Minesweeper: Implement some feature requests.

Someone was playing this game and suggested a number of improvements so here
we go trying to address them:

- Add "chording" support, where you can click a numbered square using both
  mouse buttons simultaneously to sweep all non-flagged adjacent squares.

- Mis-flagged squares are now revealed as such on game over, with a special
  "bad flag" icon.

- The game timer now shows tenths of seconds. It also doesn't start until
  you click the first square.

- Add the three difficulty modes from the classic Windows version.

Games/Minesweeper/Field.cpp

@@ -26,27 +26,78 @@ public:
     }
 };
 
+class SquareLabel final : public GLabel {
+public:
+    SquareLabel(Square& square, GWidget* parent)
+        : GLabel(parent)
+        , m_square(square)
+    {
+    }
+
+    Function<void()> on_chord_click;
+
+    virtual void mousedown_event(GMouseEvent& event) override
+    {
+        if (event.buttons() == (GMouseButton::Right | GMouseButton::Left)) {
+            if (event.button() == GMouseButton::Left || event.button() == GMouseButton::Right) {
+                m_chord = true;
+                m_square.field->set_chord_preview(m_square, true);
+            }
+        }
+        GLabel::mousedown_event(event);
+    }
+
+    virtual void mousemove_event(GMouseEvent& event) override
+    {
+        if (m_chord) {
+            if (rect().contains(event.position())) {
+                m_square.field->set_chord_preview(m_square, true);
+            } else {
+                m_square.field->set_chord_preview(m_square, false);
+            }
+        }
+        GLabel::mousemove_event(event);
+    }
+
+    virtual void mouseup_event(GMouseEvent& event) override
+    {
+        if (m_chord) {
+            if (event.button() == GMouseButton::Left || event.button() == GMouseButton::Right) {
+                if (rect().contains(event.position())) {
+                    if (on_chord_click)
+                        on_chord_click();
+                }
+                m_chord = false;
+            }
+        }
+        m_square.field->set_chord_preview(m_square, m_chord);
+        GLabel::mouseup_event(event);
+    }
+
+    Square& m_square;
+    bool m_chord { false };
+};
+
 Field::Field(GLabel& flag_label, GLabel& time_label, GButton& face_button, GWidget* parent)
     : GFrame(parent)
     , m_face_button(face_button)
     , m_flag_label(flag_label)
     , m_time_label(time_label)
 {
-    auto config = CConfigFile::get_for_app("Minesweeper");
-
-    m_mine_count = config->read_num_entry("Game", "MineCount", 10);
-    m_rows = config->read_num_entry("Game", "Rows", 9);
-    m_columns = config->read_num_entry("Game", "Columns", 9);
-
     m_timer.on_timeout = [this] {
-        m_time_label.set_text(String::format("%u", ++m_seconds_elapsed));
+        ++m_time_elapsed;
+        m_time_label.set_text(String::format("%u.%u", m_time_elapsed / 10, m_time_elapsed % 10));
     };
-    m_timer.set_interval(1000);
+    m_timer.set_interval(100);
     set_frame_thickness(2);
     set_frame_shape(FrameShape::Container);
     set_frame_shadow(FrameShadow::Sunken);
     m_mine_bitmap = GraphicsBitmap::load_from_file("/res/icons/minesweeper/mine.png");
     m_flag_bitmap = GraphicsBitmap::load_from_file("/res/icons/minesweeper/flag.png");
+    m_badflag_bitmap = GraphicsBitmap::load_from_file("/res/icons/minesweeper/badflag.png");
+    m_default_face_bitmap = GraphicsBitmap::load_from_file("/res/icons/minesweeper/face-default.png");
+    m_good_face_bitmap = GraphicsBitmap::load_from_file("/res/icons/minesweeper/face-good.png");
+    m_bad_face_bitmap = GraphicsBitmap::load_from_file("/res/icons/minesweeper/face-bad.png");
     for (int i = 0; i < 8; ++i)
         m_number_bitmap[i] = GraphicsBitmap::load_from_file(String::format("/res/icons/minesweeper/%u.png", i + 1));
 
