我想要一个ToggleButton和RadioButton的混合体。我想要 RadioButton 的“互斥”部分,以及 ToggleButton 的 gui 外观和行为(向上和向下状态)。是否已经存在?
6 回答
我已经调整了 kirushik 的解决方案并创建了一个简单的“ToggleButtonPanel”小部件,它采用任意数量的 ToggleButtons(可能还有您想要添加的任何其他小部件)和您选择的面板(默认为 VerticalPanel)并使按钮相互独家的。
这样做的好处是,当单击按钮时,面板本身会触发 ClickEvents。这样,您可以将单个 ClickHandler 添加到 ToggleGroupPanel,然后使用 event.getSource() 确定单击了哪个按钮
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
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.HandlerRegistration;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.HasWidgets;
import com.google.gwt.user.client.ui.Panel;
import com.google.gwt.user.client.ui.ToggleButton;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.ui.Widget;
public class ToggleButtonPanel extends Composite implements HasWidgets, HasClickHandlers{
public ToggleButtonPanel() {
this(new VerticalPanel());
}
public ToggleButtonPanel(Panel panel){
this.panel = panel;
initWidget(panel);
}
@Override
public void add(Widget w) {
if(w instanceof ToggleButton){
ToggleButton button = (ToggleButton) w;
button.addClickHandler(handler);
}
panel.add(w);
}
@Override
public void clear() {
panel.clear();
}
@Override
public Iterator<Widget> iterator() {
return panel.iterator();
}
@Override
public boolean remove(Widget w) {
return panel.remove(w);
}
@Override
public void setWidth(String width) {
panel.setWidth(width);
};
@Override
public void setHeight(String height) {
panel.setHeight(height);
}
private final Panel panel;
private ClickHandler handler = new ClickHandler(){
@Override
public void onClick(ClickEvent event) {
Iterator<Widget> itr = panel.iterator();
while(itr.hasNext()){
Widget w = itr.next();
if(w instanceof ToggleButton){
ToggleButton button = (ToggleButton) w;
button.setDown(false);
if(event.getSource().equals(button)) {
button.setDown(true);
}
}
}
for(ClickHandler h : handlers){
h.onClick(event);
}
}
};
private List<ClickHandler> handlers = new ArrayList<ClickHandler>();
@Override
public HandlerRegistration addClickHandler(final ClickHandler handler) {
handlers.add(handler);
return new HandlerRegistration() {
@Override
public void removeHandler() {
handlers.remove(handler);
}
};
}
}
这是我的纯 gwt 变体:
class ThreeStateMachine extends FlowPanel{
// This is the main part - it will unset all the buttons in parent widget
// and then set only clicked one.
// One mutual handler works faster and is generally better for code reuse
private final ClickHandler toggleToThis = new ClickHandler() {
@Override
public void onClick(ClickEvent clickEvent) {
for(Widget b: ThreeStateMachine.this.getChildren()){
((ToggleButton)b).setDown(false);
}
((ToggleButton)clickEvent.getSource()).setDown(true);
}
};
private ThreeStateMachine() { // Create out widget and populat it with buttons
super();
ToggleButton b = new ToggleButton("one");
b.setDown(true);
b.addClickHandler(toggleToThis);
this.add(b);
b = new ToggleButton("two");
b.addClickHandler(toggleToThis);
this.add(b);
b = new ToggleButton("three");
b.addClickHandler(toggleToThis);
this.add(b);
}
}
当然,gwt-ToggleButton 需要带有变体(-up-hovering 等)的 css 样式
我有一些既不在扩展库中,也不像其他答案那样依赖于面板的东西。定义管理按钮的此类。我们正在向按钮添加一个新的单击侦听器,这是您在“GUI 内容”类中附加的任何单击处理程序的补充。我不能复制和粘贴这个,所以希望它在语法上是正确的。
public class MutuallyExclusiveToggleButtonCollection {
List<ToggleButton> m_toggleButtons = new ArrayList<ToggleButton>();
public void add(ToggleButton button) {
m_toggleButtons.add(button);
button.addClickListener(new ExclusiveButtonClickHandler());
}
private class ExclusiveButtonClickHandler impelments ClickHandler {
public void onClick(ClickEvent event) {
for(ToggleButton button : m_toggleButtons) {
boolean isSource = event.getSource().equals(button);
button.setIsDown(isSource);
}
}
}
遇到了同样的需求,这是另一个解决方案,它取消了单独的处理程序,并在 UIBinder 中很好地工作,声明如下:
<my:RadioToggleButton buttonGroup="btnGroup" text="Button 1" />
这是扩展类:
import java.util.HashMap;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.uibinder.client.UiConstructor;
import com.google.gwt.user.client.ui.ToggleButton;
public class RadioToggleButton extends ToggleButton
{
private static HashMap<String,ButtonGroup> buttonGroups = new HashMap<>();
private ButtonGroup buttonGroup;
public @UiConstructor RadioToggleButton( String buttonGroupName )
{
buttonGroup = buttonGroups.get( buttonGroupName );
if( buttonGroup == null ){
buttonGroups.put( buttonGroupName, buttonGroup = new ButtonGroup() );
}
buttonGroup.addButton( this );
}
@Override
public void setDown( boolean isDown )
{
if( isDown ){
RadioToggleButton btn = buttonGroup.pressedBtn;
if( btn != null ){
btn.setDown( false );
}
buttonGroup.pressedBtn = this;
}
super.setDown( isDown );
}
private class ButtonGroup implements ClickHandler
{
RadioToggleButton pressedBtn = null;
public void addButton( ToggleButton button )
{
button.addClickHandler( this );
}
@Override
public void onClick( ClickEvent event )
{
Object obj = event.getSource();
if( pressedBtn != null ){
pressedBtn.setDown( false );
}
pressedBtn = (RadioToggleButton)obj;
pressedBtn.setDown( true );
}
}
}
“此示例说明了切换按钮。单击时,此类按钮会切换其“按下”状态。
粗体、斜体和下划线切换按钮相对于它们的切换状态独立操作,而文本对齐图标按钮属于同一切换组,因此当其中一个被单击时,先前按下的按钮返回其正常状态。”
在所有 ToggleButtons 上注册一个额外的 ClickHandler。例如,ToggleButtons 主页、树、摘要、详细信息。
public class Abc extends Composite implements ClickHandler {
ToggleButton home, tree, summary, detail
public Abc() {
// all your UiBinder initializations... blah, blah....
home.addClickHandler(this);
tree.addClickHandler(this);
summary.addClickHandler(this);
detail.addClickHandler(this);
}
@Override
public void onClick(ClickEvent p_event) {
Object v_source = p_event.getSource();
home.setDown(home==v_source);
tree.setDown(tree==v_source);
summary.setDown(summary==v_source);
detail.setDown(detail==v_source);
}
}
当然,您只需要添加所有其他样板代码并为每个 ToggleButton 注册额外的 ClickHandler。