eu.webtoolkit.jwt.WImage Maven / Gradle / Ivy
/*
* Copyright (C) 2009 Emweb bvba, Leuven, Belgium.
*
* See the LICENSE file for terms of use.
*/
package eu.webtoolkit.jwt;
import java.util.*;
import java.util.regex.*;
import java.io.*;
import java.lang.ref.*;
import java.util.concurrent.locks.ReentrantLock;
import javax.servlet.http.*;
import javax.servlet.*;
import eu.webtoolkit.jwt.*;
import eu.webtoolkit.jwt.chart.*;
import eu.webtoolkit.jwt.utils.*;
import eu.webtoolkit.jwt.servlet.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A widget that displays an image.
*
*
* The image may be specified either as a URL, or may be dynamically generated
* by a {@link WResource}.
*
* You may listen to events by attaching event listeners to signals such as
* {@link WInteractWidget#clicked() WInteractWidget#clicked()}. Since mouse
* events pass the coordinates through a {@link WMouseEvent} object, it is
* possible to react to clicks in specific parts of the image. An alternative is
* to define interactive areas on the image using
* {@link WImage#addArea(WAbstractArea area) addArea()}, which in addition
* allows to have customized tool tips for certain image areas (using
* {@link WAbstractArea#setToolTip(CharSequence text)
* WAbstractArea#setToolTip()}).
*
* WImage is an {@link WWidget#setInline(boolean inlined) inline} widget.
*
*
CSS
*
* The widget corresponds to the HTML <img> tag and does not
* provide styling. It can be styled using inline or external CSS as
* appropriate.
*
*
* @see WResource
* @see WPaintedWidget
*/
public class WImage extends WInteractWidget {
private static Logger logger = LoggerFactory.getLogger(WImage.class);
/**
* Creates an empty image widget.
*/
public WImage(WContainerWidget parent) {
super(parent);
this.altText_ = new WString();
this.imageLink_ = new WLink();
this.map_ = null;
this.flags_ = new BitSet();
this.setLoadLaterWhenInvisible(false);
}
/**
* Creates an empty image widget.
*
* Calls {@link #WImage(WContainerWidget parent)
* this((WContainerWidget)null)}
*/
public WImage() {
this((WContainerWidget) null);
}
/**
* Creates an image widget with a given image link.
*
* The imageLink may link to a URL or resource.
*/
public WImage(WLink link, WContainerWidget parent) {
super(parent);
this.altText_ = new WString();
this.imageLink_ = new WLink();
this.map_ = null;
this.flags_ = new BitSet();
this.setLoadLaterWhenInvisible(false);
this.setImageLink(link);
}
/**
* Creates an image widget with a given image link.
*
* Calls {@link #WImage(WLink link, WContainerWidget parent) this(link,
* (WContainerWidget)null)}
*/
public WImage(WLink link) {
this(link, (WContainerWidget) null);
}
/**
* Creates an image widget with a given image link and alternate text.
*
* The imageLink may link to a URL or resource.
*/
public WImage(WLink link, CharSequence altText, WContainerWidget parent) {
super(parent);
this.altText_ = WString.toWString(altText);
this.imageLink_ = new WLink();
this.map_ = null;
this.flags_ = new BitSet();
this.setLoadLaterWhenInvisible(false);
this.setImageLink(link);
}
/**
* Creates an image widget with a given image link and alternate text.
*
* Calls
* {@link #WImage(WLink link, CharSequence altText, WContainerWidget parent)
* this(link, altText, (WContainerWidget)null)}
*/
public WImage(WLink link, CharSequence altText) {
this(link, altText, (WContainerWidget) null);
}
/**
* Creates an image widget with given image URL (deprecated).
*
*
* @deprecated Use {@link WImage#WImage(WLink link, WContainerWidget parent)
* WImage()} instead.
*/
public WImage(String imageRef, WContainerWidget parent) {
super(parent);
this.altText_ = new WString();
this.imageLink_ = new WLink(WLink.Type.Url, imageRef);
this.map_ = null;
this.flags_ = new BitSet();
this.setLoadLaterWhenInvisible(false);
}
/**
* Creates an image widget with given image URL (deprecated).
*
* Calls {@link #WImage(String imageRef, WContainerWidget parent)
* this(imageRef, (WContainerWidget)null)}
*/
public WImage(String imageRef) {
this(imageRef, (WContainerWidget) null);
}
/**
* Creates an image widget with given image URL and alternate text
* (deprecated).
*
*
* @deprecated Use
* {@link WImage#WImage(WLink link, CharSequence altText, WContainerWidget parent)
* WImage()} instead.