@@ -66,50 +117,51 @@ void Field::set_face(Face face)
 {
     switch (face) {
     case Face::Default:
-        m_face_button.set_icon(GraphicsBitmap::load_from_file("/res/icons/minesweeper/face-default.png"));
+        m_face_button.set_icon(*m_default_face_bitmap);
         break;
     case Face::Good:
-        m_face_button.set_icon(GraphicsBitmap::load_from_file("/res/icons/minesweeper/face-good.png"));
+        m_face_button.set_icon(*m_good_face_bitmap);
         break;
     case Face::Bad:
-        m_face_button.set_icon(GraphicsBitmap::load_from_file("/res/icons/minesweeper/face-bad.png"));
+        m_face_button.set_icon(*m_bad_face_bitmap);
         break;
     }
 }
 
 template<typename Callback>
-void Field::for_each_neighbor_of(const Square& square, Callback callback)
+void Square::for_each_neighbor(Callback callback)
 {
-    int r = square.row;
-    int c = square.column;
+    int r = row;
+    int c = column;
     if (r > 0) // Up
-        callback(this->square(r - 1, c));
+        callback(field->square(r - 1, c));
     if (c > 0) // Left
-        callback(this->square(r, c - 1));
-    if (r < (m_rows - 1)) // Down
-        callback(this->square(r + 1, c));
-    if (c < (m_columns - 1)) // Right
-        callback(this->square(r, c + 1));
+        callback(field->square(r, c - 1));
+    if (r < (field->m_rows - 1)) // Down
+        callback(field->square(r + 1, c));
+    if (c < (field->m_columns - 1)) // Right
+        callback(field->square(r, c + 1));
     if (r > 0 && c > 0) // UpLeft
-        callback(this->square(r - 1, c - 1));
-    if (r > 0 && c < (m_columns - 1)) // UpRight
-        callback(this->square(r - 1, c + 1));
-    if (r < (m_rows - 1) && c > 0) // DownLeft
-        callback(this->square(r + 1, c - 1));
-    if (r < (m_rows - 1) && c < (m_columns - 1)) // DownRight
-        callback(this->square(r + 1, c + 1));
+        callback(field->square(r - 1, c - 1));
+    if (r > 0 && c < (field->m_columns - 1)) // UpRight
+        callback(field->square(r - 1, c + 1));
+    if (r < (field->m_rows - 1) && c > 0) // DownLeft
+        callback(field->square(r + 1, c - 1));
+    if (r < (field->m_rows - 1) && c < (field->m_columns - 1)) // DownRight
+        callback(field->square(r + 1, c + 1));
 }
 
 void Field::reset()
 {
-    m_seconds_elapsed = 0;
+    m_time_elapsed = 0;
     m_time_label.set_text("0");
     m_flags_left = m_mine_count;
     m_flag_label.set_text(String::format("%u", m_flags_left));
-    m_timer.start();
+    m_timer.stop();
     set_greedy_for_hits(false);
     set_face(Face::Default);
     srand(time(nullptr));
+    m_squares.clear();
     m_squares.resize(rows() * columns());
 
     HashTable<int> mines;
@@ -122,15 +174,17 @@ void Field::reset()
     int i = 0;
     for (int r = 0; r < rows(); ++r) {
         for (int c = 0; c < columns(); ++c) {
+            m_squares[i] = make<Square>();
             Rect rect = { frame_thickness() + c * square_size(), frame_thickness() + r * square_size(), square_size(), square_size() };
             auto& square = this->square(r, c);
+            square.field = this;
             square.row = r;
             square.column = c;
             square.has_mine = mines.contains(i);
             square.has_flag = false;
             square.is_swept = false;
             if (!square.label)
-                square.label = new GLabel(this);
+                square.label = new SquareLabel(square, this);
             square.label->set_relative_rect(rect);
             square.label->set_visible(false);
             square.label->set_icon(square.has_mine ? m_mine_bitmap : nullptr);
@@ -138,6 +192,8 @@ void Field::reset()
             square.label->set_fill_with_background_color(false);
             if (!square.button)
                 square.button = new SquareButton(this);
+            square.button->set_checkable(true);
+            square.button->set_checked(false);
             square.button->set_icon(nullptr);
             square.button->set_relative_rect(rect);
             square.button->set_visible(true);
@@ -147,6 +203,9 @@ void Field::reset()
             square.button->on_right_click = [this, &square] {
                 on_square_right_clicked(square);
             };
+            square.label->on_chord_click = [this, &square] {
+                on_square_chorded(square);
+            };
             ++i;
         }
     }
@@ -154,7 +213,7 @@ void Field::reset()
         for (int c = 0; c < columns(); ++c) {
             auto& square = this->square(r, c);
             int number = 0;
-            for_each_neighbor_of(square, [&number] (auto& neighbor) {
+            square.for_each_neighbor([&number] (auto& neighbor) {
                 number += neighbor.has_mine;
             });
             square.number = number;
@@ -173,7 +232,7 @@ void Field::reset()
 void Field::flood_fill(Square& square)
 {
     on_square_clicked(square);
-    for_each_neighbor_of(square, [this] (auto& neighbor) {
+    square.for_each_neighbor([this] (auto& neighbor) {
         if (!neighbor.is_swept && !neighbor.has_mine && neighbor.number == 0)
             flood_fill(neighbor);
         if (!neighbor.has_mine && neighbor.number)
@@ -208,6 +267,8 @@ void Field::on_square_clicked(Square& square)
         return;
     if (square.has_flag)
         return;
+    if (!m_timer.is_active())
+        m_timer.start();
     update();
     square.is_swept = true;
     square.button->set_visible(false);
@@ -225,6 +286,26 @@ void Field::on_square_clicked(Square& square)
         win();
 }
 
