From c56b682750e9f2a911a841e89e4e51b7d0608ab5 Mon Sep 17 00:00:00 2001
From: Aleks Kissinger <aleks0@gmail.com>
Date: Sun, 12 Apr 2020 13:31:11 +0100
Subject: added support for parsing paths

---
 src/data/graph.h              |  1 +
 src/data/graphelementdata.cpp |  8 ++++
 src/data/graphelementdata.h   |  1 +
 src/data/path.cpp             |  6 +++
 src/data/path.h               | 19 ++++++++++
 src/data/tikzassembler.cpp    | 41 ++++++++++++++++++++
 src/data/tikzassembler.h      | 14 +++++++
 src/data/tikzparser.y         | 88 ++++++++++++++++++++++++++++---------------
 src/data/tikzparserdefs.h     |  2 +
 tikzit.pro                    |  2 +
 10 files changed, 151 insertions(+), 31 deletions(-)
 create mode 100644 src/data/path.cpp
 create mode 100644 src/data/path.h

diff --git a/src/data/graph.h b/src/data/graph.h
index 286ccdc..a996bcb 100644
--- a/src/data/graph.h
+++ b/src/data/graph.h
@@ -25,6 +25,7 @@
 
 #include "node.h"
 #include "edge.h"
+#include "path.h"
 #include "graphelementdata.h"
 
 #include <QObject>
diff --git a/src/data/graphelementdata.cpp b/src/data/graphelementdata.cpp
index cd09a6d..931f86a 100644
--- a/src/data/graphelementdata.cpp
+++ b/src/data/graphelementdata.cpp
@@ -110,6 +110,14 @@ int GraphElementData::indexOfKey(QString key)
     return -1;
 }
 
+void GraphElementData::mergeData(GraphElementData *d)
+{
+    GraphElementProperty p;
+    foreach (p, d->properties()) {
+        if (!hasProperty(p.key())) add(p);
+    }
+}
+
 bool GraphElementData::removeRows(int row, int /*count*/, const QModelIndex &parent)
 {
     if (row >= 0 && row < _properties.length()) {
diff --git a/src/data/graphelementdata.h b/src/data/graphelementdata.h
index dce0d46..8a50a93 100644
--- a/src/data/graphelementdata.h
+++ b/src/data/graphelementdata.h
@@ -49,6 +49,7 @@ public:
     bool hasProperty(QString key);
     bool atom(QString atom);
     int indexOfKey(QString key);
+    void mergeData(GraphElementData *d);
     bool removeRows(int row, int count, const QModelIndex &parent) override;
     bool moveRows(const QModelIndex &sourceParent,
                   int sourceRow, int,
diff --git a/src/data/path.cpp b/src/data/path.cpp
new file mode 100644
index 0000000..f213b22
--- /dev/null
+++ b/src/data/path.cpp
@@ -0,0 +1,6 @@
+#include "path.h"
+
+Path::Path(QObject *parent) : QObject(parent)
+{
+
+}
diff --git a/src/data/path.h b/src/data/path.h
new file mode 100644
index 0000000..381d486
--- /dev/null
+++ b/src/data/path.h
@@ -0,0 +1,19 @@
+#ifndef PATH_H
+#define PATH_H
+
+#include "edge.h"
+
+#include <QObject>
+
+class Path : public QObject
+{
+    Q_OBJECT
+public:
+    explicit Path(QObject *parent = nullptr);
+
+private:
+    QVector<Edge*> _edges;
+
+};
+
+#endif // PATH_H
diff --git a/src/data/tikzassembler.cpp b/src/data/tikzassembler.cpp
index cd0b517..ee75f7b 100644
--- a/src/data/tikzassembler.cpp
+++ b/src/data/tikzassembler.cpp
@@ -29,6 +29,7 @@ TikzAssembler::TikzAssembler(Graph *graph, QObject *parent) :
 {
     yylex_init(&scanner);
     yyset_extra(this, scanner);
+    _currentEdgeData = nullptr;
 }
 