*/
public WImage(String imageRef, CharSequence altText, WContainerWidget parent) {
super(parent);
this.altText_ = WString.toWString(altText);
this.imageLink_ = new WLink(WLink.Type.Url, imageRef);
this.map_ = null;
this.flags_ = new BitSet();
this.setLoadLaterWhenInvisible(false);
}
/**
* Creates an image widget with given image URL and alternate text
* (deprecated).
*
* Calls
* {@link #WImage(String imageRef, CharSequence altText, WContainerWidget parent)
* this(imageRef, altText, (WContainerWidget)null)}
*/
public WImage(String imageRef, CharSequence altText) {
this(imageRef, altText, (WContainerWidget) null);
}
/**
* Creates an image widget with given image resource and alternate text
* (deprecated).
*
*
* @deprecated Use
* {@link WImage#WImage(WLink link, CharSequence altText, WContainerWidget parent)
* WImage()} instead.
*/
public WImage(WResource resource, CharSequence altText,
WContainerWidget parent) {
super(parent);
this.altText_ = WString.toWString(altText);
this.imageLink_ = new WLink();
this.map_ = null;
this.flags_ = new BitSet();
this.setLoadLaterWhenInvisible(false);
this.setImageLink(new WLink(resource));
}
/**
* Creates an image widget with given image resource and alternate text
* (deprecated).
*
* Calls
* {@link #WImage(WResource resource, CharSequence altText, WContainerWidget parent)
* this(resource, altText, (WContainerWidget)null)}
*/
public WImage(WResource resource, CharSequence altText) {
this(resource, altText, (WContainerWidget) null);
}
public void remove() {
if (this.map_ != null)
this.map_.remove();
super.remove();
}
/**
* Sets an alternate text.
*
* The alternate text should provide a fallback for browsers that do not
* display an image. If no sensible fallback text can be provided, an empty
* text is preferred over nonsense.
*
* This should not be confused with {@link WWebWidget#getToolTip()
* WWebWidget#getToolTip()} text, which provides additional information that
* is displayed when the mouse hovers over the image.
*
* The default alternate text is an empty text ("").
*
*
* @see WImage#getAlternateText()
*/
public void setAlternateText(CharSequence text) {
if (canOptimizeUpdates() && text.equals(this.altText_)) {
return;
}
this.altText_ = WString.toWString(text);
this.flags_.set(BIT_ALT_TEXT_CHANGED);
this.repaint(EnumSet.of(RepaintFlag.RepaintPropertyAttribute));
}
/**
* Returns the alternate text.
*
*
* @see WImage#setAlternateText(CharSequence text)
*/
public WString getAlternateText() {
return this.altText_;
}
/**
* Sets the image link.
*
* The image may be specified as a URL or as a resource. A resource
* specifies application-dependent content, which may be used to generate an
* image on demand.
*/
public void setImageLink(WLink link) {
if (link.getType() != WLink.Type.Resource && canOptimizeUpdates()
&& link.equals(this.imageLink_)) {
return;
}
this.imageLink_ = link;
if (link.getType() == WLink.Type.Resource) {
link.getResource().dataChanged().addListener(this,
new Signal.Listener() {
public void trigger() {
WImage.this.resourceChanged();
}
});
}
this.flags_.set(BIT_IMAGE_LINK_CHANGED);
this.repaint(EnumSet.of(RepaintFlag.RepaintPropertyIEMobile));
}
/**
* Returns the image link.
*
*/
public WLink getImageLink() {
return this.imageLink_;
}
/**
* Sets the image URL (deprecated).
*
*
* @deprecated Use {@link WImage#setImageLink(WLink link) setImageLink()}
* instead.
*/
public void setImageRef(String ref) {
this.setImageLink(new WLink(ref));
}
/**
* Returns the image URL (deprecated).
*
* When the image is specified as a resource, this returns the current
* resource URL.
*
*
* @deprecated Use {@link WImage#getImageLink() getImageLink()} instead.
*/
public String getImageRef() {
return this.imageLink_.getUrl();
}
/**
* Sets the image resource (deprecated).
*
*
* @deprecated Use {@link WImage#setImageLink(WLink link) setImageLink()}
* instead.
*/
public void setResource(WResource resource) {
this.setImageLink(new WLink(resource));
}
/**
* Returns the image resource (deprecated.
*
* Returns null if no image resource was set.
*
*
* @deprecated Use {@link WImage#setImageLink(WLink link) setImageLink()}
* instead.
*/
public WResource getResource() {
return this.imageLink_.getResource();
}
/**
* Adds an interactive area.
*
* Adds the area which listens to events in a specific region
* of the image. Areas are organized in an indexed list, to which the given
* area is appended. When areas overlap, the area with the
* lowest index receives the event.
*
* Ownership of the area is transferred to the image.
