package com.googlecode.gwt.test.uibinder;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Text;
import com.google.gwt.uibinder.client.UiChild;
import com.google.gwt.uibinder.client.UiConstructor;
import com.google.gwt.uibinder.client.UiFactory;
import com.google.gwt.uibinder.client.UiField;
import com.google.gwt.user.client.ui.HasHTML;
import com.google.gwt.user.client.ui.HasText;
import com.google.gwt.user.client.ui.HasWidgets;
import com.google.gwt.user.client.ui.HasWidgets.ForIsWidget;
import com.google.gwt.user.client.ui.IsWidget;
import com.google.gwt.user.client.ui.UIObject;
import com.googlecode.gwt.test.exceptions.GwtTestUiBinderException;
import com.googlecode.gwt.test.exceptions.ReflectionException;
import com.googlecode.gwt.test.internal.utils.JsoUtils;
import com.googlecode.gwt.test.utils.GwtReflectionUtils;
import com.googlecode.gwt.test.utils.JavaScriptObjects;
/**
* Base handler for any object tag (e.g. <g:Xxx /> tags, where Xxx is either {@link UIObject}
* subclass or a {@link IsWidget} subtype. This class is expected to be extended to add custom code
* to handle specific widget / attributes.
*
* @author Gael Lazzari
*
* @param <T> The wrapped object subtype
*
* @see UiObjectTag#instanciate(Class, Map, Object)
* @see UiObjectTag#initializeObject(Object, Map, Object)
* @see UiObjectTag#finalizeObject(Object)
*/
public abstract class UiObjectTag<T> implements UiTag<T> {
private static class UiChildMethodHolder {
int invocationCount;
int invocationLimit;
Method uiChildMethod;
}
private UiTag<?> parentTag;
private Map<String, UiChildMethodHolder> uiChildMethodMap;
private T wrapped;
/*
* (non-Javadoc)
*
* @see com.googlecode.gwt.test.uibinder.UiTag#addElement(com.google.gwt.dom.client .Element )
*/
public final void addElement(Element element) {
String namespaceURI = JavaScriptObjects.getString(element,
UiElementTag.UIBINDER_XML_NAMESPACE);
appendElement(this.wrapped, element, namespaceURI, UiBinderXmlUtils.getChildWidgets(element));
}
/*
* (non-Javadoc)
*
* @see com.googlecode.gwt.test.uibinder.UiTag#addUiObject(com.google.gwt.user. client
* .ui.UIObject)
*/
public final void addUiObject(UIObject uiObject) {
addUIObject(this.wrapped, uiObject);
}
/*
* (non-Javadoc)
*
* @see com.googlecode.gwt.test.uibinder.UiTag#addWidget(com.google.gwt.user.client .ui
* .IsWidget)
*/
public final void addWidget(IsWidget isWidget) {
addWidget(this.wrapped, isWidget);
}
/*
* (non-Javadoc)
*
* @see com.googlecode.gwt.test.uibinder.UiTag#appendText(java.lang.String)
*/
public final void appendText(String data) {
if (!"".equals(data.trim())) {
appendText(this.wrapped, data);
}
}
/*
* (non-Javadoc)
*
* @see com.googlecode.gwt.test.uibinder.UiTag#endTag()
*/
public final T endTag() {
finalizeObject(wrapped);
return wrapped;
}
/*
* (non-Javadoc)
*
* @see com.googlecode.gwt.test.uibinder.UiTag#getParentTag()
*/
public final UiTag<?> getParentTag() {
return parentTag;
}
/**
* Add a new UIObject which is not a {@link IsWidget} instance as a child to this uiObject. This
* implementation does nothing, the method is expected to be overridden.
*
* @param wrapped The wrapped uiObject of this tag.
* @param uiObject The UIObject instance to add, which is not a {@link IsWidget} instance.
*
*/
protected void addUIObject(T wrapped, UIObject uiObject) {
}
/**
* Add a new Widget as a child to this uiObject. This implementation just calls
* {@link ForIsWidget#add(IsWidget)} or
* {@link HasWidgets#add(com.google.gwt.user.client.ui.Widget)} according to which interface the
* wrapped uiObject is implementing.
*
* @param wrapped The wrapped uiObject of this tag.
* @param isWidget The child widget to be added.
