source: trunk/src/gui/gui_environment.cc @ 541

// Copyright (C) 2012-2015 ChaosForge Ltd
// http://chaosforge.org/
//
// This file is part of Nova libraries. 
// For conditions of distribution and use, see copying.txt file in root folder.

#include "nv/gui/gui_environment.hh"

#include "nv/gui/gui_renderer.hh"

        /*

        TODO: parse a lua stylesheet as per Trac wiki

        IDEA: Store everything in unordered_maps, with lua_value's?

        A lua_value is a variant stores strings as const char* that deletes them on destructor?
        Question is that there might not be much gained on speed anyway, due to Lua's speed.
        Special function field allows delayed per parse execution?

        */


nv::gui::environment::environment( renderer* r )
        : m_renderer( r )
{
        r->set_environment( this );
        m_screen   = create_element( handle(), m_renderer->get_area() );
}

void nv::gui::environment::load_style( const string_view& filename )
{
        m_renderer->load_style( filename );
}

nv::gui::handle nv::gui::environment::create_element( const rectangle& r )
{
        return create_element( m_screen, r );
}

nv::gui::handle nv::gui::environment::create_element( handle parent, const rectangle& r )
{
        if ( parent.is_nil() ) parent = m_screen;

        handle result  = m_elements.create();
        element* e     = m_elements.get( result );
        rectangle ar   = r;
        rectangle full = m_renderer->get_area();

        if ( ar.ul.x < 0 ) { ar.ul.x += full.lr.x; ar.lr.x += full.lr.x; }
        if ( ar.ul.y < 0 ) { ar.ul.y += full.lr.y; ar.lr.y += full.lr.y; }

        e->m_child_count = 0;
        e->m_flags[ENABLED] = true;
        e->m_flags[VISIBLE] = true;
        e->m_flags[DIRTY]   = true;
        e->m_render_data    = nullptr;
        e->m_absolute = ar;
        e->m_relative = ar;

        if ( !parent.is_nil() ) // screen creation
                add_child( parent, result );

        return result;
}

void nv::gui::environment::destroy_element( handle e )
{
        element* dead_element = m_elements.get( e );
        if ( dead_element == nullptr ) return;
        destroy_children( e );
        remove_child( dead_element->m_parent, e );

        delete dead_element->m_render_data; 
        dead_element->m_render_data = nullptr;
        dead_element->m_parent = handle();

        m_elements.destroy( e );
}

void nv::gui::environment::update( handle e, uint32 elapsed )
{
        element* el = m_elements.get( e );
        if ( !el ) return;
        //      el->on_update( elapsed );
        if ( el->m_flags[ENABLED] )
        {
                bool hover     = el->m_flags[HOVER];
                bool new_hover = el->m_absolute.contains( m_mouse_position );
                if ( hover != new_hover )
                {
                        el->m_flags[HOVER] = new_hover;
                        // gain lose hover event
                        m_renderer->on_hover_change( el );
                }
        }

        if ( el->m_flags[VISIBLE] )
        {
                for ( handle i : el->m_children )
                {
                        update( i, elapsed );
                }
        }
        if ( el->m_flags[DIRTY] || el->m_render_data == nullptr )
        {
                m_renderer->redraw( el, elapsed );
                el->m_flags[DIRTY] = false;
        }
}

void nv::gui::environment::draw( handle e )
{
        element* el = m_elements.get( e );
        if ( !el ) return;
        if ( el->m_flags[VISIBLE] )
        {
//              el->on_draw();
                m_renderer->draw( el );
                for ( handle i : el->m_children )
                {
                        draw(i);
                }
        }
}

void nv::gui::environment::update()
{
        update( m_screen, 0 );
}

void nv::gui::environment::draw()
{
        draw( m_screen );
        m_renderer->draw();
}

void nv::gui::environment::add_child( handle child )
{
        add_child( m_screen, child );
}

void nv::gui::environment::add_child( handle parent, handle child )
{
        element* e = m_elements.get( child );
        element* p = m_elements.get( parent );
        if ( e && p )
        {
                remove_child( e->m_parent, child );
                e->m_parent = parent;
                p->m_children.push_back( child );
                p->m_child_count++;
        }
}

void nv::gui::environment::destroy_children( handle e )
{
        element* parent = m_elements.get(e);
        if ( parent )
        {
                while ( !parent->m_children.empty() )
                {
                        destroy_element( parent->m_children.back() );
                }
        }
}


nv::gui::environment::~environment()
{
        destroy_children( handle() );
        delete m_renderer;
}

bool nv::gui::environment::process_io_event( const io_event& ev )
{
        switch ( ev.type )
        {
//      case EV_KEY          :
        case EV_MOUSE_BUTTON :
                if ( ev.mbutton.pressed && ev.mbutton.button == MOUSE_LEFT )
                { 
                        handle h = get_element( position( ev.mbutton.x, ev.mbutton.y ) );
                        element* e = m_elements.get( h );
                        if (e)
                        if ( e->m_on_click ) e->m_on_click();

