/*
  timeline-header-container.cpp  -  Implementation of the timeline
  header container widget

  Copyright (C)         Lumiera.org
    2008,               Joel Holdsworth <joel@airwebreathe.org.uk>

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; either version 2 of
  the License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

* *****************************************************/

#include <boost/foreach.hpp>

#include "timeline-header-container.hpp"
#include "timeline-track.hpp"
#include "gui/widgets/timeline-widget.hpp"
#include "gui/util/rectangle.hpp"

using namespace Gtk;
using namespace std;
using namespace std::tr1;
using namespace util;

namespace gui {
namespace widgets {
namespace timeline {
  
// ===== Constants ===== //

const int TimelineHeaderContainer::ScrollSlideRateDivisor = 4;
const int TimelineHeaderContainer::ScrollSlideEventInterval = 40;

// ===== Implementation ===== //

TimelineHeaderContainer::TimelineHeaderContainer(
  gui::widgets::TimelineWidget &timeline_widget) :
    Glib::ObjectBase("TimelineHeaderContainer"),
    timelineWidget(timeline_widget)
{
  // This widget will not have a window at first
  set_flags(Gtk::NO_WINDOW);
  
  set_redraw_on_allocate(false);
  
  // Connect to the timeline widget's vertical scroll event,
  // so that we get notified when the view shifts
  timelineWidget.verticalAdjustment.signal_value_changed().connect(
    sigc::mem_fun(this, &TimelineHeaderContainer::on_scroll) );
    
  // Connect to the timeline widget's hover event,
  // so that we get notified when tracks are hovered on
  timelineWidget.hovering_track_changed_signal().connect(
    sigc::mem_fun(this,
    &TimelineHeaderContainer::on_hovering_track_changed) );
    
  // Create the context menu
  Menu::MenuList& menu_list = contextMenu.items();
  menu_list.push_back( Menu_Helpers::MenuElem(_("_Add Track"),
    sigc::mem_fun(timelineWidget,
    &TimelineWidget::on_add_track_command) ) );
}
 
void
TimelineHeaderContainer::update_headers()
{  
  // Ensure headers are parented correctly
  pair<shared_ptr<model::Track>, shared_ptr<timeline::Track> > pair; 
  BOOST_FOREACH( pair, timelineWidget.trackMap )
    {
      REQUIRE(pair.second);
      Widget &widget = pair.second->get_header_widget();
      if(widget.get_parent() == NULL)  // Is the header unparented?
        widget.set_parent(*this);
      ENSURE(widget.get_parent() == this);
    }
}

void
TimelineHeaderContainer::clear_headers()
{
  // Unparent all the headers
  pair<shared_ptr<model::Track>, shared_ptr<timeline::Track> > pair; 
  BOOST_FOREACH( pair, timelineWidget.trackMap )
    {
      REQUIRE(pair.second);
      Widget &widget = pair.second->get_header_widget();
      if(widget.get_parent() != NULL)  // Is the header unparented?
        widget.unparent();
    }
}
  
void
TimelineHeaderContainer::on_realize()
{
  set_flags(Gtk::NO_WINDOW);
  
  // Call base class:
  Gtk::Container::on_realize();
  
  // Create the GdkWindow:
  GdkWindowAttr attributes;
  memset(&attributes, 0, sizeof(attributes));

  Allocation allocation = get_allocation();

  // Set initial position and size of the Gdk::Window:
  attributes.x = allocation.get_x();
  attributes.y = allocation.get_y();
  attributes.width = allocation.get_width();
  attributes.height = allocation.get_height();

  attributes.event_mask = get_events () | Gdk::EXPOSURE_MASK; 
  attributes.window_type = GDK_WINDOW_CHILD;
  attributes.wclass = GDK_INPUT_OUTPUT;

  gdkWindow = Gdk::Window::create(get_window(), &attributes,
          GDK_WA_X | GDK_WA_Y);
  unset_flags(Gtk::NO_WINDOW);
  set_window(gdkWindow);
  
  // Unset the background so as to make the colour match the parent
  // window
  unset_bg(STATE_NORMAL);

  // Make the widget receive expose events
  gdkWindow->set_user_data(gobj());
  
  // Make the widget sensitive to mouse events
  add_events(
    Gdk::POINTER_MOTION_MASK |
    Gdk::BUTTON_PRESS_MASK |
    Gdk::BUTTON_RELEASE_MASK);
}
  
void
TimelineHeaderContainer::on_unrealize()
{
  // Unreference any window we may have created
  gdkWindow.clear();

  // Call base class:
  Container::on_unrealize();
}

bool TimelineHeaderContainer::on_button_press_event (
  GdkEventButton* event)
{
  REQUIRE(event != NULL);
  
  switch(event->button)
    {
    case 1: // Left Click        
      break;
      
    case 3: // Right Click
      {
        // Popup the context menu
        shared_ptr<Track> header(
          timelineWidget.layoutHelper.header_from_point(
            Gdk::Point(event->x, event->y)));
        
