com.google.gwt.dom.client.Element Maven / Gradle / Ivy
/*
* Copyright 2008 Google Inc.
*
* Licensed 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 com.google.gwt.dom.client;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.safehtml.shared.SafeHtml;
/**
* All HTML element interfaces derive from this class.
*/
public class Element extends Node {
/**
* Fast helper method to convert small doubles to 32-bit int.
*
* Note: you should be aware that this uses JavaScript rounding and thus
* does NOT provide the same semantics as int b = (int) someDouble;.
* In particular, if x is outside the range [-2^31,2^31), then toInt32(x) would return a value
* equivalent to x modulo 2^32, whereas (int) x would evaluate to either MIN_INT or MAX_INT.
*/
private static native int toInt32(double val) /*-{
return val | 0;
}-*/;
/**
* Constant returned from {@link #getDraggable()}.
*/
public static final String DRAGGABLE_AUTO = "auto";
/**
* Constant returned from {@link #getDraggable()}.
*/
public static final String DRAGGABLE_FALSE = "false";
/**
* Constant returned from {@link #getDraggable()}.
*/
public static final String DRAGGABLE_TRUE = "true";
/**
* Assert that the given {@link Node} is an {@link Element} and automatically
* typecast it.
*/
public static Element as(JavaScriptObject o) {
assert is(o);
return (Element) o;
}
/**
* Assert that the given {@link Node} is an {@link Element} and automatically
* typecast it.
*/
public static Element as(Node node) {
assert is(node);
return (Element) node;
}
/**
* Determines whether the given {@link JavaScriptObject} can be cast to an
* {@link Element}. A null object will cause this method to
* return false.
*/
public static boolean is(JavaScriptObject o) {
if (Node.is(o)) {
return is((Node) o);
}
return false;
}
/**
* Determine whether the given {@link Node} can be cast to an {@link Element}.
* A null node will cause this method to return
* false.
*/
public static boolean is(Node node) {
return (node != null) && (node.getNodeType() == Node.ELEMENT_NODE);
}
protected Element() {
}
/**
* Adds a name to this element's class property. If the name is already
* present, this method has no effect.
*
* @param className the class name to be added
* @return true if this element did not already have the specified class name
* @see #setClassName(String)
*/
public final boolean addClassName(String className) {
className = trimClassName(className);
// Get the current style string.
String oldClassName = getClassName();
int idx = indexOfName(oldClassName, className);
// Only add the style if it's not already present.
if (idx == -1) {
if (oldClassName.length() > 0) {
setClassName(oldClassName + " " + className);
} else {
setClassName(className);
}
return true;
}
return false;
}
/**
* Removes keyboard focus from this element.
*/
public final native void blur() /*-{
this.blur();
}-*/;
/**
* Dispatched the given event with this element as its target. The event will
* go through all phases of the browser's normal event dispatch mechanism.
*
* Note: Because the browser's normal dispatch mechanism is used, exceptions
* thrown from within handlers triggered by this method cannot be caught by
* wrapping this method in a try/catch block. Such exceptions will be caught
* by the
* {@link com.google.gwt.core.client.GWT#setUncaughtExceptionHandler(com.google.gwt.core.client.GWT.UncaughtExceptionHandler) uncaught exception handler}
* as usual.
*
* @param evt the event to be dispatched
*/
public final void dispatchEvent(NativeEvent evt) {
DOMImpl.impl.dispatchEvent(this, evt);
}
/**
* Gives keyboard focus to this element.
*/
public final native void focus() /*-{
this.focus();
}-*/;
/**
* Gets an element's absolute bottom coordinate in the document's coordinate
* system.
*/
public final int getAbsoluteBottom() {
return getAbsoluteTop() + getOffsetHeight();
}
/**
* Gets an element's absolute left coordinate in the document's coordinate
* system.
*/
public final int getAbsoluteLeft() {
return DOMImpl.impl.getAbsoluteLeft(this);
}
/**
* Gets an element's absolute right coordinate in the document's coordinate
* system.
