/*
* This library is part of Geranium -
* an open source UI library for GWT.
*
* Copyright (c) Alkacon Software GmbH (http://www.alkacon.com)-
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* For further information about Alkacon Software, please see the
* company website: http://www.alkacon.com
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package com.alkacon.geranium.client.ui.input;
import com.alkacon.geranium.client.I_HasInit;
import com.alkacon.geranium.client.ui.I_AutoHider;
import com.alkacon.geranium.client.ui.I_Button.ButtonStyle;
import com.alkacon.geranium.client.ui.ToggleButton;
import com.alkacon.geranium.client.ui.css.I_InputCss;
import com.alkacon.geranium.client.ui.css.I_InputLayoutBundle;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
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.logical.shared.HasValueChangeHandlers;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.HasHorizontalAlignment;
/**
* This class represents a labeled checkbox which is not represented as an INPUT element in
* the DOM, but is displayed as an image.<p>
*
* It can be checked/unchecked and enabled/disabled, which means 4 combinations in total.
* So you need to supply 4 images, one for each of the combinations.<p>
*/
public class CheckBox extends Composite
implements HasClickHandlers, I_FormWidget, I_HasInit, HasHorizontalAlignment, HasValueChangeHandlers<Boolean> {
/** Type string for this widget. */
public static final String WIDGET_TYPE = "checkbox";
/** CSS bundle for this widget. */
private static final I_InputCss CSS = I_InputLayoutBundle.INSTANCE.inputCss();
/** The current horizontal alignment. */
private HorizontalAlignmentConstant m_align;
/** Toggle button which actually displays the checkbox. */
private final ToggleButton m_button;
/** The error display for this widget. */
private final ErrorWidget m_error;
/** Internal root widget to which all other components of this widget are attached. */
private final FlowPanel m_root;
/**
* Default constructor which creates a checkbox without a label.<p>
*/
public CheckBox() {
this(null);
}
/**
* Public constructor for a checkbox.<p>
*
* The label text passed will be displayed to the right of the checkbox. If
* it is null, no label is displayed.<p>
*
* @param labelText the label text
*/
public CheckBox(String labelText) {
m_button = new ToggleButton();
m_button.setUseMinWidth(false);
m_button.setButtonStyle(ButtonStyle.TRANSPARENT, null);
m_button.setImageClass(CSS.checkBoxImage());
if (labelText != null) {
m_button.setText(labelText);
}
setHorizontalAlignment(ALIGN_RIGHT);
m_root = new FlowPanel();
m_error = new ErrorWidget();
m_root.add(m_button);
m_root.add(m_error);
initWidget(m_root);
addStyleName(CSS.checkBox());
addStyleName(CSS.inlineBlock());
addClickHandler(new ClickHandler() {
/**
* @see com.google.gwt.event.dom.client.ClickHandler#onClick(com.google.gwt.event.dom.client.ClickEvent)
*/
public void onClick(ClickEvent event) {
Scheduler.get().scheduleDeferred(new ScheduledCommand() {
public void execute() {
fireValueChangedEvent();
}
});
}
});
}
/**
* Adds a click handler to the checkbox.<p>
*
* @see com.google.gwt.event.dom.client.HasClickHandlers#addClickHandler(com.google.gwt.event.dom.client.ClickHandler)
*/
public HandlerRegistration addClickHandler(ClickHandler handler) {
return addDomHandler(handler, ClickEvent.getType());
}
/**
* @see com.google.gwt.event.logical.shared.HasValueChangeHandlers#addValueChangeHandler(com.google.gwt.event.logical.shared.ValueChangeHandler)
*/
public HandlerRegistration addValueChangeHandler(ValueChangeHandler<Boolean> handler) {
return addHandler(handler, ValueChangeEvent.getType());
}
/**
