**
-     * Set whether default attribute values should be written by the
-     * {@code DesignAttributeHandler#writeAttribute(String, Attributes, Object, Object, Class)}
-     * method. Default is {@code false}.
-     *
-     * @param value
-     *            {@code true} to write default values of attributes,
-     *            {@code false} to disable writing of default values
-     */
-    public static void setWriteDefaultValues(boolean value) {
-        writeDefaultValues = value;
-    }
+    private final static DesignFormatter FORMATTER = new DesignFormatter();
 
     /**
      * Returns the currently used formatter. All primitive types and all types
@@ -212,7 +197,7 @@ public class DesignAttributeHandler implements Serializable {
      */
     @SuppressWarnings({ "unchecked", "rawtypes" })
     public static void writeAttribute(Object component, String attribute,
-            Attributes attr, Object defaultInstance) {
+            Attributes attr, Object defaultInstance, DesignContext context) {
         Method getter = findGetterForAttribute(component.getClass(), attribute);
         if (getter == null) {
             getLogger().warning(
@@ -223,7 +208,7 @@ public class DesignAttributeHandler implements Serializable {
                 Object value = getter.invoke(component);
                 Object defaultValue = getter.invoke(defaultInstance);
                 writeAttribute(attribute, attr, value, defaultValue,
-                        (Class) getter.getReturnType());
+                        (Class) getter.getReturnType(), context);
             } catch (Exception e) {
                 getLogger().log(Level.SEVERE,
                         "Failed to invoke getter for attribute " + attribute,
@@ -248,13 +233,14 @@ public class DesignAttributeHandler implements Serializable {
      *            the type of the input value
      */
     public static <T> void writeAttribute(String attribute,
-            Attributes attributes, T value, T defaultValue,
-            Class<T> inputType) {
+            Attributes attributes, T value, T defaultValue, Class<T> inputType,
+            DesignContext context) {
         if (!getFormatter().canConvert(inputType)) {
             throw new IllegalArgumentException(
                     "input type: " + inputType.getName() + " not supported");
         }
-        if (writeDefaultValues || !SharedUtil.equals(value, defaultValue)) {
+        if (context.shouldWriteDefaultValues()
+                || !SharedUtil.equals(value, defaultValue)) {
             String attributeValue = toAttributeValue(inputType, value);
             if ("".equals(attributeValue) && (inputType == boolean.class
                     || inputType == Boolean.class)) {
diff --git a/server/src/main/java/com/vaadin/ui/declarative/DesignContext.java b/server/src/main/java/com/vaadin/ui/declarative/DesignContext.java
index ecbd5e638c..c8e794c46a 100644
--- a/server/src/main/java/com/vaadin/ui/declarative/DesignContext.java
+++ b/server/src/main/java/com/vaadin/ui/declarative/DesignContext.java
@@ -94,6 +94,8 @@ public class DesignContext implements Serializable {
     // this cannot be static because of testability issues
     private Boolean legacyDesignPrefix = null;
 
+    private boolean shouldWriteDefaultValues = false;
+
     public DesignContext(Document doc) {
         this.doc = doc;
         // Initialize the mapping between prefixes and package names.
@@ -831,4 +833,31 @@ public class DesignContext implements Serializable {
         }
         map.put(attribute, value);
     }
+
+    /**
+     * Set whether default attribute values should be written by the
+     * {@code DesignAttributeHandler#writeAttribute(String, Attributes, Object, Object, Class, DesignContext)}
+     * method. Default is {@code false}.
+     *
+     * @since 8.0
+     * @param value
+     *            {@code true} to write default values of attributes,
+     *            {@code false} to disable writing of default values
+     */
+    public void setShouldWriteDefaultValues(boolean value) {
+        shouldWriteDefaultValues = value;
+    }
+
+    /**
+     * Determines whether default attribute values should be written by the
+     * {@code DesignAttributeHandler#writeAttribute(String, Attributes, Object, Object, Class, DesignContext)}
+     * method. Default is {@code false}.
+     *
+     * @since 8.0
+     * @return {@code true} if default values of attributes should be written,
+     *         otherwise {@code false}
+     */
+    public boolean shouldWriteDefaultValues() {
+        return shouldWriteDefaultValues;
+    }
 }