AdventuresInLestoria/Crawler/ScrollableWindowComponent.h

#pragma region License
/*
License (OLC-3)
~~~~~~~~~~~~~~~

Copyright 2018 - 2023 OneLoneCoder.com

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

1. Redistributions or derivations of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.

2. Redistributions or derivative works in binary form must reproduce the above
copyright notice. This list of conditions and the following	disclaimer must be
reproduced in the documentation and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors may
be used to endorse or promote products derived from this software without specific
prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS	"AS IS" AND ANY
EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
SHALL THE COPYRIGHT	HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL,	SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT	(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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SUCH DAMAGE.

Portions of this software are copyright © 2023 The FreeType
Project (www.freetype.org). Please see LICENSE_FT.txt for more information.
All rights reserved.
*/
#pragma endregion
#pragma once
#include "Menu.h"
#include "MenuComponent.h"
#include "MenuItemButton.h"
#include "Crawler.h"

typedef Attribute A;

class ScrollableWindowComponent:public MenuComponent{
protected:
    Renderable r;
    std::vector<MenuComponent*>components;
    MenuComponent*upButton=nullptr;
    MenuComponent*downButton=nullptr;
    geom2d::rect<float>bounds; //It's for the scrollbar.
    float scrollBarHeight=0;
    float scrollBarTop=0;
    bool scrollBarSelected=false;
    float scrollBarHoverTime=0;
protected:
    inline bool OnScreen(MenuComponent*component){
        return geom2d::overlaps(geom2d::rect<float>{{},rect.size},geom2d::rect<float>{component->rect.pos+V(A::SCROLL_OFFSET)+vf2d{2,2},component->rect.size-vf2d{2,2}});
    }
public:
    inline ScrollableWindowComponent(MenuType parent,geom2d::rect<float>rect,ComponentAttr attributes=ComponentAttr::BACKGROUND|ComponentAttr::OUTLINE)
        :MenuComponent(parent,rect,"",[](MenuFuncData data){return true;},ButtonAttr::UNSELECTABLE|ButtonAttr::UNSELECTABLE_VIA_KEYBOARD){
        background=attributes&ComponentAttr::BACKGROUND;
        border=attributes&ComponentAttr::OUTLINE;
        r.Create(uint32_t(rect.size.x),uint32_t(rect.size.y));
    }
protected:
    virtual inline void AfterCreate()override{
        upButton=NEW MenuComponent(parentMenu,{rect.pos+vf2d{rect.size.x-12,0},{12,12}},"^",[&](MenuFuncData dat){V(A::SCROLL_OFFSET).y+="ThemeGlobal.MenuButtonScrollSpeed"_I;return true;},ButtonAttr::UNSELECTABLE_VIA_KEYBOARD);
        downButton=NEW MenuComponent(parentMenu,{rect.pos+rect.size-vf2d{12,12},{12,12}},"v",[&](MenuFuncData dat){V(A::SCROLL_OFFSET).y-="ThemeGlobal.MenuButtonScrollSpeed"_I;return true;},ButtonAttr::UNSELECTABLE_VIA_KEYBOARD);
        //Let's use the internal name of this component to add unique names for sub-components.
        Menu::menus[parentMenu]->AddComponent(name+upButton->rect.pos.str()+"_"+upButton->rect.size.str(),upButton); 
        Menu::menus[parentMenu]->AddComponent(name+downButton->rect.pos.str()+"_"+downButton->rect.size.str(),downButton);
    }
protected:
    virtual inline void Update(Crawler*game)override{
	    MenuComponent::Update(game);

        vf2d windowAbsPos=Menu::menus[parentMenu]->pos+rect.pos;

        bool mouseOverScrollbar=geom2d::overlaps(geom2d::rect<float>(windowAbsPos+vf2d{rect.size.x-12,scrollBarTop+12},{12,scrollBarHeight}),game->GetMousePos());

        if(mouseOverScrollbar||scrollBarSelected){
            scrollBarHoverTime=std::min(scrollBarHoverTime+game->GetElapsedTime(),"ThemeGlobal.HighlightTime"_F);
            if(game->GetMouse(0).bPressed){
                scrollBarSelected=true;
            }
            if(game->GetMouse(0).bReleased){
                scrollBarSelected=false;
            }
            if(scrollBarSelected){
                float spaceBetweenTopAndBottomArrows=rect.size.y-24;
                float viewHeight=rect.size.y;


                float totalContentHeight=bounds.size.y;
                if(totalContentHeight==0)totalContentHeight=1;
                float scrollBarScale=(spaceBetweenTopAndBottomArrows/totalContentHeight);
                //The scroll amount moves centered on the position the mouse is at.