* Disables the checkbox and changes the checkbox title attribute to the disabled reason.<p>
*
* @param disabledReason the disabled reason
*/
public void disable(String disabledReason) {
m_button.disable(disabledReason);
}
/**
* Enables the checkbox, switching the checkbox title attribute from the disabled reason to the original title.<p>
*/
public void enable() {
m_button.enable();
}
/**
* @see com.alkacon.geranium.client.ui.input.I_FormWidget#getApparentValue()
*/
public String getApparentValue() {
return getFormValueAsString();
}
/**
* @see com.alkacon.geranium.client.ui.input.I_FormWidget#getFieldType()
*/
public FieldType getFieldType() {
return I_FormWidget.FieldType.BOOLEAN;
}
/**
* @see com.alkacon.geranium.client.ui.input.I_FormWidget#getFormValue()
*/
public Boolean getFormValue() {
return isChecked() ? Boolean.TRUE : Boolean.FALSE;
}
/**
* @see com.alkacon.geranium.client.ui.input.I_FormWidget#getFormValueAsString()
*/
public String getFormValueAsString() {
return "" + isChecked();
}
/**
* This is the alignment of the text in reference to the checkbox, possible values are left or right.<p>
*
* @see com.google.gwt.user.client.ui.HasHorizontalAlignment#getHorizontalAlignment()
*/
public HorizontalAlignmentConstant getHorizontalAlignment() {
return m_align;
}
/**
* Returns true if the checkbox is checked.<p>
*
* @return true if the checkbox is checked
*/
public boolean isChecked() {
return m_button.isDown();
}
/**
* Returns true if the checkbox is enabled.<p>
*
* @return true if the checkbox is enabled
*/
public boolean isEnabled() {
return m_button.isEnabled();
}
/**
* @see com.alkacon.geranium.client.ui.input.I_FormWidget#reset()
*/
public void reset() {
setChecked(false);
}
/**
* @see com.alkacon.geranium.client.ui.input.I_FormWidget#setAutoHideParent(com.alkacon.geranium.client.ui.I_AutoHider)
*/
public void setAutoHideParent(I_AutoHider autoHideParent) {
// do nothing
}
/**
* Checks or unchecks the checkbox.<p>
*
* @param checked if true, check the checkbox else uncheck it
*/
public void setChecked(boolean checked) {
m_button.setDown(checked);
}
/**
* Enables or disables the checkbox.<p>
*
* @param enabled if true, enable the checkbox, else disable it
*/
public void setEnabled(boolean enabled) {
m_button.setEnabled(enabled);
}
/**
* @see com.alkacon.geranium.client.ui.input.I_FormWidget#setErrorMessage(java.lang.String)
*/
public void setErrorMessage(String errorMessage) {
m_error.setText(errorMessage);
}
/**
* Sets the value of the widget.<p>
*
* @param value the new value
*/
public void setFormValue(Object value) {
if (value instanceof Boolean) {
Boolean boolValue = (Boolean)value;
setChecked(boolValue.booleanValue());
}
}
/**
* @see com.alkacon.geranium.client.ui.input.I_FormWidget#setFormValueAsString(java.lang.String)
*/
public void setFormValueAsString(String value) {
setChecked(Boolean.parseBoolean(value) || "checked".equalsIgnoreCase(value));
}
/**
* This is the alignment of the text in reference to the checkbox, possible values are left or right.<p>
*
* @see com.google.gwt.user.client.ui.HasHorizontalAlignment#setHorizontalAlignment(com.google.gwt.user.client.ui.HasHorizontalAlignment.HorizontalAlignmentConstant)
*/
public void setHorizontalAlignment(HorizontalAlignmentConstant align) {
if (align.equals(HasHorizontalAlignment.ALIGN_CENTER)) {
// ignore center alignment
return;
}
m_button.setHorizontalAlignment(align);
m_align = align;
}
/**
* Sets the text.<p>
*
* @param text the text to set
*/
public void setText(String text) {
m_button.setText(text);
}
/**
* Helper method for firing a 'value changed' event.<p>
*/
protected void fireValueChangedEvent() {
ValueChangeEvent.fire(this, getFormValue());
}
}