/*  Starshatter: The Open Source Project
    Copyright (c) 2021-2024, Starshatter: The Open Source Project Contributors
    Copyright (c) 2011-2012, Starshatter OpenSource Distribution Contributors
    Copyright (c) 1997-2006, Destroyer Studios LLC.

    AUTHOR:       John DiCamillo


    OVERVIEW
    ========
    ScrollWindow ActiveWindow class
*/

#include "ScrollWindow.h"
#include "Button.h"
#include "Bitmap.h"
#include "FormWindow.h"
#include "Video.h"
#include "Font.h"
#include "Keyboard.h"
#include "Mouse.h"
#include "Clock.h"

// +--------------------------------------------------------------------+

static int old_cursor;

// +--------------------------------------------------------------------+

ScrollWindow::ScrollWindow(ActiveWindow* p, int ax, int ay, int aw, int ah, DWORD aid, DWORD s, ActiveWindow* paw)
: ActiveWindow(p->GetScreen(), ax, ay, aw, ah, aid, s, paw)
{
    captured          = false;
    dragging          = false;
    selecting         = false;
    scrolling         = SCROLL_NONE;

    leading           = 0;
    scroll_bar        = SCROLL_AUTO;
    dragdrop          = false;
    scroll_count      = 0;
    line_count        = 0;
    page_count        = 0;
    page_size         = 1;
    top_index         = 0;
    line_height       = 0;
    mouse_x           = 0;
    mouse_y           = 0;

    smooth_scroll     = false;
    smooth_offset     = 0;

    track_length      = ah - 2*TRACK_START - THUMB_HEIGHT;
    thumb_pos         = TRACK_START;

    char buf[32];
    sprintf_s(buf, "ScrollWindow %d", id);
    desc = buf;
}

ScrollWindow::ScrollWindow(Screen* s, int ax, int ay, int aw, int ah, DWORD aid, DWORD s1, ActiveWindow* paw)
: ActiveWindow(s, ax, ay, aw, ah, aid, s1, paw)
{
    captured          = false;
    dragging          = false;
    selecting         = false;
    scrolling         = SCROLL_NONE;

    leading           = 0;
    scroll_bar        = SCROLL_AUTO;
    dragdrop          = false;
    scroll_count      = 0;
    line_count        = 0;
    page_count        = 0;
    page_size         = 1;
    top_index         = 0;
    line_height       = 0;
    mouse_x           = 0;
    mouse_y           = 0;

    smooth_scroll     = false;
    smooth_offset     = 0;

    track_length      = ah - 2*TRACK_START - THUMB_HEIGHT;
    thumb_pos         = TRACK_START;

    char buf[32];
    sprintf_s(buf, "ScrollWindow %d", id);
    desc = buf;
}

ScrollWindow::~ScrollWindow()
{ }

// +--------------------------------------------------------------------+

void
ScrollWindow::MoveTo(const Rect& r)
{
    ActiveWindow::MoveTo(r);

    track_length      = rect.h - 2*TRACK_START - THUMB_HEIGHT;
    thumb_pos         = TRACK_START;
}

// +--------------------------------------------------------------------+

void
ScrollWindow::Paint()
{
    if (transparent) {
        DrawTransparent();
    }

    else {
        ActiveWindow::Paint();
    }
}

// +--------------------------------------------------------------------+

void
ScrollWindow::Draw()
{
    int x = 0;
    int y = 0;
    int w = rect.w;
    int h = rect.h;

    if (w < 1 || h < 1 || !shown)
    return;

    ActiveWindow::Draw();

    if (line_height < 1)
    line_height = GetFont()->Height();
    page_size = h / (line_height + leading);

    Rect ctrl_rect(x,y,w,h);
    ctrl_rect.Deflate(BORDER_WIDTH, BORDER_WIDTH);

    if (IsScrollVisible()) {
        ctrl_rect.w -= SCROLL_TRACK;
    }

    DrawContent(ctrl_rect);
    DrawScrollBar();
}

// +--------------------------------------------------------------------+

void
ScrollWindow::DrawTransparent()
{
    int x = 0;
    int y = 0;
    int w = rect.w;
    int h = rect.h;

    if (w < 1 || h < 1 || !shown)
    return;

    if (line_height < 1)
    line_height = GetFont()->Height();
    page_size = h / (line_height + leading);

