/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.wicket.markup.html.image.resource;
import java.util.Locale;
import org.apache.wicket.Application;
import org.apache.wicket.Component;
import org.apache.wicket.IResourceFactory;
import org.apache.wicket.MarkupContainer;
import org.apache.wicket.WicketRuntimeException;
import org.apache.wicket.markup.ComponentTag;
import org.apache.wicket.markup.html.border.Border;
import org.apache.wicket.request.cycle.RequestCycle;
import org.apache.wicket.request.mapper.parameter.PageParameters;
import org.apache.wicket.request.resource.IResource;
import org.apache.wicket.request.resource.IResource.Attributes;
import org.apache.wicket.request.resource.PackageResourceReference;
import org.apache.wicket.request.resource.ResourceReference;
import org.apache.wicket.util.io.IClusterable;
import org.apache.wicket.util.lang.Objects;
import org.apache.wicket.util.parse.metapattern.Group;
import org.apache.wicket.util.parse.metapattern.MetaPattern;
import org.apache.wicket.util.parse.metapattern.OptionalMetaPattern;
import org.apache.wicket.util.parse.metapattern.parsers.MetaPatternParser;
import org.apache.wicket.util.string.Strings;
/**
* THIS CLASS IS INTENDED FOR INTERNAL USE IN IMPLEMENTING LOCALE SENSITIVE COMPONENTS THAT USE
* IMAGE RESOURCES AND SHOULD NOT BE USED DIRECTLY BY END-USERS.
* <p>
* This class contains the logic for extracting static image resources referenced by the SRC
* attribute of component tags and keeping these static image resources in sync with the component
* locale.
* <p>
* If no image is specified by the SRC attribute of an IMG tag, then any VALUE attribute is
* inspected. If there is a VALUE attribute, it must be of the form
* "[factoryName]:[sharedImageName]?:[specification]". [factoryName] is the name of a resource
* factory that has been added to Application (for example, DefaultButtonImageResourceFactory is
* installed by default under the name "buttonFactory"). The [sharedImageName] value is optional and
* gives a name under which a given generated image is shared. For example, a cancel button image
* generated by the VALUE attribute "buttonFactory:cancelButton:Cancel" is shared under the name
* "cancelButton" and this specification will cause a component to reference the same image resource
* no matter what page it appears on, which is a very convenient and efficient way to create and
* share images. The [specification] string which follows the second colon is passed directly to the
* image factory and its format is dependent on the specific image factory. For details on the
* default buttonFactory, see
* {@link org.apache.wicket.markup.html.image.resource.DefaultButtonImageResourceFactory}.
* <p>
* Finally, if there is no SRC attribute and no VALUE attribute, the Image component's model is
* inspected. If the model contains a resource or resource reference, this image is used, otherwise
* the model is converted to a String and that value is used as a path to load the image.
*
* @author Jonathan Locke
*/
public final class LocalizedImageResource implements IClusterable
{
private static final long serialVersionUID = 1L;
/**
* What kind of resource it is. TRUE==Resource is set, FALSE==ResourceReference is set, null
* none
*/
private Boolean resourceKind;
/** The component that is referencing this image resource */
private final Component component;
/** The image resource this image component references */
private IResource resource;
/** The resource reference */
private ResourceReference resourceReference;
/** The resource parameters */
private PageParameters resourceParameters;
/** The locale of the image resource */
private Locale locale;
/** The style of the image resource */
private String style;
/** The component's variation (of the style) */
private String variation;
/**
* Parses image value specifications of the form "[factoryName]:
* [shared-image-name]?:[specification]"
*
* @author Jonathan Locke
*/
private static final class ImageValueParser extends MetaPatternParser
{
/** Factory name */
private static final Group factoryName = new Group(MetaPattern.VARIABLE_NAME);
/** Image reference name */
private static final Group imageReferenceName = new Group(MetaPattern.VARIABLE_NAME);
/** Factory specification string */
private static final Group specification = new Group(MetaPattern.ANYTHING_NON_EMPTY);
/** Meta pattern. */
private static final MetaPattern pattern = new MetaPattern(factoryName, MetaPattern.COLON,
new OptionalMetaPattern(new MetaPattern[] { imageReferenceName }), MetaPattern.COLON,
specification);
/**
* Construct.
