Java tutorial
/* * Copyright 2014-2015 CyberVision, Inc. * * 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.kaaproject.avro.ui.gwt.client.widget.grid; import com.google.gwt.cell.client.FieldUpdater; import com.google.gwt.core.client.GWT; import com.google.gwt.dom.client.Style; import com.google.gwt.dom.client.Style.Unit; import com.google.gwt.event.shared.HandlerRegistration; import com.google.gwt.safehtml.shared.SafeHtml; import com.google.gwt.safehtml.shared.SafeHtmlUtils; import com.google.gwt.user.cellview.client.Column; import com.google.gwt.user.cellview.client.ColumnSortList; import com.google.gwt.user.cellview.client.DataGrid; import com.google.gwt.user.cellview.client.Header; import com.google.gwt.user.cellview.client.SafeHtmlHeader; import com.google.gwt.user.cellview.client.SimplePager; import com.google.gwt.user.cellview.client.SimplePager.TextLocation; import com.google.gwt.user.client.ui.DockLayoutPanel; import com.google.gwt.user.client.ui.HTMLPanel; import com.google.gwt.user.client.ui.Label; import com.google.gwt.view.client.DefaultSelectionEventManager; import com.google.gwt.view.client.HasRows; import com.google.gwt.view.client.MultiSelectionModel; import com.google.gwt.view.client.ProvidesKey; import com.google.gwt.view.client.Range; import com.google.gwt.view.client.SelectionChangeEvent; import org.kaaproject.avro.ui.gwt.client.util.Utils; import org.kaaproject.avro.ui.gwt.client.widget.dialog.ConfirmDialog; import org.kaaproject.avro.ui.gwt.client.widget.dialog.ConfirmDialog.ConfirmListener; import org.kaaproject.avro.ui.gwt.client.widget.grid.ColumnFilterEvent.HasColumnFilterEventHandlers; import org.kaaproject.avro.ui.gwt.client.widget.grid.cell.ActionButtonCell; import org.kaaproject.avro.ui.gwt.client.widget.grid.cell.ActionButtonCell.ActionListener; import org.kaaproject.avro.ui.gwt.client.widget.grid.cell.ActionButtonCell.ActionValidator; import org.kaaproject.avro.ui.gwt.client.widget.grid.cell.ActionsButtonCell; import org.kaaproject.avro.ui.gwt.client.widget.grid.cell.LinkCell; import org.kaaproject.avro.ui.gwt.client.widget.grid.cell.UneditableCheckboxCell; import org.kaaproject.avro.ui.gwt.client.widget.grid.event.HasRowActionEventHandlers; import org.kaaproject.avro.ui.gwt.client.widget.grid.event.RowActionEvent; import org.kaaproject.avro.ui.gwt.client.widget.grid.event.RowActionEventHandler; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.HashMap; import java.util.List; import java.util.Map; public abstract class AbstractGrid<T, K> extends DockLayoutPanel implements HasRowActionEventHandlers<K>, HasColumnFilterEventHandlers { public static final int DEFAULT_GRID_MARGIN = 10; protected static final int ACTION_COLUMN_WIDTH = 40; private static final int DEFAULT_PAGE_SIZE = 20; private static SimplePager.Resources pagerResourcesDefault = GWT.create(SimplePager.Resources.class); private static AvroUiPagerResourcesSmall pagerResourcesSmall = GWT.create(AvroUiPagerResourcesSmall.class); protected DataGrid<T> table; private int pageSize; private MultiSelectionModel<T> selectionModel; private float prefferredWidth = 0f; protected boolean enableActions; protected boolean embedded; protected AvroUiGridResources gridResources; protected SimplePager.Resources pagerResources; protected Column<T, T> deleteColumn; private final Map<Column<?, ?>, Comparator<T>> comparators = new HashMap<Column<?, ?