                        set_selected( h );
                        return true;
                }
                return false;
        case EV_MOUSE_MOVE:
                m_mouse_position = position( ev.mmove.x, ev.mmove.y );
                return false;
//      case EV_MOUSE_WHEEL  :
        default:
                break;
        }
        return false;
}

nv::string_view nv::gui::environment::get_string( shash64 h )
{
        return m_strings[h];
}

bool nv::gui::environment::set_selected( handle e )
{
        if ( e != m_selected )
        {
                element* eold = m_elements.get( m_selected );
                element* el   = m_elements.get( e );
                if ( eold )
                {
                        eold->m_flags[SELECTED] = false;
                        m_renderer->on_select_change( eold );
                }
                if ( el )
                {
                        el->m_flags[SELECTED] = true;
                        m_renderer->on_select_change( el );
                }
                m_selected = e;
                return true;
        }
        return false;
}

bool nv::gui::environment::process_io_event( handle e, const io_event& ev )
{
        element* el = m_elements.get( e );
        return el && el->m_parent.is_valid() ? process_io_event( el->m_parent, ev ) : false;
}

nv::gui::handle nv::gui::environment::get_element( const position& p )
{
        return get_deepest_child( m_screen, p );
}

nv::gui::handle nv::gui::environment::get_deepest_child( handle e, const position& p )
{
        element* el = m_elements.get(e);
        if ( !el && !el->m_flags[VISIBLE] ) return handle();

        handle result;
        auto it = el->m_children.rbegin();

        while ( it != el->m_children.rend() )
        {
                result = get_deepest_child( *it, p );
                if ( result.is_valid() ) return result;
                ++it;
        }

        if ( el->m_absolute.contains(p) ) return e;
        return handle();
}

void nv::gui::environment::move_to_top( handle child )
{
        element* e      = m_elements.get( child );
        element* parent = m_elements.get( e->m_parent );
        if ( e && parent )
        {
                auto it = find( parent->m_children.begin(), parent->m_children.end(), child );
                if ( it != parent->m_children.end() )
                {
                        parent->m_children.erase( it );
                        parent->m_children.push_back( child );
                        parent->m_flags[DIRTY] = true;
                }       
        }
}

void nv::gui::environment::set_relative( handle e, const rectangle& r )
{
        element* el = m_elements.get(e);
        if ( el )
        {
                el->m_flags[DIRTY] = true;
                el->m_relative     = r;
                recalculate_absolute( e );
        }
}

void nv::gui::environment::set_relative( handle e, const position& p )
{
        element* el = m_elements.get(e);
        if ( el )
        {
                set_relative( e, rectangle( p, p + el->m_relative.get_size() ) );
        }
}

void nv::gui::environment::recalculate_absolute( handle e )
{
        element* el = m_elements.get(e);
        rectangle pabsolute = m_elements.get( el->m_parent )->m_absolute;
        el->m_absolute = el->m_relative + pabsolute.ul;

        for ( handle o : el->m_children )
        {
                recalculate_absolute( o );
        }
}

void nv::gui::environment::set_class( handle e, const string_view& text )
{
        element* ep = m_elements.get(e);
        if ( ep != nullptr )
        {
                ep->m_class        = m_strings.insert( text );
                ep->m_flags[DIRTY] = true;
                m_renderer->on_style_change( ep );
        }
}

void nv::gui::environment::set_on_click( handle e, const function< void() >& on_click )
{
        element* ep = m_elements.get( e );
        if ( ep != nullptr )
        {
                ep->m_on_click = on_click;
        }
}

void nv::gui::environment::set_text( handle e, const string_twine& text )
{
        element* ep = m_elements.get(e);
        if ( ep != nullptr )
        {
                // TODO : implement twine == operator
                ep->m_text.assign( text );
                ep->m_flags[DIRTY] = true;
        }
}

void nv::gui::environment::remove_child( handle parent, handle child )
{
        element* p = m_elements.get( parent );
        if ( p )
        {
                auto it = find( p->m_children.begin(), p->m_children.end(), child );
                if ( it != p->m_children.end() )
                {
                        element* e = m_elements.get( *it );
                        e->m_parent = handle();
                        p->m_children.erase( it );
                }
        }
}