    Rect ctrl_rect(x,y,w,h);
    ctrl_rect.Deflate(BORDER_WIDTH, BORDER_WIDTH);

    if (IsScrollVisible()) {
        ctrl_rect.w -= SCROLL_TRACK;
    }

    DrawTransparentContent(ctrl_rect);
    DrawScrollBar();
}

// +--------------------------------------------------------------------+

void
ScrollWindow::DrawContent(const Rect& ctrl_rect)
{
    // override to do control-specific drawing
}

void
ScrollWindow::DrawTransparentContent(const Rect& ctrl_rect)
{
    // override (if necessary) to do control-specific drawing
    DrawContent(ctrl_rect);
}

void
ScrollWindow::DrawScrollBar()
{
    // draw scroll bar if necessary:
    if (IsScrollVisible()) {
        Color save_color = back_color;
        back_color = ShadeColor(back_color, 1.3);

        // draw scroll track border:
        DrawLine(rect.w-SCROLL_TRACK, BORDER_WIDTH, rect.w-SCROLL_TRACK, rect.h-BORDER_WIDTH, back_color);

        // draw top button
        Rect btn_rect(rect.w-SCROLL_WIDTH, BORDER_WIDTH, SCROLL_WIDTH-BORDER_WIDTH, SCROLL_HEIGHT);
        FillRect(btn_rect, back_color);
        DrawStyleRect(btn_rect, WIN_RAISED_FRAME);

        // draw bottom button:
        btn_rect.y = rect.h - (SCROLL_HEIGHT+BORDER_WIDTH);
        FillRect(btn_rect, back_color);
        DrawStyleRect(btn_rect, WIN_RAISED_FRAME);

        // draw thumb:
        btn_rect.y = thumb_pos;
        btn_rect.h = btn_rect.w;
        FillRect(btn_rect, back_color);
        DrawStyleRect(btn_rect, WIN_RAISED_FRAME);

        back_color = save_color;
    }

    if (scrolling && scroll_count)
    Scroll(scrolling, scroll_count);
}

// +--------------------------------------------------------------------+

bool
ScrollWindow::IsScrollVisible()
{
    bool vis = false;

    if (scroll_bar == SCROLL_ALWAYS ||
            (scroll_bar == SCROLL_AUTO   &&
                line_count > page_size)) {
        vis = true;
    }

    return vis;
}

int   ScrollWindow::GetLineHeight()
{
    return line_height;
}

void  ScrollWindow::SetLineHeight(int h)
{
    if (h >= 0)
    line_height = h;
}

int   ScrollWindow::GetLeading()
{
    return leading;
}

void  ScrollWindow::SetLeading(int nNewValue)
{
    if (leading != nNewValue && nNewValue >= 0) {
        leading = nNewValue;
    }
}

int   ScrollWindow::GetDragDrop()
{
    return dragdrop;
}

void  ScrollWindow::SetDragDrop(int nNewValue)
{
    if (dragdrop != nNewValue && (nNewValue == 0 || nNewValue == 1)) {
        dragdrop = nNewValue;
    }
}

int   ScrollWindow::GetScrollBarVisible()
{
    return scroll_bar;
}

void  ScrollWindow::SetScrollBarVisible(int nNewValue)
{
    if (scroll_bar != nNewValue) {
        scroll_bar = nNewValue;
    }
}

bool  ScrollWindow::GetSmoothScroll()
{
    return smooth_scroll;
}

void  ScrollWindow::SetSmoothScroll(bool bNewValue)
{
    if (smooth_scroll != bNewValue) {
        smooth_scroll = bNewValue;
        smooth_offset = top_index;
    }
}

bool  ScrollWindow::CanScroll(int direction, int nlines)
{
    return false;
}

void  ScrollWindow::EnsureVisible(int index)
{
    if (index < top_index)
    ScrollTo(index);

