Java tutorial
/* * 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.gafactory.core.client.ui.grids; import com.google.gwt.cell.client.AbstractInputCell; import com.google.gwt.cell.client.ValueUpdater; import com.google.gwt.core.client.GWT; 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.safehtml.client.SafeHtmlTemplates; import com.google.gwt.safehtml.shared.SafeHtml; import com.google.gwt.safehtml.shared.SafeHtmlBuilder; import com.google.gwt.text.shared.SafeHtmlRenderer; /** * An {@link com.google.gwt.cell.client.AbstractCell} used to render a text input. */ public class TextInputCell extends AbstractInputCell<String, TextInputCell.ViewData> { interface Template extends SafeHtmlTemplates { @Template("<input type=\"text\" value=\"{0}\" class=\"form-control\" tabindex=\"-1\"></input>") SafeHtml input(String value); } /** * The {@code ViewData} for this cell. */ public static class ViewData { /** * The last value that was updated. */ private String lastValue; /** * The current value. */ private String curValue; /** * Construct a ViewData instance containing a given value. * * @param value a String value */ public ViewData(String value) { this.lastValue = value; this.curValue = value; } /** * Return true if the last and current values of this ViewData object * are equal to those of the other object. */ @Override public boolean equals(Object other) { if (!(other instanceof ViewData)) { return false; } ViewData vd = (ViewData) other; return equalsOrNull(lastValue, vd.lastValue) && equalsOrNull(curValue, vd.curValue); } /** * Return the current value of the input element. * * @return the current value String * @see #setCurrentValue(String) */ public String getCurrentValue() { return curValue; } /** * Return the last value sent to the {@link com.google.gwt.cell.client.ValueUpdater}. * * @return the last value String * @see #setLastValue(String) */ public String getLastValue() { return lastValue; } /** * Return a hash code based on the last and current values. */ @Override public int hashCode() { return (lastValue + "_*!@HASH_SEPARATOR@!*_" + curValue).hashCode(); } /** * Set the current value. * * @param curValue the current value * @see #getCurrentValue() */ protected void setCurrentValue(String curValue) { this.curValue = curValue; } /** * Set the last value. * * @param lastValue the last value * @see #getLastValue() */ protected void setLastValue(String lastValue) { this.lastValue = lastValue; } private boolean equalsOrNull(Object a, Object b) { return (a != null) ? a.equals(b) : ((b == null)); } } private static Template template; /** * Constructs a TextInputCell that renders its text without HTML markup. */ public TextInputCell() { super(BrowserEvents.CHANGE, BrowserEvents.KEYUP); if (template == null) { template = GWT.create(Template.class); } } /** * Constructs a TextInputCell that renders its text using the given * {@link com.google.gwt.text.shared.SafeHtmlRenderer}. * * @param renderer parameter is ignored * @deprecated the value of a text input is never treated as html */ @Deprecated public TextInputCell(SafeHtmlRenderer<String> renderer) { this(); } @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. InputElement input = getInputElement(parent); Element target = event.getEventTarget().cast(); if (!input.isOrHasChild(target)) { return; } String eventType = event.getType(); Object key = context.getKey(); if (BrowserEvents.CHANGE.equals(eventType)) { finishEditing(parent, value, key, valueUpdater); } else if (BrowserEvents.KEYUP.equals(eventType)) { // Record keys as they are typed. ViewData vd = getViewData(key); if (vd == null) { vd = new ViewData(value); setViewData(key, vd); } vd.setCurrentValue(input.getValue()); } } @Override public void render(Context context, String value, SafeHtmlBuilder sb) { // Get the view data. Object key = context.getKey(); ViewData viewData = getViewData(key); if (viewData != null && viewData.getCurrentValue().equals(value)) { clearViewData(key); viewData = null; } String s = (viewData != null) ? viewData.getCurrentValue() : value; if (s != null) { sb.append(template.input(s)); } else { sb.appendHtmlConstant("<input type=\"text\" class=\"form-control\" tabindex=\"-1\"></input>"); } } @Override protected void finishEditing(Element parent, String value, Object key, ValueUpdater<String> valueUpdater) { String newValue = getInputElement(parent).getValue(); // Get the view data. ViewData vd = getViewData(key); if (vd == null) { vd = new ViewData(value); setViewData(key, vd); } vd.setCurrentValue(newValue); // Fire the value updater if the value has changed. if (valueUpdater != null && !vd.getCurrentValue().equals(vd.getLastValue())) { vd.setLastValue(newValue); valueUpdater.update(newValue); } // Blur the element. super.finishEditing(parent, newValue, key, valueUpdater); } @Override protected InputElement getInputElement(Element parent) { return super.getInputElement(parent).cast(); } }