*/
protected void addWidget(T wrapped, IsWidget isWidget) {
if (ForIsWidget.class.isInstance(wrapped)) {
((ForIsWidget) wrapped).add(isWidget);
} else if (HasWidgets.class.isInstance(wrapped)) {
((HasWidgets) wrapped).add(isWidget.asWidget());
}
}
/**
* Append an element declared in the .ui.xml to this uiObject, which is supposed to be its
* parent. This implementation has one of the following behavior :
* <ul>
* <li>If a {@link UiChild} annotated method which correspond to the element to append is found,
* it will be called with the element's first child Widget.</li>
* <li>Else if the wrapped {@link UIObject} implements {@link HasHTML}, the child would be
* appended through {@link Element#appendChild(com.google.gwt.dom.client.Node)}</li>
* <li>Otherwise, a {@link GwtTestUiBinderException} would be thrown with message: 'Found
* unexpected child element : <x:xxxx>'</li>
* </ul>
*
* @param wrapped The wrapped uiObject of this tag.
* @param element The child element to be appended.
* @param namespaceURI The namespace URI of the child element.
* @param childWidgets The element's childs widgets, which could be empty if no child has been
* added to it.
*/
protected void appendElement(T wrapped, Element element, String namespaceURI,
List<IsWidget> childWidgets) {
UiChildMethodHolder uiChildMethodHolder = uiChildMethodMap.get(element.getTagName());
if (uiChildMethodHolder != null) {
invokeUiChildMethod(wrapped, childWidgets, uiChildMethodHolder);
} else if (HasHTML.class.isInstance(wrapped)) {
getElement(wrapped).appendChild(element);
} else {
String elementToString = (namespaceURI != null && namespaceURI.length() > 0)
? namespaceURI + ":" + element.getTagName() : element.getTagName();
throw new GwtTestUiBinderException("Found unexpected child element : <" + elementToString
+ "> in " + wrapped.getClass().getName());
}
}
/**
* Append text to this uiObject. This implementation calls {@link HasText#setText(String)} if the
* current uiObject is implementing the {@link HasText} interface, or append a new {@link Text}
* node wrapping the data value to the Widget's element.
*
* @param wrapped The wrapped uiObject of this tag.
* @param data The string value.
*/
protected void appendText(T wrapped, String data) {
if (HasText.class.isInstance(wrapped)) {
((HasText) wrapped).setText(data);
} else {
Element element = getElement(wrapped);
Text text = JsoUtils.newText(data, element.getOwnerDocument());
element.appendChild(text);
}
}
/**
* A callback executed after every standard uiObject properties have been setup to be able to
* process any custom finalization on the wrapped uiObject.
*
* @param uiObject The uiObject to finalize.
*/
protected abstract void finalizeObject(T uiObject);
protected Element getElement(T wrapped) {
if (wrapped instanceof UIObject) {
return ((UIObject) wrapped).getElement();
} else if (wrapped instanceof IsWidget) {
return ((IsWidget) wrapped).asWidget().getElement();
} else {
throw new GwtTestUiBinderException(
"Cannot retrieve the Element instance in instances of '"
+ wrapped.getClass().getName() + "', you have to override "
+ this.getClass() + ".getElement(..) protected method");
}
}
/**
* A callback method executed just after the corresponding UiBinder tag was opened to be able to
* process any custom initialization on the wrapped uiObject.
*
* @param wrapped The uiObject to initialize
* @param attributes map of attributes of the wrapped uiObject, with attribute XML names as keys,
* corresponding objects as values. This map will be used to populate the wrapped
* uiObject just after this callback would be executed.
* @param owner The owner of the UiBinder template, with {@link UiField} fields.
*/
protected abstract void initializeObject(T wrapped, Map<String, Object> attributes, Object owner);
/**
* Method responsible for the uiObject instanciation. It is called only if the uiBinder tag is
* not a provided {@link UiField} and not annotated with either {@link UiFactory} nor
* {@link UiConstructor}. This implementation simply check for a zero-arg constructor to call and
* would throw an exception if it does not exist.
*
* @param clazz The uiObject class to instanciate.
* @param attributes map of attributes of the wrapped uiObject, with attribute XML names as keys,
* corresponding objects as values.
* @param owner The owner of the UiBinder template, with {@link UiField} fields.
* @return The created instance.
