Games: Add GameOfLife

This patch introduces a new game based on Conway's Game of Life.

Userland/Games/GameOfLife/BoardWidget.cpp

@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2021, Andres Crucitti <dasc495@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "BoardWidget.h"
+#include <LibGUI/Painter.h>
+
+BoardWidget::BoardWidget(size_t rows, size_t columns)
+{
+    m_timer = add<Core::Timer>();
+    m_timer->stop();
+    m_timer->on_timeout = [this] {
+        run_generation();
+    };
+    m_timer->set_interval(m_running_timer_interval);
+
+    update_board(rows, columns);
+}
+
+void BoardWidget::run_generation()
+{
+    m_board->run_generation();
+    update();
+    if (m_board->is_stalled()) {
+        if (on_stall)
+            on_stall();
+        update();
+    };
+}
+
+void BoardWidget::update_board(size_t rows, size_t columns)
+{
+    set_running(false);
+
+    m_last_cell_toggled = columns * rows;
+
+    if (m_board) {
+        if (columns == m_board->columns() && rows == m_board->rows()) {
+            return;
+        }
+    }
+
+    m_board = make<Board>(rows, columns);
+}
+
+void BoardWidget::set_running_timer_interval(int interval)
+{
+    if (is_running())
+        return;
+
+    m_running_timer_interval = interval;
+    m_timer->set_interval(m_running_timer_interval);
+
+    if (on_running_state_change)
+        on_running_state_change();
+}
+
+void BoardWidget::set_running(bool running)
+{
+    if (running == m_running)
+        return;
+
+    m_running = running;
+
+    if (m_running) {
+        m_timer->start();
+    } else {
+        m_timer->stop();
+    }
+
+    if (on_running_state_change)
+        on_running_state_change();
+
+    update();
+}
+
+void BoardWidget::toggle_cell(size_t index)
+{
+    if (m_running || !m_toggling_cells || m_last_cell_toggled == index)
+        return;
+
+    m_last_cell_toggled = index;
+    m_board->toggle_cell(index);
+
+    if (on_cell_toggled)
+        on_cell_toggled(m_board, index);
+
+    update();
+}
+
+int BoardWidget::get_cell_size() const
+{
+    int width = rect().width() / m_board->columns();
+    int height = rect().height() / m_board->rows();
+
+    return min(width, height);
+}
+
+Gfx::IntSize BoardWidget::get_board_offset() const
+{
+    int cell_size = get_cell_size();
+    return {
+        (width() - cell_size * m_board->columns()) / 2,
+        (height() - cell_size * m_board->rows()) / 2,
+    };
+}
+
+void BoardWidget::paint_event(GUI::PaintEvent& event)
+{
+    GUI::Widget::paint_event(event);
+
+    GUI::Painter painter(*this);
+    painter.add_clip_rect(event.rect());
+    painter.fill_rect(event.rect(), Color::Black);
+
+    int cell_size = get_cell_size();
+    Gfx::IntSize board_offset = get_board_offset();
+
+    for (size_t row = 0; row < m_board->rows(); ++row) {
+        for (size_t column = 0; column < m_board->columns(); ++column) {
+            int cell_x = column * cell_size + board_offset.width();
+            int cell_y = row * cell_size + board_offset.height();
+
+            Gfx::Rect cell_rect(cell_x, cell_y, cell_size, cell_size);
+
+            Color border_color = Color::DarkGray;
+            Color fill_color;
+
+            bool on = m_board->cell(row, column);
+            if (on) {
+                fill_color = Color::from_rgb(Gfx::make_rgb(220, 220, 80));
+            } else {
+                fill_color = Color::MidGray;
+            }
+
+            painter.fill_rect(cell_rect, fill_color);
+            if (cell_size > 4) {
+                painter.draw_rect(cell_rect, border_color);
+            }
+        }
+    }
+}
+
+void BoardWidget::mousedown_event(GUI::MouseEvent& event)
+{
+    size_t index = get_index_for_point(event.x(), event.y());
+    set_toggling_cells(true);
+    toggle_cell(index);
+}
+
+void BoardWidget::mousemove_event(GUI::MouseEvent& event)
+{
+    size_t index = get_index_for_point(event.x(), event.y());
+    if (is_toggling()) {
+        if (last_toggled() != index)
+            toggle_cell(index);
+    }
+}
+
+void BoardWidget::mouseup_event(GUI::MouseEvent&)
+{
+    set_toggling_cells(false);
+}
+
+size_t BoardWidget::get_index_for_point(int x, int y) const
+{
+    int cell_size = get_cell_size();
+    Gfx::IntSize board_offset = get_board_offset();
+    return m_board->columns() * ((y - board_offset.height()) / cell_size) + (x - board_offset.width()) / cell_size;
+}