java.lang.Object

cloud.opencode.base.graph.layout.LayoutUtil

public final class LayoutUtil extends Object

Layout Util - Graph Layout Algorithms for Visualization 布局工具类 - 图可视化布局算法

Utility class providing layout algorithms for graph visualization. These algorithms compute 2D positions for graph vertices.

提供图可视化布局算法的工具类。这些算法为图顶点计算二维位置。

Layout Algorithms | 布局算法:

Force-Directed (Fruchterman-Reingold) - 力导向布局
Circular Layout - 环形布局
Grid Layout - 网格布局
Hierarchical Layout - 层次布局
Random Layout - 随机布局
Spring Layout - 弹簧布局

Features | 主要功能:

Force-directed layout using Fruchterman-Reingold algorithm - 使用Fruchterman-Reingold算法的力导向布局
Spring layout with configurable spring length and iterations - 弹簧布局，可配置弹簧长度和迭代次数
Circular, grid, hierarchical, and random layout algorithms - 环形、网格、层次和随机布局算法
Layout transformation utilities: center and scale - 布局变换工具：居中和缩放
Immutable Point2D record for vertex positioning - 不可变Point2D记录用于顶点定位

Usage Examples | 使用示例:

// Force-directed layout
Map<String, Point2D> positions = LayoutUtil.forceDirected(graph, 800, 600);

// Circular layout
Map<String, Point2D> positions = LayoutUtil.circular(graph, 400, 300, 250);

// Hierarchical layout
Map<String, Point2D> positions = LayoutUtil.hierarchical(graph, 800, 600);

// Apply layout to GEXF export
Map<String, VisualData> visuals = positions.entrySet().stream()
    .collect(Collectors.toMap(Map.Entry::getKey,
        e -> VisualData.position(e.getValue().x(), e.getValue().y())));

Security | 安全性:

Thread-safe: Yes (stateless utility class) - 线程安全: 是（无状态工具类）
Null-safe: Yes (returns empty map for null graph) - 空值安全: 是（null图返回空映射）

Performance | 性能特性:

Time complexity: O(V^2 * iterations) for force-directed - 时间复杂度: O(V^2 * iterations)（力导向布局）
Space complexity: O(V) - 空间复杂度: O(V)

Since:

JDK 25, opencode-base-graph V1.0.0

Author:

Leon Soo www.LeonSoo.com

See Also:

Nested Class Summary

Nested Classes

Modifier and Type

Class

Description

static final record

LayoutUtil.Point2D

Immutable 2D point for graph layout.
Field Summary

Fields

Modifier and Type

Field

Description

static final double

DEFAULT_COOLING

Default cooling factor for simulated annealing | 模拟退火默认冷却因子

static final int

DEFAULT_ITERATIONS

Default number of iterations for force-directed algorithms | 力导向算法默认迭代次数
Method Summary

Modifier and Type

Method

Description

static <V> Map<V, LayoutUtil.Point2D>

center(Map<V, LayoutUtil.Point2D> positions, double width, double height)

Center layout in the given bounds.

static <V> Map<V, LayoutUtil.Point2D>

circular(Graph<V> graph, double width, double height)

Compute circular layout with default center.

static <V> Map<V, LayoutUtil.Point2D>

circular(Graph<V> graph, double centerX, double centerY, double radius)

Compute circular layout.

static <V> Map<V, LayoutUtil.Point2D>

forceDirected(Graph<V> graph, double width, double height)

Compute force-directed layout using Fruchterman-Reingold algorithm.

static <V> Map<V, LayoutUtil.Point2D>

forceDirected(Graph<V> graph, double width, double height, int iterations)

Compute force-directed layout with custom iterations.

static <V> Map<V, LayoutUtil.Point2D>

grid(Graph<V> graph, double width, double height)

Compute grid layout.

static <V> Map<V, LayoutUtil.Point2D>

hierarchical(Graph<V> graph, double width, double height)

Compute hierarchical layout (top-down).

static <V> Map<V, LayoutUtil.Point2D>

random(Graph<V> graph, double width, double height)

Compute random layout.

static <V> Map<V, LayoutUtil.Point2D>

scale(Map<V, LayoutUtil.Point2D> positions, double width, double height, double margin)

Scale layout to fit in the given bounds.

static <V> Map<V, LayoutUtil.Point2D>

spring(Graph<V> graph, double width, double height, double springLength)

Compute spring layout (simplified force-directed).

static <V> Map<V, LayoutUtil.Point2D>

spring(Graph<V> graph, double width, double height, double springLength, int iterations)

Compute spring layout with custom parameters.

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details
- DEFAULT_ITERATIONS
  public static final int DEFAULT_ITERATIONS
  
  Default number of iterations for force-directed algorithms | 力导向算法默认迭代次数
  
  See Also:
  
  Constant Field Values
- DEFAULT_COOLING
  public static final double DEFAULT_COOLING
  
  Default cooling factor for simulated annealing | 模拟退火默认冷却因子
  
  See Also:
  
  Constant Field Values
Method Details
- forceDirected
  
  public static <V> Map<V, LayoutUtil.Point2D> forceDirected(Graph<V> graph, double width, double height)
  
  Compute force-directed layout using Fruchterman-Reingold algorithm. 使用Fruchterman-Reingold算法计算力导向布局。
  The algorithm simulates a physical system where vertices repel each other and edges act as springs pulling connected vertices together.
  