 TikzAssembler::TikzAssembler(TikzStyles *tikzStyles, QObject *parent) :
@@ -36,6 +37,7 @@ TikzAssembler::TikzAssembler(TikzStyles *tikzStyles, QObject *parent) :
 {
     yylex_init(&scanner);
     yyset_extra(this, scanner);
+    _currentEdgeData = nullptr;
 }
 
 void TikzAssembler::addNodeToMap(Node *n) { _nodeMap.insert(n->name(), n); }
@@ -70,3 +72,42 @@ bool TikzAssembler::isTikzStyles() const
     return _tikzStyles != 0;
 }
 
+Node *TikzAssembler::currentEdgeSource() const
+{
+    return _currentEdgeSource;
+}
+
+void TikzAssembler::setCurrentEdgeSource(Node *currentEdgeSource)
+{
+    _currentEdgeSource = currentEdgeSource;
+}
+
+GraphElementData *TikzAssembler::currentEdgeData() const
+{
+    return _currentEdgeData;
+}
+
+void TikzAssembler::setCurrentEdgeData(GraphElementData *currentEdgeData)
+{
+    _currentEdgeData = currentEdgeData;
+}
+
+QString TikzAssembler::currentEdgeSourceAnchor() const
+{
+    return _currentEdgeSourceAnchor;
+}
+
+void TikzAssembler::setCurrentEdgeSourceAnchor(const QString &currentEdgeSourceAnchor)
+{
+    _currentEdgeSourceAnchor = currentEdgeSourceAnchor;
+}
+
+void TikzAssembler::finishCurrentPath()
+{
+    if (_currentEdgeData) {
+        delete _currentEdgeData;
+        _currentEdgeData = nullptr;
+    }
+    // TODO: create a path and add it to graph
+}
+
diff --git a/src/data/tikzassembler.h b/src/data/tikzassembler.h
index 7b32224..f3cabb6 100644
--- a/src/data/tikzassembler.h
+++ b/src/data/tikzassembler.h
@@ -46,6 +46,17 @@ public:
     bool isTikzStyles() const;
 
 
+    Node *currentEdgeSource() const;
+    void setCurrentEdgeSource(Node *currentEdgeSource);
+
+    GraphElementData *currentEdgeData() const;
+    void setCurrentEdgeData(GraphElementData *currentEdgeData);
+
+    QString currentEdgeSourceAnchor() const;
+    void setCurrentEdgeSourceAnchor(const QString &currentEdgeSourceAnchor);
+
+    void finishCurrentPath();
+
 signals:
 
 public slots:
@@ -54,6 +65,9 @@ private:
     QHash<QString,Node*> _nodeMap;
     Graph *_graph;
     TikzStyles *_tikzStyles;
+    Node *_currentEdgeSource;
+    GraphElementData *_currentEdgeData;
+    QString _currentEdgeSourceAnchor;
     void *scanner;
 };
 
diff --git a/src/data/tikzparser.y b/src/data/tikzparser.y
index 4473107..895f75d 100644
--- a/src/data/tikzparser.y
+++ b/src/data/tikzparser.y
@@ -32,13 +32,13 @@
 /* we use features added to bison 2.4 */
 %require "2.3"
 
-%error-verbose
+%define parse.error verbose
 /* enable maintaining locations for better error messages */
 %locations
 /* the name of the header file */
 /*%defines "common/tikzparser.h"*/
 /* make it re-entrant (no global variables) */
-%pure-parser
+%define api.pure
 /* We use a pure (re-entrant) lexer.  This means yylex
    will take a void* (opaque) type to maintain its state */
 %lex-param {void *scanner}
@@ -214,10 +214,13 @@ noderef: "(" REFSTRING optanchor ")"
         $$.node = assembler->nodeWithName(QString($2));
         free($2);
         $$.anchor = $3;
+        $$.loop = false;
+        $$.cycle = false;
 	};
 optnoderef:
-	noderef { $$ = $1; }
-	| "(" ")" { $$.node = 0; $$.anchor = 0; }
+    noderef { $$ = $1; }
+    | "(" ")" { $$.node = 0; $$.anchor = 0; $$.loop = true; $$.cycle = false; }
+    | "cycle" { $$.node = 0; $$.anchor = 0; $$.loop = false; $$.cycle = true; }
 optedgenode:
 	{ $$ = 0; }
 	| "node" optproperties DELIMITEDSTRING
@@ -228,45 +231,68 @@ optedgenode:
         $$->setLabel(QString($3));
         free($3);
 	}
-edge: "\\draw" optproperties noderef "to" optedgenode optnoderef ";"
-	{
-        Node *s;
+
+edgesource: optproperties noderef {
+        assembler->setCurrentEdgeSource($2.node);
+        if ($2.anchor) {
+            assembler->setCurrentEdgeSourceAnchor(QString($2.anchor));
+            free($2.anchor);
+        } else {
+            assembler->setCurrentEdgeSourceAnchor(QString());
+        }
+        assembler->setCurrentEdgeData($1);
+    }
+
+optedgetargets: edgetarget optedgetargets |
+
+edgetarget: "to" optproperties optedgenode optnoderef {
+        Node *s = assembler->currentEdgeSource();;
         Node *t;
-		
-        s = $3.node;
 
