plugin: add image analyser

5 files changed, 285 insertions, 241 deletions

diff --git a/plugin/src/Caelestia/CMakeLists.txt b/plugin/src/Caelestia/CMakeLists.txt
index 4ad308f..9dea712 100644
--- a/plugin/src/Caelestia/CMakeLists.txt
+++ b/plugin/src/Caelestia/CMakeLists.txt
@@ -45,6 +45,7 @@ qml_module(caelestia
         appdb.hpp appdb.cpp
         requests.hpp requests.cpp
         toaster.hpp toaster.cpp
+        imageanalyser.hpp imageanalyser.cpp
     LIBRARIES
         Qt::Gui
         Qt::Quick
diff --git a/plugin/src/Caelestia/cutils.cpp b/plugin/src/Caelestia/cutils.cpp
index b5f7167..27074ee 100644
--- a/plugin/src/Caelestia/cutils.cpp
+++ b/plugin/src/Caelestia/cutils.cpp
@@ -116,232 +116,6 @@ bool CUtils::deleteFile(const QUrl& path) const {
     return QFile::remove(path.toLocalFile());
 }
 
-void CUtils::getDominantColour(QQuickItem* item, QJSValue callback) {
-    this->getDominantColour(item, 128, callback);
-}
-
-void CUtils::getDominantColour(QQuickItem* item, int rescaleSize, QJSValue callback) {
-    if (!item) {
-        qWarning() << "CUtils::getDominantColour: an item is required";
-        return;
-    }
-
-    if (!item->window()) {
-        // Fail silently to avoid warning
-        return;
-    }
-
-    const QSharedPointer<const QQuickItemGrabResult> grabResult = item->grabToImage();
-
-    QObject::connect(
-        grabResult.data(), &QQuickItemGrabResult::ready, this, [grabResult, rescaleSize, callback, this]() {
-            const auto future = QtConcurrent::run(&CUtils::findDominantColour, this, grabResult->image(), rescaleSize);
-            auto* watcher = new QFutureWatcher<QColor>(this);
-            auto* engine = qmlEngine(this);
-
-            QObject::connect(watcher, &QFutureWatcher<QColor>::finished, this, [=]() {
-                if (callback.isCallable()) {
-                    callback.call({ engine->toScriptValue(QVariant::fromValue(watcher->result())) });
-                }
-                watcher->deleteLater();
-            });
-            watcher->setFuture(future);
-        });
-}
-
-void CUtils::getDominantColour(const QString& path, QJSValue callback) {
-    this->getDominantColour(path, 128, callback);
-}
-
-void CUtils::getDominantColour(const QString& path, int rescaleSize, QJSValue callback) {
-    if (path.isEmpty()) {
-        qWarning() << "CUtils::getDominantColour: given path is empty";
-        return;
-    }
-
-    const auto future = QtConcurrent::run([=, this]() {
-        const QImage image(path);
-
-        if (image.isNull()) {
-            qWarning() << "CUtils::getDominantColour: failed to load image" << path;
-            return QColor();
-        }
-
-        return findDominantColour(image, rescaleSize);
-    });
-    auto* watcher = new QFutureWatcher<QColor>(this);
-    auto* engine = qmlEngine(this);
-
-    QObject::connect(watcher, &QFutureWatcher<QColor>::finished, this, [=]() {
-        if (watcher->result().isValid() && callback.isCallable()) {
-            callback.call({ engine->toScriptValue(QVariant::fromValue(watcher->result())) });
-        }
-        watcher->deleteLater();
-    });
-    watcher->setFuture(future);
-}
-
-QColor CUtils::findDominantColour(const QImage& image, int rescaleSize) const {
-    if (image.isNull()) {
-        qWarning() << "CUtils::findDominantColour: image is null";
-        return QColor();
-    }
-
-    QImage img = image;
-
-    if (rescaleSize > 0 && (img.width() > rescaleSize || img.height() > rescaleSize)) {
-        img = img.scaled(rescaleSize, rescaleSize, Qt::KeepAspectRatio, Qt::FastTransformation);
-    }
-
-    if (img.format() != QImage::Format_ARGB32) {
-        img = img.convertToFormat(QImage::Format_ARGB32);
-    }
-
-    std::unordered_map<quint32, int> colours;
-    const uchar* data = img.bits();
-    const int width = img.width();
-    const int height = img.height();
-    const qsizetype bytesPerLine = img.bytesPerLine();
-
-    for (int y = 0; y < height; ++y) {
-        const uchar* line = data + y * bytesPerLine;
-        for (int x = 0; x < width; ++x) {
-            const uchar* pixel = line + x * 4;
