Scrollable.cc

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "pedigree/kernel/debugger/Scrollable.h"

Scrollable::Scrollable()
    : m_x(0), m_y(0), m_width(0), m_height(0), m_line(0), m_ScrollUp('j'),
      m_ScrollDown('k')
{
}
Scrollable::~Scrollable() = default;

void Scrollable::move(size_t x, size_t y)
{
    m_x = x;
    m_y = y;
}

void Scrollable::resize(size_t width, size_t height)
{
    m_width = width;
    m_height = height;
}

void Scrollable::scroll(ssize_t lines)
{
    m_line += lines;

    if (m_line >
        (static_cast<ssize_t>(getLineCount()) - static_cast<ssize_t>(m_height)))
        m_line = static_cast<ssize_t>(getLineCount()) -
                 static_cast<ssize_t>(m_height);

    if (m_line < 0)
        m_line = 0;
}

void Scrollable::scrollTo(size_t absolute)
{
    m_line = absolute;

    if (m_line >
        (static_cast<ssize_t>(getLineCount()) - static_cast<ssize_t>(m_height)))
        m_line = static_cast<ssize_t>(getLineCount()) -
                 static_cast<ssize_t>(m_height);

    if (m_line < 0)
        m_line = 0;
}

void Scrollable::refresh(DebuggerIO *pScreen)
{
    pScreen->disableRefreshes();

    // TODO: Add a scroll bar on the right side of the window

    // Can we scroll up?
    bool bCanScrollUp = (m_line > 0);
    bool bCanScrollDown = ((m_line + m_height) < getLineCount());

    // For every available line.
    ssize_t line = m_line;
    for (size_t i = 0; i < m_height; i++)
    {
        pScreen->drawHorizontalLine(
            ' ', m_y + i, m_x, m_x + m_width - 1, DebuggerIO::White,
            DebuggerIO::Black);

        if (line >= 0 && line < static_cast<ssize_t>(getLineCount()))
        {
            DebuggerIO::Colour colour = DebuggerIO::White;
            DebuggerIO::Colour bgColour = DebuggerIO::Black;
            size_t colOffset;
            const char *Line = getLine1(line, colour, bgColour);
            if (Line)
                pScreen->drawString(Line, m_y + i, m_x, colour, bgColour);

            colour = DebuggerIO::White;
            bgColour = DebuggerIO::Black;
            Line = getLine2(line, colOffset, colour, bgColour);
            if (Line)
                pScreen->drawString(
                    Line, m_y + i, m_x + colOffset, colour, bgColour);
        }
        line++;
    }

    // Draw scroll marks.
    char str[4] = {'^', ' ', m_ScrollUp, '\0'};
    if (bCanScrollUp)
        pScreen->drawString(
            str, m_y, m_x + m_width - 3, DebuggerIO::White, DebuggerIO::Blue);
    str[0] = 'v';
    str[2] = m_ScrollDown;
    if (bCanScrollDown)
        pScreen->drawString(
            str, m_y + m_height - 1, m_x + m_width - 3, DebuggerIO::White,
            DebuggerIO::Blue);

    pScreen->enableRefreshes();
}

void Scrollable::setScrollKeys(char up, char down)
{
    m_ScrollUp = up;
    m_ScrollDown = down;
}

ssize_t Scrollable::getLine()
{
    return m_line;
}

void Scrollable::centreOn(size_t line)
{
    if (line > getLineCount())
        line = getLineCount();

    if (line < m_height)
    {
        scrollTo(0);
        return;
    }

    scrollTo(line - (m_height / 2));
}

size_t Scrollable::height() const
{
    return m_height;
}
size_t Scrollable::width() const
{
    return m_width;
}