src/Pure/PIDE/document_editor.scala

tuned comments;

/*  Title:      Pure/PIDE/document_editor.scala
    Author:     Makarius

Central resources and configuration for interactive document preparation.
*/

package isabelle


object Document_Editor {
  /* document output */

  def document_name: String = "document"
  def document_output_dir(): Path = Path.explode("$ISABELLE_HOME_USER/document_output")
  def document_output(): Path = document_output_dir() + Path.basic(document_name)

  def view_document(): Unit = {
    val path = document_output().pdf
    if (path.is_file) Isabelle_System.pdf_viewer(path)
  }


  /* progress */

  class Log_Progress(session: Session) extends Progress {
    def show(text: String): Unit = {}

    private val syslog = session.make_syslog()

    private def update(text: String = syslog.content()): Unit = show(text)
    private val delay = Delay.first(session.update_delay, gui = true) { update() }

    override def echo(msg: String): Unit = { syslog += msg; delay.invoke() }

    def load(): Unit = GUI_Thread.require {
      val path = document_output().log
      val text = if (path.is_file) File.read(path) else ""
      GUI_Thread.later { delay.revoke(); update(text) }
    }

    GUI_Thread.later { update() }
  }


  /* configuration state */

  sealed case class State(
    session_background: Option[Sessions.Background] = None,
    selection: Set[Document.Node.Name] = Set.empty,
    views: Set[AnyRef] = Set.empty,
  ) {
    def is_active: Boolean = session_background.isDefined && views.nonEmpty

    def is_required(name: Document.Node.Name): Boolean =
      is_active && selection.contains(name) && all_document_theories.contains(name)

    def required: List[Document.Node.Name] =
      if (is_active) all_document_theories.filter(selection) else Nil

    def all_document_theories: List[Document.Node.Name] =
      session_background match {
        case Some(background) => background.base.all_document_theories
        case None => Nil
      }

    def active_document_theories: List[Document.Node.Name] =
      if (is_active) all_document_theories else Nil

    def select(
      names: Iterable[Document.Node.Name],
      set: Boolean = false,
      toggle: Boolean = false
    ): State = {
      copy(selection =
        names.foldLeft(selection) {
          case (sel, name) =>
            val b = if (toggle) !selection(name) else set
            if (b) sel + name else sel - name
        })
    }

    def register_view(id: AnyRef): State = copy(views = views + id)
    def unregister_view(id: AnyRef): State = copy(views = views - id)
  }
}