GWT DatePicker，按年份滚动

Question

我可能会错过一些东西，但GWT中的DatePicker（我使用的是2.0.3版本）并不能让您按年份来回滚动，只有一个月。我错过了什么吗？我知道有一个我可以使用的外部库（code.google.com/p/gwt-datepicker/），但是我希望避免导入另一个第三方库，当你应该能够在DatePicker提供的库中执行此操作时在GWT。

Answer 1

您需要创建一个DatePicker子类，该子类使用您自己的MonthSelector实现。

有一个在GWT谷歌集团最近的线程上这个题目，与示例代码：

Getting the default DateBox() picker to advance year at a time

Answer 2

我想你想的东西像下面。

这里我修改了GWT DatePicker来添加月份和年份选择器。 我指定压延范围高达2100，您可以根据自己的意愿通过在其

import com.google.gwt.user.datepicker.client.CalendarModel; 
import com.google.gwt.user.datepicker.client.DatePicker; 
import com.google.gwt.user.datepicker.client.DefaultCalendarView; 
public class DatePickerWithYearSelectorNew extends DatePicker { 

    public DatePickerWithYearSelectorNew() { 
     super(new MonthAndYearSelectorWithYear(), new DefaultCalendarView(), 
       new CalendarModel()); 
    MonthAndYearSelectorWithYear monthSelector = (MonthAndYearSelectorWithYear)    
this.getMonthSelector(); 
     monthSelector.setPicker(this); 
      monthSelector.setModel(this.getModel()); 
    } 
    public void refreshComponents() { 
     super.refreshAll(); 
    } 
}  
import java.util.Date; 
import com.google.gwt.event.dom.client.ChangeEvent; 
import com.google.gwt.event.dom.client.ChangeHandler; 
import com.google.gwt.event.dom.client.ClickEvent; 
import com.google.gwt.event.dom.client.ClickHandler; 
import com.google.gwt.user.client.ui.Grid; 
import com.google.gwt.user.client.ui.ListBox; 
import com.google.gwt.user.client.ui.PushButton; 
import com.google.gwt.user.client.ui.HTMLTable.CellFormatter; 
import com.google.gwt.user.datepicker.client.CalendarModel; 
import com.google.gwt.user.datepicker.client.MonthSelector;  



public class MonthAndYearSelectorWithYear extends MonthSelector { 

    private static String BASE_NAME = "datePicker"; 
    private PushButton backwards; 
    private PushButton forwards; 
    private PushButton backwardsYear; 
    private PushButton forwardsYear; 
    private Grid grid; 
    private int previousYearColumn = 0; 
    private int previousMonthColumn = 1; 

    private int nextMonthColumn = 4; 
    private int nextYearColumn = 5; 
    private CalendarModel model; 
    private DatePickerWithYearSelectorNew picker; 

    private ListBox monthListBox; 
    private ListBox yearListBox; 

    public MonthAndYearSelectorWithYear() { 

     yearListBox = new ListBox(); 

     for (int i = 1900; i < 2100; i++) { 
      yearListBox.addItem(i + ""); 
     } 

     String[] items = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", 
       "Aug", "Sep", "Oct", "Nov", "Dec" }; 

     monthListBox = new ListBox(); 

     for (int i = 0; i < items.length; i++) { 
      monthListBox.addItem(items[i]); 
     } 

    } 

    public void setModel(CalendarModel model) { 
     this.model = model; 
    } 

    public void setPicker(DatePickerWithYearSelectorNew picker) { 
     this.picker = picker; 
    } 

    @Override 
    protected void refresh() { 
     int monthIndex = getModel().getCurrentMonth().getMonth(); 
     monthListBox.setItemSelected(monthIndex, true); 
     int yearIndex = getModel().getCurrentMonth().getYear(); 
     // System.out.println(yearIndex); 
     yearListBox.setItemSelected(yearIndex, true); 
    } 

