Manage playing cards from C++ only

CMakeLists.txt

@@ -21,7 +21,8 @@ qt_add_qml_module(appSolitare
     QML_FILES
         Main.qml
         QML_FILES ScoreBar.qml
-        QML_FILES PlayingCard.qml
+        QML_FILES CardModel.qml
+        SOURCES playingcard.h playingcard.cpp
 )
 
 # Qt for iOS sets MACOSX_BUNDLE_GUI_IDENTIFIER automatically since Qt 6.1.

CardModel.qml

@@ -1,24 +1,24 @@
+import Solitare
 import QtQuick
 
 Item {
-    id: playingCard
+    id: cardModel
     width: 100
     height: width * 1.4 // Maintian the aspect ratio of a playing card
 
+    required property PlayingCard card;
+    property string backStyle: "red"
+
     // Annoyingly, there is no easy way to make this type-safe, QML does have enums
     // but they only act as ints, and since we need the string names for the img paths
     // anyways, typing these as simple strings is the easiest way to do this.
-    required property string color
-    required property string value
-    property string backStyle: "red"
-    property bool isFaceDown: false
 
     Image {
         id: cardImage
         anchors.fill: parent
-        source: playingCard.isFaceDown
-            ? "qrc:/img/playing_cards/backs/" + playingCard.backStyle + ".svg"
-            : "qrc:/img/playing_cards/fronts/" + playingCard.color + "_" + playingCard.value + ".svg"
+        source: cardModel.card.isFaceDown
+            ? "qrc:/img/playing_cards/backs/" + cardModel.backStyle + ".svg"
+            : "qrc:/img/playing_cards/fronts/" + cardModel.card.color + "_" + cardModel.card.value + ".svg"
         fillMode: Image.PreserveAspectFit
     }
 }

Main.qml

@@ -1,3 +1,4 @@
+import Solitare
 import QtQuick
 import QtQuick.Controls
 import QtQuick.Layouts
@@ -17,9 +18,8 @@ ApplicationWindow {
         moves: 64
     }
 
-    PlayingCard {
-        color: "clubs"
-        value: "ace"
-        isFaceDown: true
+    CardModel {
+        anchors.centerIn: parent
+        card: myCard
     }
 }

main.cpp

@@ -1,5 +1,7 @@
 #include <QGuiApplication>
 #include <QQmlApplicationEngine>
+#include <QQmlContext>
+#include "playingcard.h"
 
 int main(int argc, char *argv[])
 {
@@ -12,6 +14,12 @@ int main(int argc, char *argv[])
         &app,
         []() { QCoreApplication::exit(-1); },
         Qt::QueuedConnection);
+
+    qmlRegisterUncreatableType<PlayingCard>("Solitare", 1, 0, "PlayingCard", "PlayingCard cannot be directly created in QML. Use C++ logic to instantiate.");
+
+    PlayingCard myCard("clubs", "ace");
+    engine.rootContext()->setContextProperty("myCard", &myCard);
+
     engine.loadFromModule("Solitare", "Main");
 
     return app.exec();

playingcard.cpp

@@ -0,0 +1,47 @@
+#include "playingcard.h"
+
+PlayingCard::PlayingCard(const QString &color, const QString &value, bool isFaceDown, QObject *parent)
+     : QObject{parent}, m_color{color}, m_value{value}, m_isFaceDown{isFaceDown}
+{ }
+
+QString PlayingCard::color() const
+{
+    return m_color;
+}
+
+void PlayingCard::setColor(const QString &color)
+{
+    if (m_color == color)
+        return;
+
+    m_color = color;
+    emit onColorChanged();
+}
+
+QString PlayingCard::value() const
+{
+    return m_value;
+}
+
+void PlayingCard::setValue(const QString &value)
+{
+    if (m_value == value)
+        return;
+
+    m_value = value;
+    emit onValueChanged();
+}
+
+bool PlayingCard::isFaceDown() const
+{
+    return m_isFaceDown;
+}
+
+void PlayingCard::setIsFaceDown(bool faceDown)
+{
+    if (m_isFaceDown == faceDown)
+        return;
+
+    m_isFaceDown = faceDown;
+    emit onIsFaceDownChanged();
+}

playingcard.h

@@ -0,0 +1,37 @@
+#ifndef PLAYINGCARD_H
+#define PLAYINGCARD_H
+
+#include <QObject>
+
+class PlayingCard : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(QString color READ color WRITE setColor NOTIFY onColorChanged REQUIRED)
+    Q_PROPERTY(QString value READ value WRITE setValue NOTIFY onValueChanged REQUIRED)
+    Q_PROPERTY(bool isFaceDown READ isFaceDown WRITE setIsFaceDown NOTIFY onIsFaceDownChanged)
+
+public:
+    explicit PlayingCard(const QString &color = "", const QString &value = "", bool isFaceDown = false, QObject *parent = nullptr);
+
+    QString color() const;
+    void setColor(const QString &color);
+
+    QString value() const;
+    void setValue(const QString &value);
+
+    bool isFaceDown() const;
+    void setIsFaceDown(bool faceDown);
+
+signals:
+    void onColorChanged();
+    void onValueChanged();
+    void onIsFaceDownChanged();
+
+private:
+    QString m_color;
+    QString m_value;
+    bool m_isFaceDown;
+    QString m_imgUrl;
+};
+
+#endif // PLAYINGCARD_H