>, Comparator<T>>(); private final List<FiltrableStringColumn<T>> filtrableColumns = new ArrayList<>(); public AbstractGrid(Style.Unit unit) { this(unit, true); } public AbstractGrid(Style.Unit unit, int pageSize) { this(unit, true, pageSize); } public AbstractGrid(Style.Unit unit, boolean enableActions) { this(unit, enableActions, false); } public AbstractGrid(Style.Unit unit, boolean enableActions, int pageSize) { this(unit, enableActions, false, pageSize); } public AbstractGrid(Style.Unit unit, boolean enableActions, boolean embedded) { this(unit, enableActions, embedded, true); } public AbstractGrid(Style.Unit unit, boolean enableActions, boolean embedded, int pageSize) { this(unit, enableActions, embedded, pageSize, true); } public AbstractGrid(Style.Unit unit, boolean enableActions, boolean embedded, boolean init) { this(unit, enableActions, embedded, DEFAULT_PAGE_SIZE, init); } public AbstractGrid(Style.Unit unit, boolean enableActions, boolean embedded, int pageSize, boolean init) { this(unit, enableActions, embedded, pageSize, init, embedded ? AvroUiDataGrid.gridResourcesSmall : AvroUiDataGrid.gridResources, embedded ? pagerResourcesSmall : pagerResourcesDefault); } public AbstractGrid(Style.Unit unit, boolean enableActions, boolean embedded, int pageSize, boolean init, AvroUiGridResources gridResources, SimplePager.Resources pagerResources) { super(unit); this.enableActions = enableActions; this.embedded = embedded; this.pageSize = pageSize; this.gridResources = gridResources; this.pagerResources = pagerResources; if (init) { init(); } } protected void init() { ProvidesKey<T> keyProvider = new ProvidesKey<T>() { @Override public Object getKey(T item) { return item != null ? getObjectId(item) : null; } }; table = new AvroUiDataGrid<T>(this.pageSize, keyProvider, gridResources); table.setAutoHeaderRefreshDisabled(true); Label emptyTableLabel = new Label(Utils.constants.dataGridEmpty()); if (embedded) { emptyTableLabel.getElement().getStyle().setFontSize(14, Unit.PX); emptyTableLabel.getElement().getStyle().setColor("#999999"); } table.setEmptyTableWidget(emptyTableLabel); selectionModel = new MultiSelectionModel<T>(keyProvider); table.setSelectionModel(selectionModel, DefaultSelectionEventManager.<T>createCheckboxManager()); selectionModel.addSelectionChangeHandler(new SelectionChangeEvent.Handler() { @Override public void onSelectionChange(SelectionChangeEvent event) { table.redrawHeaders(); } }); prefferredWidth = initColumns(table); table.setMinimumTableWidth(prefferredWidth, Unit.PX); if (!filtrableColumns.isEmpty()) { table.setHeaderBuilder(new StringFilterHeaderBuilder<T>(this)); } SimplePager pager = getPager(); pager.setDisplay(table); String pagerId = "pager_" + pager.hashCode(); String html = "<table " + "style='width:100%'>" + " <tr>" + " <td" + " align='right'>" + " <div id='" + pagerId + "'/>" + " </td>" + " </tr>" + "</table>"; HTMLPanel htmlPanel = new HTMLPanel(html); htmlPanel.add(pager, pagerId); addNorth(htmlPanel, 40); add(table); // center showShadow(embedded); } public void showShadow(boolean show) { if (show) { getElement().getStyle().clearMargin(); getElement().getStyle().setProperty("boxShadow", "0px 0px 8px rgba(0,0,0,0.5)"); table.getElement().getStyle().setMargin(DEFAULT_GRID_MARGIN, Unit.PX); } else { getElement().getStyle().clearProperty("boxShadow"); table.getElement().getStyle().clearMargin(); getElement().getStyle().setMargin(DEFAULT_GRID_MARGIN, Unit.PX); } } public MultiSelectionModel<T> getSelectionModel() { return selectionModel; } public DataGrid<T> getDataGrid() { return table; } public void sort(List<T> data, Column<?, ?