-        if ($6.node) {
-            t = $6.node;
+        if ($4.loop) {
+            t = assembler->currentEdgeSource();
+        } else if ($4.cycle) {
+            // TODO: should be source of first edge in path
+            t = assembler->currentEdgeSource();
         } else {
-            t = s;
+            t = $4.node;
         }
 
-        // if the source or the target of the edge doesn't exist, quietly ignore it.
-        if (s != 0 && t != 0) {
-            Edge *edge = new Edge(s, t);
-            if ($2) {
-                edge->setData($2);
-                edge->setAttributesFromData();
-            }
+        if (s != 0 && t != 0) { // if source or target don't exist, quietly ignore edge
+            Edge *e = new Edge(s, t);
+            assembler->setCurrentEdgeSource(t);
 
-            if ($5)
-                edge->setEdgeNode($5);
-            if ($3.anchor) {
-                edge->setSourceAnchor(QString($3.anchor));
-                free($3.anchor);
+            if (!assembler->currentEdgeSourceAnchor().isEmpty()) {
+                e->setSourceAnchor(assembler->currentEdgeSourceAnchor());
             }
 
-            if ($6.node) {
-                if ($6.anchor) {
-                    edge->setTargetAnchor(QString($6.anchor));
-                    free($6.anchor);
-                }
+            if ($4.anchor) {
+                QString a($4.anchor);
+                free($4.anchor);
+                e->setTargetAnchor(a);
+                assembler->setCurrentEdgeSourceAnchor(a);
             } else {
-                edge->setTargetAnchor(edge->sourceAnchor());
+                assembler->setCurrentEdgeSourceAnchor(QString());
             }
 
-            assembler->graph()->addEdge(edge);
+            if ($3) e->setEdgeNode($3);
+
+            GraphElementData *cd = assembler->currentEdgeData();
+            if ($2) {
+                if (cd) $2->mergeData(cd);
+                 e->setData($2);
+            } else {
+                if (cd) e->setData(cd->copy());
+            }
+            e->setAttributesFromData();
+            assembler->graph()->addEdge(e);
         }
+    }
+
+
+edge: "\\draw" edgesource edgetarget optedgetargets ";"
+	{
+        assembler->finishCurrentPath();
 	};
 
 ignoreprop: val | val "=" val;
diff --git a/src/data/tikzparserdefs.h b/src/data/tikzparserdefs.h
index 02743fe..da60bbf 100644
--- a/src/data/tikzparserdefs.h
+++ b/src/data/tikzparserdefs.h
@@ -33,6 +33,8 @@
 struct noderef {
     Node *node;
     char *anchor;
+    bool cycle;
+    bool loop;
 };
 
 inline int isatty(int) { return 0; }
diff --git a/tikzit.pro b/tikzit.pro
index e0f3544..878caaa 100644
--- a/tikzit.pro
+++ b/tikzit.pro
@@ -53,6 +53,7 @@ include(flex.pri)
 include(bison.pri)
 
 SOURCES += src/gui/mainwindow.cpp \
+    src/data/path.cpp \
     src/gui/toolpalette.cpp \
     src/gui/tikzscene.cpp \
     src/data/graph.cpp \
@@ -85,6 +86,7 @@ SOURCES += src/gui/mainwindow.cpp \
     src/gui/preferencedialog.cpp
 
 HEADERS  += src/gui/mainwindow.h \
+    src/data/path.h \
     src/gui/toolpalette.h \
     src/gui/tikzscene.h \
     src/data/graph.h \
-- 
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