/*
  WindowLocator  -  manage all top level windows

  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.

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


/** @file window-locator.cpp
 ** Implementation details of management and access to all top level windows and docking panels.
 ** @see ui-manager.hpp
 */


#include "stage/ctrl/global-ctx.hpp"
#include "stage/ctrl/panel-locator.hpp"
#include "stage/ctrl/window-locator.hpp"
#include "stage/interact/elem-access-dir.hpp"
#include "stage/workspace/workspace-window.hpp"
#include "lib/util.hpp"

#include <memory>
#include <list>

using util::cStr;
using util::isnil;
using std::list;


namespace stage {
namespace ctrl {
  
  using workspace::WorkspaceWindow;
  
  
  
  PanelLocator::PanelLocator (WindowList& all_top_level_wndows)
    : windowList_{all_top_level_wndows}
    { }
  
  
  
  WindowLocator::WindowLocator (GlobalCtx& globals)
    : globalCtx_{globals}
    , windowList_{}
    , panelLoc_{windowList_}
    , elementAccess_{*this, panelLoc_}
    { }
  
  WindowLocator::~WindowLocator () { }
  
  
  
  void
  WindowLocator::newWindow ()
  { 
    PWindow window (new WorkspaceWindow{globalCtx_.uiManager_});
    REQUIRE(window);
    
    window->signal_delete_event().connect(sigc::mem_fun(
      this, &WindowLocator::on_window_closed));
    
    windowList_.push_back(window);
    
    window->show();
  
    updateCloseWindowInMenus();
  }
  
  
  /** close (and thus destroy) the current active window.
   * @note closing the last window terminates the application
   * @warning when no window is currently active,
   *          the fist one in list will be killed
   */
  void
  WindowLocator::closeWindow()
    {
      findActiveWindow().hide();
    }
  
  
  /** find and retrieve a WorkspaceWindow (top-level window)
   *  marked as 'active' by GTK.
   * @return the first matching window, or the first window
   *         in list, when no window is marked active
   * @note never `NULL`, but assuming this function is only ever
   *       called when there is at least one Lumiera window.
   */
  WorkspaceWindow&
  WindowLocator::findActiveWindow()
  {
    REQUIRE (not isnil (windowList_));
    
    for (auto pwin : windowList_)
      if (pwin->is_active())
        return *pwin;
    
    // use the first window in list when none is active
    return *windowList_.front();
  }
  
  
  /** similar to #findActiveWindow(), for the 'has_focus' property
   * @note likewise we return the first window in list, in case no window
   *       has keyboard focus. This may very well be the case.
   */
  WorkspaceWindow&
  WindowLocator::findFocusWindow()
  {
    REQUIRE (not isnil (windowList_));
    
    for (auto pwin : windowList_)
      if (pwin->has_focus())
        return *pwin;
    
    // use the first window in list when none has focus
    return *windowList_.front();
  }
  
  
  bool
  WindowLocator::on_window_closed (GdkEventAny* event)
  {
    REQUIRE(event);
    REQUIRE(event->window);
    
    list<PWindow>::iterator iterator{windowList_.begin()};
    
    while (iterator != windowList_.end())
      {
        PWindow workspace_window(*iterator);
        REQUIRE(workspace_window);
        
        Glib::RefPtr<Gdk::Window> window = workspace_window->get_window();
        REQUIRE(window);
        if (window->gobj() == event->window)
          {
            // This window has been closed
            iterator = windowList_.erase(iterator);
          }
        else
          iterator++;
      }
    
    if (windowList_.empty())
      // All windows have been closed - we should exit
      globalCtx_.uiManager_.terminateUI();
    
    updateCloseWindowInMenus();
    
    // Unless this is false, the window won't close
    return false;
  }
  
  
  void
  WindowLocator::updateCloseWindowInMenus()
  {
    globalCtx_.uiManager_.allowCloseWindow ( 1 < windowList_.size());
  }
  
  
  /**
   * @internal preliminary implementation of docking panel lookup and allocation.
   * @todo 8/2018 the actual implementation shall eventually be provided by the ViewLocator
   *       on a higher abstraction level, and configurable through the ViewSpec-DSL.
   *       For now we use a braindead iterate-through-all-windows approach.
   */
  panel::Panel&
  PanelLocator::preliminary_impl_PanelLookup (int typeID)
  {
    REQUIRE (not isnil(windowList_));
    
    for (auto window : windowList_)
      if (window->getPanelManager().hasPanel (typeID))
        return window->getPanelManager().showPanel (typeID);
    
    // no instance of the desired panel type exists yet...
    for (auto window : windowList_)
      if (window->is_active())
        return window->getPanelManager().showPanel (typeID);
    
    // use the first window in list when none is active
    return windowList_.front()->getPanelManager().showPanel (typeID);
  }

  
  
  
  
}}// namespace stage::ctrl
