//
// Urho3D Engine
// Copyright (c) 2008-2011 Lasse Öörni
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//

#include "Precompiled.h"
#include "Context.h"
#include "InputEvents.h"
#include "Log.h"
#include "Slider.h"
#include "UIEvents.h"

#include "DebugNew.h"

OBJECTTYPESTATIC(Slider);

Slider::Slider(Context* context) :
    BorderImage(context),
    orientation_(O_HORIZONTAL),
    range_(1.0f),
    value_(0.0f),
    dragSlider_(false)
{
    active_ = true;
    knob_ = new BorderImage(context_);
    AddChild(knob_);
    
    UpdateSlider();
}

Slider::~Slider()
{
}

void Slider::RegisterObject(Context* context)
{
    context->RegisterFactory<Slider>();
}

void Slider::SetStyle(const XMLElement& element)
{
    BorderImage::SetStyle(element);
    
    if (element.HasChildElement("orientation"))
    {
        String orientation = element.GetChildElement("orientation").GetStringLower("value");
        if ((orientation == "horizontal") || (orientation == "h"))
            SetOrientation(O_HORIZONTAL);
        if ((orientation == "vertical") || (orientation == "v"))
            SetOrientation(O_VERTICAL);
    }
    if (element.HasChildElement("range"))
    {
        XMLElement rangeElem = element.GetChildElement("range");
        SetRange(rangeElem.GetFloat("max"));
        SetValue(rangeElem.GetFloat("value"));
    }
    
    XMLElement knobElem = element.GetChildElement("knob");
    if (knobElem)
        knob_->SetStyle(knobElem);
}

void Slider::Update(float timeStep)
{
    if (dragSlider_)
        hovering_ = true;
    
    // Propagate hover and selection effect to the slider knob
    knob_->SetHovering(hovering_);
    knob_->SetSelected(selected_);
}

void Slider::OnHover(const IntVector2& position, const IntVector2& screenPosition, int buttons, int qualifiers, Cursor* cursor)
{
    // Show hover effect if inside the slider knob
    hovering_ = knob_->IsInside(screenPosition, true);
}

void Slider::OnDragStart(const IntVector2& position, const IntVector2& screenPosition, int buttons, int qualifiers, Cursor* cursor)
{
    dragStartCursor_ = position;
    dragStartPosition_ = knob_->GetPosition();
    dragSlider_ = knob_->IsInside(screenPosition, true);
}

void Slider::OnDragMove(const IntVector2& position, const IntVector2& screenPosition, int buttons, int qualifiers, Cursor* cursor)
{
    if (!dragSlider_)
        return;
    
    float newValue = value_;
    IntVector2 delta = position - dragStartCursor_;
    
    if (orientation_ == O_HORIZONTAL)
    {
        int newX = Clamp(dragStartPosition_.x_ + delta.x_, 0, GetWidth() - knob_->GetWidth());
        knob_->SetPosition(newX, dragStartPosition_.y_);
        newValue = Clamp((float)newX * (range_ + 1.0f) / (float)GetWidth(), 0.0f, range_);
    }
    else
    {
        int newY = Clamp(dragStartPosition_.y_ + delta.y_, 0, GetHeight() - knob_->GetHeight());
        knob_->SetPosition(dragStartPosition_.x_, newY);
        newValue = Clamp((float)newY * (range_ + 1.0f) / (float)GetHeight(), 0.0f, range_);
    }
    
    SetValue(newValue);
}

void Slider::OnDragEnd(const IntVector2& position, const IntVector2& screenPosition, Cursor* cursor)
{
    dragSlider_ = false;
}

void Slider::OnResize()
{
    UpdateSlider();
}

void Slider::SetOrientation(Orientation type)
{
    orientation_ = type;
    UpdateSlider();
}

void Slider::SetRange(float range)
{
    range = Max(range, 0.0f);
    if (range != range_)
    {
        range_ = range;
        UpdateSlider();
    }
}

void Slider::SetValue(float value)
{
    value = Clamp(value, 0.0f, range_);
    if (value != value_)
    {
        value_ = value;
        UpdateSlider();
        
        using namespace SliderChanged;
        
        VariantMap eventData;
        eventData[P_ELEMENT] = (void*)this;
        eventData[P_VALUE] = value_;
        SendEvent(E_SLIDERCHANGED, eventData);
    }
}

void Slider::ChangeValue(float delta)
{
    SetValue(value_ + delta);
}

void Slider::UpdateSlider()
{
    if (orientation_ == O_HORIZONTAL)
    {
        float width = (float)GetWidth();
        if (width < M_EPSILON)
            return;
        float sliderLength = width / (range_ + 1.0f);
        float sliderPos = width * value_ / (range_ + 1.0f);
        knob_->SetSize((int)sliderLength, GetHeight());
        knob_->SetPosition(Clamp((int)(sliderPos + 0.5f), 0, GetWidth() - knob_->GetWidth()), 0);
    }
    else
    {
        float height = (float)GetHeight();
        if (height < M_EPSILON)
            return;
        float sliderLength = height / (range_ + 1.0f);
        float sliderPos = height * value_ / (range_ + 1.0f);
        knob_->SetSize(GetWidth(), (int)sliderLength);
        knob_->SetPosition(0, Clamp((int)(sliderPos + 0.5f), 0, GetHeight() - knob_->GetHeight()));
    }
}