gwtquery/gwtquery-core/src/main/java/com/google/gwt/query/client/impl/SelectorEngineNative.java

/*
 * Copyright 2011, The gwtquery team.
 *
 * 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.query.client.impl;

import static com.google.gwt.query.client.GQuery.console;

import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Node;
import com.google.gwt.dom.client.NodeList;
import com.google.gwt.query.client.js.JsNamedArray;

/**
 * Runtime selector engine implementation for browsers with native
 * querySelectorAll support.
 */
public class SelectorEngineNative extends SelectorEngineImpl {

  // querySelectorAll unsupported selectors
  public static String NATIVE_EXCEPTIONS_REGEXP =
      "(^[\\./]/.*)|(.*(:contains|:first([^-]|$)|:last([^-]|$)|:even|:odd)).*";

  private static HasSelector impl;

  static JsNamedArray<String> cache;

  public SelectorEngineNative() {
    if (impl == null) {
      impl = GWT.create(HasSelector.class);
      GWT.log("GQuery - Created HasSelector: " + impl.getClass().getName());
    }
  }

  public NodeList<Element> select(String selector, Node ctx) {
    // querySelectorAllImpl does not support ids starting with a digit.
    //    if (selector.matches("#[\\w\\-]+")) {
    //      return SelectorEngine.veryQuickId(selector.substring(1), ctx);
    //    } else
    if (selector.contains("!=")) {
      if (cache == null) {
        cache = JsNamedArray.create();
      }
      String xsel = cache.get(selector);
      if (xsel == null) {
        xsel = selector.replaceAll("(\\[\\w+)!(=[^\\]]+\\])", ":not($1$2)");
        cache.put(selector, xsel);
      }
      selector = xsel;
    }

    if (!SelectorEngine.HAS_QUERY_SELECTOR || selector.matches(NATIVE_EXCEPTIONS_REGEXP)) {
      return impl.select(selector, ctx);
    } else {
      try {
        return SelectorEngine.querySelectorAllImpl(selector, ctx);
      } catch (Exception e) {
        console.info("ERROR SelectorEngineNative " + e.getMessage()
            + " " + selector + ", falling back to "
            + impl.getClass().getName().replaceAll(".*\\.", ""));
        return impl.select(selector, ctx);
      }
    }
  }
}