platform/platform-impl/src/com/intellij/ui/ColorPickerListenerFactory.java

/*
 * Copyright 2000-2014 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.ui;

import com.intellij.openapi.extensions.ExtensionPointName;
import com.intellij.psi.PsiElement;
import com.intellij.util.SmartList;
import com.intellij.util.containers.ContainerUtil;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.util.List;

public abstract class ColorPickerListenerFactory {
  private static final ExtensionPointName<ColorPickerListenerFactory> EP_NAME =
    ExtensionPointName.create("com.intellij.colorPickerListenerFactory");

  @NotNull
  public static List<ColorPickerListener> createListenersFor(@Nullable PsiElement element) {
    List<ColorPickerListener> listeners = null;
    for (ColorPickerListenerFactory factory : EP_NAME.getExtensions()) {
      ColorPickerListener listener = factory.createListener(element);
      if (listener != null) {
        if (listeners == null) {
          listeners = new SmartList<ColorPickerListener>();
        }
        listeners.add(listener);
      }
    }
    return ContainerUtil.notNullize(listeners);
  }

  @Nullable
  public abstract ColorPickerListener createListener(@Nullable PsiElement element);
}