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38 ** |
40 ****************************************************************************/ |
39 ****************************************************************************/ |
41 |
40 |
42 #include <QGraphicsScene> |
41 #include <QGraphicsScene> |
46 |
45 |
47 #include "edge.h" |
46 #include "edge.h" |
48 #include "node.h" |
47 #include "node.h" |
49 #include "graphwidget.h" |
48 #include "graphwidget.h" |
50 |
49 |
|
50 //! [0] |
51 Node::Node(GraphWidget *graphWidget) |
51 Node::Node(GraphWidget *graphWidget) |
52 : graph(graphWidget) |
52 : graph(graphWidget) |
53 { |
53 { |
54 setFlag(ItemIsMovable); |
54 setFlag(ItemIsMovable); |
55 setFlag(ItemSendsGeometryChanges); |
55 setFlag(ItemSendsGeometryChanges); |
56 setCacheMode(DeviceCoordinateCache); |
56 setCacheMode(DeviceCoordinateCache); |
57 setZValue(-1); |
57 setZValue(-1); |
58 } |
58 } |
59 |
59 //! [0] |
|
60 |
|
61 //! [1] |
60 void Node::addEdge(Edge *edge) |
62 void Node::addEdge(Edge *edge) |
61 { |
63 { |
62 edgeList << edge; |
64 edgeList << edge; |
63 edge->adjust(); |
65 edge->adjust(); |
64 } |
66 } |
65 |
67 |
66 QList<Edge *> Node::edges() const |
68 QList<Edge *> Node::edges() const |
67 { |
69 { |
68 return edgeList; |
70 return edgeList; |
69 } |
71 } |
70 |
72 //! [1] |
|
73 |
|
74 //! [2] |
71 void Node::calculateForces() |
75 void Node::calculateForces() |
72 { |
76 { |
73 if (!scene() || scene()->mouseGrabberItem() == this) { |
77 if (!scene() || scene()->mouseGrabberItem() == this) { |
74 newPos = pos(); |
78 newPos = pos(); |
75 return; |
79 return; |
76 } |
80 } |
77 |
81 //! [2] |
|
82 |
|
83 //! [3] |
78 // Sum up all forces pushing this item away |
84 // Sum up all forces pushing this item away |
79 qreal xvel = 0; |
85 qreal xvel = 0; |
80 qreal yvel = 0; |
86 qreal yvel = 0; |
81 foreach (QGraphicsItem *item, scene()->items()) { |
87 foreach (QGraphicsItem *item, scene()->items()) { |
82 Node *node = qgraphicsitem_cast<Node *>(item); |
88 Node *node = qgraphicsitem_cast<Node *>(item); |
83 if (!node) |
89 if (!node) |
84 continue; |
90 continue; |
85 |
91 |
86 QLineF line(mapFromItem(node, 0, 0), QPointF(0, 0)); |
92 QPointF vec = mapToItem(node, 0, 0); |
87 qreal dx = line.dx(); |
93 qreal dx = vec.x(); |
88 qreal dy = line.dy(); |
94 qreal dy = vec.y(); |
89 double l = 2.0 * (dx * dx + dy * dy); |
95 double l = 2.0 * (dx * dx + dy * dy); |
90 if (l > 0) { |
96 if (l > 0) { |
91 xvel += (dx * 150.0) / l; |
97 xvel += (dx * 150.0) / l; |
92 yvel += (dy * 150.0) / l; |
98 yvel += (dy * 150.0) / l; |
93 } |
99 } |
94 } |
100 } |
95 |
101 //! [3] |
|
102 |
|
103 //! [4] |
96 // Now subtract all forces pulling items together |
104 // Now subtract all forces pulling items together |
97 double weight = (edgeList.size() + 1) * 10; |
105 double weight = (edgeList.size() + 1) * 10; |
98 foreach (Edge *edge, edgeList) { |
106 foreach (Edge *edge, edgeList) { |
99 QPointF pos; |
107 QPointF vec; |
100 if (edge->sourceNode() == this) |
108 if (edge->sourceNode() == this) |
101 pos = mapFromItem(edge->destNode(), 0, 0); |
109 vec = mapToItem(edge->destNode(), 0, 0); |
102 else |
110 else |
103 pos = mapFromItem(edge->sourceNode(), 0, 0); |
111 vec = mapToItem(edge->sourceNode(), 0, 0); |
104 xvel += pos.x() / weight; |
112 xvel -= vec.x() / weight; |
105 yvel += pos.y() / weight; |
113 yvel -= vec.y() / weight; |
106 } |
114 } |
107 |
115 //! [4] |
|
116 |
|
117 //! [5] |
108 if (qAbs(xvel) < 0.1 && qAbs(yvel) < 0.1) |
118 if (qAbs(xvel) < 0.1 && qAbs(yvel) < 0.1) |
109 xvel = yvel = 0; |
119 xvel = yvel = 0; |
110 |
120 //! [5] |
|
121 |
|
122 //! [6] |
111 QRectF sceneRect = scene()->sceneRect(); |
123 QRectF sceneRect = scene()->sceneRect(); |
112 newPos = pos() + QPointF(xvel, yvel); |
124 newPos = pos() + QPointF(xvel, yvel); |
113 newPos.setX(qMin(qMax(newPos.x(), sceneRect.left() + 10), sceneRect.right() - 10)); |
125 newPos.setX(qMin(qMax(newPos.x(), sceneRect.left() + 10), sceneRect.right() - 10)); |
114 newPos.setY(qMin(qMax(newPos.y(), sceneRect.top() + 10), sceneRect.bottom() - 10)); |
126 newPos.setY(qMin(qMax(newPos.y(), sceneRect.top() + 10), sceneRect.bottom() - 10)); |
115 } |
127 } |
116 |
128 //! [6] |
|
129 |
|
130 //! [7] |
117 bool Node::advance() |
131 bool Node::advance() |
118 { |
132 { |
119 if (newPos == pos()) |
133 if (newPos == pos()) |
120 return false; |
134 return false; |
121 |
135 |
122 setPos(newPos); |
136 setPos(newPos); |
123 return true; |
137 return true; |
124 } |
138 } |
125 |
139 //! [7] |
|
140 |
|
141 //! [8] |
126 QRectF Node::boundingRect() const |
142 QRectF Node::boundingRect() const |
127 { |
143 { |
128 qreal adjust = 2; |
144 qreal adjust = 2; |
129 return QRectF(-10 - adjust, -10 - adjust, |
145 return QRectF(-10 - adjust, -10 - adjust, |
130 23 + adjust, 23 + adjust); |
146 23 + adjust, 23 + adjust); |
131 } |
147 } |
132 |
148 //! [8] |
|
149 |
|
150 //! [9] |
133 QPainterPath Node::shape() const |
151 QPainterPath Node::shape() const |
134 { |
152 { |
135 QPainterPath path; |
153 QPainterPath path; |
136 path.addEllipse(-10, -10, 20, 20); |
154 path.addEllipse(-10, -10, 20, 20); |
137 return path; |
155 return path; |
138 } |
156 } |
139 |
157 //! [9] |
|
158 |
|
159 //! [10] |
140 void Node::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *) |
160 void Node::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *) |
141 { |
161 { |
142 painter->setPen(Qt::NoPen); |
162 painter->setPen(Qt::NoPen); |
143 painter->setBrush(Qt::darkGray); |
163 painter->setBrush(Qt::darkGray); |
144 painter->drawEllipse(-7, -7, 20, 20); |
164 painter->drawEllipse(-7, -7, 20, 20); |