ability to make paths from edges

10 files changed, 242 insertions, 6 deletions

diff --git a/src/data/graph.cpp b/src/data/graph.cpp
index 24a17a5..979423e 100644
--- a/src/data/graph.cpp
+++ b/src/data/graph.cpp
@@ -269,10 +269,10 @@ QString Graph::tikz()
                 code << ")";

 

                 foreach (Edge *e1, p->edges()) {

-                    e1->setTikzLine(line);

-                    e1->updateData();

                     code << "\n\t\t\t to ";

                     line++;

+                    e1->setTikzLine(line);

+                    e1->updateData();

 

                     GraphElementData *pd = e1->data()->pathData();

                     if (!pd->isEmpty())

diff --git a/src/data/tikzdocument.cpp b/src/data/tikzdocument.cpp
index 1099779..633242d 100644
--- a/src/data/tikzdocument.cpp
+++ b/src/data/tikzdocument.cpp
@@ -90,6 +90,7 @@ void TikzDocument::open(QString fileName)
         refreshTikz();

         setClean();

     } else {

+        // TODO: should not quietly fail to open

         newGraph->deleteLater();

         _parseSuccess = false;

     }

diff --git a/src/gui/mainmenu.cpp b/src/gui/mainmenu.cpp
index 7b7623b..092d8b4 100644
--- a/src/gui/mainmenu.cpp
+++ b/src/gui/mainmenu.cpp
@@ -239,6 +239,18 @@ void MainMenu::on_actionMerge_Nodes_triggered()
         tikzit->activeWindow()->tikzScene()->mergeNodes();
 }
 
+void MainMenu::on_actionMake_Path_triggered()
+{
+    if (tikzit->activeWindow() != 0)
+        tikzit->activeWindow()->tikzScene()->makePath();
+}
+
+void MainMenu::on_actionSplit_Path_triggered()
+{
+    if (tikzit->activeWindow() != 0)
+        tikzit->activeWindow()->tikzScene()->splitPath();
+}
+
 
 // Tikz
 void MainMenu::on_actionParse_triggered()
@@ -333,8 +345,10 @@ void MainMenu::on_actionZoom_Out_triggered()
 
 void MainMenu::on_actionShow_Node_Labels_triggered()
 {
-    tikzit->activeWindow()->tikzScene()->setDrawNodeLabels(ui.actionShow_Node_Labels->isChecked());
-    tikzit->activeWindow()->tikzScene()->invalidate();
+    if (tikzit->activeWindow() != 0) {
+        tikzit->activeWindow()->tikzScene()->setDrawNodeLabels(ui.actionShow_Node_Labels->isChecked());
+        tikzit->activeWindow()->tikzScene()->invalidate();
+    }
 }
 
 void MainMenu::on_actionAbout_triggered()
diff --git a/src/gui/mainmenu.h b/src/gui/mainmenu.h
index 8268802..431e43a 100644
--- a/src/gui/mainmenu.h
+++ b/src/gui/mainmenu.h
@@ -67,6 +67,8 @@ public slots:
     void on_actionExtendRight_triggered();
     void on_actionReverse_Edge_Direction_triggered();
     void on_actionMerge_Nodes_triggered();
+    void on_actionMake_Path_triggered();
+    void on_actionSplit_Path_triggered();
 
