/***********************************************************************
* scrollview.cpp - Shows client widgets in a scroll area               *
*                                                                      *
* This file is part of the FINAL CUT widget toolkit                    *
*                                                                      *
* Copyright 2017-2021 Markus Gans                                      *
*                                                                      *
* FINAL CUT is free software; you can redistribute it and/or modify    *
* it under the terms of the GNU Lesser General Public License as       *
* published by the Free Software Foundation; either version 3 of       *
* the License, or (at your option) any later version.                  *
*                                                                      *
* FINAL CUT 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 Lesser General Public License for more details.                  *
*                                                                      *
* You should have received a copy of the GNU Lesser General Public     *
* License along with this program.  If not, see                        *
* <http://www.gnu.org/licenses/>.                                      *
***********************************************************************/

#include <final/final.h>

using finalcut::FPoint;
using finalcut::FSize;


//----------------------------------------------------------------------
// class Scrollview
//----------------------------------------------------------------------

class Scrollview final : public finalcut::FScrollView
{
  public:
    // Constructor
    explicit Scrollview (finalcut::FWidget* = nullptr);

    // Disable copy constructor
    Scrollview (const Scrollview&) = delete;

    // Destructor
    ~Scrollview() override = default;

    // Disable copy assignment operator (=)
    Scrollview& operator = (const Scrollview&) = delete;

    // Mutator
    void setScrollSize (const FSize&) override;

  private:
    // Method
    void draw() override;

    // Callback methods
    void cb_goEast();
    void cb_goSouth();
    void cb_goWest();
    void cb_goNorth();

    // Data members
    finalcut::UniChar pointer_right{finalcut::UniChar::BlackRightPointingPointer};
    finalcut::UniChar pointer_down{finalcut::UniChar::BlackDownPointingTriangle};
    finalcut::UniChar pointer_left{finalcut::UniChar::BlackLeftPointingPointer};
    finalcut::UniChar pointer_up{finalcut::UniChar::BlackUpPointingTriangle};
    finalcut::FButton go_east{pointer_right, this};
    finalcut::FButton go_south{pointer_down, this};
    finalcut::FButton go_west{pointer_left, this};
    finalcut::FButton go_north{pointer_up, this};
};

//----------------------------------------------------------------------
Scrollview::Scrollview (finalcut::FWidget* parent)
  : finalcut::FScrollView{parent}
{
  // Sets the navigation button geometry
  go_east.setGeometry (FPoint{1, 1}, FSize{5, 1});
  go_south.setGeometry ( FPoint{int(getScrollWidth()) - 5, 1}
                       , FSize{5, 1} );
  go_west.setGeometry ( FPoint{ int(getScrollWidth()) - 5
                              , int(getScrollHeight()) - 2 }
                      , FSize{5, 1} );
  go_north.setGeometry ( FPoint{1, int(getScrollHeight()) - 2}
                       , FSize{5, 1} );

  // Add scroll function callbacks to the buttons
  go_east.addCallback
  (
    "clicked",
    this, &Scrollview::cb_goEast
  );

  go_south.addCallback
  (
    "clicked",
    this, &Scrollview::cb_goSouth
  );

  go_west.addCallback
  (
    "clicked",
    this, &Scrollview::cb_goWest
  );

  go_north.addCallback
  (
    "clicked",
    this, &Scrollview::cb_goNorth
  );
}

//----------------------------------------------------------------------
void Scrollview::setScrollSize (const FSize& size)
{
  FScrollView::setScrollSize (size);
  const auto width = int(size.getWidth());
  const auto height = int(size.getHeight());
  go_south.setPos (FPoint{width - 5, 1});
  go_west.setPos (FPoint{width - 5, height - 1});
  go_north.setPos (FPoint{1, height - 1});
}

//----------------------------------------------------------------------
void Scrollview::draw()
{
  if ( finalcut::FTerm::isMonochron() )
    setReverse(true);

  const auto& wc = getColorTheme();
  setColor (wc->label_inactive_fg, wc->dialog_bg);
  clearArea();

  for (auto y{0}; y < int(getScrollHeight()); y++)
  {
    print() << FPoint{1, 1 + y};

    for (auto x{0}; x < int(getScrollWidth()); x++)
      print (32 + ((x + y) % 0x5f));
  }

  if ( finalcut::FTerm::isMonochron() )
    setReverse(false);

  FScrollView::draw();
}

//----------------------------------------------------------------------
void Scrollview::cb_goEast()
{
  scrollToX (int(getScrollWidth() - getViewportWidth()) + 1);
  go_south.setFocus();
  go_east.redraw();
  go_south.redraw();
}

//----------------------------------------------------------------------
void Scrollview::cb_goSouth()
{
  scrollToY (int(getScrollHeight() - getViewportHeight()) + 1);
  go_west.setFocus();
  go_south.redraw();
  go_west.redraw();
}

//----------------------------------------------------------------------
void Scrollview::cb_goWest()
{
  scrollToX (1);
  go_north.setFocus();
  go_west.redraw();
  go_north.redraw();
}

//----------------------------------------------------------------------
void Scrollview::cb_goNorth()
{
  scrollToY (1);
  go_east.setFocus();
  go_north.redraw();
  go_east.redraw();
}


//----------------------------------------------------------------------
// class Scrollviewdemo
//----------------------------------------------------------------------

class Scrollviewdemo final : public finalcut::FDialog
{
  public:
    // Constructor
    explicit Scrollviewdemo (finalcut::FWidget* = nullptr);

    // Destructor
    ~Scrollviewdemo() override = default;

    // Event handler
    void onClose (finalcut::FCloseEvent*) override;

    // Callback method
    void cb_quit();

    // Data members
    Scrollview sview{this};
    finalcut::FButton quit_btn{"&Quit", this};
    finalcut::FLabel label{this};
};


//----------------------------------------------------------------------
Scrollviewdemo::Scrollviewdemo (finalcut::FWidget* parent)
  : finalcut::FDialog{parent}
{
  FDialog::setGeometry (FPoint{16, 3}, FSize{50, 19});
  FDialog::setText ("Scrolling viewport example");

  // The scrolling viewport widget
  sview.setGeometry(FPoint{3, 2}, FSize{44, 12});
  sview.setScrollSize(FSize{188, 124});

  // Quit button
  quit_btn.setGeometry(FPoint{37, 15}, FSize{10, 1});

  // Add function callback
  quit_btn.addCallback
  (
    "clicked",
    this,
    &Scrollviewdemo::cb_quit
  );

  // Text label
  label.setGeometry(FPoint{2, 1}, FSize{46, 1});
  label.setEmphasis();
  label << L"Use scrollbars to change the viewport position";
}

//----------------------------------------------------------------------
void Scrollviewdemo::cb_quit()
{
  close();
}

//----------------------------------------------------------------------
void Scrollviewdemo::onClose (finalcut::FCloseEvent* ev)
{
  finalcut::FApplication::closeConfirmationDialog (this, ev);
}


//----------------------------------------------------------------------
//                               main part
//----------------------------------------------------------------------
int main (int argc, char* argv[])
{
  // Create the application object
  finalcut::FApplication app{argc, argv};

  // Create a simple dialog box
  Scrollviewdemo svdemo{&app};

  // Set dialog main_dlg as main widget
  finalcut::FWidget::setMainWidget(&svdemo);

  // Show and start the application
  svdemo.show();
  return app.exec();
}