| /* |
| * Copyright 2010 Google 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 com.google.gwt.cell.client; |
| |
| import com.google.gwt.dom.client.BrowserEvents; |
| import com.google.gwt.dom.client.Element; |
| import com.google.gwt.dom.client.InputElement; |
| import com.google.gwt.dom.client.NativeEvent; |
| import com.google.gwt.event.dom.client.KeyCodes; |
| import com.google.gwt.safehtml.shared.SafeHtml; |
| import com.google.gwt.safehtml.shared.SafeHtmlBuilder; |
| import com.google.gwt.safehtml.shared.SafeHtmlUtils; |
| |
| /** |
| * A {@link Cell} used to render a checkbox. The value of the checkbox may be |
| * toggled using the ENTER key as well as via mouse click. |
| */ |
| public class CheckboxCell extends AbstractEditableCell<Boolean, Boolean> { |
| |
| /** |
| * An html string representation of a checked input box. |
| */ |
| private static final SafeHtml INPUT_CHECKED = SafeHtmlUtils.fromSafeConstant("<input type=\"checkbox\" tabindex=\"-1\" checked/>"); |
| |
| /** |
| * An html string representation of an unchecked input box. |
| */ |
| private static final SafeHtml INPUT_UNCHECKED = SafeHtmlUtils.fromSafeConstant("<input type=\"checkbox\" tabindex=\"-1\"/>"); |
| |
| private final boolean dependsOnSelection; |
| private final boolean handlesSelection; |
| |
| /** |
| * Construct a new {@link CheckboxCell}. |
| */ |
| public CheckboxCell() { |
| this(false); |
| } |
| |
| /** |
| * Construct a new {@link CheckboxCell} that optionally controls selection. |
| * |
| * @param isSelectBox true if the cell controls the selection state |
| * @deprecated use {@link #CheckboxCell(boolean, boolean)} instead |
| */ |
| @Deprecated |
| public CheckboxCell(boolean isSelectBox) { |
| this(isSelectBox, isSelectBox); |
| } |
| |
| /** |
| * Construct a new {@link CheckboxCell} that optionally controls selection. |
| * |
| * @param dependsOnSelection true if the cell depends on the selection state |
| * @param handlesSelection true if the cell modifies the selection state |
| */ |
| public CheckboxCell(boolean dependsOnSelection, boolean handlesSelection) { |
| super(BrowserEvents.CHANGE, BrowserEvents.KEYDOWN); |
| this.dependsOnSelection = dependsOnSelection; |
| this.handlesSelection = handlesSelection; |
| } |
| |
| @Override |
| public boolean dependsOnSelection() { |
| return dependsOnSelection; |
| } |
| |
| @Override |
| public boolean handlesSelection() { |
| return handlesSelection; |
| } |
| |
| @Override |
| public boolean isEditing(Context context, Element parent, Boolean value) { |
| // A checkbox is never in "edit mode". There is no intermediate state |
| // between checked and unchecked. |
| return false; |
| } |
| |
| @Override |
| public void onBrowserEvent(Context context, Element parent, Boolean value, |
| NativeEvent event, ValueUpdater<Boolean> valueUpdater) { |
| String type = event.getType(); |
| |
| boolean enterPressed = BrowserEvents.KEYDOWN.equals(type) |
| && event.getKeyCode() == KeyCodes.KEY_ENTER; |
| if (BrowserEvents.CHANGE.equals(type) || enterPressed) { |
| InputElement input = parent.getFirstChild().cast(); |
| Boolean isChecked = input.isChecked(); |
| |
| /* |
| * Toggle the value if the enter key was pressed and the cell handles |
| * selection or doesn't depend on selection. If the cell depends on |
| * selection but doesn't handle selection, then ignore the enter key and |
| * let the SelectionEventManager determine which keys will trigger a |
| * change. |
| */ |
| if (enterPressed && (handlesSelection() || !dependsOnSelection())) { |
| isChecked = !isChecked; |
| input.setChecked(isChecked); |
| } |
| |
| /* |
| * Save the new value. However, if the cell depends on the selection, then |
| * do not save the value because we can get into an inconsistent state. |
| */ |
| if (value != isChecked && !dependsOnSelection()) { |
| setViewData(context.getKey(), isChecked); |
| } else { |
| clearViewData(context.getKey()); |
| } |
| |
| if (valueUpdater != null) { |
| valueUpdater.update(isChecked); |
| } |
| } |
| } |
| |
| @Override |
| public void render(Context context, Boolean value, SafeHtmlBuilder sb) { |
| // Get the view data. |
| Object key = context.getKey(); |
| Boolean viewData = getViewData(key); |
| if (viewData != null && viewData.equals(value)) { |
| clearViewData(key); |
| viewData = null; |
| } |
| |
| if (value != null && ((viewData != null) ? viewData : value)) { |
| sb.append(INPUT_CHECKED); |
| } else { |
| sb.append(INPUT_UNCHECKED); |
| } |
| } |
| } |