source: ps/trunk/source/gui/ObjectTypes/CSlider.cpp

/* Copyright (C) 2022 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. 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.
 *
 * 0 A.D. 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 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "precompiled.h"

#include "CSlider.h"

#include "gui/CGUI.h"
#include "maths/MathUtil.h"

const CStr CSlider::EventNameValueChange = "ValueChange";

CSlider::CSlider(CGUI& pGUI)
    : IGUIObject(pGUI),
      IGUIButtonBehavior(*static_cast<IGUIObject*>(this)),
      m_ButtonSide(this, "button_width"),
      m_MaxValue(this, "max_value"),
      m_MinValue(this, "min_value"),
      m_Sprite(this, "sprite"),
      m_SpriteDisabled(this, "sprite_disabled"),
      m_SpriteBar(this, "sprite_bar"),
      m_SpriteBarDisabled(this, "sprite_bar_disabled"),
      m_Value(this, "value")
{
    m_Value.Set(Clamp<float>(m_Value, m_MinValue, m_MaxValue), false);
}

CSlider::~CSlider()
{
}

void CSlider::ResetStates()
{
    IGUIObject::ResetStates();
    IGUIButtonBehavior::ResetStates();
}

float CSlider::GetSliderRatio() const
{
    return (m_MaxValue - m_MinValue) / (m_CachedActualSize.GetWidth() - m_ButtonSide);
}

void CSlider::IncrementallyChangeValue(const float difference)
{
    m_Value.Set(Clamp<float>(m_Value + difference, m_MinValue, m_MaxValue), true);
    UpdateValue();
}

void CSlider::HandleMessage(SGUIMessage& Message)
{
    IGUIObject::HandleMessage(Message);
    IGUIButtonBehavior::HandleMessage(Message);

    switch (Message.type)
    {
    /*
    case GUIM_SETTINGS_UPDATED:
    {
        m_Value.Set(Clamp<float>(m_Value, m_MinValue, m_MaxValue), true);
        break;
    }
    */
    case GUIM_MOUSE_WHEEL_DOWN:
    {
        if (m_Pressed)
            break;
        IncrementallyChangeValue(-0.01f);
        break;
    }
    case GUIM_MOUSE_WHEEL_UP:
    {
        if (m_Pressed)
            break;
        IncrementallyChangeValue(0.01f);
        break;
    }
    case GUIM_MOUSE_PRESS_LEFT:
        FALLTHROUGH;
    case GUIM_MOUSE_MOTION:
    {
        if (m_Pressed)
        {
            m_Mouse = m_pGUI.GetMousePos();
            IncrementallyChangeValue((m_Mouse.X - GetButtonRect().CenterPoint().X) * GetSliderRatio());
        }
        break;
    }
    default:
        break;
    }
}

void CSlider::Draw(CCanvas2D& canvas)
{
    CRect sliderLine(m_CachedActualSize);
    sliderLine.left += m_ButtonSide / 2.0f;
    sliderLine.right -= m_ButtonSide / 2.0f;
    m_pGUI.DrawSprite(IsEnabled() ? m_SpriteBar : m_SpriteBarDisabled, canvas, sliderLine);
    m_pGUI.DrawSprite(IsEnabled() ? m_Sprite : m_SpriteDisabled, canvas, GetButtonRect());
}

void CSlider::UpdateValue()
{
    ScriptEvent(EventNameValueChange);
}

CRect CSlider::GetButtonRect() const
{
    // Even if the value is incorrect it doesn't make sense to draw it outside
    // of the element bounds. Because that value might be set intentionally in the
    // config for debug purposes.
    const float value = Clamp<float>(m_Value, m_MinValue, m_MaxValue);
    float ratio = m_MaxValue > m_MinValue ? (value - m_MinValue) / (m_MaxValue - m_MinValue) : 0.0f;
    float x = m_CachedActualSize.left + ratio * (m_CachedActualSize.GetWidth() - m_ButtonSide);
    float y = m_CachedActualSize.top + (m_CachedActualSize.GetHeight() - m_ButtonSide) / 2.0;
    return CRect(x, y, x + m_ButtonSide, y + m_ButtonSide);
}