+void Field::on_square_chorded(Square& square)
+{
+    if (!square.is_swept)
+        return;
+    if (!square.number)
+        return;
+    int adjacent_flags = 0;
+    square.for_each_neighbor([&] (auto& neighbor) {
+        if (neighbor.has_flag)
+            ++adjacent_flags;
+    });
+    if (square.number != adjacent_flags)
+        return;
+    square.for_each_neighbor([&] (auto& neighbor) {
+        if (neighbor.has_flag)
+            return;
+        on_square_clicked(neighbor);
+    });
+}
+
 void Field::on_square_right_clicked(Square& square)
 {
     if (square.is_swept)
@@ -266,11 +347,51 @@ void Field::reveal_mines()
     for (int r = 0; r < rows(); ++r) {
         for (int c = 0; c < columns(); ++c) {
             auto& square = this->square(r, c);
-            if (square.has_mine) {
+            if (square.has_mine && !square.has_flag) {
                 square.button->set_visible(false);
                 square.label->set_visible(true);
             }
+            if (!square.has_mine && square.has_flag) {
+                square.button->set_icon(*m_badflag_bitmap);
+                square.button->set_visible(true);
+                square.label->set_visible(false);
+            }
         }
     }
     update();
 }
+
+void Field::set_chord_preview(Square& square, bool chord_preview)
+{
+    if (m_chord_preview == chord_preview)
+        return;
+    m_chord_preview = chord_preview;
+    square.for_each_neighbor([&] (auto& neighbor) {
+        neighbor.button->set_checked(false);
+        if (!neighbor.has_flag)
+            neighbor.button->set_checked(chord_preview);
+    });
+}
+
+void Field::set_field_size(int rows, int columns, int mine_count)
+{
+    if (m_rows == rows && m_columns == columns && m_mine_count == mine_count)
+        return;
+    auto config = CConfigFile::get_for_app("Minesweeper");
+    config->write_num_entry("Game", "MineCount", mine_count);
+    config->write_num_entry("Game", "Rows", rows);
+    config->write_num_entry("Game", "Columns", columns);
+    m_rows = rows;
+    m_columns = columns;
+    m_mine_count = mine_count;
+    reset();
+    set_preferred_size({ frame_thickness() * 2 + m_columns * square_size(), frame_thickness() * 2 + m_rows * square_size() });
+    if (on_size_changed)
+        on_size_changed();
+}
+
+Square::~Square()
+{
+    delete label;
+    delete button;
+}

Games/Minesweeper/Field.h

@@ -2,12 +2,21 @@
 
 #include <LibGUI/GFrame.h>
 #include <LibCore/CTimer.h>
+#include <AK/Noncopyable.h>
 
-class SquareButton;
+class Field;
 class GButton;
 class GLabel;
+class SquareButton;
+class SquareLabel;
 
-struct Square {
+class Square {
+    AK_MAKE_NONCOPYABLE(Square)
+public:
+    Square() { }
+    ~Square();
+
+    Field* field { nullptr };
     bool is_swept { false };
     bool has_mine { false };
     bool has_flag { false };
@@ -15,10 +24,14 @@ struct Square {
     int column { 0 };
     int number { 0 };
     SquareButton* button { nullptr };
-    GLabel* label { nullptr };
+    SquareLabel* label { nullptr };
+
+    template<typename Callback> void for_each_neighbor(Callback);
 };
 
 class Field final : public GFrame {
+    friend class Square;
+    friend class SquareLabel;
 public:
     Field(GLabel& flag_label, GLabel& time_label, GButton& face_button, GWidget* parent);
     virtual ~Field() override;
@@ -28,19 +41,25 @@ public:
     int mine_count() const { return m_mine_count; }
     int square_size() const { return 15; }
 
