Basic implementation

qml/Main.qml

@@ -1,8 +1,107 @@
 import QtQuick
+import QtQuick.Controls
+import QtQuick.Layouts
+import PrimeNumbers
 
-Window {
+ApplicationWindow {
-    width: 640
-    height: 480
     visible: true
-    title: qsTr("Hello World")
+    width: 400
+    height: 500
+    title: "Factorization"
+
+    FactorizationController {
+        id: factorizationController
+    }
+
+    ColumnLayout {
+        anchors.fill: parent
+        spacing: 10
+
+        Text {
+            text: "Enter a number to factorize:"
+            font.pixelSize: 16
+            Layout.alignment: Qt.AlignHCenter
+        }
+
+        TextField {
+            id: numberInput
+            placeholderText: "Enter number"
+            // NOTE: We can't use the IntValidator here, since it doesn't support 64-bit values (long long)
+            Layout.fillWidth: true
+            onTextChanged: {
+                // If the number changes, reset
+                factorizationController.reset();
+            }
+        }
+
+        RowLayout {
+            Layout.fillWidth: true
+            spacing: 10
+
+            Button {
+                text: {
+                    if (factorizationController.isPaused) {
+                        return "Resume";
+                    } else if (factorizationController.isRunning) {
+                        return "...";
+                    } else {
+                        return "Start";
+                    }
+                }
+                Layout.fillWidth: true
+                enabled: !factorizationController.isRunning
+                onClicked: {
+                    if (factorizationController.isPaused) {
+                        factorizationController.resume();
+                    } else {
+                        factorizationController.start(parseInt(numberInput.text, 10));
+                    }
+                }
+            }
+
+            Button {
+                text: "Pause"
+                Layout.fillWidth: true
+                enabled: factorizationController.isRunning
+                onClicked: factorizationController.stop()
+            }
+        }
+
+        ProgressBar {
+            Layout.fillWidth: true
+            from: 0
+            to: 100
+            value: factorizationController.progress
+        }
+
+        Text {
+            text: "Current Factor: " + factorizationController.currentFactor
+            font.pixelSize: 14
+            Layout.alignment: Qt.AlignHCenter
+        }
+
+        Text {
+            text: "Factors Found:"
+            font.pixelSize: 14
+            Layout.alignment: Qt.AlignHCenter
+        }
+
+        ListView {
+            Layout.fillWidth: true
+            Layout.fillHeight: true
+            model: factorizationController.factors
+            delegate: Text {
+                text: modelData
+                font.pixelSize: 14
+                horizontalAlignment: Text.AlignHCenter
+                width: parent.width
+            }
+        }
+
+        Text {
+            text: "Warning: This only shows factors below sqrt(num)"
+            font.pixelSize: 12
+            Layout.alignment: Qt.AlignHCenter
+        }
+    }
 }

