/*
* 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.sample.showcase.client.content.cell;
import com.google.gwt.cell.client.AbstractInputCell;
import com.google.gwt.cell.client.FieldUpdater;
import com.google.gwt.cell.client.TextCell;
import com.google.gwt.cell.client.ValueUpdater;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.RunAsyncCallback;
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.i18n.client.Constants;
import com.google.gwt.safecss.shared.SafeStyles;
import com.google.gwt.safecss.shared.SafeStylesUtils;
import com.google.gwt.safehtml.client.SafeHtmlTemplates;
import com.google.gwt.safehtml.shared.SafeHtml;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.safehtml.shared.SimpleHtmlSanitizer;
import com.google.gwt.sample.showcase.client.ContentWidget;
import com.google.gwt.sample.showcase.client.ShowcaseAnnotations.ShowcaseData;
import com.google.gwt.sample.showcase.client.ShowcaseAnnotations.ShowcaseRaw;
import com.google.gwt.sample.showcase.client.ShowcaseAnnotations.ShowcaseSource;
import com.google.gwt.sample.showcase.client.content.cell.ContactDatabase.ContactInfo;
import com.google.gwt.user.cellview.client.CellTable;
import com.google.gwt.user.cellview.client.Column;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.ui.Widget;
/**
* Example file.
*/
@ShowcaseRaw({"ContactDatabase.java"})
public class CwCellValidation extends ContentWidget {
/**
* The constants used in this Content Widget.
*/
@ShowcaseSource
public static interface CwConstants extends Constants {
String cwCellValidationColumnAddress();
String cwCellValidationColumnName();
String cwCellValidationDescription();
String cwCellValidationError();
String cwCellValidationName();
}
interface Template extends SafeHtmlTemplates {
@Template("<input type=\"text\" value=\"{0}\" style=\"{1}\" tabindex=\"-1\"/>")
SafeHtml input(String value, SafeStyles color);
}
/**
* An input cell that changes color based on the validation status.
*/
@ShowcaseSource
private static class ValidatableInputCell extends
AbstractInputCell<String, ValidationData> {
private SafeHtml errorMessage;
public ValidatableInputCell(String errorMessage) {
super("change");
if (template == null) {
template = GWT.create(Template.class);
}
this.errorMessage = SimpleHtmlSanitizer.sanitizeHtml(errorMessage);
}
@Override
public void onBrowserEvent(Context context, Element parent, String value,
NativeEvent event, ValueUpdater<String> valueUpdater) {
super.onBrowserEvent(context, parent, value, event, valueUpdater);
// Ignore events that don't target the input.
Element target = event.getEventTarget().cast();
if (!parent.getFirstChildElement().isOrHasChild(target)) {
return;
}
Object key = context.getKey();
ValidationData viewData = getViewData(key);
String eventType = event.getType();
if ("change".equals(eventType)) {
InputElement input = parent.getFirstChild().cast();
// Mark cell as containing a pending change
input.getStyle().setColor("blue");
// Save the new value in the view data.
if (viewData == null) {
viewData = new ValidationData();
setViewData(key, viewData);
}
String newValue = input.getValue();
viewData.setValue(newValue);
finishEditing(parent, newValue, key, valueUpdater);
// Update the value updater, which updates the field updater.
if (valueUpdater != null) {
valueUpdater.update(newValue);
}
}
}
@Override
public void render(Context context, String value, SafeHtmlBuilder sb) {
// Get the view data.
Object key = context.getKey();
ValidationData viewData = getViewData(key);
if (viewData != null && viewData.getValue().equals(value)) {
// Clear the view data if the value is the same as the current value.
clearViewData(key);
viewData = null;
}
/*
* If viewData is null, just paint the contents black. If it is non-null,
* show the pending value and paint the contents red if they are known to
* be invalid.