*/
public final int getAbsoluteRight() {
return getAbsoluteLeft() + getOffsetWidth();
}
/**
* Gets an element's absolute top coordinate in the document's coordinate
* system.
*/
public final int getAbsoluteTop() {
return DOMImpl.impl.getAbsoluteTop(this);
}
/**
* Retrieves an attribute value by name. Attribute support can be
* inconsistent across various browsers. Consider using the accessors in
* {@link Element} and its specific subclasses to retrieve attributes and
* properties.
*
* @param name The name of the attribute to retrieve
* @return The Attr value as a string, or the empty string if that attribute
* does not have a specified or default value
*/
public final String getAttribute(String name) {
return DOMImpl.impl.getAttribute(this, name);
}
/**
* The class attribute of the element. This attribute has been renamed due to
* conflicts with the "class" keyword exposed by many languages.
*
* @see W3C
* HTML Specification
*/
public final native String getClassName() /*-{
return this.className;
}-*/;
/**
* Returns the inner height of an element in pixels, including padding but not
* the horizontal scrollbar height, border, or margin.
*
* @return the element's client height
*/
public final int getClientHeight() {
return toInt32(getSubPixelClientHeight());
}
/**
* Returns the inner width of an element in pixels, including padding but not
* the vertical scrollbar width, border, or margin.
*
* @return the element's client width
*/
public final int getClientWidth() {
return toInt32(getSubPixelClientWidth());
}
/**
* Specifies the base direction of directionally neutral text and the
* directionality of tables.
*/
public final native String getDir() /*-{
return this.dir;
}-*/;
/**
* Returns the draggable attribute of this element.
*
* @return one of {@link #DRAGGABLE_AUTO}, {@link #DRAGGABLE_FALSE}, or
* {@link #DRAGGABLE_TRUE}
*/
public final native String getDraggable() /*-{
return this.draggable || null;
}-*/;
/**
* Returns a NodeList of all descendant Elements with a given tag name, in the
* order in which they are encountered in a preorder traversal of this Element
* tree.
*
* @param name The name of the tag to match on. The special value "*" matches
* all tags
* @return A list of matching Element nodes
*/
public final native NodeList getElementsByTagName(String name) /*-{
return this.getElementsByTagName(name);
}-*/;
/**
* The first child of element this element. If there is no such element, this
* returns null.
*/
public final Element getFirstChildElement() {
return DOMImpl.impl.getFirstChildElement(this);
}
/**
* The element's identifier.
*
* @see W3C
* HTML Specification
*/
public final native String getId() /*-{
return this.id;
}-*/;
/**
* All of the markup and content within a given element.
*/
public final String getInnerHTML() {
return DOMImpl.impl.getInnerHTML(this);
}
/**
* The text between the start and end tags of the object.
*/
public final String getInnerText() {
return DOMImpl.impl.getInnerText(this);
}
/**
* Language code defined in RFC 1766.
*/
public final native String getLang() /*-{
return this.lang;
}-*/;
/**
* The element immediately following this element. If there is no such
* element, this returns null.
*/
public final Element getNextSiblingElement() {
return DOMImpl.impl.getNextSiblingElement(this);
}
/**
* The height of an element relative to the layout.
*/
public final int getOffsetHeight() {
return toInt32(getSubPixelOffsetHeight());
}
/**
* The number of pixels that the upper left corner of the current element is
* offset to the left within the offsetParent node.
*/
public final int getOffsetLeft() {
return toInt32(getSubPixelOffsetLeft());
}
/**
* Returns a reference to the object which is the closest (nearest in the
* containment hierarchy) positioned containing element.
*/
public final native Element getOffsetParent() /*-{
return this.offsetParent;
}-*/;
/**
* The number of pixels that the upper top corner of the current element is
* offset to the top within the offsetParent node.
