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vendor/github.com/awalterschulze/gographviz/graph.go

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+//Copyright 2013 GoGraphviz Authors
+//
+//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 gographviz
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Graph is the analysed representation of the Graph parsed from the DOT format.
+type Graph struct {
+	Attrs     Attrs
+	Name      string
+	Directed  bool
+	Strict    bool
+	Nodes     *Nodes
+	Edges     *Edges
+	SubGraphs *SubGraphs
+	Relations *Relations
+}
+
+// NewGraph creates a new empty graph, ready to be populated.
+func NewGraph() *Graph {
+	return &Graph{
+		Attrs:     make(Attrs),
+		Name:      "",
+		Directed:  false,
+		Strict:    false,
+		Nodes:     NewNodes(),
+		Edges:     NewEdges(),
+		SubGraphs: NewSubGraphs(),
+		Relations: NewRelations(),
+	}
+}
+
+// SetStrict sets whether a graph is strict.
+// If the graph is strict then multiple edges are not allowed between the same pairs of nodes,
+// see dot man page.
+func (g *Graph) SetStrict(strict bool) error {
+	g.Strict = strict
+	return nil
+}
+
+// SetDir sets whether the graph is directed (true) or undirected (false).
+func (g *Graph) SetDir(dir bool) error {
+	g.Directed = dir
+	return nil
+}
+
+// SetName sets the graph name.
+func (g *Graph) SetName(name string) error {
+	g.Name = name
+	return nil
+}
+
+// AddPortEdge adds an edge to the graph from node src to node dst.
+// srcPort and dstPort are the port the node ports, leave as empty strings if it is not required.
+// This does not imply the adding of missing nodes.
+func (g *Graph) AddPortEdge(src, srcPort, dst, dstPort string, directed bool, attrs map[string]string) error {
+	as, err := NewAttrs(attrs)
+	if err != nil {
+		return err
+	}
+	g.Edges.Add(&Edge{src, srcPort, dst, dstPort, directed, as})
+	return nil
+}
+
+// AddEdge adds an edge to the graph from node src to node dst.
+// This does not imply the adding of missing nodes.
+// If directed is set to true then SetDir(true) must also be called or there will be a syntax error in the output.
+func (g *Graph) AddEdge(src, dst string, directed bool, attrs map[string]string) error {
+	return g.AddPortEdge(src, "", dst, "", directed, attrs)
+}
+
+// AddNode adds a node to a graph/subgraph.
+// If not subgraph exists use the name of the main graph.
+// This does not imply the adding of a missing subgraph.
+func (g *Graph) AddNode(parentGraph string, name string, attrs map[string]string) error {
+	as, err := NewAttrs(attrs)
+	if err != nil {
+		return err
+	}
+	g.Nodes.Add(&Node{name, as})
+	g.Relations.Add(parentGraph, name)
+	return nil
+}
+
+// RemoveNode removes a node from the graph
+func (g *Graph) RemoveNode(parentGraph string, name string) error {
+	err := g.Nodes.Remove(name)
+	if err != nil {
+		return err
+	}
+
+	g.Relations.Remove(parentGraph, name)
+
+	edges := NewEdges()
+	for _, e := range g.Edges.Edges {
+		if e.Dst == name || e.Src == name {
+			continue
+		}
+
+		edges.Add(e)
+	}
+
+	g.Edges = edges
+
+	return nil
+}
+
+func (g *Graph) getAttrs(graphName string) (Attrs, error) {
+	if g.Name == graphName {
+		return g.Attrs, nil
+	}
+	sub, ok := g.SubGraphs.SubGraphs[graphName]
+	if !ok {
+		return nil, fmt.Errorf("graph or subgraph %s does not exist", graphName)
+	}
+	return sub.Attrs, nil
+}
+
+// AddAttr adds an attribute to a graph/subgraph.
+func (g *Graph) AddAttr(parentGraph string, field string, value string) error {
+	a, err := g.getAttrs(parentGraph)
+	if err != nil {
+		return err
+	}
+	return a.Add(field, value)
+}
+
+// AddSubGraph adds a subgraph to a graph/subgraph.
+func (g *Graph) AddSubGraph(parentGraph string, name string, attrs map[string]string) error {
+	g.Relations.Add(parentGraph, name)
+	g.SubGraphs.Add(name)
+	for key, value := range attrs {
+		if err := g.AddAttr(name, key, value); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// RemoveSubGraph removes the subgraph including nodes
+func (g *Graph) RemoveSubGraph(parentGraph string, name string) error {
+	for child := range g.Relations.ParentToChildren[name] {
+		err := g.RemoveNode(parentGraph, child)
+		if err != nil {
+			return err
+		}
+	}
+
+	g.Relations.Remove(parentGraph, name)
+	g.SubGraphs.Remove(name)
+
+	edges := NewEdges()
+	for _, e := range g.Edges.Edges {
+		if e.Dst == name || e.DstPort == name || e.Src == name || e.SrcPort == name {
+			continue
+		}
+
+		edges.Add(e)
+	}
+
+	g.Edges = edges
+
+	return nil
+}
+
+// IsNode returns whether a given node name exists as a node in the graph.
+func (g *Graph) IsNode(name string) bool {
+	_, ok := g.Nodes.Lookup[name]
+	return ok
+}
+
+// IsSubGraph returns whether a given subgraph name exists as a subgraph in the graph.
+func (g *Graph) IsSubGraph(name string) bool {
+	_, ok := g.SubGraphs.SubGraphs[name]
+	return ok
+}
+
+func (g *Graph) isClusterSubGraph(name string) bool {
+	isSubGraph := g.IsSubGraph(name)
+	isCluster := strings.HasPrefix(name, "cluster")
+	return isSubGraph && isCluster
+}