*
*
* @see WImage#insertArea(int index, WAbstractArea area)
*/
public void addArea(WAbstractArea area) {
this.insertArea(this.map_ != null ? this.map_.getCount() : 0, area);
}
/**
* Inserts an interactive area.
*
* Inserts the area which listens to events in the coresponding
* area of the image. Areas are organized in a list, and the area is
* inserted at index index. When areas overlap, the area with
* the lowest index receives the event.
*
* Ownership of the area is transferred to the image.
*
*
* @see WImage#addArea(WAbstractArea area)
*/
public void insertArea(int index, WAbstractArea area) {
if (!(this.map_ != null)) {
this.addChild(this.map_ = new MapWidget());
this.flags_.set(BIT_MAP_CREATED);
this.repaint(EnumSet.of(RepaintFlag.RepaintPropertyAttribute));
}
this.map_.insertWidget(index, area.getImpl());
}
/**
* Removes an interactive area.
*
* Removes the area from this widget, and also returns the
* ownership.
*
*
* @see WImage#addArea(WAbstractArea area)
*/
public void removeArea(WAbstractArea area) {
if (!(this.map_ != null)) {
logger.error(new StringWriter()
.append("removeArea(): no such area").toString());
return;
}
this.map_.removeWidget(area.getImpl());
}
/**
* Returns the interactive area at the given index.
*
* Returns null if index was invalid.
*
*
* @see WImage#insertArea(int index, WAbstractArea area)
*/
public WAbstractArea getArea(int index) {
if (this.map_ != null && index < this.map_.getCount()) {
return WAbstractArea.areaForImpl(this.map_.getWidget(index));
} else {
return null;
}
}
/**
* Returns the interactive areas set for this widget.
*
*
* @see WImage#addArea(WAbstractArea area)
*/
public List getAreas() {
List result = new ArrayList();
if (this.map_ != null) {
for (int i = 0; i < this.map_.getCount(); ++i) {
result.add(WAbstractArea.areaForImpl(this.map_.getWidget(i)));
}
}
return result;
}
/**
* Event emitted when the image was loaded.
*/
public EventSignal imageLoaded() {
return this.voidEventSignal(LOAD_SIGNAL, true);
}
private static final int BIT_ALT_TEXT_CHANGED = 0;
private static final int BIT_IMAGE_LINK_CHANGED = 1;
private static final int BIT_MAP_CREATED = 2;
private WString altText_;
private WLink imageLink_;
private MapWidget map_;
BitSet flags_;
private void resourceChanged() {
this.flags_.set(BIT_IMAGE_LINK_CHANGED);
this.repaint(EnumSet.of(RepaintFlag.RepaintPropertyIEMobile));
}
void getDomChanges(List result, WApplication app) {
if (this.map_ != null) {
DomElement e = DomElement.getForUpdate("i" + this.getId(),
DomElementType.DomElement_IMG);
this.updateDom(e, false);
result.add(e);
} else {
super.getDomChanges(result, app);
}
}
void updateDom(DomElement element, boolean all) {
DomElement img = element;
if (all && element.getType() == DomElementType.DomElement_SPAN) {
DomElement map = this.map_.createSDomElement(WApplication
.getInstance());
element.addChild(map);
img = DomElement.createNew(DomElementType.DomElement_IMG);
img.setId("i" + this.getId());
}
if (this.flags_.get(BIT_IMAGE_LINK_CHANGED) || all) {
if (!this.imageLink_.isNull()) {
String url = resolveRelativeUrl(this.imageLink_.getUrl());
WApplication app = WApplication.getInstance();
url = app.encodeUntrustedUrl(url);
img.setProperty(Property.PropertySrc, url);
} else {
img.setProperty(Property.PropertySrc, "#");
}
this.flags_.clear(BIT_IMAGE_LINK_CHANGED);
}
if (this.flags_.get(BIT_ALT_TEXT_CHANGED) || all) {
img.setAttribute("alt", this.altText_.toString());
this.flags_.clear(BIT_ALT_TEXT_CHANGED);
}
if (this.flags_.get(BIT_MAP_CREATED) || all && this.map_ != null) {
img.setAttribute("usemap", '#' + this.map_.getId());
this.flags_.clear(BIT_MAP_CREATED);
}
super.updateDom(img, all);
if (element != img) {
element.addChild(img);
}
}
DomElementType getDomElementType() {
return this.map_ != null ? DomElementType.DomElement_SPAN
: DomElementType.DomElement_IMG;
}
void propagateRenderOk(boolean deep) {
this.flags_.clear(BIT_IMAGE_LINK_CHANGED);
this.flags_.clear(BIT_ALT_TEXT_CHANGED);
super.propagateRenderOk(deep);
}
private static String LOAD_SIGNAL = "load";
}