filterhandler.java

分页查询控件 分页查询控件

/*
 * Copyright 2004 original author or authors.
 *
 * 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 org.extremecomponents.table.handler;

import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.apache.commons.lang.StringUtils;
import org.extremecomponents.base.BaseModel;
import org.extremecomponents.table.bean.Column;
import org.extremecomponents.table.callback.FilterRowsCallback;
import org.extremecomponents.table.cell.Cell;
import org.extremecomponents.table.core.ParameterRegistry;
import org.extremecomponents.table.core.TableModelUtils;

/**
 * Deal with the filtering.
 * 
 * @author Jeff Johnston
 */
public class FilterHandler {
    public final static String CLEAR = "clear";
    public final static String SEARCH = "search";
    public final static String BUTTON = "button";
    public final static String SEARCH_ARROW_IMAGE = "searchArrow";
    public final static String SEARCH_IMAGE = "search";
    public final static String CLEAR_IMAGE = "clear";
    private String button;

    private BaseModel model;

    public FilterHandler(BaseModel model) {
        this.model = model;
    }

    public boolean doFilter() {
        Map parameters = model.getRegistry().getParameters(ParameterRegistry.FILTER);
        return parameters.size() > 0;
    }

    public boolean doClear() {
        if (!StringUtils.isEmpty(getButton()) && getButton().equals(CLEAR)) {
            return true;
        }

        return false;
    }

    public String getButton() {
        if (button == null) {
            button = model.getRegistry().getParameter(ParameterRegistry.FILTER + BUTTON);
        }

        return button;
    }

    /**
     * Filter out the table using the Predicate pattern.
     */
    public Collection filterRows(BaseModel model, Collection rows)
            throws Exception {
        if (doClear()) //we pressed the clear button
        {
            model.getRegistry().clearParameters(ParameterRegistry.FILTER);
            return rows;
        }

        if (!doFilter()) {
            return rows;
        }

        FilterRowsCallback filterRowsCallback = (FilterRowsCallback) model.getCallback(model.getTableHandler()
                .getTable().getFilterRowsCallback());

        return filterRowsCallback.filterRows(model, rows);
    }

    public List getFilterColumns() {
        List columns = model.getColumnHandler().getColumns();
        for (Iterator iter = columns.iterator(); iter.hasNext();) {
            Column column = (Column) iter.next();
            String value = model.getRegistry().getParameter(ParameterRegistry.FILTER + column.getProperty());
            if ((!StringUtils.isEmpty(button) && button.equals(CLEAR)) || StringUtils.isEmpty(value))
            {
                value = "";
            }
            Cell cell = TableModelUtils.buildFilterCell(model, column, value);
            column.setValue(cell.html());
            cell.destroy();
        }

        return columns;
    }
    
    public Map getFilters() {
        return TableModelUtils.getSortedOrFilteredParameters(model, ParameterRegistry.FILTER);
    }

    public void destroy() {
        button = null;
    }
}