*/
protected T instanciate(Class<? extends T> clazz, Map<String, Object> attributes, Object owner) {
try {
Constructor<? extends T> defaultCons = clazz.getDeclaredConstructor();
return GwtReflectionUtils.instantiateClass(defaultCons);
} catch (NoSuchMethodException e) {
throw new GwtTestUiBinderException(
clazz.getName()
+ " has no default (zero args) constructor. You have to register a custom "
+ UiObjectTagFactory.class.getSimpleName()
+ " by calling the protected method 'addUiObjectTagFactory' of your test class and override the 'instanciate(Class<T>) method in it");
}
}
/**
* Callback method called whenever a new uiBinder tag is opened, so implementation could apply
* some custom initialization.
*
* @param clazz The class of the object to be wrapped in this UiTag.
* @param namespaceURI The namespace URI of the opened tag
* @param attributes map of attributes of the wrapped uiObject, with attribute XML names as keys,
* corresponding objects as values.
* @param parentTag The parent tag
* @param owner The owner of the UiBinder template, with {@link UiField} fields.
*/
final void startTag(Class<? extends T> clazz, Map<String, Object> attributes,
UiTag<?> parentTag, Object owner) {
this.parentTag = parentTag;
this.uiChildMethodMap = collectUiChildMethods(clazz);
wrapped = UiBinderInstanciator.getInstance(clazz, attributes, owner);
if (wrapped == null) {
wrapped = instanciate(clazz, attributes, owner);
}
String uiFieldValue = (String) attributes.get("ui:field");
if (uiFieldValue != null) {
attributes.remove("ui:field");
try {
GwtReflectionUtils.setPrivateFieldValue(owner, uiFieldValue, wrapped);
} catch (ReflectionException e) {
// ui:field has no corresponding @UiField declared : just ignore it
}
}
initializeObject(wrapped, attributes, owner);
UiBinderBeanUtils.populateObject(wrapped, attributes);
}
private Map<String, UiChildMethodHolder> collectUiChildMethods(Class<? extends T> clazz) {
Map<String, UiChildMethodHolder> map = new HashMap<String, UiObjectTag.UiChildMethodHolder>();
Map<Method, UiChild> uiChildMap = GwtReflectionUtils.getAnnotatedMethod(clazz, UiChild.class);
for (Map.Entry<Method, UiChild> entry : uiChildMap.entrySet()) {
Method method = entry.getKey();
UiChild annotation = entry.getValue();
UiChildMethodHolder holder = new UiChildMethodHolder();
holder.uiChildMethod = method;
holder.invocationLimit = annotation.limit(); // default is -1
holder.invocationCount = 0;
String tagName = (annotation.tagname().equals("")) ? computeUiChildMethodTagName(method)
: annotation.tagname();
map.put(tagName, holder);
}
return map;
}
private String computeUiChildMethodTagName(Method method) {
if (!method.getName().startsWith("add")) {
throw new GwtTestUiBinderException(
"Cannot compute tagname of @UiChild annotated method '"
+ method.toGenericString()
+ "': you have to fill the 'tagname' property of the @UiChild or to prefix your the method name with 'add'");
}
return method.getName().substring(3).toLowerCase();
}
private void invokeUiChildMethod(T wrapped, List<IsWidget> childWidgets,
UiChildMethodHolder uiChildMethodHolder) {
if (uiChildMethodHolder.invocationLimit > -1
&& uiChildMethodHolder.invocationCount > uiChildMethodHolder.invocationLimit) {
throw new GwtTestUiBinderException("@UiChild method '"
+ uiChildMethodHolder.uiChildMethod.toGenericString()
+ "' cannot be invoked more than " + uiChildMethodHolder.invocationLimit
+ " times");
} else if (childWidgets.size() != 1) {
throw new GwtTestUiBinderException("@UiChild method '"
+ uiChildMethodHolder.uiChildMethod.toGenericString()
+ "' can only be applied to add one Widget, but " + childWidgets.size()
+ " have been found");
}
try {
uiChildMethodHolder.uiChildMethod.invoke(wrapped, childWidgets.get(0));
} catch (Exception e) {
throw new GwtTestUiBinderException(
"An exception has been thrown during invocation of @UiChild method: "
+ uiChildMethodHolder.uiChildMethod.toGenericString(), e);
}
uiChildMethodHolder.invocationCount++;
}
}