src/Tools/Graphview/graph_panel.scala

more formal Graph_Display.Node (with ordering) and Graph_Display.Edge;
misc tuning;
tuned signature;

/*  Title:      Tools/Graphview/graph_panel.scala
    Author:     Markus Kaiser, TU Muenchen
    Author:     Makarius

Graphview Java2D drawing panel.
*/

package isabelle.graphview


import isabelle._

import java.awt.{Dimension, Graphics2D, Point}
import java.awt.geom.{AffineTransform, Point2D}
import java.awt.image.BufferedImage
import javax.swing.{JScrollPane, JComponent, SwingUtilities}

import scala.swing.{Panel, ScrollPane}
import scala.swing.event.{Event, Key, KeyTyped, MousePressed, MouseDragged, MouseClicked, MouseEvent}


class Graph_Panel(val visualizer: Visualizer) extends ScrollPane
{
  panel =>

  tooltip = ""

  override lazy val peer: JScrollPane = new JScrollPane with SuperMixin {
    override def getToolTipText(event: java.awt.event.MouseEvent): String =
      find_node(Transform.pane_to_graph_coordinates(event.getPoint)) match {
        case Some(node) =>
          visualizer.model.complete_graph.get_node(node) match {
            case Nil => null
            case content => visualizer.make_tooltip(panel.peer, event.getX, event.getY, content)
          }
        case None => null
      }
  }

  focusable = true
  requestFocus()

  horizontalScrollBarPolicy = ScrollPane.BarPolicy.Always
  verticalScrollBarPolicy = ScrollPane.BarPolicy.Always

  peer.getVerticalScrollBar.setUnitIncrement(10)

  def find_node(at: Point2D): Option[Graph_Display.Node] =
  {
    val m = visualizer.metrics()
    visualizer.model.visible_nodes_iterator
      .find(node => visualizer.Drawer.shape(m, node).contains(at))
  }

  def refresh()
  {
    if (paint_panel != null) {
      paint_panel.set_preferred_size()
      paint_panel.repaint()
    }
  }

  def fit_to_window() = {
    Transform.fit_to_window()
    refresh()
  }

  val zoom = new GUI.Zoom_Box { def changed = rescale(0.01 * factor) }

  def rescale(s: Double)
  {
    Transform.scale = s
    if (zoom != null) zoom.set_item((Transform.scale_discrete * 100).round.toInt)
    refresh()
  }

  def apply_layout() = visualizer.Coordinates.update_layout()

  private class Paint_Panel extends Panel
  {
    def set_preferred_size()
    {
      val box = visualizer.Coordinates.bounding_box()
      val s = Transform.scale_discrete

      preferredSize =
        new Dimension((box.width * s).ceil.toInt, (box.height * s).ceil.toInt)

      revalidate()
    }

    override def paint(g: Graphics2D)
    {
      super.paintComponent(g)
      g.setColor(visualizer.background_color)
      g.fillRect(0, 0, peer.getWidth, peer.getHeight)
      g.transform(Transform())

      visualizer.Drawer.paint_all_visible(g, true)
    }
  }
  private val paint_panel = new Paint_Panel
  contents = paint_panel

  listenTo(keys)
  listenTo(mouse.moves)
  listenTo(mouse.clicks)
  reactions += Interaction.Mouse.react
  reactions += Interaction.Keyboard.react
  reactions +=
  {
    case KeyTyped(_, _, _, _) => repaint(); requestFocus()
    case MousePressed(_, _, _, _, _) => repaint(); requestFocus()
    case MouseDragged(_, _, _) => repaint(); requestFocus()
    case MouseClicked(_, _, _, _, _) => repaint(); requestFocus()
  }

  visualizer.model.Colors.events += { case _ => repaint() }
  visualizer.model.Mutators.events += { case _ => repaint() }

  apply_layout()
  rescale(1.0)

  private object Transform
  {
    private var _scale: Double = 1.0
    def scale: Double = _scale
    def scale_=(s: Double)
    {
      _scale = (s min 10.0) max 0.1
    }
    def scale_discrete: Double =
      (_scale * visualizer.font_size).round.toDouble / visualizer.font_size

    def apply() =
    {
      val box = visualizer.Coordinates.bounding_box()
      val at = AffineTransform.getScaleInstance(scale_discrete, scale_discrete)
      at.translate(- box.x, - box.y)
      at
    }

