platform/lang-impl/src/com/intellij/ui/ColorLineMarkerProvider.java

/*
 * Copyright 2000-2012 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.codeHighlighting.Pass;
import com.intellij.codeInsight.daemon.GutterIconNavigationHandler;
import com.intellij.codeInsight.daemon.LineMarkerInfo;
import com.intellij.codeInsight.daemon.LineMarkerProvider;
import com.intellij.codeInsight.daemon.MergeableLineMarkerInfo;
import com.intellij.icons.AllIcons;
import com.intellij.openapi.application.AccessToken;
import com.intellij.openapi.application.ApplicationManager;
import com.intellij.openapi.editor.Editor;
import com.intellij.openapi.editor.ElementColorProvider;
import com.intellij.openapi.editor.markup.GutterIconRenderer;
import com.intellij.psi.PsiElement;
import com.intellij.psi.util.PsiUtilBase;
import com.intellij.util.Function;
import com.intellij.util.FunctionUtil;
import com.intellij.util.ui.ColorIcon;
import com.intellij.util.ui.TwoColorsIcon;
import org.jetbrains.annotations.NotNull;

import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseEvent;
import java.util.Collection;
import java.util.List;

/**
 * @author Konstantin Bulenkov
 */
public final class ColorLineMarkerProvider implements LineMarkerProvider {
  private final ElementColorProvider[] myExtensions = ElementColorProvider.EP_NAME.getExtensions();

  @Override
  public LineMarkerInfo getLineMarkerInfo(@NotNull PsiElement element) {
    for (ElementColorProvider colorProvider : myExtensions) {
      final Color color = colorProvider.getColorFrom(element);
      if (color != null) {
        return new MyInfo(element, color, colorProvider);
      }
    }
    return null;
  }

  @Override
  public void collectSlowLineMarkers(@NotNull List<PsiElement> elements, @NotNull Collection<LineMarkerInfo> result) {
  }
  
  private static class MyInfo extends MergeableLineMarkerInfo<PsiElement> {

    private final Color myColor;

    public MyInfo(@NotNull final PsiElement element, final Color color, final ElementColorProvider colorProvider) {
      super(element, 
            element.getTextRange(),
            new ColorIcon(12, color),
            Pass.UPDATE_ALL, 
            FunctionUtil.<Object, String>nullConstant(), 
            new GutterIconNavigationHandler<PsiElement>() {
              @Override
              public void navigate(MouseEvent e, PsiElement elt) {
                if (!elt.isWritable()) return;

                final Editor editor = PsiUtilBase.findEditor(element);
                assert editor != null;
                final Color c = ColorChooser.chooseColor(editor.getComponent(), "Choose color", color, true);
                if (c != null) {
                  AccessToken token = ApplicationManager.getApplication().acquireWriteActionLock(ColorLineMarkerProvider.class);
                  try {
                    colorProvider.setColorTo(element, c);
                  }
                  finally {
                    token.finish();
                  }
                }
              }
            }, 
            GutterIconRenderer.Alignment.LEFT);
      myColor = color;
    }

    @Override
    public boolean canMergeWith(@NotNull MergeableLineMarkerInfo<?> info) {
      return info instanceof MyInfo;
    }

    @Override
    public Icon getCommonIcon(@NotNull List<MergeableLineMarkerInfo> infos) {
      if (infos.size() == 2 && infos.get(0) instanceof MyInfo && infos.get(1) instanceof MyInfo) {
         return new TwoColorsIcon(12, ((MyInfo)infos.get(1)).myColor, ((MyInfo)infos.get(0)).myColor);
      }
      return AllIcons.Gutter.Colors;
    }

    @Override
    public Function<? super PsiElement, String> getCommonTooltip(@NotNull List<MergeableLineMarkerInfo> infos) {
      return FunctionUtil.nullConstant();
    }
  }
}