*/
public final int getOffsetTop() {
return toInt32(getSubPixelOffsetTop());
}
/**
* The width of an element relative to the layout.
*/
public final int getOffsetWidth() {
return toInt32(getSubPixelOffsetWidth());
}
/**
* The element immediately preceeding this element. If there is no such
* element, this returns null.
*/
public final Element getPreviousSiblingElement() {
return DOMImpl.impl.getPreviousSiblingElement(this);
}
/**
* Gets a boolean property from this element.
*
* @param name the name of the property to be retrieved
* @return the property value
*/
public final native boolean getPropertyBoolean(String name) /*-{
return !!this[name];
}-*/;
/**
* Gets a double property from this element.
*
* @param name the name of the property to be retrieved
* @return the property value
*/
public final native double getPropertyDouble(String name) /*-{
return parseFloat(this[name]) || 0.0;
}-*/;
/**
* Gets an integer property from this element.
*
* @param name the name of the property to be retrieved
* @return the property value
*/
public final native int getPropertyInt(String name) /*-{
return parseInt(this[name]) | 0;
}-*/;
/**
* Gets a JSO property from this element.
*
* @param name the name of the property to be retrieved
* @return the property value
*/
public final native JavaScriptObject getPropertyJSO(String name) /*-{
return this[name] || null;
}-*/;
/**
* Gets an object property from this element.
*
* @param name the name of the property to be retrieved
* @return the property value
*/
public final native Object getPropertyObject(String name) /*-{
return this[name] || null;
}-*/;
/**
* Gets a property from this element.
*
* @param name the name of the property to be retrieved
* @return the property value
*/
public final native String getPropertyString(String name) /*-{
return (this[name] == null) ? null : String(this[name]);
}-*/;
/**
* The height of the scroll view of an element.
*/
public final int getScrollHeight() {
return toInt32(getSubPixelScrollHeight());
}
/**
* The number of pixels that an element's content is scrolled from the left.
*
*
* If the element is in RTL mode, this method will return a negative value of
* the number of pixels scrolled from the right.
*
*/
public final int getScrollLeft() {
return DOMImpl.impl.getScrollLeft(this);
}
/**
* The number of pixels that an element's content is scrolled from the top.
*/
public final int getScrollTop() {
return toInt32(getSubPixelScrollTop());
}
/**
* The width of the scroll view of an element.
*/
public final int getScrollWidth() {
return toInt32(getSubPixelScrollWidth());
}
/**
* Gets a string representation of this element (as outer HTML).
*
* We do not override {@link #toString()} because it is final in
* {@link com.google.gwt.core.client.JavaScriptObject}.
*
* @return the string representation of this element
*/
public final String getString() {
return DOMImpl.impl.toString(this);
}
/**
* Gets this element's {@link Style} object.
*/
public final native Style getStyle() /*-{
return this.style;
}-*/;
/**
* The index that represents the element's position in the tabbing order.
*
* @see W3C HTML Specification
*/
public final int getTabIndex() {
return DOMImpl.impl.getTabIndex(this);
}
/**
* Gets the element's full tag name, including the namespace-prefix if
* present.
*
* @return the element's tag name
*/
public final String getTagName() {
return DOMImpl.impl.getTagName(this);
}
/**
* The element's advisory title.
*/
public final native String getTitle() /*-{
return this.title;
}-*/;
/**
* Determines whether an element has an attribute with a given name.
*
*
* Note that IE, prior to version 8, will return false-positives for names
* that collide with element properties (e.g., style, width, and so forth).
*
*
* @param name the name of the attribute
* @return true if this element has the specified attribute
*/
public final boolean hasAttribute(String name) {
return DOMImpl.impl.hasAttribute(this, name);
}
/**
* Checks if this element's class property contains specified class name.
*
* @param className the class name to be added
* @return true if this element has the specified class name
*/
public final boolean hasClassName(String className) {
className = trimClassName(className);
int idx = indexOfName(getClassName(), className);
return idx != -1;
}
/**
* Determines whether this element has the given tag name.