*
* @param input
* to parse
*/
private ImageValueParser(final CharSequence input)
{
super(pattern, input);
}
/**
* @return The factory name
*/
private String getFactoryName()
{
return factoryName.get(matcher());
}
/**
* @return Returns the imageReferenceName.
*/
private String getImageReferenceName()
{
return imageReferenceName.get(matcher());
}
/**
* @return Returns the specification.
*/
private String getSpecification()
{
return specification.get(matcher());
}
}
/**
* Constructor
*
* @param component
* The component that owns this localized image resource
*/
public LocalizedImageResource(final Component component)
{
this.component = component;
locale = component.getLocale();
style = component.getStyle();
variation = component.getVariation();
}
/**
* Binds this resource if it is shared
*/
public final void bind()
{
// If we have a resource reference
if (resourceReference != null && resourceReference.canBeRegistered() &&
Application.exists())
{
// Bind the reference to the application
Application.get()
.getResourceReferenceRegistry()
.registerResourceReference(resourceReference);
}
}
/**
* @param parameters
* page parameters
*/
public final void onResourceRequested(PageParameters parameters)
{
bind();
RequestCycle requestCycle = RequestCycle.get();
Attributes attributes = new Attributes(requestCycle.getRequest(),
requestCycle.getResponse(), parameters);
resource.respond(attributes);
}
/**
* @param resource
* The resource to set.
*/
public final void setResource(final IResource resource)
{
if (this.resource != resource)
{
resourceKind = Boolean.TRUE;
this.resource = resource;
}
}
/**
* @param resourceReference
* The resource to set.
*/
public final void setResourceReference(final ResourceReference resourceReference)
{
setResourceReference(resourceReference, resourceParameters);
}
/**
* @return true if it has a resourceReference. (it points to a shared resource)
*/
public final boolean isStateless()
{
return resourceReference != null;
}
/**
* @param resourceReference
* The resource to set.
* @param resourceParameters
* The resource parameters for the shared resource
*/
public final void setResourceReference(final ResourceReference resourceReference,
final PageParameters resourceParameters)
{
if (resourceReference != this.resourceReference)
{
resourceKind = Boolean.FALSE;
this.resourceReference = resourceReference;
}
this.resourceParameters = resourceParameters;
bind();
}
/**
* @param tag
* The tag to inspect for an optional src attribute that might reference an image.
* @throws WicketRuntimeException
* Thrown if an image is required by the caller, but none can be found.
*/
public final void setSrcAttribute(final ComponentTag tag)
{
// If locale has changed from the initial locale used to attach image
// resource, then we need to reload the resource in the new locale
Locale l = component.getLocale();
String s = component.getStyle();
String v = component.getVariation();
if (resourceKind == null &&
(!Objects.equal(locale, l) || !Objects.equal(style, s) || !Objects.equal(variation, v)))
{
// Get new component locale and style
locale = l;
style = s;
variation = v;
// Invalidate current resource so it will be reloaded/recomputed
resourceReference = null;
resource = null;
}
else
{
// TODO post 1.2: should we have support for locale changes when the
// resource reference (or resource??) is set manually..
// We should get a new resource reference for the current locale
// then that points to the same resource but with another locale if
// it exists. Something like
// SharedResource.getResourceReferenceForLocale(resourceReference);
}
// check if the model contains a resource, if so, load the resource from
// the model.