    else if (index > top_index+page_size)
    ScrollTo(index-page_size);
}

void  ScrollWindow::Scroll(int direction, int nlines)
{
    if (nlines) {
        scrolling = direction;

        if (direction == SCROLL_UP || direction == SCROLL_PAGE_UP) {
            top_index--;

            if (top_index < 0)
            top_index = 0;

            else
            scroll_count = nlines-1;
        }

        else if (direction == SCROLL_DOWN || direction == SCROLL_PAGE_DOWN) {
            top_index++;

            if (top_index >= line_count)
            top_index = line_count-1;

            else
            scroll_count = nlines-1;
        }

        smooth_offset = top_index;
        thumb_pos = TRACK_START + (int) (track_length * (double) top_index/(line_count-1));

        if (scroll_count < 1)
        scrolling = SCROLL_NONE;
    }
}

void  ScrollWindow::SmoothScroll(int direction, double nlines)
{
    if (!smooth_scroll) {
        Scroll(direction, (int) nlines);
        return;
    }

    if (direction == SCROLL_UP || direction == SCROLL_PAGE_UP) {
        smooth_offset -= nlines;

        if (smooth_offset < 0)
        smooth_offset = 0;
    }

    else if (direction == SCROLL_DOWN || direction == SCROLL_PAGE_DOWN) {
        smooth_offset += nlines;

        if (smooth_offset >= line_count)
        smooth_offset = line_count-1;
    }

    top_index = (int) smooth_offset;
    thumb_pos = TRACK_START + (int) (track_length * smooth_offset/(line_count-1));
    scrolling = SCROLL_NONE;
}

void  ScrollWindow::ScrollTo(int index)
{
    if (index >= 0 && index < line_count) {
        top_index     = index;
        smooth_offset = index;

        thumb_pos = TRACK_START + (int) (track_length * smooth_offset/(line_count-1));
    }
}

int   ScrollWindow::GetTopIndex()
{
    return top_index;
}

int   ScrollWindow::GetPageCount()
{
    return line_count / GetPageSize();
}

int   ScrollWindow::GetPageSize()
{
    return page_size;
}

int   ScrollWindow::GetScrollTrack()
{
    return rect.w-SCROLL_TRACK;
}

int   ScrollWindow::GetLineCount()
{
    return line_count;
}

// +--------------------------------------------------------------------+

int ScrollWindow::OnMouseMove(int x, int y)
{
    bool dirty = false;

    if (captured) {
        ActiveWindow* test = GetCapture();

        if (test != this) {
            captured = false;
            dirty = true;
        }

        else {
            if (selecting && !dragging) {
                if (dragdrop && (x < rect.x        ||
                            x > rect.x+rect.w ||
                            y < rect.y        ||
                            y > rect.y+rect.h)) {

                    dragging = true;
                    OnDragStart(x,y);
                }
            }

            if (scrolling == SCROLL_THUMB) {
                mouse_y = y - rect.y - TRACK_START;

                int dest = (int) ((double) mouse_y/track_length * (line_count-1));
                ScrollTo(dest);
                dirty = true;
            }
        }
    }

    return ActiveWindow::OnMouseMove(x,y);
}

// +--------------------------------------------------------------------+

int ScrollWindow::OnLButtonDown(int x, int y)
{
    if (!captured)
    captured = SetCapture();

    mouse_x = x - rect.x;
    mouse_y = y - rect.y;

    int x_scroll_bar = rect.w;

    if (scroll_bar == SCROLL_ALWAYS ||
            (scroll_bar == SCROLL_AUTO   &&
                line_count > page_size))
    x_scroll_bar -= SCROLL_WIDTH;

    if (mouse_x < x_scroll_bar) {
        scrolling = SCROLL_NONE;
        selecting = true;
    }

    else {
        selecting = false;

        if (mouse_y < TRACK_START) {
            scrolling = SCROLL_UP;
            Scroll(scrolling, 1);
            Button::PlaySound(Button::SND_LIST_SCROLL);
        }

        else if (mouse_y > rect.h-TRACK_START) {
            scrolling = SCROLL_DOWN;
            if (top_index < line_count-1)
            top_index++;
            Button::PlaySound(Button::SND_LIST_SCROLL);
        }

