I am trying to have a table that displays data that the user inputs as well as edit the data. I have figured out how to do this with text (ie, they can edit the name of something in the table), but I cannot get it to work with selection cells.
It works correctly if the items in the selection cell are predefined, but I cannot dynamically update the items in the cell to include new things after I have created the cell.
To explain more, i have a "type" column. The user enters items into the table with a given type, but that can also add new types later. When they click on the item in the type column, I want the dropdown box to contain all the new types that they have entered, but I don't know how to accomplish this.
Here is the code I have so far (that doesn't update like I want it to). record.getTypeList() will contain additional entries after the user enters new types.
SelectionCell editTypeComboBox = new SelectionCell(record.getTypeList());
Column<Assignment, String> typeColumn = new Column<Assignment, String>(editTypeComboBox) {
@Override
public String getValue(Assignment object) {
return object.getType();
}
};
typeColumn.setFieldUpdater(new FieldUpdater<Assignment, String>() {
@Override
public void update(int index, Assignment object, String value) {
int row = index;
String newType = value;
record.editAssignType(row, newType);
updateClassGradeLabel();
log.info("Set type to "
+ value);
cellTable.redraw();
}
});
cellTable.addColumn(typeColumn, "Type");
Edit: Thanks to Peter Knego foe helping me figure this out. Here is the modified DynamicSelectionCell class if anyone if interested:
/*
* 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.core.client.GWT;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.NativeEvent;
import com.google.gwt.dom.client.SelectElement;
import com.google.gwt.safehtml.client.SafeHtmlTemplates;
import com.google.gwt.safehtml.shared.SafeHtml;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
/**
* A {@link Cell} used to render a drop-down list.
*/
public class DynamicSelectionCell extends AbstractInputCell<String, String> {
interface Template extends SafeHtmlTemplates {
@Template("<option value=\"{0}\">{0}</option>")
SafeHtml deselected(String option);
@Template("<option value=\"{0}\" selected=\"selected\">{0}</option>")
SafeHtml selected(String option);
}
private static Template template;
private HashMap<String, Integer> indexForOption = new HashMap<String, Integer>();
private final List<String> options;
/**
* Construct a new {@link SelectionCell} with the specified options.
*
* @param options the options in the cell
*/
public DynamicSelectionCell(List<String> options) {
super("change");
if (template == null) {
template = GWT.create(Template.class);
}
this.options = new ArrayList<String>(options);
int index = 0;
for (String option : options) {
indexForOption.put(option, index++);
}
}
public void addOption(String newOp){
String option = new String(newOp);
options.add(option);
refreshIndexes();
}
public void removeOption(String op){
String option = new String(op);
options.remove(indexForOption.get(option));
refreshIndexes();
}
private void refreshIndexes(){
int index = 0;
for (String option : options) {
indexForOption.put(option, index++);
}
}
@Override
public void onBrowserEvent(Context context, Element parent, String value,
NativeEvent event, ValueUpdater<String> valueUpdater) {
super.onBrowserEvent(context, parent, value, event, valueUpdater);
String type = event.getType();
if ("change".equals(type)) {
Object key = context.getKey();
SelectElement select = parent.getFirstChild().cast();
String newValue = options.get(select.getSelectedIndex());
setViewData(key, newValue);
finishEditing(parent, newValue, key, valueUpdater);
if (valueUpdater != null) {
valueUpdater.update(newValue);
}
}
}
@Override
public void render(Context context, String value, SafeHtmlBuilder sb) {
// Get the view data.
Object key = context.getKey();
String viewData = getViewData(key);
if (viewData != null && viewData.equals(value)) {
clearViewData(key);
viewData = null;
}
int selectedIndex = getSelectedIndex(viewData == null ? value : viewData);
sb.appendHtmlConstant("<select tabindex=\"-1\">");
int index = 0;
for (String option : options) {
if (index++ == selectedIndex) {
sb.append(template.selected(option));
} else {
sb.append(template.deselected(option));
}
}
sb.appendHtmlConstant("</select>");
}
private int getSelectedIndex(String value) {
Integer index = indexForOption.get(value);
if (index == null) {
return -1;
}
return index.intValue();
}
}
