PagedDataTableUIBean.java

/*
 * RHQ Management Platform
 * Copyright (C) 2005-2008 Red Hat, Inc.
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation version 2 of the License.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package org.rhq.enterprise.gui.common.framework;

import javax.faces.event.ActionEvent;
import javax.faces.model.DataModel;
import javax.faces.model.SelectItem;

import org.rhq.enterprise.gui.common.paging.PageControlSettingsUIBean;
import org.richfaces.component.UIDataTable;
import org.richfaces.component.UIDatascroller;

import org.rhq.core.domain.util.PageControl;
import org.rhq.enterprise.gui.common.paging.PageControlView;
import org.rhq.enterprise.gui.legacy.WebUser;
import org.rhq.enterprise.gui.legacy.WebUserPreferences;

public abstract class PagedDataTableUIBean extends EnterpriseFacesContextUIBean {
    private PageControl pageControl;
    protected DataModel dataModel;
    private UIDataTable dataTable;
    private UIDatascroller datascroller;
    private PageControlSettingsUIBean pageControlSettings = new PageControlSettingsUIBean();

    public PageControl getPageControl(WebUser user, PageControlView view) {
        if (pageControl == null) {
            pageControl = user.getWebPreferences().getPageControl(view, getMinimumPageSize());
        }

        /*
         * if an invalid value was already persisted to the database, this needs to be fixed; 
         * this can occur when the value was valid at some point in the past, but new overrides
         * changes the valid list of page sizes; generally, the user can correct this themselves
         * at the user interface by selecting a different pageSize (which would cause the new
         * value to be persisted), unless there is only one allowable value in which case it's
         * not possible for the user to correct the issue themselves; to handle both of these
         * cases, let's just pessimistically determine whether we need to "fix" the PageControl
         * and, if so, repersist the adjusted values
         */
        if (view.isUnlimited() == false) {
            String pageSize = String.valueOf(pageControl.getPageSize());
            boolean hasValidSize = false;
            for (SelectItem validPageSize : getPageSizes()) {
                if (validPageSize.getValue().toString().equals(pageSize)) {
                    hasValidSize = true;
                    break;
                }
            }
            if (hasValidSize == false) {
                pageControl.setPageSize(getMinimumPageSize());
                setPageControl(user, view, pageControl);
            }
        }

        return pageControl;
    }

    public PageControl getDefaultPageControl(WebUser user, PageControlView view) {
        return user.getWebPreferences().getDefaultPageControl(view, getMinimumPageSize());
    }

    public void setPageControl(WebUser user, PageControlView view, PageControl pageControl) {
        WebUserPreferences preferences = user.getWebPreferences();
        preferences.setPageControl(view, pageControl);
        this.pageControl = pageControl;
    }

    public UIDataTable getDataTable() {
        return dataTable;
    }

    public void setDataTable(UIDataTable dataTable) {
        this.dataTable = dataTable;
    }

    public void setDataModel(DataModel dataModel) {
        this.dataModel = dataModel;
    }

    public abstract DataModel getDataModel();

    public UIDatascroller getDatascroller() {
        return datascroller;
    }

    public void setDatascroller(UIDatascroller datascroller) {
        this.datascroller = datascroller;

        /* this can be externalized later, but at least
         * all PagedDataTableUIBeans will be consistent now
         */
        this.datascroller.setMaxPages(5);
    }

    public SelectItem[] getPageSizes() {
        return pageControlSettings.getPageSizes();
    }

    public int getMinimumPageSize() {
        return pageControlSettings.getMinimumPageSize();
    }

    public void clearDataModel(ActionEvent event) {
        dataModel = null;
    }
}