src/FactorizationController.cpp

@@ -0,0 +1,142 @@
+#include "FactorizationController.h"
+#include <cassert>
+#include <cmath>
+
+FactorizationController::FactorizationController(QObject* parent) : QObject{parent}, m_isRunning(false), m_currentFactNumber(0), m_currentFactor(2) {
+    assert(connect(&m_timer, &QTimer::timeout, this, &FactorizationController::onTimerTick));
+}
+
+long long FactorizationController::number() const {
+    return m_originalNumber;
+}
+
+int FactorizationController::progress() const {
+    // If current factor is at or below 2 already, we must be done,
+    // stopFactor can never be less than 2, that makes no sense.
+    if (m_currentFactNumber == 1 || m_currentFactor <= 2 || m_currentFactor > m_stopFactor)
+        return 100;
+
+    // Determine the progress based on the current factor, in comparison to stop factor.
+    // since factor being <= 2 means 100%, we sub 2 here.
+    double progress = static_cast<double>(m_currentFactor - 2) / static_cast<double>(m_stopFactor - 2);
+
+    // Return the value as int percentage
+    return static_cast<int>(std::clamp(progress * 100, 0.0, 100.0));
+}
+
+bool FactorizationController::isFinished() const {
+    return m_isFinished;
+}
+
+bool FactorizationController::isRunning() const {
+    return m_isRunning;
+}
+
+bool FactorizationController::isPaused() const {
+    return m_isPaused;
+}
+
+long long FactorizationController::currentFactor() const {
+    return m_currentFactor;
+}
+
+QList<long long> FactorizationController::factors() const {
+    return m_factors;
+}
+
+void FactorizationController::start(long long number) {
+    m_originalNumber = number;
+    m_currentFactNumber = number;
+    m_currentFactor = 2;
+    // we could also just compute this every time, but sqrt is pretty expensive
+    m_stopFactor = static_cast<long long>(std::sqrt(m_currentFactNumber));
+    m_isRunning = true;
+    m_isFinished = false;
+    m_factors.clear();
+    emit isRunningChanged();
+    emit isFinishedChanged();
+    emit numberChanged();
+    emit currentFactorChanged();
+    emit progressChanged();
+    emit factorsChanged();
+
+    m_timer.start(0);
+}
+
+void FactorizationController::resume() {
+    if (!m_isPaused)
+        return;
+
+    m_isRunning = true;
+    m_isPaused = false;
+    emit isRunningChanged();
+    emit isPausedChanged();
+
+    m_timer.start(0);
+}
+
+void FactorizationController::stop() {
+    if (!m_isRunning)
+        return;
+
+    m_isRunning = false;
+    m_isPaused = true;
+    emit isRunningChanged();
+    emit isPausedChanged();
+
+    m_timer.stop();
+}
+
+void FactorizationController::reset() {
+    if (m_isRunning)
+        stop();
+
+    // Only continue if we were in a paused state, or running state
+    // (since we called stop before, that would put is into a paused state now)
+    // Otherwise, it means start wasn't yet called, or reset was called already.
+    if (!m_isPaused)
+        return;
+
+    m_isPaused = false;
+    m_currentFactNumber = m_originalNumber;
+    m_currentFactor = 2;
+    m_factors.clear();
+    emit isPausedChanged();
+    emit currentFactorChanged();
+    emit progressChanged();
+    emit factorsChanged();
+}
+
+void FactorizationController::onTimerTick() {
+    factorize();
+}
+
+void FactorizationController::factorize() {
+    if (!m_isRunning)
+        return;
+
+    if (m_currentFactNumber == 1 || m_currentFactor > m_stopFactor) {
+        // Computation done
+        m_timer.stop();
+        m_isRunning = false;
+        m_isFinished = true;
+        emit isRunningChanged();
+        emit isFinishedChanged();
+        emit progressChanged();
+        return;
+    }
+
+    // The factorization process (very basic factorization example)
+    if (m_currentFactNumber % m_currentFactor == 0) {
+        m_currentFactNumber /= m_currentFactor;
+
+        m_factors.append(m_currentFactor);
+        emit factorsChanged();
+
+        // Don't increase current factor, keep dividing by it until no longer divisible
+    } else {
+        m_currentFactor++;
+        emit currentFactorChanged();
+        emit progressChanged();
+    }
+}