*/
String pendingValue = (viewData == null) ? null : viewData.getValue();
boolean invalid = (viewData == null) ? false : viewData.isInvalid();
String color = pendingValue != null ? (invalid ? "red" : "blue") : "black";
SafeStyles safeColor = SafeStylesUtils.fromTrustedString("color: " + color + ";");
sb.append(template.input(pendingValue != null ? pendingValue : value, safeColor));
if (invalid) {
sb.appendHtmlConstant(" <span style='color:red;'>");
sb.append(errorMessage);
sb.appendHtmlConstant("</span>");
}
}
@Override
protected void onEnterKeyDown(Context context, Element parent, String value,
NativeEvent event, ValueUpdater<String> valueUpdater) {
Element target = event.getEventTarget().cast();
if (getInputElement(parent).isOrHasChild(target)) {
finishEditing(parent, value, context.getKey(), valueUpdater);
} else {
super.onEnterKeyDown(context, parent, value, event, valueUpdater);
}
}
}
/**
* The ViewData used by {@link ValidatableInputCell}.
*/
@ShowcaseSource
private static class ValidationData {
private boolean invalid;
private String value;
public String getValue() {
return value;
}
public boolean isInvalid() {
return invalid;
}
public void setInvalid(boolean invalid) {
this.invalid = invalid;
}
public void setValue(String value) {
this.value = value;
}
}
// Used by ValidatableInputCell
private static Template template;
/**
* Checks if an address is valid. A valid address consists of a number
* followed by a street name, which may be composed of multiple words.
*
* @param address the address
* @return true if valid, false if invalid
*/
@ShowcaseSource
public static boolean isAddressValid(String address) {
// Cannot be null.
if (address == null) {
return false;
}
// Must have two or more parts.
String[] parts = address.split(" ");
if (parts.length < 2) {
return false;
}
// First part is a number.
try {
Integer.parseInt(parts[0]);
} catch (NumberFormatException e) {
return false;
}
// The remaining parts form the street name.
return true;
}
/**
* An instance of the constants.
*/
@ShowcaseData
private final CwConstants constants;
/**
* Constructor.
*
* @param constants the constants
*/
public CwCellValidation(CwConstants constants) {
super(constants.cwCellValidationName(),
constants.cwCellValidationDescription(), false, "ContactDatabase.java");
this.constants = constants;
}
/**
* Initialize this example.
*/
@ShowcaseSource
@Override
public Widget onInitialize() {
// Create a table.
final CellTable<ContactInfo> table = new CellTable<ContactInfo>(10,
ContactInfo.KEY_PROVIDER);
// Add the Name column.
table.addColumn(new Column<ContactInfo, String>(new TextCell()) {
@Override
public String getValue(ContactInfo object) {
return object.getFullName();
}
}, constants.cwCellValidationColumnName());
// Add an editable address column.
final ValidatableInputCell addressCell = new ValidatableInputCell(
constants.cwCellValidationError());
Column<ContactInfo, String> addressColumn = new Column<ContactInfo, String>(
addressCell) {
@Override
public String getValue(ContactInfo object) {
return object.getAddress();
}
};
table.addColumn(addressColumn, constants.cwCellValidationColumnAddress());
addressColumn.setFieldUpdater(new FieldUpdater<ContactInfo, String>() {
public void update(int index, final ContactInfo object, final String value) {
// Perform validation after 2 seconds to simulate network delay.
new Timer() {
@Override
public void run() {
if (isAddressValid(value)) {
// The cell will clear the view data when it sees the updated
// value.
object.setAddress(value);
// Push the change to the views.
ContactDatabase.get().refreshDisplays();
} else {
// Update the view data to mark the pending value as invalid.
ValidationData viewData = addressCell.getViewData(ContactInfo.KEY_PROVIDER.getKey(object));
viewData.setInvalid(true);
// We only modified the cell, so do a local redraw.
table.redraw();
}
}
}.schedule(1000);
}
});
// Add the table to the database.
ContactDatabase.get().addDataDisplay(table);
return table;
}
@Override
protected void asyncOnInitialize(final AsyncCallback<Widget> callback) {
GWT.runAsync(CwCellValidation.class, new RunAsyncCallback() {
public void onFailure(Throwable caught) {
callback.onFailure(caught);
}
public void onSuccess() {
callback.onSuccess(onInitialize());
}
});
}
}