echopointng.ui.util.ImageManager Maven / Gradle / Ivy
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/*
* This file is part of the Echo Point Project. This project is a collection
* of Components that have extended the Echo Web Application Framework.
*
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
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* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*/
package echopointng.ui.util;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import nextapp.echo2.app.AwtImageReference;
import nextapp.echo2.app.Component;
import nextapp.echo2.app.FillImage;
import nextapp.echo2.app.HttpImageReference;
import nextapp.echo2.app.ImageReference;
import nextapp.echo2.app.StreamImageReference;
import nextapp.echo2.webcontainer.ContainerInstance;
import nextapp.echo2.webcontainer.RenderContext;
import nextapp.echo2.webcontainer.RenderState;
import nextapp.echo2.webcontainer.image.AwtImageService;
import nextapp.echo2.webcontainer.image.StreamImageService;
import nextapp.echo2.webcontainer.propertyrender.ExtentRender;
import nextapp.echo2.webrender.WebRenderServlet;
import nextapp.echo2.webrender.output.CssStyle;
import org.w3c.dom.Element;
/**
* ImageManager is used to manage ImageReference
* 's within the EPNG code.
*
* The base nextapp.echo2.webcontainer.image.ImageRenderSupport does not do a
* simple enough job of managing images as it uses a component based
* lookup in a callback to implement image serving.
*
* This ImageManager class will allow URI's for images to be
* generated as well as IMG HTML tag elements to be created without needing the
* component as the lookup context.
*
* All that is needed is the ImageReference itself.
*
* And instance of this class can be used to store images against a logical name
* via the setImage() and getImage() methods.
*
* ImageManager implements RenderState and hence can be stored
* against a given renderer per component.
*/
public class ImageManager implements RenderState {
public static interface ImageReferenceURIHandler {
/**
* This method is called to return an URI for the given image. if the
* handler can handle this type of ImageReference then it
* should return null.
*
* @param containerInstance -
* the ContainerInstance that is current in play
* @param imageReference -
* the ImageReference to return a URI for
*
* @return the URI that can be used to serve up the
* ImageReference or null if the handler can
* handle this type of ImageReference
*/
public String getImageURI(ContainerInstance containerInstance, ImageReference imageReference);
}
private static Set handlerSet = new HashSet();
/**
* Registers a ImageReferenceURIHandler to the static set of
* handlers
*
* @param handler -
* the handler to add
*/
public static void registerURIHandler(ImageReferenceURIHandler handler) {
handlerSet.add(handler);
}
/**
* Deregisters a ImageReferenceURIHandler from the static set
* of handlers
*
* @param handler -
* the handler to deregister
*/
public static void deregisterURIHandler(ImageReferenceURIHandler handler) {
handlerSet.remove(handler);
}
private static ImageReferenceURIHandler DEFAULT_HANDLER;
static {
// create a default ImageHandler
DEFAULT_HANDLER = new ImageReferenceURIHandler() {
/**
* @see echopointng.ui.util.ImageManager.ImageReferenceURIHandler#getImageURI(ContainerInstance,
* ImageReference)
*/
public String getImageURI(ContainerInstance containerInstance, ImageReference imageReference) {
if (imageReference instanceof StreamImageReference) {
containerInstance.getIdTable().register(imageReference);
return StreamImageService.INSTANCE.createUri(containerInstance, imageReference.getRenderId());
} else if (imageReference instanceof HttpImageReference) {
return ((HttpImageReference) imageReference).getUri();
} else if (imageReference instanceof AwtImageReference) {
containerInstance.getIdTable().register(imageReference);
return AwtImageService.INSTANCE.createUri(containerInstance, imageReference.getRenderId());
} else {
return null;
}
}
};
}
/**
* This returns the URI that can be used to serve up the specified
* ImageReference.
*
*
* @param rc -
* the RenderContext to use
* @param imageReference -
* the ImageReference in question
* @return an URI for the ImageReference
*/
public static String getURI(RenderContext rc, ImageReference imageReference) {
return getURIImpl(rc.getContainerInstance(), imageReference);
}
/**
* This returns the URI that can be used to serve up the specified
* ImageReference.
*
*
* @param imageReference -
* the ImageReference in question
* @return an URI for the ImageReference
*
* @throws NullPointerException if there is no action connection
* in place when this call is made.
*/
public static String getURI(ImageReference imageReference) {
ContainerInstance containerInstance = (ContainerInstance) WebRenderServlet.getActiveConnection().getUserInstance();
return getURIImpl(containerInstance, imageReference);
}
/*
* The actual implementation that returns a URI for a ImageReference
*/
private static String getURIImpl(ContainerInstance containerInstance, ImageReference imageReference) {
String imageURI = null;
for (Iterator iter = handlerSet.iterator(); iter.hasNext();) {
ImageReferenceURIHandler handler = (ImageReferenceURIHandler) iter.next();
imageURI = handler.getImageURI(containerInstance, imageReference);
if (imageURI != null) {
break;
}
}
if (imageURI == null) {
imageURI = DEFAULT_HANDLER.getImageURI(containerInstance, imageReference);
}
return imageURI;
}
/**
* This returns the URI that can be used to serve up the specified property
* if its an ImageReference or FillImage value.
*
* @param rc
* the RenderContext to use
* @param component -
* the component to look up render properties in
* @param propertyName -
* the name of the property
* @return an URI or null
*/
public static String getURI(RenderContext rc, Component component, String propertyName) {
ImageReference imageRef = getImageRefFromProperty(component, propertyName);
return getURI(rc, imageRef);
}
/**
* This returns the URI that can be used to serve up the specified property
* if its an ImageReference or FillImage value.