Object modelObject = component.getDefaultModelObject();
if (modelObject instanceof ResourceReference)
{
resourceReference = (ResourceReference)modelObject;
}
else if (modelObject instanceof IResource)
{
resource = (IResource)modelObject;
}
// Need to load image resource for this component?
if (resource == null && resourceReference == null)
{
// Get SRC attribute of tag
final CharSequence src = tag.getAttribute("src");
if (src != null)
{
// Try to load static image
loadStaticImage(src.toString());
}
else
{
// Get VALUE attribute of tag
final CharSequence value = tag.getAttribute("value");
if (value != null)
{
// Try to generate an image using an image factory
newImage(value);
}
else
{
// Load static image using model object as the path
loadStaticImage(component.getDefaultModelObjectAsString());
}
}
}
// Get URL for resource
final CharSequence url;
if (resourceReference != null)
{
// Create URL to resource
url = RequestCycle.get().urlFor(resourceReference, resourceParameters);
}
else
{
// Create URL to component
url = component.urlForListener(resourceParameters);
}
// Set the SRC attribute to point to the component or shared resource
tag.put("src", url);
}
/**
* @param application
* The application
* @param factoryName
* The name of the image resource factory
* @return The resource factory
* @throws WicketRuntimeException
* Thrown if factory cannot be found
*/
private IResourceFactory getResourceFactory(final Application application,
final String factoryName)
{
final IResourceFactory factory = application.getResourceSettings().getResourceFactory(
factoryName);
// Found factory?
if (factory == null)
{
throw new WicketRuntimeException("Could not find image resource factory named " +
factoryName);
}
return factory;
}
static class SimpleStaticResourceReference extends ResourceReference
{
final IResource resource;
public SimpleStaticResourceReference(Class<?> scope, String name, Locale locale,
String style, String variation, IResource resource)
{
super(scope, name, locale, style, variation);
this.resource = resource;
}
private static final long serialVersionUID = 1L;
@Override
public IResource getResource()
{
return resource;
}
}
/**
* Tries to load static image at the given path and throws an exception if the image cannot be
* located.
*
* @param path
* The path to the image
* @throws WicketRuntimeException
* Thrown if the image cannot be located
*/
private void loadStaticImage(final String path)
{
MarkupContainer parent = component.findParentWithAssociatedMarkup();
if (parent instanceof Border)
{
parent = parent.getParent();
}
final Class<?> scope = parent.getClass();
resourceReference = new PackageResourceReference(scope, path, locale, style, variation);
bind();
}
/**
* Generates an image resource based on the attribute values on tag
*
* @param value
* The value to parse
*/
private void newImage(final CharSequence value)
{
// Parse value
final ImageValueParser valueParser = new ImageValueParser(value);
// Does value match parser?
if (valueParser.matches())
{
final String imageReferenceName = valueParser.getImageReferenceName();
final String specification = Strings.replaceHtmlEscapeNumber(valueParser.getSpecification());
final String factoryName = valueParser.getFactoryName();
final Application application = component.getApplication();
// Do we have a reference?
if (!Strings.isEmpty(imageReferenceName))
{
// Is resource already available via the application?
if (application.getResourceReferenceRegistry().getResourceReference(
Application.class, imageReferenceName, locale, style, variation, true, false) == null)
{
// Resource not available yet, so create it with factory and
// share via Application
final IResource imageResource = getResourceFactory(application, factoryName).newResource(
specification, locale, style, variation);
ResourceReference ref = new SimpleStaticResourceReference(Application.class,
imageReferenceName, locale, style, variation, imageResource);
application.getResourceReferenceRegistry().registerResourceReference(ref);
}
// Create resource reference
resourceReference = new PackageResourceReference(Application.class,
imageReferenceName, locale, style, variation);
}
else
{
resource = getResourceFactory(application, factoryName).newResource(specification,
locale, style, variation);
}
}
else
{
throw new WicketRuntimeException(
"Could not generate image for value attribute '" +
value +
"'. Was expecting a value attribute of the form \"[resourceFactoryName]:[resourceReferenceName]?:[factorySpecification]\".");
}
}
/**
* return the resource
*
* @return resource or <code>null</code> if there is none
*/
public final IResource getResource()
{
return resource;
}
/**
* return the resource
*
* @return resource or <code>null</code> if there is none
*/
public final ResourceReference getResourceReference()
{
return resourceReference;
}
}