     // Tools
     void on_actionParse_triggered();
diff --git a/src/gui/mainmenu.ui b/src/gui/mainmenu.ui
index 46f4881..2e390f9 100644
--- a/src/gui/mainmenu.ui
+++ b/src/gui/mainmenu.ui
@@ -58,6 +58,13 @@
     <addaction name="actionRotateCW"/>
     <addaction name="actionRotateCCW"/>
    </widget>
+   <widget class="QMenu" name="menuPath">
+    <property name="title">
+     <string>Path</string>
+    </property>
+    <addaction name="actionMake_Path"/>
+    <addaction name="actionSplit_Path"/>
+   </widget>
    <addaction name="actionUndo"/>
    <addaction name="actionRedo"/>
    <addaction name="separator"/>
@@ -74,6 +81,8 @@
    <addaction name="menuTransform"/>
    <addaction name="actionReverse_Edge_Direction"/>
    <addaction name="actionMerge_Nodes"/>
+   <addaction name="separator"/>
+   <addaction name="menuPath"/>
   </widget>
   <widget class="QMenu" name="menuTikz">
    <property name="title">
@@ -460,6 +469,22 @@
     <string>Ctrl+Shift+Space</string>
    </property>
   </action>
+  <action name="actionMake_Path">
+   <property name="text">
+    <string>Make Path</string>
+   </property>
+   <property name="shortcut">
+    <string>Ctrl+P</string>
+   </property>
+  </action>
+  <action name="actionSplit_Path">
+   <property name="text">
+    <string>Split Path</string>
+   </property>
+   <property name="shortcut">
+    <string>Ctrl+Shift+P</string>
+   </property>
+  </action>
   <addaction name="menuFile"/>
   <addaction name="menuEdit"/>
   <addaction name="menuView"/>
diff --git a/src/gui/tikzscene.cpp b/src/gui/tikzscene.cpp
index 087f621..cebf5be 100644
--- a/src/gui/tikzscene.cpp
+++ b/src/gui/tikzscene.cpp
@@ -27,6 +27,7 @@
 #include <QDebug>
 #include <QClipboard>
 #include <QInputDialog>
+#include <QMessageBox>
 #include <cmath>
 #include <delimitedstringvalidator.h>
 #include <QSettings>
@@ -295,6 +296,99 @@ void TikzScene::reverseSelectedEdges()
     _tikzDocument->undoStack()->push(cmd);
 }
 
+void TikzScene::makePath()
+{
+    QSet<Node*> selNodes;
+    QSet<Edge*> edges;
+    getSelection(selNodes, edges);
+
+    // if no edges are selected, try to infer edges from nodes
+    if (edges.isEmpty()) {
+        foreach(Edge *e, graph()->edges()) {
+            if (selNodes.contains(e->source()) && selNodes.contains(e->target()))
+                edges << e;
+        }
+    }
+
+    if (edges.size() < 2) {
+        //QMessageBox::warning(nullptr, "Error", "Paths must contain at least 2 edges.");
+        return;
+    }
+
+    foreach (Edge *e, edges) {
+        if (e->path() != nullptr) {
+            //QMessageBox::warning(nullptr, "Error", "Edges must not already be in another path.");
+            // TODO: maybe we want to automatically split paths if edges are in a path already?
+            return;
+        }
+    }
+
+    // try to turn selected edges into one contiguous chain or cycle, recording
+    // which edges need to be flipped.
+
+    // n.b. this is O(n^2) in path length. This could be optimised by saving
+    // vertex neighbourhoods, but probably doesn't win anything for n < 100.
+
+    QSet<Edge*> flip;
+    QVector<Edge*> p;
+    int pLen = -1;
+
+    // keep going as long as 'p' grows
+    while (pLen < p.length()) {
+        pLen = p.length();
+        Edge *e = nullptr;
+        foreach (e, edges) {
+            Node *s = e->source();
+            Node *t = e->target();
+            if (p.isEmpty()) {
+                p.append(e);
+                break;
+            }
+
+            Node *head = (flip.contains(p.first())) ? p.first()->target() : p.first()->source();
+            Node *tail = (flip.contains(p.last())) ? p.last()->source() : p.last()->target();
+
+            if (s == head || t == head) {
+                if (s == head) flip << e;
+                p.prepend(e);
+                break;
+            }
+
+            if (s == tail || t == tail) {
+                if (t == tail) flip << e;
+                p.append(e);
+                break;
+            }
+        }
+
+        if (e) edges.remove(e);
+    }
+
+    if (!edges.isEmpty()) {
+        QMessageBox::warning(nullptr, "Error", "Selected edges do not form a path.");
+        return;
+    }
+
+    //qDebug() << p;
+    //qDebug() << flip;
+
+    QMap<Edge*, GraphElementData*> oldEdgeData;
+    foreach (Edge *e, p) {
+        if (e != p.first()) oldEdgeData[e] = e->data()->copy();
+    }
+    qDebug() << oldEdgeData;
+
+    _tikzDocument->undoStack()->beginMacro("Make Path");
+    _tikzDocument->undoStack()->push(new ReverseEdgesCommand(this, flip));
+    _tikzDocument->undoStack()->push(new MakePathCommand(this, p, oldEdgeData));
+    _tikzDocument->undoStack()->endMacro();
+}
+
+void TikzScene::splitPath()
+{
+    // TODO: stub
+}
+
 void TikzScene::refreshZIndices()
 {
     qreal z = 0.0;
diff --git a/src/gui/tikzscene.h b/src/gui/tikzscene.h
index 2e7baa5..5996263 100644
--- a/src/gui/tikzscene.h
+++ b/src/gui/tikzscene.h
@@ -81,6 +81,8 @@ public:
 