        // Are we hovering on a header?
        if(header)
          {
            // Yes - show the header's context menu
            header->show_header_context_menu(
              event->button, event->time);
          }
        else
          {
            // No - show the default context menu
            contextMenu.popup(event->button, event->time);
          }
        break;
      }
    }
  
  return true;
}

bool TimelineHeaderContainer::on_button_release_event (
  GdkEventButton* event)
{
  end_drag();
  return Container::on_button_release_event(event);    
}

bool TimelineHeaderContainer::on_motion_notify_event (
  GdkEventMotion* event)
{
  REQUIRE(event != NULL);
  REQUIRE(gdkWindow);
  
  const bool result = Container::on_motion_notify_event(event);  

  TimelineLayoutHelper &layout = timelineWidget.layoutHelper;  

  // Get the mouse point
  int window_x = 0, window_y = 0;
  gdkWindow->get_origin(window_x, window_y);
  mousePoint = Gdk::Point(event->x_root - window_x,
    event->y_root - window_y);
  
  // Are we beginning to drag a header?
  if((event->state & GDK_BUTTON1_MASK) && hoveringTrack &&
    !layout.is_dragging_track())
    {
      begin_drag();      
      return result;
    }
    
  // Are we currently dragging?
  if(layout.is_dragging_track())
    {
      // Forward the message to the layout manager
      layout.drag_to_point(mousePoint);
      
      // Is the mouse out of bounds? if so we must begin scrolling
      const int height = get_allocation().get_height();
      const int y = mousePoint.get_y();
      
      if(y < 0)
        begin_scroll_slide(y / ScrollSlideRateDivisor);
      else if(y > height)
        begin_scroll_slide((y - height) / ScrollSlideRateDivisor);
      else end_scroll_slide();
      
      return result;
    }
  
  // Hit test the rectangle
  hoveringTrack = layout.header_from_point(mousePoint);
    
  return result;
}

void
TimelineHeaderContainer::on_size_request (Requisition* requisition)
{ 
  // We don't care about the size of all the child widgets, but if we
  // don't send the size request down the tree, some widgets fail to
  // calculate their text layout correctly. 
    
  const TimelineLayoutHelper::TrackTree &layout_tree =
    timelineWidget.layoutHelper.get_layout_tree();
  
  // Send a size request to all the children
  if(!layout_tree.empty())
    {
      TimelineLayoutHelper::TrackTree::pre_order_iterator iterator;
      for(iterator = ++layout_tree.begin(); // ++ so that we skip the sequence root
        iterator != layout_tree.end();
        iterator++)
        {
          Widget &widget =
            lookup_timeline_track(*iterator)->get_header_widget();
          if(widget.is_visible())
            widget.size_request();
        }
    }
    
  // Initialize the output parameter:
  *requisition = Gtk::Requisition();
  requisition->width = TimelineWidget::HeaderWidth; 
  requisition->height = 0;
}
  
void
TimelineHeaderContainer::on_size_allocate (Allocation& allocation)
{ 
  // Use the offered allocation for this container:
  set_allocation(allocation);
  
  // Resize the widget's window
  if(gdkWindow)
    {
      gdkWindow->move_resize(allocation.get_x(), allocation.get_y(),
        allocation.get_width(), allocation.get_height());
    }
  
  // Relayout the child widgets of the headers
  layout_headers();
}
  
void
TimelineHeaderContainer::forall_vfunc(gboolean /* include_internals */,
        GtkCallback callback, gpointer callback_data)
{ 
  REQUIRE(callback != NULL);
  
  pair<shared_ptr<model::Track>, shared_ptr<timeline::Track> > pair; 
  BOOST_FOREACH( pair, timelineWidget.trackMap )
    {
      REQUIRE(pair.second);
      GtkWidget *widget = pair.second->get_header_widget().gobj();
      
      REQUIRE(widget);
      callback(widget, callback_data);
    }
}

void
TimelineHeaderContainer::on_remove(Widget* widget)
{
  REQUIRE(widget);
  
  // Ensure headers are parented correctly
  pair<shared_ptr<model::Track>, shared_ptr<timeline::Track> > pair; 
  BOOST_FOREACH( pair, timelineWidget.trackMap )
    {
      REQUIRE(pair.second);
      Widget &this_widget = pair.second->get_header_widget();
      if(&this_widget == widget)
        this_widget.unparent();
    }
}

void
TimelineHeaderContainer::on_layout_changed()
{
  layout_headers();
}

void
TimelineHeaderContainer::on_scroll()
{
  // If the scroll has changed, we will have to shift all the
  // header widgets
  layout_headers();
}

void
TimelineHeaderContainer::on_hovering_track_changed( shared_ptr<timeline::Track>)
{
  /* do nothing */
}

bool
TimelineHeaderContainer::on_scroll_slide_timer()
{   
  // Shift the view
  const int view_height = get_allocation().get_height();
  timelineWidget.set_y_scroll_offset(
    timelineWidget.get_y_scroll_offset() +
    scrollSlideRate * view_height / 256);
    