*
* @param component -
* the component to look up render properties in
* @param propertyName -
* the name of the property
* @return an URI or null
*
* @throws NullPointerException if there is no action connection
* in place when this call is made.
*/
public static String getURI(Component component, String propertyName) {
ImageReference imageRef = getImageRefFromProperty(component, propertyName);
ContainerInstance containerInstance = (ContainerInstance) WebRenderServlet.getActiveConnection().getUserInstance();
return getURIImpl(containerInstance, imageRef);
}
/**
* This will create an 'img' element for the specified ImageReference.
*
* This assumes that the image URI is based on the
* ImageReference.getRenderId().
*
* @param rc -
* the RenderContext to use
* @param imageRef -
* the ImageReference in question. This must not be null.
*
* @return an 'img' element
*/
public static Element createImgE(RenderContext rc, ImageReference imageRef) {
return createImgE(rc, null, imageRef);
}
/**
* This will create an 'img' element for the specified ImageReference.
*
* This assumes that the image URI is based on the
* ImageReference.getRenderId().
*
* If the CssStyle passsed in is non null, then it will be used to set extra
* 'img' tag styles such a "border:none;width:x;height:y". It will only set
* these properties if they are not already set in the style.
*
* @param rc -
* the RenderContext to use
* @param cssStyle -
* a CssStyle to use on the 'img' tag. Can be null
* @param imageRef -
* the ImageReference in question. This must not be null.
*
* @return an 'img' element
*/
public static Element createImgE(RenderContext rc, CssStyle cssStyle, ImageReference imageRef) {
String imageURI = getURI(rc, imageRef);
return createImgImpl(rc, cssStyle, imageURI, imageRef);
}
/**
* Creates an IMG tag by using extracting the value of the named property
* from the component. It can handle ImageReference properties as well as
* FillImage properties.
*
* @param rc -
* the RenderingContext to use
* @param cssStyle -
* the CssStyle to use if applicable.
* @param component -
* the component whose property will be looked up
* @param propertyName -
* the name of the property
* @return
*/
public static Element createImgEFromProperty(RenderContext rc, CssStyle cssStyle, Component component, String propertyName) {
ImageReference imageRef = getImageRefFromProperty(component, propertyName);
String imageURI = getURI(rc, imageRef);
return createImgImpl(rc, cssStyle, imageURI, imageRef);
}
/**
* @see ImageManager#createImgEFromProperty(RenderContext, CssStyle,
* Component, String)
*/
public static Element createImgEFromProperty(RenderContext rc, Component component, String propertyName) {
return createImgEFromProperty(rc, null, component, propertyName);
}
/*
* Implementation that can handle ImageReference and FillImages
*/
private static ImageReference getImageRefFromProperty(Component component, String propertyName) {
ImageReference imageRef = null;
Object propertyValue = component.getRenderProperty(propertyName);
if (propertyValue instanceof ImageReference) {
imageRef = (ImageReference) propertyValue;
} else if (propertyValue instanceof FillImage) {
imageRef = ((FillImage) propertyValue).getImage();
}
return imageRef;
}
/*
* The implementation of creating an img element.
*/
private static Element createImgImpl(RenderContext rc, CssStyle cssStyle, String imageURI, ImageReference imageRef) {
Element imgElement = rc.getServerMessage().getDocument().createElement("img");
imgElement.setAttribute("src", imageURI);
if (cssStyle == null) {
cssStyle = new CssStyle();
}
if (cssStyle.getAttribute("border") == null) {
cssStyle.setAttribute("border", "none");
}
if (imageRef != null) {
if (imageRef.getHeight() != null && cssStyle.getAttribute("height") == null) {
ExtentRender.renderToStyle(cssStyle, "height", imageRef.getHeight());
}
if (imageRef.getWidth() != null && cssStyle.getAttribute("width") == null) {
ExtentRender.renderToStyle(cssStyle, "width", imageRef.getWidth());
}
}
imgElement.setAttribute("style", cssStyle.renderInline());
return imgElement;
}
private Map imageMap;
/**
* Constructs a ImageManager
*/
public ImageManager() {
imageMap = new HashMap();
}
/**
* Stores an ImageReference into the
* ImageManager using a given imageId.
*
* @param imageId -
* the id to use to store the ImageReference
* @param imageReference -
* the ImageReference to store
*/
public void setImage(String imageId, ImageReference imageReference) {
imageMap.put(imageId, imageReference);
}
/**
* Returns an ImageReference from the
* ImageManager by imageId
*
* @param imageId -
* the id used to store the ImageReference in the
* ImageManager.
* @return - the ImageReference or null
*
*/
public ImageReference getImage(String imageId) {
return (ImageReference) imageMap.get(imageId);
}
/**
* Adds the ImageReference to the ImageManager
* via its renderId.
*
* @param imageReference -
* the ImageReference to add. If this is null then
* nothing happens.
*
*/
public void addImage(ImageReference imageReference) {
if (imageReference != null) {
imageMap.put(imageReference.getRenderId(), imageReference);
}
}
/**
* Removes the ImageReference from the
* ImageManager via its renderId.
*
* @param imageReference -
* the ImageReference to remove
*
*/
public void removeImage(ImageReference imageReference) {
if (imageReference != null) {
imageMap.remove(imageReference.getRenderId());
}
}
/**
* Removes all ImageReferences from the
* ImageManager
*
*/
public void removeAllImages() {
imageMap.clear();
}
}