    @Override 
    protected void setup() { 
     // Set up backwards. 
     backwards = new PushButton(); 
     backwards.addClickHandler(new ClickHandler() { 
      public void onClick(ClickEvent event) { 
       addMonths(-1); 
      } 
     }); 

     backwards.getUpFace().setHTML("&lsaquo;"); 
     backwards.setStyleName(BASE_NAME + "PreviousButton"); 

     forwards = new PushButton(); 
     forwards.getUpFace().setHTML("&rsaquo;"); 
     forwards.setStyleName(BASE_NAME + "NextButton"); 
     forwards.addClickHandler(new ClickHandler() { 
      public void onClick(ClickEvent event) { 
       if (model.getCurrentMonth().getYear() < 199) { 
        addMonths(+1); 
       } 
       else if(model.getCurrentMonth().getMonth()<11 
            &&model.getCurrentMonth().getYear()==199) 
       { 
        addMonths(+1); 
       } 
      } 
     }); 

     // Set up backwards year 
     backwardsYear = new PushButton(); 
     backwardsYear.addClickHandler(new ClickHandler() { 
      public void onClick(ClickEvent event) { 

       addMonths(-12); 
       picker.refreshComponents(); 
      } 
     }); 

     backwardsYear.getUpFace().setHTML("&laquo;"); 
     backwardsYear.setStyleName(BASE_NAME + "PreviousButton"); 

     forwardsYear = new PushButton(); 
     forwardsYear.getUpFace().setHTML("&raquo;"); 
     forwardsYear.setStyleName(BASE_NAME + "NextButton"); 
     forwardsYear.addClickHandler(new ClickHandler() { 
      public void onClick(ClickEvent event) { 
       if (model.getCurrentMonth().getYear() < 199) { 
        addMonths(+12); 
        picker.refreshComponents(); 
       } 
      } 
     }); 

     yearListBox.addChangeHandler(new ChangeHandler() { 

      @Override 
      public void onChange(ChangeEvent event) { 
       // int yearIndex = yearListBox.getSelectedIndex(); 
       //  
       setYear(Integer.parseInt(yearListBox.getValue(yearIndex))); 
       setYear(yearListBox.getSelectedIndex()); 
      } 
     }); 
     monthListBox.addChangeHandler(new ChangeHandler() { 

      @Override 
      public void onChange(ChangeEvent event) { 
       int monthIndex = monthListBox.getSelectedIndex(); 
       setMonth(monthIndex); 
      } 
     }); 

     // Set up grid. 
     grid = new Grid(1, 6); 
     grid.setWidget(0, previousYearColumn, backwardsYear); 
     grid.setWidget(0, previousMonthColumn, backwards); 
     grid.setWidget(0, 2, monthListBox); 
     grid.setWidget(0, 3, yearListBox); 
     grid.setWidget(0, nextMonthColumn, forwards); 
     grid.setWidget(0, nextYearColumn, forwardsYear); 

     CellFormatter formatter = grid.getCellFormatter(); 

     formatter.setWidth(0, previousYearColumn, "1"); 
     formatter.setWidth(0, previousMonthColumn, "1"); 

     formatter.setWidth(0, nextMonthColumn, "1"); 
     formatter.setWidth(0, nextYearColumn, "1"); 
     grid.setStyleName(BASE_NAME + "MonthSelector"); 
     initWidget(grid); 
    } 

    public void addMonths(int numMonths) { 
     model.shiftCurrentMonth(numMonths); 
     picker.refreshComponents(); 
    } 

    @SuppressWarnings("deprecation") 
    public void setMonth(int month) { 
     Date tempMonth = new Date(); 
     tempMonth.setMonth(month); 

     model.setCurrentMonth(tempMonth); 
     picker.refreshComponents(); 
    } 

    @SuppressWarnings("deprecation") 
    public void setYear(int year) { 
     // to set year 
     model.getCurrentMonth().setYear(year); 
     picker.refreshComponents(); 
    } 
}