Method layout

python/examples/custom_graph_layout.py:28–86

(self, graph: FlowGraph, nodes: list[FlowGraphNode])

class RandomLayout(FlowGraphLayout):
    def layout(self, graph: FlowGraph, nodes: list[FlowGraphNode]):
        min_x = 0
        max_x = 0
        min_y = 0
        max_y = 0

        max_extent = len(nodes) * 50

        # Place nodes
        for node in nodes:
            x = random.randint(0, max_extent)
            y = random.randint(0, max_extent)

            min_x = min(x, min_x)
            max_x = max(x + node.width, max_x)

            min_y = min(y, min_y)
            max_y = max(y + node.height, max_y)

            node.x = x
            node.y = y

        # Place edges
        for node in nodes:
            for edge_num,edge in enumerate(node.outgoing_edges):
                points = [
                    (node.x + node.width/2, node.y + node.height),
                    (edge.target.x + edge.target.width/2, edge.target.y + edge.target.height)
                ]
                node.set_outgoing_edge_points(edge_num, points)

        # Calculate graph size and node visibility
        for node in nodes:
            min_node_x = node.x
            max_node_x = node.x + node.width

            min_node_y = node.y
            max_node_y = node.y + node.height
            for edge in node.outgoing_edges:
                for point in edge.points:
                    px, py = point
                    min_x = min(min_x, px)
                    min_y = min(min_y, py)

                    max_x = max(max_x, px + 1)
                    max_y = max(max_y, py + 1)

                    min_node_x = min(min_node_x, px)
                    max_node_x = max(max_node_x, px+1)

                    min_node_y = min(min_node_y, py)
                    max_node_y = max(max_node_y, py+1)

            node.set_visibility_region(int(min_node_x), int(min_node_y), int(max_node_x - min_node_x), int(max_node_y - min_node_y))

        graph.width = int(max_x - min_x) + graph.horizontal_block_margin*2
        graph.height = int(max_y - min_y) + graph.vertical_block_margin*2