  该算法模拟一个物理系统，其中顶点相互排斥，边像弹簧一样将连接的顶点拉在一起。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  width - layout width | 布局宽度
  
  height - layout height | 布局高度
  
  Returns:
  
  map of vertex to position | 顶点到位置的映射
- forceDirected
  
  public static <V> Map<V, LayoutUtil.Point2D> forceDirected(Graph<V> graph, double width, double height, int iterations)
  
  Compute force-directed layout with custom iterations. 使用自定义迭代次数计算力导向布局。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  width - layout width | 布局宽度
  
  height - layout height | 布局高度
  
  iterations - number of iterations | 迭代次数
  
  Returns:
  
  map of vertex to position | 顶点到位置的映射
- spring
  
  public static <V> Map<V, LayoutUtil.Point2D> spring(Graph<V> graph, double width, double height, double springLength)
  
  Compute spring layout (simplified force-directed). 计算弹簧布局（简化的力导向）。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  width - layout width | 布局宽度
  
  height - layout height | 布局高度
  
  springLength - natural spring length | 弹簧自然长度
  
  Returns:
  
  map of vertex to position | 顶点到位置的映射
- spring
  
  public static <V> Map<V, LayoutUtil.Point2D> spring(Graph<V> graph, double width, double height, double springLength, int iterations)
  
  Compute spring layout with custom parameters. 使用自定义参数计算弹簧布局。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  width - layout width | 布局宽度
  
  height - layout height | 布局高度
  
  springLength - natural spring length | 弹簧自然长度
  
  iterations - number of iterations | 迭代次数
  
  Returns:
  
  map of vertex to position | 顶点到位置的映射
- circular
  
  public static <V> Map<V, LayoutUtil.Point2D> circular(Graph<V> graph, double centerX, double centerY, double radius)
  
  Compute circular layout. 计算环形布局。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  centerX - center x-coordinate | 中心x坐标
  
  centerY - center y-coordinate | 中心y坐标
  
  radius - circle radius | 圆半径
  
  Returns:
  
  map of vertex to position | 顶点到位置的映射
- circular
  
  public static <V> Map<V, LayoutUtil.Point2D> circular(Graph<V> graph, double width, double height)
  
  Compute circular layout with default center. 使用默认中心计算环形布局。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  width - layout width | 布局宽度
  
  height - layout height | 布局高度
  
  Returns:
  
  map of vertex to position | 顶点到位置的映射
- grid
  
  public static <V> Map<V, LayoutUtil.Point2D> grid(Graph<V> graph, double width, double height)
  
  Compute grid layout. 计算网格布局。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  width - layout width | 布局宽度
  
  height - layout height | 布局高度
  
  Returns:
  
  map of vertex to position | 顶点到位置的映射
- hierarchical
  
  public static <V> Map<V, LayoutUtil.Point2D> hierarchical(Graph<V> graph, double width, double height)
  
  Compute hierarchical layout (top-down). 计算层次布局（自上而下）。
  This algorithm places vertices in layers based on their distance from root vertices (vertices with no incoming edges). Best suited for DAGs.
  
  该算法根据顶点到根顶点（无入边的顶点）的距离将顶点放置在不同层。最适合DAG。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  width - layout width | 布局宽度
  
  height - layout height | 布局高度
  
  Returns:
  
  map of vertex to position | 顶点到位置的映射
- random
  
  public static <V> Map<V, LayoutUtil.Point2D> random(Graph<V> graph, double width, double height)
  
  Compute random layout. 计算随机布局。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  graph - the graph | 图
  
  width - layout width | 布局宽度
  
  height - layout height | 布局高度
  
  Returns:
  
  map of vertex to position | 顶点到位置的映射
- center
  
  public static <V> Map<V, LayoutUtil.Point2D> center(Map<V, LayoutUtil.Point2D> positions, double width, double height)
  
  Center layout in the given bounds. 在给定边界内居中布局。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  positions - the positions to center | 要居中的位置
  
  width - target width | 目标宽度
  
  height - target height | 目标高度
  
  Returns:
  
  centered positions | 居中后的位置
- scale
  
  public static <V> Map<V, LayoutUtil.Point2D> scale(Map<V, LayoutUtil.Point2D> positions, double width, double height, double margin)
  
  Scale layout to fit in the given bounds. 缩放布局以适应给定边界。
  
  Type Parameters:
  
  V - the vertex type | 顶点类型
  
  Parameters:
  
  positions - the positions to scale | 要缩放的位置
  
  width - target width | 目标宽度
  
  height - target height | 目标高度
  
  margin - margin from edges | 边缘距离
  
  Returns:
  
  scaled positions | 缩放后的位置

Class LayoutUtil

Nested Class Summary

Field Summary

Method Summary

Methods inherited from class Object

Field Details

DEFAULT_ITERATIONS

DEFAULT_COOLING

Method Details

forceDirected

forceDirected

spring

spring

circular

circular

grid

hierarchical

random

center

scale