src/FactorizationController.h

@@ -0,0 +1,164 @@
+#ifndef FACTORIZATIONCONTROLLER_H
+#define FACTORIZATIONCONTROLLER_H
+
+#include <QObject>
+#include <QTimer>
+#include <qqmlintegration.h>
+#include <qtmetamacros.h>
+
+/**
+ * @class FactorizationController
+ * @brief A class that performs integer factorization in a step-by-step manner.
+ *
+ * This class uses a timer to progressively factorize a given number, allowing
+ * for real-time updates on progress and discovered factors. It is designed
+ * to be used in a Qt-based QML application.
+ */
+class FactorizationController : public QObject {
+    Q_OBJECT
+    QML_ELEMENT
+    Q_PROPERTY(bool isRunning READ isRunning NOTIFY isRunningChanged)
+    Q_PROPERTY(bool isFinished READ isFinished NOTIFY isFinishedChanged)
+    Q_PROPERTY(bool isPaused READ isPaused NOTIFY isPausedChanged)
+    Q_PROPERTY(long long number READ number NOTIFY numberChanged)
+    Q_PROPERTY(long long currentFactor READ currentFactor NOTIFY currentFactorChanged)
+    Q_PROPERTY(int progress READ progress NOTIFY progressChanged)
+    Q_PROPERTY(QList<long long> factors READ factors NOTIFY factorsChanged)
+
+  public:
+    explicit FactorizationController(QObject* parent = nullptr);
+
+    // region: Getters
+
+    /**
+     * @brief Gets the current progress of factorization.
+     * @return The progress percentage (0-100).
+     */
+    int progress() const;
+
+    /**
+     * @brief Checks if the factorization process is running.
+     * @return True if the factorization is in progress, otherwise false.
+     *
+     * This just informs whether the task is active (scheduled to run), not whether it's
+     * running at this very moment, as this implementation doesn't use threads.
+     */
+    bool isRunning() const;
+
+    /**
+     * @brief Checks if the factorization process is done.
+     * @return True if the factorization is completed, otherwise false.
+     *
+     * This will only be true if the factorization process finished without being
+     * explicitly stopped ahead of time (e.g. when the computation is done and we
+     * have all the factors).
+     */
+    bool isFinished() const;
+
+    /**
+     * @brief Checks if the factorization process is currently paused.
+     * @return True if the factorization process is paused, otherwise false.
+     *
+     * This function differs from just !isRunning, as this will only be set when
+     * the computation is currently paused, but can still be resumed. E.g. the
+     * computation was already started at some point, and stopped (paused) later,
+     * without having been reset.
+     *
+     * This being true is a prerequisite to resuming.
+     */
+    bool isPaused() const;
+
+    /**
+     * @brief Gets the original number being factorized.
+     * @return The number being factorized.
+     */
+    long long number() const;
+
+    /**
+     * @brief Gets the current factor being tested.
+     * @return The current factor.
+     *
+     * The factorization process is implemented in a way that simply checks whether a number
+     * is a factor, going one by one. This returns the current factor (to be checked in the
+     * next iteration).
+     */
+    long long currentFactor() const;
+
+    /**
+     * @brief Gets the list of discovered factors (may not be complete).
+     * @return A QList of extracted prime factors.
+     *
+     * This returns the factors that were already discovered Note that this list might not
+     * be complete (if the computation is still running). If you need to know whether you
+     * can trust this result, check isFinished first.
+     */
+    QList<long long> factors() const;
+
+    // endregion
+    // region: Functions
+
+    /**
+     * @brief Starts the factorization process for a given number.
+     * @param number The number to be factorized.
+     *
+     * This will start a 0-tick timer, which triggers a partial computation on each run,
+     * to let the event loop cycle in between. This implementation does NOT rely on threads.
+     */
+    Q_INVOKABLE void start(long long number);
+
+    /**
+     * @brief Stops the ongoing factorization process.
+     *
+     * This will stop the timer, meaning the computation will no longer get triggered
+     * by the event loop, essentially pausing it. Note that this does not reset the already
+     * computed details, which means the computation can be resumed later, allowing for
+     * inspection of the currently computed values.
+     */
+    Q_INVOKABLE void stop();
+
+    /**
+     * @brief Resumes a previously stopped factorization process.
+     */
+    Q_INVOKABLE void resume();
+
+    /**
+     * @brief Resets the factorization process data.
+     *
+     * This will clear the current progress (if any). If the factorization process is running,
+     * this will stop it. If the factorization process is paused, this will reset isPaused,
+     * forcing a restart.
+     */
+    Q_INVOKABLE void reset();
+
+    // endregion
+
+  signals:
+    void isRunningChanged();
+    void isFinishedChanged();
+    void numberChanged();
+    void currentFactorChanged();
+    void factorsChanged();
+    void progressChanged();
+    void isPausedChanged();
+
+  private slots:
+    void onTimerTick();
+
+  private:
+    bool m_isRunning; ///< Indicates whether factorization is active.
+    bool m_isFinished; ///< Indicates whether the factorization process is done.
+    bool m_isPaused; ///< Indicates whether the factorization process is paused (can be resumed).
+    long long m_currentFactNumber; ///< The number currently being factorized.
+    long long m_originalNumber; ///< The original input number.
+    long long m_currentFactor; ///< The current divisor being checked.
+    long long m_stopFactor; ///< The stopping limit (square root of original number, saved for efficiency).
+    QList<long long> m_factors; ///< List of discovered prime factors.
+    QTimer m_timer; ///< Timer for stepwise execution.
+
+    /**
+     * @brief Performs one step of the factorization process.
+     */
+    void factorize();
+};
+
+#endif // FACTORIZATIONCONTROLLER_H

src/main.cpp

@@ -1,13 +1,13 @@
+#include "FactorizationController.h"
 #include <QGuiApplication>
 #include <QQmlApplicationEngine>
+#include <QQmlContext>
 
 int main(int argc, char* argv[]) {
     QGuiApplication app(argc, argv);
 
     QQmlApplicationEngine engine;
-  QObject::connect(
+    QObject::connect(&engine, &QQmlApplicationEngine::objectCreationFailed, &app, []() { QCoreApplication::exit(-1); }, Qt::QueuedConnection);
-      &engine, &QQmlApplicationEngine::objectCreationFailed, &app,
-      []() { QCoreApplication::exit(-1); }, Qt::QueuedConnection);
 
     engine.load(QStringLiteral("qrc:/qml/Main.qml"));