     void reverseSelectedEdges();
 
+    void makePath();
+    void splitPath();
 
     void getSelection(QSet<Node*> &selNodes, QSet<Edge*> &selEdges) const;
     QSet<Node*> getSelectedNodes() const;
diff --git a/src/gui/undocommands.cpp b/src/gui/undocommands.cpp
index 9a1ef34..a07f251 100644
--- a/src/gui/undocommands.cpp
+++ b/src/gui/undocommands.cpp
@@ -594,3 +594,51 @@ void ReverseEdgesCommand::redo()
     GraphUpdateCommand::redo();
 }
 
+
+MakePathCommand::MakePathCommand(TikzScene *scene,
+                                 const QVector<Edge *> &edgeList,
+                                 const QMap<Edge *, GraphElementData *> &oldEdgeData,
+                                 QUndoCommand *parent) :
+    GraphUpdateCommand(scene, parent),
+    _edgeList(edgeList), _oldEdgeData(oldEdgeData)
+{
+}
+
+void MakePathCommand::undo()
+{
+    Path *p = _edgeList.first()->path();
+    p->removeEdges();
+    _scene->graph()->removePath(p);
+
+    foreach (Edge *e, _edgeList) {
+        if (e != _edgeList.first()) {
+            // setData transfers ownership, so make a copy
+            e->setData(_oldEdgeData[e]->copy());
+        }
+    }
+
+    GraphUpdateCommand::undo();
+}
+
+void MakePathCommand::redo()
+{
+    GraphElementData *npd = _edgeList.first()->data()->nonPathData();
+    GraphElementData *d;
+
+    Path *p = new Path();
+    foreach (Edge *e, _edgeList) {
+        p->addEdge(e);
+
+        if (e != _edgeList.first()) {
+            d = e->data()->pathData();
+            d->mergeData(npd);
+            e->setData(d);
+        }
+    }
+
+    delete npd;
+
+    _scene->graph()->addPath(p);
+
+    GraphUpdateCommand::redo();
+}
diff --git a/src/gui/undocommands.h b/src/gui/undocommands.h
index 40f0a3b..a1daa07 100644
--- a/src/gui/undocommands.h
+++ b/src/gui/undocommands.h
@@ -255,4 +255,20 @@ private:
     QVector<Edge*> _newEdgeOrder;
 };
 
