/*
* Copyright 2000-2016 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.codeHighlighting;
import com.intellij.ui.JBColor;
import org.jetbrains.annotations.NotNull;
import java.awt.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class ColorGenerator {
@NotNull
public static List<Color> generateLinearColorSequence(@NotNull List<Color> anchorColors, int colorsBetweenAnchors) {
assert colorsBetweenAnchors >= 0;
if (anchorColors.isEmpty()) return Collections.singletonList(JBColor.GRAY);
if (anchorColors.size() == 1) return Collections.singletonList(anchorColors.get(0));
int segmentCount = anchorColors.size() - 1;
List<Color> result = new ArrayList<>(anchorColors.size() + segmentCount * colorsBetweenAnchors);
result.add(anchorColors.get(0));
for (int i = 0; i < segmentCount; i++) {
Color color1 = anchorColors.get(i);
Color color2 = anchorColors.get(i + 1);
List<Color> linearColors = generateLinearColorSequence(color1, color2, colorsBetweenAnchors);
// skip first element from sequence to avoid duplication from connected segments
result.addAll(linearColors.subList(1, linearColors.size()));
}
return result;
}
@NotNull
public static List<Color> generateLinearColorSequence(@NotNull Color color1, @NotNull Color color2, int colorsBetweenAnchors) {
assert colorsBetweenAnchors >= 0;
List<Color> result = new ArrayList<>(colorsBetweenAnchors + 2);
result.add(color1);
for (int i = 1; i <= colorsBetweenAnchors; i++) {
float ratio = (float)i / (colorsBetweenAnchors + 1);
//noinspection UseJBColor
result.add(new Color(
ratio(color1.getRed(), color2.getRed(), ratio),
ratio(color1.getGreen(), color2.getGreen(), ratio),
ratio(color1.getBlue(), color2.getBlue(), ratio)
));
}
result.add(color2);
return result;
}
private static int ratio(int val1, int val2, float ratio) {
int value = (int)(val1 + ((val2 - val1) * ratio));
return Math.max(Math.min(value, 255), 0);
}
}