com.google.gwt.user.client.ui.SimpleCheckBox 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.user.client.ui;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.InputElement;
import com.google.gwt.editor.client.IsEditor;
import com.google.gwt.editor.client.LeafValueEditor;
import com.google.gwt.editor.client.adapters.TakesValueEditor;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
/**
* A simple checkbox widget, with no label.
*
* CSS Style Rules
*
* - .gwt-SimpleCheckBox { }
* - .gwt-SimpleCheckBox-disabled { Applied when checkbox is disabled }
*
*/
public class SimpleCheckBox extends FocusWidget implements HasName,
HasValue, IsEditor> {
/**
* Creates a SimpleCheckBox widget that wraps an existing <input
* type='checkbox'> element.
*
* This element must already be attached to the document. If the element is
* removed from the document, you must call
* {@link RootPanel#detachNow(Widget)}.
*
* @param element the element to be wrapped
*/
public static SimpleCheckBox wrap(Element element) {
// Assert that the element is attached.
assert Document.get().getBody().isOrHasChild(element);
SimpleCheckBox checkBox = new SimpleCheckBox(element);
// Mark it attached and remember it for cleanup.
checkBox.onAttach();
RootPanel.detachOnWindowClose(checkBox);
return checkBox;
}
private LeafValueEditor editor;
private boolean valueChangeHandlerInitialized;
/**
* Creates a new simple checkbox.
*/
public SimpleCheckBox() {
this(Document.get().createCheckInputElement(), "gwt-SimpleCheckBox");
}
/**
* This constructor may be used by subclasses to explicitly use an existing
* element. This element must be an <input> element whose type is either
* 'checkbox'.
*
* @param element the element to be used
*/
protected SimpleCheckBox(Element element) {
assert InputElement.as(element).getType().equalsIgnoreCase("checkbox");
setElement(element);
}
SimpleCheckBox(Element element, String styleName) {
setElement(element);
if (styleName != null) {
setStyleName(styleName);
}
}
@Override
public HandlerRegistration addValueChangeHandler(
ValueChangeHandler handler) {
// Is this the first value change handler? If so, time to add handlers
if (!valueChangeHandlerInitialized) {
ensureDomEventHandlers();
valueChangeHandlerInitialized = true;
}
return addHandler(handler, ValueChangeEvent.getType());
}
public LeafValueEditor asEditor() {
if (editor == null) {
editor = TakesValueEditor.of(this);
}
return editor;
}
/**
* Returns the value property of the input element that backs this widget.
* This is the value that will be associated with the check box name and
* submitted to the server if a {@link FormPanel} that holds it is submitted
* and the box is checked.
*
* Don't confuse this with {@link #getValue}, which returns true or false if
* the widget is checked.
*/
public String getFormValue() {
return getInputElement().getValue();
}
public String getName() {
return getInputElement().getName();
}
/**
* Determines whether this check box is currently checked.
*
* Note that this does not return the value property of the checkbox
* input element wrapped by this widget. For access to that property, see
* {@link #getFormValue()}
*
* @return true if the check box is checked, false otherwise.
* Will not return null
*/
public Boolean getValue() {
String propName = isAttached() ? "checked" : "defaultChecked";
return getInputElement().getPropertyBoolean(propName);
}
/**
* Determines whether this check box is currently checked.
*
* @return true if the check box is checked
* @deprecated Use {@link #getValue} instead
*/
@Deprecated
public boolean isChecked() {
// Funny comparison b/c getValue could in theory return null
return getValue() == true;
}
/**
* Checks or unchecks this check box.
*
* @param checked true to check the check box
* @deprecated Use {@link #setValue(Boolean)} instead
*/
@Deprecated
public void setChecked(boolean checked) {
setValue(checked);
}
@Override
public void setEnabled(boolean enabled) {
super.setEnabled(enabled);
if (enabled) {
removeStyleDependentName("disabled");
} else {
addStyleDependentName("disabled");
}
}
/**
* Set the value property on the input element that backs this widget. This is
* the value that will be associated with the check box's name and submitted
* to the server if a {@link FormPanel} that holds it is submitted and the box
* is checked.
*
* Don't confuse this with {@link #setValue}, which actually checks and
* unchecks the box.
*
* @param value
*/
public void setFormValue(String value) {
getInputElement().setAttribute("value", value);
}
public void setName(String name) {
getInputElement().setName(name);
}
/**
* Checks or unchecks the check box.
*
* Note that this does not set the value property of the checkbox
* input element wrapped by this widget. For access to that property, see
* {@link #setFormValue(String)}
*
* @param value true to check, false to uncheck; null value implies false
*/
public void setValue(Boolean value) {
setValue(value, false);
}
/**
* Checks or unchecks the check box, firing {@link ValueChangeEvent} if
* appropriate.
*
* Note that this does not set the value property of the checkbox
* input element wrapped by this widget. For access to that property, see
* {@link #setFormValue(String)}
*
* @param value true to check, false to uncheck; null value implies false
* @param fireEvents If true, and value has changed, fire a
* {@link ValueChangeEvent}
*/
@Override
public void setValue(Boolean value, boolean fireEvents) {
if (value == null) {
value = Boolean.FALSE;
}
Boolean oldValue = fireEvents ? getValue() : null;
getInputElement().setChecked(value);
getInputElement().setDefaultChecked(value);
if (fireEvents) {
ValueChangeEvent.fireIfNotEqual(this, oldValue, value);
}
}
protected void ensureDomEventHandlers() {
addClickHandler(new ClickHandler() {
@Override
public void onClick(ClickEvent event) {
ValueChangeEvent.fire(SimpleCheckBox.this, getValue());
}
});
}
/**
* This method is called when a widget is detached from the browser's
* document. Overridden because of IE bug that throws away checked state.
*/
@Override
protected void onUnload() {
setValue(getValue());
}
private InputElement getInputElement() {
return InputElement.as(getElement());
}
}