+class MakePathCommand : public GraphUpdateCommand
+{
+public:
+    explicit MakePathCommand(TikzScene *scene,
+                             const QVector<Edge*> &edgeList,
+                             const QMap<Edge*,GraphElementData*> &oldEdgeData,
+                             QUndoCommand *parent = nullptr);
+    void undo() override;
+    void redo() override;
+private:
+    QVector<Edge*> _edgeList;
+
+    // creating path clobbers data on all but first edge
+    QMap<Edge*,GraphElementData*> _oldEdgeData;
+};
+
 #endif // UNDOCOMMANDS_H
diff --git a/tex/tikzit-logo.tikz b/tex/tikzit-logo.tikz
index 4cc1b06..be1eb66 100755
--- a/tex/tikzit-logo.tikz
+++ b/tex/tikzit-logo.tikz
@@ -36,7 +36,41 @@
 		\node [style=none] (88) at (2.9, 0.775) {};
 	\end{pgfonlayer}
 	\begin{pgfonlayer}{edgelayer}
-		\draw [fill=black] (36.center) to [in=135, out=45] (6.center) to [in=-90, out=-45, looseness=1.25] (8.center) to [in=-180, out=90] (11.center) to [in=90, out=0] (10.center) to [in=0, out=-90] (9.center) to [in=135, out=180, looseness=1.25] (7.center) to [in=45, out=-45] (35.center) to [in=180, out=-135, looseness=1.25] (23.center) to [in=90, out=0] (20.center) to [in=0, out=-90] (22.center) to [in=-90, out=180] (18.center) to [in=45, out=90, looseness=1.25] (32.center) to [in=-45, out=-135, looseness=1.25] (5.center) to [in=90, out=135, looseness=1.25] (28.center) to [in=0, out=-90] (30.center) to [in=-90, out=180] (26.center) to [in=-180, out=90] (31.center) to [in=-45, out=0, looseness=1.25] (33.center) to [in=-135, out=135] (37.center) to cycle;
-		\draw (72.center) to [in=90, out=-30, looseness=0.75] (71.center) to [in=0, out=-90] (70.center) to [in=-60, out=180, looseness=0.75] (69.center) to [in=-15, out=-165] (81.center) to [in=0, out=-120, looseness=0.75] (82.center) to [in=-90, out=180] (83.center) to [in=-150, out=90, looseness=0.75] (84.center) to [in=-90, out=105, looseness=0.75] (80.center) to [in=-180, out=90] (65.center) to [in=165, out=0, looseness=0.75] (85.center) to [in=-180, out=60, looseness=0.75] (86.center) to [in=90, out=0] (87.center) to [in=30, out=-90, looseness=0.75] (88.center) to [in=75, out=-75] cycle;
+		\draw [style=bg] (72.center)
+			 to [in=90, out=-30, looseness=0.75] (71.center)
+			 to [in=0, out=-90] (70.center)
+			 to [in=-60, out=180, looseness=0.75] (69.center)
+			 to [in=-15, out=-165] (81.center)
+			 to [in=0, out=-120, looseness=0.75] (82.center)
+			 to [in=-90, out=180] (83.center)
+			 to [in=-150, out=90, looseness=0.75] (84.center)
+			 to [in=-90, out=105, looseness=0.75] (80.center)
+			 to [in=-180, out=90] (65.center)
+			 to [in=165, out=0, looseness=0.75] (85.center)
+			 to [in=-180, out=60, looseness=0.75] (86.center)
+			 to [in=90, out=0] (87.center)
+			 to [in=30, out=-90, looseness=0.75] (88.center)
+			 to [in=75, out=-75] cycle;
+		\draw [style=fg] (36.center)
+			 to [in=135, out=45] (6.center)
+			 to [in=-90, out=-45, looseness=1.25] (8.center)
+			 to [in=-180, out=90] (11.center)
+			 to [in=90, out=0] (10.center)
+			 to [in=0, out=-90] (9.center)
+			 to [in=135, out=180, looseness=1.25] (7.center)
+			 to [in=45, out=-45] (35.center)
+			 to [in=180, out=-135, looseness=1.25] (23.center)
+			 to [in=90, out=0] (20.center)
+			 to [in=0, out=-90] (22.center)
+			 to [in=-90, out=180] (18.center)
+			 to [in=45, out=90, looseness=1.25] (32.center)
+			 to [in=-45, out=-135, looseness=1.25] (5.center)
+			 to [in=90, out=135, looseness=1.25] (28.center)
+			 to [in=0, out=-90] (30.center)
+			 to [in=-90, out=180] (26.center)
+			 to [in=-180, out=90] (31.center)
+			 to [in=-45, out=0, looseness=1.25] (33.center)
+			 to [in=-135, out=135] (37.center)
+			 to cycle;
 	\end{pgfonlayer}
 \end{tikzpicture}