xml/impl/src/com/intellij/xml/XmlNamespaceHelper.java

/*
 * Copyright 2000-2013 JetBrains s.r.o.
 *
 * 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.intellij.xml;

import com.intellij.openapi.editor.Document;
import com.intellij.openapi.editor.Editor;
import com.intellij.openapi.extensions.ExtensionPointName;
import com.intellij.openapi.extensions.Extensions;
import com.intellij.psi.PsiElement;
import com.intellij.psi.PsiFile;
import com.intellij.psi.xml.XmlFile;
import com.intellij.psi.xml.XmlTag;
import com.intellij.util.IncorrectOperationException;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.util.Set;

/**
 * @author yole
 */
public abstract class XmlNamespaceHelper {
  private static final ExtensionPointName<XmlNamespaceHelper> EP_NAME = new ExtensionPointName<XmlNamespaceHelper>("com.intellij.xml.namespaceHelper");

  public static final XmlNamespaceHelper DEFAULT_EXTENSION = new DefaultXmlNamespaceHelper();

  public static XmlNamespaceHelper getHelper(PsiFile file) {
    for (XmlNamespaceHelper extension : Extensions.getExtensions(EP_NAME)) {
      if (extension.isAvailable(file)) {
        return extension;
      }
    }
    return DEFAULT_EXTENSION;
  }

  protected abstract boolean isAvailable(PsiFile file);

  public interface Runner<P, T extends Throwable> {
    void run(P param) throws T;
  }

  @Nullable
  public String getNamespacePrefix(PsiElement element) {
    final PsiElement tag = element instanceof XmlTag ? element : element.getParent();
    if (tag instanceof XmlTag) {
      return ((XmlTag)tag).getNamespacePrefix();
    } else {
      return null;
    }
  }

  public abstract void insertNamespaceDeclaration(@NotNull final XmlFile file,
                                                  @Nullable final Editor editor,
                                                  @NonNls @NotNull final Set<String> possibleNamespaces,
                                                  @NonNls @Nullable final String nsPrefix,
                                                  @Nullable Runner<String, IncorrectOperationException> runAfter) throws IncorrectOperationException;

  public boolean qualifyWithPrefix(final String namespacePrefix, final PsiElement element, final Document document) throws
                                                                                                                    IncorrectOperationException {
    final PsiElement tag = element instanceof XmlTag ? element : element.getParent();
    if (tag instanceof XmlTag) {
      final String prefix = ((XmlTag)tag).getNamespacePrefix();
      if (!prefix.equals(namespacePrefix)) {
        final String name = namespacePrefix + ":" + ((XmlTag)tag).getLocalName();
        ((XmlTag)tag).setName(name);
      }
      return true;
    }
    return false;
  }

  @NotNull
  public abstract Set<String> guessUnboundNamespaces(@NotNull PsiElement element, final XmlFile file);

  @NotNull
  public abstract Set<String> getNamespacesByTagName(@NotNull final String tagName, @NotNull final XmlFile context);

  public String getNamespaceAlias(@NotNull final XmlFile file) {
    return XmlBundle.message("namespace.alias");
  }
}