        else if (mouse_y < thumb_pos) {
            scrolling = SCROLL_PAGE_UP;
            Scroll(scrolling, page_size);
            Button::PlaySound(Button::SND_LIST_SCROLL);
        }

        else if (mouse_y > thumb_pos+THUMB_HEIGHT) {
            scrolling = SCROLL_PAGE_DOWN;
            Scroll(scrolling, page_size);
            Button::PlaySound(Button::SND_LIST_SCROLL);
        }

        else {
            scrolling = SCROLL_THUMB;
        }
    }

    return ActiveWindow::OnLButtonDown(x,y);
}

// +--------------------------------------------------------------------+

int ScrollWindow::OnLButtonUp(int x, int y)
{
    if (captured) {
        mouse_x = x-rect.x;
        mouse_y = y-rect.y;

        if (dragging) {
            if (mouse_x < 0 || mouse_x > rect.w || mouse_y < 0 || mouse_y > rect.h) {
                FormWindow* parent_form = (FormWindow*) form;

                if (parent_form) {
                    ActiveWindow* drop_target = parent_form->FindControl(x,y);

                    if (drop_target && drop_target->IsEnabled() && drop_target->IsShown())
                    drop_target->OnDragDrop(x,y,this);
                }
            }
        }

        ReleaseCapture();
        captured = false;

        Mouse::SetCursor((Mouse::CURSOR) old_cursor);
    }

    dragging    = false;
    selecting   = false;

    return ActiveWindow::OnLButtonUp(x,y);
}

// +--------------------------------------------------------------------+

int ScrollWindow::OnMouseWheel(int wheel)
{
    if (wheel > 0)
    Scroll(SCROLL_UP, 1);

    else if (wheel < 0)
    Scroll(SCROLL_DOWN, 1);

    if (GetLineCount() > 0) {
        static double scroll_time = 0;
        Clock* clock = Clock::GetInstance();

        if (clock->RealTime() - scroll_time > 0.5) {
            scroll_time = clock->RealTime();
            Button::PlaySound(Button::SND_LIST_SCROLL);
        }
    }

    return ActiveWindow::OnMouseWheel(wheel);
}

// +--------------------------------------------------------------------+

int ScrollWindow::OnClick()
{
    int fire_select = !scrolling;

    if (scrolling == SCROLL_THUMB)
    scrolling = SCROLL_NONE;

    if (fire_select)
    return ActiveWindow::OnSelect();
    else
    return ActiveWindow::OnClick();

    return 0;
}

// +--------------------------------------------------------------------+

int ScrollWindow::OnKeyDown(int vk, int flags)
{
    switch (vk) {
    case VK_UP:    Scroll(SCROLL_UP,    1);
        Button::PlaySound(Button::SND_LIST_SCROLL);
        break;

    case VK_DOWN:  Scroll(SCROLL_DOWN,  1);
        Button::PlaySound(Button::SND_LIST_SCROLL);
        break;

    case VK_PRIOR: Scroll(SCROLL_UP,    page_count);
        Button::PlaySound(Button::SND_LIST_SCROLL);
        break;

    case VK_NEXT:  Scroll(SCROLL_DOWN,  page_count);
        Button::PlaySound(Button::SND_LIST_SCROLL);
        break;

    case VK_HOME:  EnsureVisible(0);
        Button::PlaySound(Button::SND_LIST_SCROLL);
        break;

    case VK_END:   EnsureVisible(line_count-1);
        Button::PlaySound(Button::SND_LIST_SCROLL);
        break;

    default: break;
    }

    return ActiveWindow::OnKeyDown(vk, flags);
}

// +--------------------------------------------------------------------+

int ScrollWindow::OnDragStart(int x, int y)
{
    old_cursor = Mouse::SetCursor(Mouse::DRAG);
    return ActiveWindow::OnDragStart(x,y);
}

// +--------------------------------------------------------------------+

int ScrollWindow::OnDragDrop(int x, int y, ActiveWindow* source)
{
    return ActiveWindow::OnDragDrop(x,y,source);
}