Java tutorial
/* * Copyright (C) 2011 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.api.explorer.client.parameter.schema; import com.google.api.explorer.client.Resources; import com.google.api.explorer.client.base.ApiService; import com.google.api.explorer.client.base.Schema; import com.google.common.base.Function; import com.google.common.base.Joiner; import com.google.common.base.Predicate; import com.google.common.collect.Iterables; import com.google.common.collect.Lists; import com.google.common.collect.Maps; import com.google.gwt.dom.client.Document; import com.google.gwt.dom.client.Style.Unit; import com.google.gwt.event.dom.client.ClickEvent; import com.google.gwt.event.dom.client.ClickHandler; import com.google.gwt.event.logical.shared.ValueChangeEvent; import com.google.gwt.event.logical.shared.ValueChangeHandler; import com.google.gwt.event.shared.HandlerRegistration; import com.google.gwt.user.client.ui.CheckBox; import com.google.gwt.user.client.ui.HTMLPanel; import com.google.gwt.user.client.ui.HasValue; import com.google.gwt.user.client.ui.InlineLabel; import java.util.Collections; import java.util.List; import java.util.Map; import java.util.Map.Entry; /** * Tree-based UI for selecting fields to request, based on the response schema * for a method. * * @author jasonhall@google.com (Jason Hall) */ public class FieldsEditor extends HTMLPanel implements HasValue<Boolean> { private static final Joiner JOINER = Joiner.on(',').skipNulls(); private final ApiService service; private final String key; private final CheckBox root; private final Map<String, HasValue<Boolean>> children = Maps.newHashMap(); public FieldsEditor(ApiService service, String key) { super(""); this.service = service; this.key = key; root = new CheckBox(key.isEmpty() ? "Select all/none" : key); root.setValue(false); root.addValueChangeHandler(new ValueChangeHandler<Boolean>() { @Override public void onValueChange(ValueChangeEvent<Boolean> event) { for (HasValue<Boolean> checkBox : children.values()) { checkBox.setValue(event.getValue(), true); } } }); add(root); } /** * Sets the properties this field will have, if it is an object. */ public void setProperties(Map<String, Schema> properties) { List<String> keys = Lists.newArrayList(properties.keySet()); Collections.sort(keys); HTMLPanel inner = new HTMLPanel(""); inner.getElement().getStyle().setPaddingLeft(20, Unit.PX); for (String childKey : keys) { final Schema property = properties.get(childKey); final Map<String, Schema> childProperties = property.getProperties(); final Schema items = property.getItems(); if (childProperties == null && items == null) { // This is a simple field CheckBox checkBox = new CheckBox(childKey); checkBox.setValue(root.getValue()); checkBox.setTitle(property.getDescription()); children.put(childKey, checkBox); checkBox.getElement().appendChild(Document.get().createBRElement()); inner.add(checkBox); } else { final FieldsEditor editor = new FieldsEditor(service, childKey); children.put(childKey, editor); inner.add(editor); if (childProperties != null) { editor.setProperties(childProperties); } else if (property.getRef() != null) { editor.setRef(property.getRef()); } else if (items != null) { if (items.getProperties() != null) { editor.setProperties(items.getProperties()); } else if (items.getRef() != null) { editor.setRef(items.getRef()); } } } } add(inner); } /** * Denotes that this is an object whose definition is in another Schema, and * that it should be filled in with the correct fields when expanded. */ void setRef(final String ref) { final InlineLabel expando = new InlineLabel("+"); add(expando); expando.addStyleName(Resources.INSTANCE.style().clickable()); expando.setTitle("Click to show more fields"); expando.addClickHandler(new ClickHandler() { @Override public void onClick(ClickEvent event) { Schema sch = service.getSchemas().get(ref); setProperties(sch.getProperties()); remove(expando); } }); } /** Returns the string for this field, including sub-fields if it has any. */ public String genFieldsString() { // If there are no children, that means it's an expandable item that is not // expanded. Return just the key in this case. if (children.isEmpty() && root.getValue()) { return key; } // If all fields are checked, rather than return // "object(all,fields,in,the,object)" just return "object" if (getValue()) { return key; } // Recursively construct the fields string of all selected children. String directFields = JOINER.join(Iterables.transform(children.entrySet(), new Function<Map.Entry<String, HasValue<Boolean>>, String>() { @Override public String apply(Entry<String, HasValue<Boolean>> input) { if (input.getValue() instanceof FieldsEditor) { return ((FieldsEditor) input.getValue()).genFieldsString(); } else { return input.getValue().getValue() ? input.getKey() : null; } } })); if (directFields.isEmpty()) { // No children were selected, so this object is not needed. return null; } else if (!directFields.contains(",")) { // If only one field is checked, rather than return // "object(onlyOneField)", return "object/onlyOneField" if (key.isEmpty()) { return directFields; } else { return key + '/' + directFields; } } StringBuilder sb = new StringBuilder(); if (!key.isEmpty()) { sb.append(key).append('('); } sb.append(directFields); if (!key.isEmpty()) { sb.append(')'); } return sb.toString(); } /** * Returns this field's checked value, or if it has children, whether all its * children are checked. */ @Override public Boolean getValue() { if (children.isEmpty()) { return root.getValue(); } return Iterables.all(children.entrySet(), new Predicate<Map.Entry<String, HasValue<Boolean>>>() { @Override public boolean apply(Entry<String, HasValue<Boolean>> input) { return input.getValue().getValue(); } }); } /** * Sets this field's checked value, and all of its childrens' if it has any. */ @Override public void setValue(Boolean value) { for (HasValue<Boolean> hasValue : children.values()) { hasValue.setValue(value); } this.root.setValue(value); } /** Adds a ValueChangeHandler to this field. */ @Override public HandlerRegistration addValueChangeHandler(ValueChangeHandler<Boolean> handler) { return root.addValueChangeHandler(handler); } /** Sets this checkboxes value. */ @Override public void setValue(Boolean value, boolean fireEvents) { root.setValue(value, fireEvents); } }