+    void set_field_size(int rows, int columns, int mine_count);
+
     void reset();
 
+    Function<void()> on_size_changed;
+
 private:
     virtual void paint_event(GPaintEvent&) override;
 
     void on_square_clicked(Square&);
     void on_square_right_clicked(Square&);
+    void on_square_chorded(Square&);
     void game_over();
     void win();
     void reveal_mines();
+    void set_chord_preview(Square&, bool);
 
-    Square& square(int row, int column) { return m_squares[row * columns() + column]; }
-    const Square& square(int row, int column) const { return m_squares[row * columns() + column]; }
+    Square& square(int row, int column) { return *m_squares[row * columns() + column]; }
+    const Square& square(int row, int column) const { return *m_squares[row * columns() + column]; }
 
     void flood_fill(Square&);
 
@@ -53,15 +72,20 @@ private:
     int m_columns { 9 };
     int m_mine_count { 10 };
     int m_unswept_empties { 0 };
-    Vector<Square> m_squares;
+    Vector<OwnPtr<Square>> m_squares;
     RetainPtr<GraphicsBitmap> m_mine_bitmap;
     RetainPtr<GraphicsBitmap> m_flag_bitmap;
+    RetainPtr<GraphicsBitmap> m_badflag_bitmap;
+    RetainPtr<GraphicsBitmap> m_default_face_bitmap;
+    RetainPtr<GraphicsBitmap> m_good_face_bitmap;
+    RetainPtr<GraphicsBitmap> m_bad_face_bitmap;
     RetainPtr<GraphicsBitmap> m_number_bitmap[8];
     GButton& m_face_button;
     GLabel& m_flag_label;
     GLabel& m_time_label;
     CTimer m_timer;
-    int m_seconds_elapsed { 0 };
+    int m_time_elapsed { 0 };
     int m_flags_left { 0 };
     Face m_face { Face::Default };
+    bool m_chord_preview { false };
 };

Games/Minesweeper/main.cpp

@@ -7,6 +7,7 @@
 #include <LibGUI/GMenuBar.h>
 #include <LibGUI/GAction.h>
 #include <LibGUI/GLabel.h>
+#include <LibCore/CConfigFile.h>
 
 int main(int argc, char** argv)
 {
@@ -31,11 +32,28 @@ int main(int argc, char** argv)
     flag_icon_label->set_icon(GraphicsBitmap::load_from_file("/res/icons/minesweeper/flag.png"));
     auto* flag_label = new GLabel(container);
     auto* face_button = new GButton(container);
+    face_button->set_button_style(ButtonStyle::CoolBar);
+    face_button->set_size_policy(SizePolicy::Fixed, SizePolicy::Fill);
+    face_button->set_preferred_size({ 36, 0 });
     auto* time_icon_label = new GLabel(container);
     time_icon_label->set_icon(GraphicsBitmap::load_from_file("/res/icons/minesweeper/timer.png"));
     auto* time_label = new GLabel(container);
     auto* field = new Field(*flag_label, *time_label, *face_button, widget);
 
+    field->on_size_changed = [&] {
+        auto size = field->preferred_size();
+        size.set_height(size.height() + container->preferred_size().height());
+        window->resize(size);
+    };
+
+    {
+        auto config = CConfigFile::get_for_app("Minesweeper");
+        int mine_count = config->read_num_entry("Game", "MineCount", 10);
+        int rows = config->read_num_entry("Game", "Rows", 9);
+        int columns = config->read_num_entry("Game", "Columns", 9);
+        field->set_field_size(rows, columns, mine_count);
+    }
+
     auto menubar = make<GMenuBar>();
 
     auto app_menu = make<GMenu>("Minesweeper");
@@ -49,6 +67,16 @@ int main(int argc, char** argv)
     game_menu->add_action(GAction::create("New game", { Mod_None, Key_F2 }, [field] (const GAction&) {
         field->reset();
     }));
+    game_menu->add_separator();
+    game_menu->add_action(GAction::create("Beginner", { Mod_Ctrl, Key_B }, [field] (const GAction&) {
+        field->set_field_size(9, 9, 10);
+    }));
+    game_menu->add_action(GAction::create("Intermediate", { Mod_Ctrl, Key_I }, [field] (const GAction&) {
+        field->set_field_size(16, 16, 40);
+    }));
+    game_menu->add_action(GAction::create("Expert", { Mod_Ctrl, Key_E }, [field] (const GAction&) {
+        field->set_field_size(16, 30, 99);
+    }));
     menubar->add_menu(move(game_menu));
 
     auto help_menu = make<GMenu>("Help");