    def fit_to_window()
    {
      if (visualizer.model.visible_nodes_iterator.isEmpty)
        rescale(1.0)
      else {
        val box = visualizer.Coordinates.bounding_box()
        rescale((size.width / box.width) min (size.height / box.height))
      }
    }

    def pane_to_graph_coordinates(at: Point2D): Point2D =
    {
      val s = Transform.scale_discrete
      val p = Transform().inverseTransform(peer.getViewport.getViewPosition, null)

      p.setLocation(p.getX + at.getX / s, p.getY + at.getY / s)
      p
    }
  }

  object Interaction
  {
    object Keyboard
    {
      val react: PartialFunction[Event, Unit] =
      {
        case KeyTyped(_, c, m, _) => typed(c, m)
      }

      def typed(c: Char, m: Key.Modifiers) =
        c match {
          case '+' => rescale(Transform.scale * 5.0/4)
          case '-' => rescale(Transform.scale * 4.0/5)
          case '0' => Transform.fit_to_window()
          case '1' => apply_layout()
          case _ =>
        }
    }

    object Mouse
    {
      type Dummy = (Graph_Display.Edge, Int)

      private var draginfo: (Point, List[Graph_Display.Node], List[Dummy]) = null

      val react: PartialFunction[Event, Unit] =
      {
        case MousePressed(_, p, _, _, _) => pressed(p)
        case MouseDragged(_, to, _) =>
          drag(draginfo, to)
          val (_, p, d) = draginfo
          draginfo = (to, p, d)
        case e @ MouseClicked(_, p, m, n, _) => click(p, m, n, e)
      }

      def dummy(at: Point2D): Option[Dummy] =
      {
        val m = visualizer.metrics()
        visualizer.model.visible_edges_iterator.map(
          edge => visualizer.Coordinates(edge).zipWithIndex.map((edge, _))).flatten.find(
            {
              case (_, ((x, y), _)) =>
                visualizer.Drawer.shape(m, Graph_Display.Node.dummy).
                  contains(at.getX() - x, at.getY() - y)
            }) match {
              case None => None
              case Some((edge, (_, index))) => Some((edge, index))
            }
      }

      def pressed(at: Point)
      {
        val c = Transform.pane_to_graph_coordinates(at)
        val l =
          find_node(c) match {
            case Some(node) =>
              if (visualizer.Selection.contains(node)) visualizer.Selection.get()
              else List(node)
            case None => Nil
          }
        val d =
          l match {
            case Nil =>
              dummy(c) match {
                case Some(d) => List(d)
                case None => Nil
              }
            case _ => Nil
          }
        draginfo = (at, l, d)
      }

      def click(at: Point, m: Key.Modifiers, clicks: Int, e: MouseEvent)
      {
        val c = Transform.pane_to_graph_coordinates(at)

        def left_click()
        {
          (find_node(c), m) match {
            case (Some(node), Key.Modifier.Control) => visualizer.Selection.add(node)
            case (None, Key.Modifier.Control) =>

            case (Some(node), Key.Modifier.Shift) => visualizer.Selection.add(node)
            case (None, Key.Modifier.Shift) =>

            case (Some(node), _) =>
              visualizer.Selection.clear()
              visualizer.Selection.add(node)
            case (None, _) =>
              visualizer.Selection.clear()
          }
        }

        def right_click()
        {
          val menu = Popups(panel, find_node(c), visualizer.Selection.get())
          menu.show(panel.peer, at.x, at.y)
        }

        if (clicks < 2) {
          if (SwingUtilities.isRightMouseButton(e.peer)) right_click()
          else left_click()
        }
      }

      def drag(draginfo: (Point, List[Graph_Display.Node], List[Dummy]), to: Point)
      {
        val (from, p, d) = draginfo

        val s = Transform.scale_discrete
        val (dx, dy) = (to.x - from.x, to.y - from.y)
        (p, d) match {
          case (Nil, Nil) =>
            val r = panel.peer.getViewport.getViewRect
            r.translate(-dx, -dy)

            paint_panel.peer.scrollRectToVisible(r)

          case (Nil, ds) =>
            ds.foreach(d => visualizer.Coordinates.translate(d, (dx / s, dy / s)))

          case (ls, _) =>
            ls.foreach(l => visualizer.Coordinates.translate(l, (dx / s, dy / s)))
        }
      }
    }
  }
}