*
* @param tagName the tag name, including namespace-prefix (if present)
* @return true if the element has the given tag name
*/
public final boolean hasTagName(String tagName) {
assert tagName != null : "tagName must not be null";
return tagName.equalsIgnoreCase(getTagName());
}
/**
* Removes an attribute by name.
*/
public final native void removeAttribute(String name) /*-{
this.removeAttribute(name);
}-*/;
/**
* Removes a name from this element's class property. If the name is not
* present, this method has no effect.
*
* @param className the class name to be removed
* @return true if this element had the specified class name
* @see #setClassName(String)
*/
public final boolean removeClassName(String className) {
className = trimClassName(className);
// Get the current style string.
String oldStyle = getClassName();
int idx = indexOfName(oldStyle, className);
// Don't try to remove the style if it's not there.
if (idx != -1) {
// Get the leading and trailing parts, without the removed name.
String begin = oldStyle.substring(0, idx).trim();
String end = oldStyle.substring(idx + className.length()).trim();
// Some contortions to make sure we don't leave extra spaces.
String newClassName;
if (begin.length() == 0) {
newClassName = end;
} else if (end.length() == 0) {
newClassName = begin;
} else {
newClassName = begin + " " + end;
}
setClassName(newClassName);
return true;
}
return false;
}
/**
* Returns the index of the first occurrence of name in a space-separated list of names,
* or -1 if not found.
*
* @param nameList list of space delimited names
* @param name a non-empty string. Should be already trimmed.
*/
static int indexOfName(String nameList, String name) {
int idx = nameList.indexOf(name);
// Calculate matching index.
while (idx != -1) {
if (idx == 0 || nameList.charAt(idx - 1) == ' ') {
int last = idx + name.length();
int lastPos = nameList.length();
if ((last == lastPos)
|| ((last < lastPos) && (nameList.charAt(last) == ' '))) {
break;
}
}
idx = nameList.indexOf(name, idx + 1);
}
return idx;
}
private static String trimClassName(String className) {
assert (className != null) : "Unexpectedly null class name";
className = className.trim();
assert !className.isEmpty() : "Unexpectedly empty class name";
return className;
}
/**
* Add the class name if it doesn't exist or removes it if does.
*
* @param className the class name to be toggled
*/
public final void toggleClassName(String className) {
boolean added = addClassName(className);
if (!added) {
removeClassName(className);
}
}
/**
* Replace one class name with another.
*
* @param oldClassName the class name to be replaced
* @param newClassName the class name to replace it
*/
public final void replaceClassName(String oldClassName, String newClassName) {
removeClassName(oldClassName);
addClassName(newClassName);
}
/**
* Scrolls this element into view.
*
*
* This method crawls up the DOM hierarchy, adjusting the scrollLeft and
* scrollTop properties of each scrollable element to ensure that the
* specified element is completely in view. It adjusts each scroll position by
* the minimum amount necessary.
*
*/
public final void scrollIntoView() {
DOMImpl.impl.scrollIntoView(this);
}
/**
* Adds a new attribute. If an attribute with that name is already present in
* the element, its value is changed to be that of the value parameter.
*
* @param name The name of the attribute to create or alter
* @param value Value to set in string form
*/
public final native void setAttribute(String name, String value) /*-{
this.setAttribute(name, value);
}-*/;
/**
* The class attribute of the element. This attribute has been renamed due to
* conflicts with the "class" keyword exposed by many languages.
*
* @see W3C
* HTML Specification
*/
public final native void setClassName(String className) /*-{
this.className = className;
}-*/;
/**
* Specifies the base direction of directionally neutral text and the
* directionality of tables.
*/
public final native void setDir(String dir) /*-{
this.dir = dir;
}-*/;
/**
* Changes the draggable attribute to one of {@link #DRAGGABLE_AUTO},
* {@link #DRAGGABLE_FALSE}, or {@link #DRAGGABLE_TRUE}.
