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package com.sksamuel.jqm4gwt.html;
import com.google.gwt.dom.client.AnchorElement;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.ImageElement;
import com.google.gwt.dom.client.SpanElement;
import com.google.gwt.dom.client.Style;
import com.google.gwt.dom.client.Style.Display;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.dom.client.Style.VerticalAlign;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.HasClickHandlers;
import com.google.gwt.event.shared.GwtEvent.Type;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.ui.HasEnabled;
import com.google.gwt.user.client.ui.UIObject;
import com.google.gwt.user.client.ui.Widget;
import com.sksamuel.jqm4gwt.Empty;
import com.sksamuel.jqm4gwt.HasText;
import com.sksamuel.jqm4gwt.JQMCommon;
import com.sksamuel.jqm4gwt.Orientation;
import com.sksamuel.jqm4gwt.events.HasTapHandlers;
import com.sksamuel.jqm4gwt.events.JQMComponentEvents;
import com.sksamuel.jqm4gwt.events.JQMHandlerRegistration;
import com.sksamuel.jqm4gwt.events.JQMHandlerRegistration.WidgetHandlerCounter;
import com.sksamuel.jqm4gwt.events.TapEvent;
import com.sksamuel.jqm4gwt.events.TapHandler;
/**
* @author Stephen K Samuel [email protected] 17 Jul 2011 15:38:47
*
* An implementation of an anchor tag that wraps an image tag and optional text.
* <a href='mylink'><img src='myimage'/></a>
*
*/
public class ImageLink extends Widget implements HasClickHandlers, HasTapHandlers, HasEnabled,
HasText {
protected static final String JQM4GWT_IMAGE_LINK_A = "jqm4gwt-image-link-a";
protected static final String JQM4GWT_IMAGE_LINK_IMG = "jqm4gwt-image-link-img";
protected static final String DATA_RESIZE_PRIORITY = "data-resize-priority";
protected ImageElement img;
protected AnchorElement a;
protected SpanElement txt;
private Boolean external;
public ImageLink() {
a = Document.get().createAnchorElement();
setElement(a);
initA();
img = Document.get().createImageElement();
initImg();
a.appendChild(img);
}
protected void initA() {
JQMCommon.setDataRole(a, "none");
// Let's set proper initial default href value.
// If no real href is defined later, then something is expected in onClick handler.
a.setAttribute("href", "javascript:;");
setStyleName(a, JQM4GWT_IMAGE_LINK_A);
}
protected void initImg() {
setStyleName(img, JQM4GWT_IMAGE_LINK_IMG);
setImageResizePriority(Orientation.HORIZONTAL);
img.getStyle().setVerticalAlign(VerticalAlign.TOP); // eliminates excessive/strange margin at the bottom
img.getStyle().setDisplay(Display.NONE);
}
public ImageLink(String href, String src) {
this();
setHref(href);
setSrc(src);
}
public String getSrc() {
return img.getAttribute("src");
}
public String getHref() {
return a.getAttribute("href");
}
/**
* The URL of the source image
*
* @param src
*/
public void setSrc(String src) {
JQMCommon.setAttribute(img, "src", src);
refreshPositioning();
}
private void refreshPositioning() {
String src = getSrc();
String text = getText();
Style imgSt = img.getStyle();
if (src == null || src.isEmpty()) {
imgSt.setVerticalAlign(VerticalAlign.TOP);
imgSt.clearMarginRight();
imgSt.setDisplay(Display.NONE);
if (txt != null) txt.getStyle().setVerticalAlign(VerticalAlign.TOP);
} else {
imgSt.setVerticalAlign(VerticalAlign.MIDDLE);
imgSt.clearDisplay();
if (txt != null) txt.getStyle().setVerticalAlign(VerticalAlign.MIDDLE);
if (text == null || text.isEmpty()) imgSt.clearMarginRight();
else imgSt.setMarginRight(0.3d, Unit.EM);
}
}
/**
* The destination URL of the link
*
* @param href
*/
public void setHref(String href) {
JQMCommon.setAttribute(a, "href", href);
if (external == null /*only if not explicitly set*/ && !Empty.is(href)
&& (href.startsWith("http:") || href.startsWith("https:"))) {
setExternal(true);
}
}
public boolean isExternal() {
return external != null ? external : false;
}
public void setExternal(boolean value) {
this.external = value;
if (value) {
a.setAttribute("rel", "external");
a.setAttribute("data-rel", "external");
} else {
a.removeAttribute("rel");
a.removeAttribute("data-rel");
}
}
/**
* Set the width of the image
*/
@Override
public void setWidth(String width) {
img.getStyle().setProperty("width", width);
}
/**
* Set the height of the image
*/
@Override
public void setHeight(String height) {
img.getStyle().setProperty("height", height);
}
public Orientation getImageResizePriority() {
String s = img.getAttribute(DATA_RESIZE_PRIORITY);
if (s == null || s.isEmpty()) return null;
if (Orientation.HORIZONTAL.getJqmValue().equals(s)) return Orientation.HORIZONTAL;
if (Orientation.VERTICAL.getJqmValue().equals(s)) return Orientation.VERTICAL;
return null;
}
/**
* Defines how to resize image in case of limited/explicit button size.
* HORIZONTAL - width is 100% and height is auto (default mode).
* VERTICAL - height is 100% and width is auto.
* See Flexible images
*/
public void setImageResizePriority(Orientation value) {
if (value == null) img.removeAttribute(DATA_RESIZE_PRIORITY);
else img.setAttribute(DATA_RESIZE_PRIORITY, value.getJqmValue());
}
@Override
public HandlerRegistration addClickHandler(ClickHandler handler) {
return addDomHandler(handler, ClickEvent.getType());
}
@Override
public HandlerRegistration addTapHandler(TapHandler handler) {
// this is not a native browser event so we will have to manage it via JS
return JQMHandlerRegistration.registerJQueryHandler(new WidgetHandlerCounter() {
@Override
public int getHandlerCountForWidget(Type type) {
return getHandlerCount(type);
}
}, this, handler, JQMComponentEvents.TAP_EVENT, TapEvent.getType());
}
@Override
public boolean isEnabled() {
return JQMCommon.isEnabled(this);
}
@Override
public void setEnabled(boolean enabled) {
JQMCommon.setEnabled(this, enabled);
}
/**
* Gives realistic visibility (parent chain considered, ...)
* If you need logical visibility of this particular widget,
* use {@link UIObject#isVisible(Element elem)}
*/
@Override
public boolean isVisible() {
return super.isVisible() && JQMCommon.isVisible(this);
}
@Override
public String getText() {
return txt != null ? txt.getInnerText() : null;
}
@Override
public void setText(String text) {
boolean emptyText = text == null || text.isEmpty();
if (emptyText) {
if (txt != null) txt.setInnerText(text);
} else {
if (txt == null) {
txt = Document.get().createSpanElement();
a.appendChild(txt);
}
txt.setInnerText(text);
}
refreshPositioning();
}
@Override
public ImageLink withText(String text) {
setText(text);
return this;
}
}