FilesExpand file tree

 master

/

NodeZipper.java

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

143 lines (116 loc) · 4.83 KB

 master

/

NodeZipper.java

Copy path

Top

File metadata and controls

• Code
• Blame

143 lines (116 loc) · 4.83 KB

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

package graphql.util;

import graphql.PublicApi;

import java.util.ArrayList;

import java.util.Collections;

import java.util.HashMap;

import java.util.LinkedHashMap;

import java.util.List;

import java.util.Map;

import java.util.function.Function;

import static graphql.Assert.assertNotNull;

@PublicApi

public class NodeZipper<T> {

public enum ModificationType {

REPLACE,

DELETE,

INSERT_AFTER,

INSERT_BEFORE

}

private final T curNode;

private final NodeAdapter<T> nodeAdapter;

// reverse: the breadCrumbs start from curNode upwards

private final List<Breadcrumb<T>> breadcrumbs;

private final ModificationType modificationType;

public NodeZipper(T curNode, List<Breadcrumb<T>> breadcrumbs, NodeAdapter<T> nodeAdapter) {

this(curNode, breadcrumbs, nodeAdapter, ModificationType.REPLACE);

}

public NodeZipper(T curNode, List<Breadcrumb<T>> breadcrumbs, NodeAdapter<T> nodeAdapter, ModificationType modificationType) {

this.curNode = assertNotNull(curNode);

this.breadcrumbs = Collections.unmodifiableList(new ArrayList<>(assertNotNull(breadcrumbs)));

this.nodeAdapter = nodeAdapter;

this.modificationType = modificationType;

}

public ModificationType getModificationType() {

return modificationType;

}

public T getCurNode() {

return curNode;

}

public List<Breadcrumb<T>> getBreadcrumbs() {

return breadcrumbs;

}

public T getParent() {

return breadcrumbs.get(0).getNode();

}

public static <T> NodeZipper<T> rootZipper(T rootNode, NodeAdapter<T> nodeAdapter) {

return new NodeZipper<T>(rootNode, new ArrayList<>(), nodeAdapter);

}

public NodeZipper<T> modifyNode(Function<T, T> transform) {

return new NodeZipper<T>(transform.apply(curNode), breadcrumbs, nodeAdapter, this.modificationType);

}

public NodeZipper<T> deleteNode() {

return new NodeZipper<T>(this.curNode, breadcrumbs, nodeAdapter, ModificationType.DELETE);

}

public NodeZipper<T> insertAfter(T toInsertAfter) {

return new NodeZipper<T>(toInsertAfter, breadcrumbs, nodeAdapter, ModificationType.INSERT_AFTER);

}

public NodeZipper<T> insertBefore(T toInsertBefore) {

return new NodeZipper<T>(toInsertBefore, breadcrumbs, nodeAdapter, ModificationType.INSERT_BEFORE);

}

public NodeZipper<T> withNewNode(T newNode) {

return new NodeZipper<T>(newNode, breadcrumbs, nodeAdapter, this.modificationType);

}

public NodeZipper<T> moveUp() {

T node = getParent();

List<Breadcrumb<T>> newBreadcrumbs = breadcrumbs.subList(1, breadcrumbs.size());

return new NodeZipper<>(node, newBreadcrumbs, nodeAdapter, this.modificationType);

}

/**

* @return null if it is the root node and marked as deleted, otherwise never null

*/

public T toRoot() {

if (breadcrumbs.size() == 0 && modificationType != ModificationType.DELETE) {

return this.curNode;

}

if (breadcrumbs.size() == 0 && modificationType == ModificationType.DELETE) {

return null;

}

T curNode = this.curNode;

Breadcrumb<T> firstBreadcrumb = breadcrumbs.get(0);

Map<String, List<T>> childrenForParent = new HashMap<>(nodeAdapter.getNamedChildren(firstBreadcrumb.getNode()));

NodeLocation locationInParent = firstBreadcrumb.getLocation();

int ix = locationInParent.getIndex();

String name = locationInParent.getName();

List<T> childList = new ArrayList<>(childrenForParent.get(name));

switch (modificationType) {

case REPLACE:

childList.set(ix, curNode);

break;

case DELETE:

childList.remove(ix);

break;

case INSERT_BEFORE:

childList.add(ix, curNode);

break;

case INSERT_AFTER:

childList.add(ix + 1, curNode);

break;

}

childrenForParent.put(name, childList);

curNode = nodeAdapter.withNewChildren(firstBreadcrumb.getNode(), childrenForParent);

if (breadcrumbs.size() == 1) {

return curNode;

}

for (Breadcrumb<T> breadcrumb : breadcrumbs.subList(1, breadcrumbs.size())) {

// just handle replace

Map<String, List<T>> newChildren = new LinkedHashMap<>(nodeAdapter.getNamedChildren(breadcrumb.getNode()));

final T newChild = curNode;

NodeLocation location = breadcrumb.getLocation();

List<T> list = new ArrayList<>(newChildren.get(location.getName()));

list.set(location.getIndex(), newChild);

newChildren.put(location.getName(), list);

curNode = nodeAdapter.withNewChildren(breadcrumb.getNode(), newChildren);

}

return curNode;

}

}