                float newScrollbarTop=(game->GetMousePos().y-windowAbsPos.y-12)-scrollBarHeight/2;
                V(A::SCROLL_OFFSET).y=(-newScrollbarTop+1)/scrollBarScale; //Derived formula from the draw code.
            }
        }else{
            scrollBarHoverTime=std::max(scrollBarHoverTime-game->GetElapsedTime(),0.f);
        }

        if(game->GetMouseWheel()!=0){
            if(game->GetMouseWheel()>0){
                V(A::SCROLL_OFFSET).y+="ThemeGlobal.MenuScrollWheelSpeed"_I;
            }else{
                V(A::SCROLL_OFFSET).y-="ThemeGlobal.MenuScrollWheelSpeed"_I;
            }
        }

        if(bounds.size.y-rect.size.y>0){
            V(A::SCROLL_OFFSET).y=std::clamp(V(A::SCROLL_OFFSET).y,-(bounds.size.y-rect.size.y),0.f);
        }else{
            V(A::SCROLL_OFFSET).y=0;
        }

        for(MenuComponent*component:components){
            component->disabled=!OnScreen(component);
            component->_Update(game);
        }

        upButton->disabled=false;
        downButton->disabled=false;
        if(geom2d::contains(rect,bounds)){//This means we have no reason to show a scrollbar.
            upButton->disabled=true;
            downButton->disabled=true;
        }
    }
    virtual inline void Draw(Crawler*game,vf2d parentPos)override{
	    MenuComponent::Draw(game,parentPos);
        Sprite*prevDrawTarget=game->GetDrawTarget();
        game->SetDrawTarget(r.Sprite());
        game->Clear(BLANK);
        for(MenuComponent*component:components){
            component->_Draw(game,V(A::SCROLL_OFFSET));
        }
        game->SetDrawTarget(prevDrawTarget);
        game->DrawSprite(parentPos+rect.pos,r.Sprite());
    }

    inline void DrawScrollbar(Crawler*game,vf2d parentPos,bool focused){
        float spaceBetweenTopAndBottomArrows=rect.size.y-24;
        float viewHeight=rect.size.y;
        float totalContentHeight=bounds.size.y;
        if(totalContentHeight==0)totalContentHeight=1;
        float scrollBarScale=(spaceBetweenTopAndBottomArrows/totalContentHeight);
        scrollBarHeight=std::min(spaceBetweenTopAndBottomArrows,viewHeight*scrollBarScale-1);
        scrollBarTop=-V(A::SCROLL_OFFSET).y*scrollBarScale+1;

        float focusedWindowColorMult=(focused?1:"ThemeGlobal.MenuUnfocusedColorMult"_F);

        game->FillRectDecal(rect.pos+parentPos+vf2d{rect.size.x-11.75f,scrollBarTop+12},{12,scrollBarHeight},PixelLerp(Menu::GetCurrentTheme().GetButtonCol(),Menu::GetCurrentTheme().GetHighlightCol(),scrollBarHoverTime/"ThemeGlobal.HighlightTime"_F)*focusedWindowColorMult);
        game->DrawRectDecal(rect.pos+parentPos+vf2d{rect.size.x-11.75f,scrollBarTop+12},{12,scrollBarHeight},WHITE*focusedWindowColorMult);
    }

    virtual inline void DrawDecal(Crawler*game,vf2d parentPos,bool focused)override{
	    MenuComponent::DrawDecal(game,parentPos,focused);
        if(border){
            game->DrawRectDecal(rect.pos+Menu::menus[parentMenu]->pos,rect.size);
        }
        for(MenuComponent*component:components){
            component->_DrawDecal(game,rect.pos+Menu::menus[parentMenu]->pos+V(A::SCROLL_OFFSET),focused);
        }
        DrawScrollbar(game,Menu::menus[parentMenu]->pos,focused);
    }
    virtual bool GetHoverState(Crawler*game,MenuComponent*child)override{
		return geom2d::overlaps(geom2d::rect<float>{Menu::menus[parentMenu]->pos+rect.pos+child->rect.pos+V(A::SCROLL_OFFSET),child->rect.size},game->GetMousePos());
    }
    //Calculates the bounds of all components.