  // Keep the layout manager updated
  timelineWidget.layoutHelper.drag_to_point(mousePoint);
  
  // Return true to keep the timer going
  return true;
}
  
void
TimelineHeaderContainer::layout_headers()
{ 
  // We can't layout before the widget has been set up
  if(!gdkWindow)
    return;
    
  bool headers_shown = false;
    
  TimelineLayoutHelper &layout_helper =
    timelineWidget.layoutHelper;
  const TimelineLayoutHelper::TrackTree &layout_tree =
    layout_helper.get_layout_tree();
    
  if(!layout_tree.empty())
    {
      TimelineLayoutHelper::TrackTree::pre_order_iterator iterator;
      for(iterator = ++layout_tree.begin(); // ++ so that we skip the sequence root
        iterator != layout_tree.end();
        iterator++)
        {      
          const shared_ptr<timeline::Track> timeline_track =
            lookup_timeline_track(*iterator);
          
          Widget &widget = timeline_track->get_header_widget();
          
          boost::optional<Gdk::Rectangle> header_rect =
            layout_helper.get_track_header_rect(timeline_track);
          
          if(header_rect)
            {
              REQUIRE(header_rect->get_width() >= 0);
              REQUIRE(header_rect->get_height() >= 0);
              
              // Apply the allocation to the header
              widget.size_allocate (*header_rect);
              if(!widget.is_visible())
                {
                  widget.show();
                  headers_shown = true;
                }
            }
          else // No header rect, so the track must be hidden
            if(widget.is_visible())
              widget.hide();
        }
        
      // If headers have been shown while we're dragging, the dragging
      // branch headers have to be brought back to the top again
      if(headers_shown && layout_helper.is_dragging_track())
        raise_recursive(layout_helper.get_dragging_track_iter());
      
      // Repaint the background of our parenting
      queue_draw();
    }
}

shared_ptr<timeline::Track>
TimelineHeaderContainer::lookup_timeline_track(
  shared_ptr<model::Track> modelTrack)
{
  REQUIRE(modelTrack != NULL);
  
  shared_ptr<timeline::Track> timeline_track =
    timelineWidget.lookup_timeline_track(modelTrack);
  ENSURE(timeline_track);
  
  return timeline_track;
}

void
TimelineHeaderContainer::begin_drag()
{
  TimelineLayoutHelper &layout = timelineWidget.layoutHelper;
  layout.begin_dragging_track(mousePoint);

  // Raise all the header widgets so they float above the widgets not
  // being dragged
  raise_recursive(layout.get_dragging_track_iter());
  
  // Set the cursor to a hand
  REQUIRE(gdkWindow);
  gdkWindow->set_cursor(Gdk::Cursor(Gdk::FLEUR));
}

void
TimelineHeaderContainer::end_drag(bool apply)
{
  TimelineLayoutHelper &layout = timelineWidget.layoutHelper;
   
  // Has the user been dragging?
  if(layout.is_dragging_track())
    layout.end_dragging_track(apply);
  
  // End the scroll slide
  end_scroll_slide();
    
  // Reset the arrow as a cursor
  REQUIRE(gdkWindow);
  gdkWindow->set_cursor(Gdk::Cursor(Gdk::LEFT_PTR));
}

void
TimelineHeaderContainer::raise_recursive(
  TimelineLayoutHelper::TrackTree::iterator_base node)
{
  TimelineLayoutHelper::TrackTree::pre_order_iterator iter;
  
  const TimelineLayoutHelper::TrackTree &layout_tree =
    timelineWidget.layoutHelper.get_layout_tree();
    
  shared_ptr<timeline::Track> timeline_track =
    lookup_timeline_track(*node);
  REQUIRE(timeline_track);

  Glib::RefPtr<Gdk::Window> window =
    timeline_track->get_header_widget().get_window();
  ENSURE(window); // Something strange has happened if there was no
                  // window
  window->raise();
  
  for(iter = layout_tree.begin(node);
    iter != layout_tree.end(node);
    iter++)
    {
      raise_recursive(iter);
    }
}

void
TimelineHeaderContainer::begin_scroll_slide(int scroll_slide_rate)
{
  scrollSlideRate = scroll_slide_rate;
  if(!scrollSlideEvent.connected())
    scrollSlideEvent = Glib::signal_timeout().connect(sigc::mem_fun(
      this, &TimelineHeaderContainer::on_scroll_slide_timer),
      ScrollSlideEventInterval);
}

void
TimelineHeaderContainer::end_scroll_slide()
{
  scrollSlideRate = 0;
  if(scrollSlideEvent.connected())
    scrollSlideEvent.disconnect();
}

}   // namespace timeline
}   // namespace widgets
}   // namespace gui