> column, boolean isSortAscending) { final Comparator<T> comparator = comparators.get(column); if (comparator == null) { return; } if (isSortAscending) { Collections.sort(data, comparator); } else { Collections.sort(data, new Comparator<T>() { public int compare(T o1, T o2) { return -comparator.compare(o1, o2); } }); } } public List<T> filter(List<T> data) { List<T> filteredData = data; for (FiltrableStringColumn<T> filtrableStringColumn : filtrableColumns) { if (!filtrableStringColumn.isFilterEmpty()) { List<T> newFilteredData = new ArrayList<>(); for (T object : filteredData) { if (filtrableStringColumn.matched(object)) { newFilteredData.add(object); } } filteredData = newFilteredData; } } return filteredData; } protected void onRowClicked(K id) { RowActionEvent<K> rowClickEvent = new RowActionEvent<>(id, RowActionEvent.CLICK); fireEvent(rowClickEvent); } protected void onRowDelete(K id) { RowActionEvent<K> rowClickEvent = new RowActionEvent<>(id, RowActionEvent.DELETE); fireEvent(rowClickEvent); } @Override public HandlerRegistration addRowActionHandler(RowActionEventHandler<K> handler) { return this.addHandler(handler, RowActionEvent.getType()); } @Override public HandlerRegistration addColumnFilterEventHandler(ColumnFilterEvent.Handler handler) { return this.addHandler(handler, ColumnFilterEvent.getType()); } private float initColumns(DataGrid<T> table) { float prefWidth = 0f; prefWidth += constructColumnsImpl(table); prefWidth += constructActions(table, prefWidth); return prefWidth; } protected float constructStringColumn(DataGrid<T> table, String title, final StringValueProvider<T> valueProvider, float prefWidth) { return constructStringColumn(table, title, valueProvider, null, null, prefWidth); } protected float constructStringColumn(DataGrid<T> table, String title, final StringValueProvider<T> valueProvider, Comparator<T> comparator, Boolean isSortAscending, float prefWidth) { return constructStringColumn(table, title, valueProvider, comparator, isSortAscending, false, prefWidth); } protected float constructStringColumn(DataGrid<T> table, String title, final StringValueProvider<T> valueProvider, Comparator<T> comparator, Boolean isSortAscending, boolean filtrable, float prefWidth) { Header<SafeHtml> header = new SafeHtmlHeader(SafeHtmlUtils.fromSafeConstant(title)); Column<T, String> column = null; if (filtrable) { FiltrableStringColumn<T> filtrableColumn = new FiltrableStringColumn<T>(new LinkCell()) { @Override public String getValue(T item) { return valueProvider.getValue(item); } }; filtrableColumns.add(filtrableColumn); column = filtrableColumn; } else { column = new Column<T, String>(new LinkCell()) { @Override public String getValue(T item) { return valueProvider.getValue(item); } }; } column.setFieldUpdater(new FieldUpdater<T, String>() { @Override public void update(int index, T object, String value) { onRowClicked(getObjectId(object)); } }); table.addColumn(column, header); table.setColumnWidth(column, prefWidth, Unit.PX); processColumnSort(table, column, comparator, isSortAscending); return prefWidth; } protected float constructBooleanColumn(DataGrid<T> table, String title, final BooleanValueProvider<T> valueProvider, float prefWidth) { return constructBooleanColumn(table, title, valueProvider, null, null, prefWidth); } protected float constructBooleanColumn(DataGrid<T> table, String title, final BooleanValueProvider<T> valueProvider, Comparator<T> comparator, Boolean isSortAscending, float prefWidth) { Header<SafeHtml> header = new SafeHtmlHeader(SafeHtmlUtils.fromSafeConstant(title)); Column<T, Boolean> column = new Column<T, Boolean>(new UneditableCheckboxCell()) { @Override public Boolean getValue(T item) { return valueProvider.getValue(item); } }; column.setFieldUpdater(new FieldUpdater<T, Boolean>() { @Override public void update(int index, T object, Boolean value) { onRowClicked(getObjectId(object)); } }); table.addColumn(column, header); table.setColumnWidth(column, prefWidth, Unit.PX); processColumnSort(table, column, comparator, isSortAscending); return prefWidth; } private void processColumnSort(DataGrid<T> table, Column<?, ?