    geom2d::rect<float> inline CalculateBounds(){
        geom2d::rect<float>bounds;
        for(MenuComponent*component:components){
            if(component->rect.pos.x<bounds.pos.x){
                float sizeIncrease=bounds.pos.x-component->rect.pos.x;
                bounds.size.x+=sizeIncrease;
                bounds.pos.x=component->rect.pos.x;
            }
            if(component->rect.right().start.x>bounds.right().start.x){
                float sizeIncrease=component->rect.right().start.x-bounds.right().start.x;
                bounds.size.x+=sizeIncrease;
            }
            if(component->rect.pos.y<bounds.pos.y){
                float sizeIncrease=bounds.pos.y-component->rect.pos.y;
                bounds.size.y+=sizeIncrease;
                bounds.pos.y=component->rect.pos.y;
            }
            if(component->rect.bottom().start.y>bounds.bottom().start.y){
                float sizeIncrease=component->rect.bottom().start.y-bounds.bottom().start.y;
                bounds.size.y+=sizeIncrease;
            }
        }
        return bounds;
    }
public:
    void inline AddComponent(Menu*parentMenu,std::string key,MenuComponent*button){
        components.push_back(button);
        button->renderInMain=false; //Now we are in control!
        button->parentComponent=this;

        if(button->rect.pos.x<bounds.pos.x){
            float sizeIncrease=bounds.pos.x-button->rect.pos.x;
            bounds.size.x+=sizeIncrease;
            bounds.pos.x=button->rect.pos.x;
        }
        if(button->rect.right().start.x>bounds.right().start.x){
            float sizeIncrease=button->rect.right().start.x-bounds.right().start.x;
            bounds.size.x+=sizeIncrease;
        }
        if(button->rect.pos.y<bounds.pos.y){
            float sizeIncrease=bounds.pos.y-button->rect.pos.y;
            bounds.size.y+=sizeIncrease;
            bounds.pos.y=button->rect.pos.y;
        }
        if(button->rect.bottom().start.y>bounds.bottom().start.y){
            float sizeIncrease=button->rect.bottom().start.y-bounds.bottom().start.y;
            bounds.size.y+=sizeIncrease;
        }

        parentMenu->AddComponent(key,button);
    }
    virtual inline bool PointWithinParent(MenuComponent*child,vi2d drawPos)override{
        return geom2d::overlaps(geom2d::rect<float>{Menu::menus[parentMenu]->pos+rect.pos,rect.size},drawPos);
    }
    virtual inline bool HandleOutsideDisabledButtonSelection(MenuComponent*disabledButton)override{
        //Set the offset so the center is highlighted by this button.
        V(A::SCROLL_OFFSET).y=-(disabledButton->rect.pos.y-disabledButton->rect.size.y/2);
        V(A::SCROLL_OFFSET).y+=rect.size.y/2;
        return true;
    };
    virtual void Cleanup()override{}
    inline std::vector<MenuComponent*>&GetComponents(){
        return components;
    }
};