*
* @param draggable a String constants
*/
public final void setDraggable(String draggable) {
DOMImpl.impl.setDraggable(this, draggable);
}
/**
* The element's identifier.
*
* @see W3C
* HTML Specification
*/
public final native void setId(String id) /*-{
this.id = id;
}-*/;
/**
* All of the markup and content within a given element.
*/
public final native void setInnerHTML(String html) /*-{
this.innerHTML = html || '';
}-*/;
/**
* All of the markup and content within a given element.
*/
public final void setInnerSafeHtml(SafeHtml html) {
setInnerHTML(html.asString());
}
/**
* The text between the start and end tags of the object.
*/
public final void setInnerText(String text) {
DOMImpl.impl.setInnerText(this, text);
}
/**
* Language code defined in RFC 1766.
*/
public final native void setLang(String lang) /*-{
this.lang = lang;
}-*/;
/**
* Sets a boolean property on this element.
*
* @param name the name of the property to be set
* @param value the new property value
*/
public final native void setPropertyBoolean(String name, boolean value) /*-{
this[name] = value;
}-*/;
/**
* Sets a double property on this element.
*
* @param name the name of the property to be set
* @param value the new property value
*/
public final native void setPropertyDouble(String name, double value) /*-{
this[name] = value;
}-*/;
/**
* Sets an integer property on this element.
*
* @param name the name of the property to be set
* @param value the new property value
*/
public final native void setPropertyInt(String name, int value) /*-{
this[name] = value;
}-*/;
/**
* Sets a JSO property on this element.
*
* @param name the name of the property to be set
* @param value the new property value
*/
public final native void setPropertyJSO(String name, JavaScriptObject value) /*-{
this[name] = value;
}-*/;
/**
* Sets an object property on this element.
*
* @param name the name of the property to be set
* @param value the new property value
*/
public final native void setPropertyObject(String name, Object value) /*-{
this[name] = value;
}-*/;
/**
* Sets a property on this element.
*
* @param name the name of the property to be set
* @param value the new property value
*/
public final native void setPropertyString(String name, String value) /*-{
this[name] = value;
}-*/;
/**
* The number of pixels that an element's content is scrolled to the left.
*/
public final void setScrollLeft(int scrollLeft) {
DOMImpl.impl.setScrollLeft(this, scrollLeft);
}
/**
* The number of pixels that an element's content is scrolled to the top.
*/
public final native void setScrollTop(int scrollTop) /*-{
this.scrollTop = scrollTop;
}-*/;
/**
* The index that represents the element's position in the tabbing order.
*
* @see W3C HTML Specification
*/
public final native void setTabIndex(int tabIndex) /*-{
this.tabIndex = tabIndex;
}-*/;
/**
* The element's advisory title.
*/
public final native void setTitle(String title) /*-{
// Setting the title to null results in the string "null" being displayed
// on some browsers.
this.title = title || '';
}-*/;
private final native double getSubPixelClientHeight() /*-{
return this.clientHeight;
}-*/;
private final native double getSubPixelClientWidth() /*-{
return this.clientWidth;
}-*/;
private final native double getSubPixelOffsetHeight() /*-{
return this.offsetHeight || 0;
}-*/;
private final native double getSubPixelOffsetLeft() /*-{
return this.offsetLeft || 0;
}-*/;
private final native double getSubPixelOffsetTop() /*-{
return this.offsetTop || 0;
}-*/;
private final native double getSubPixelOffsetWidth() /*-{
return this.offsetWidth || 0;
}-*/;
private final native double getSubPixelScrollHeight() /*-{
return this.scrollHeight || 0;
}-*/;
private final native double getSubPixelScrollTop() /*-{
return this.scrollTop || 0;
}-*/;
private final native double getSubPixelScrollWidth() /*-{
return this.scrollWidth || 0;
}-*/;
}