> column, Comparator<T> comparator, Boolean isSortAscending) { if (comparator != null) { comparators.put(column, comparator); column.setSortable(true); if (isSortAscending != null) { ColumnSortList.ColumnSortInfo sortInfo = new ColumnSortList.ColumnSortInfo(column, isSortAscending.booleanValue()); ColumnSortList sortList = table.getColumnSortList(); sortList.insert(sortList.size(), sortInfo); } } } protected float constructActions(DataGrid<T> table, float prefWidth) { if (enableActions) { if (deleteColumn == null || table.getColumnIndex(deleteColumn) == -1) { Header<SafeHtml> deleteHeader = new SafeHtmlHeader( SafeHtmlUtils.fromSafeConstant(Utils.constants.delete())); deleteColumn = constructDeleteColumn(""); table.addColumn(deleteColumn, deleteHeader); table.setColumnWidth(deleteColumn, ACTION_COLUMN_WIDTH, Unit.PX); return ACTION_COLUMN_WIDTH; } else { return 0; } } else { return 0; } } protected float removeActions(DataGrid<T> table) { int index = table.getColumnIndex(deleteColumn); if (index > -1) { table.removeColumn(deleteColumn); return ACTION_COLUMN_WIDTH; } return 0; } public void setEnableActions(boolean enableActions) { this.enableActions = enableActions; if (enableActions) { prefferredWidth += constructActions(table, prefferredWidth); table.setMinimumTableWidth(prefferredWidth, Unit.PX); } else { prefferredWidth -= removeActions(table); table.setMinimumTableWidth(prefferredWidth, Unit.PX); } } protected void constructAdditionalActions(ActionsButtonCell<T> cell) { } protected Column<T, T> constructDeleteColumn(String text) { ActionButtonCell<T> cell = new ActionButtonCell<T>(Utils.resources.remove(), text, embedded, new ActionListener<T>() { @Override public void onItemAction(T value) { deleteItem(value); } }, new ActionValidator<T>() { @Override public boolean canPerformAction(T value) { return canDelete(value); } }); Column<T, T> column = new Column<T, T>(cell) { @Override public T getValue(T item) { return item; } }; return column; } protected void deleteItem(final T value) { ConfirmListener listener = new ConfirmListener() { @Override public void onNo() { } @Override public void onYes() { onRowDelete(getObjectId(value)); } }; String question = deleteQuestion(); String title = deleteTitle(); ConfirmDialog dialog = new ConfirmDialog(listener, title, question); dialog.center(); dialog.show(); } protected String deleteQuestion() { return Utils.messages.deleteSelectedEntryQuestion(); } protected String deleteTitle() { return Utils.messages.deleteSelectedEntryTitle(); } protected boolean canDelete(T value) { return true; } protected K getObjectId(T value) { return null; } protected abstract float constructColumnsImpl(DataGrid<T> table); public interface StringValueProvider<T> { String getValue(T item); } public interface BooleanValueProvider<T> { Boolean getValue(T item); } protected SimplePager getPager() { return new SimplePager(TextLocation.CENTER, pagerResources, false, 0, true) { @Override protected String createText() { HasRows display = getDisplay(); Range range = display.getVisibleRange(); int currentPage = range.getStart() / (range.getLength() != 0 ? range.getLength() : 1) + 1; int total = ((int) Math.ceil((float) display.getRowCount() / (float) range.getLength())); if (total == 0) { total = 1; } return Utils.messages.pagerText(String.valueOf(currentPage), String.valueOf(total)); } @Override public void setPageStart(int index) { if (getDisplay() != null) { Range range = getDisplay().getVisibleRange(); int pageSize = range.getLength(); index = Math.max(0, index); if (index != range.getStart()) { getDisplay().setVisibleRange(index, pageSize); } } } }; } public int getPageSize() { return table.getPageSize(); } public void setPageSize(int pageSize) { table.setPageSize(pageSize); } }