-
-            if (pixel[3] == 0) {
-                continue;
-            }
-
-            quint32 r = static_cast<quint32>(pixel[0] & 0xF8);
-            quint32 g = static_cast<quint32>(pixel[1] & 0xF8);
-            quint32 b = static_cast<quint32>(pixel[2] & 0xF8);
-
-            quint32 colour = (r << 16) | (g << 8) | b;
-            ++colours[colour];
-        }
-    }
-
-    quint32 dominantColour = 0;
-    int maxCount = 0;
-    for (const auto& [colour, count] : colours) {
-        if (count > maxCount) {
-            dominantColour = colour;
-            maxCount = count;
-        }
-    }
-
-    return QColor((0xFFu << 24) | dominantColour);
-}
-
-void CUtils::getAverageLuminance(QQuickItem* item, QJSValue callback) {
-    this->getAverageLuminance(item, 128, callback);
-}
-
-void CUtils::getAverageLuminance(QQuickItem* item, int rescaleSize, QJSValue callback) {
-    if (!item) {
-        qWarning() << "CUtils::getAverageLuminance: an item is required";
-        return;
-    }
-
-    if (!item->window()) {
-        // Fail silently to avoid warning
-        return;
-    }
-
-    const QSharedPointer<const QQuickItemGrabResult> grabResult = item->grabToImage();
-
-    QObject::connect(
-        grabResult.data(), &QQuickItemGrabResult::ready, this, [grabResult, rescaleSize, callback, this]() {
-            const auto future =
-                QtConcurrent::run(&CUtils::findAverageLuminance, this, grabResult->image(), rescaleSize);
-            auto* watcher = new QFutureWatcher<qreal>(this);
-
-            QObject::connect(watcher, &QFutureWatcher<qreal>::finished, this, [=]() {
-                if (callback.isCallable()) {
-                    callback.call({ QJSValue(watcher->result()) });
-                }
-                watcher->deleteLater();
-            });
-            watcher->setFuture(future);
-        });
-}
-
-void CUtils::getAverageLuminance(const QString& path, QJSValue callback) {
-    this->getAverageLuminance(path, 128, callback);
-}
-
-void CUtils::getAverageLuminance(const QString& path, int rescaleSize, QJSValue callback) {
-    if (path.isEmpty()) {
-        qWarning() << "CUtils::getAverageLuminance: given path is empty";
-        return;
-    }
-
-    const auto future = QtConcurrent::run([=, this]() {
-        const QImage image(path);
-
-        if (image.isNull()) {
-            qWarning() << "CUtils::getAverageLuminance: failed to load image" << path;
-            return 0.0;
-        }
-
-        return findAverageLuminance(image, rescaleSize);
-    });
-    auto* watcher = new QFutureWatcher<qreal>(this);
-
-    QObject::connect(watcher, &QFutureWatcher<qreal>::finished, this, [=]() {
-        if (callback.isCallable()) {
-            callback.call({ QJSValue(watcher->result()) });
-        }
-        watcher->deleteLater();
-    });
-    watcher->setFuture(future);
-}
-
-qreal CUtils::findAverageLuminance(const QImage& image, int rescaleSize) const {
-    if (image.isNull()) {
-        qWarning() << "CUtils::findAverageLuminance: image is null";
-        return 0.0;
-    }
-
-    QImage img = image;
-
-    if (rescaleSize > 0 && (img.width() > rescaleSize || img.height() > rescaleSize)) {
-        img = img.scaled(rescaleSize, rescaleSize, Qt::KeepAspectRatio, Qt::FastTransformation);
-    }
-
-    if (img.format() != QImage::Format_ARGB32) {
-        img = img.convertToFormat(QImage::Format_ARGB32);
-    }
-
-    const uchar* data = img.bits();
-    const int width = img.width();
-    const int height = img.height();
-    const qsizetype bytesPerLine = img.bytesPerLine();
-
-    qreal totalLuminance = 0.0;
-    int count = 0;
-
-    for (int y = 0; y < height; ++y) {
-        const uchar* line = data + y * bytesPerLine;
-        for (int x = 0; x < width; ++x) {
-            const uchar* pixel = line + x * 4;
-
-            if (pixel[3] == 0) {
-                continue;
-            }
-
-            const qreal r = pixel[0] / 255.0;
-            const qreal g = pixel[1] / 255.0;
-            const qreal b = pixel[2] / 255.0;
-
-            totalLuminance += std::sqrt(0.299 * r * r + 0.587 * g * g + 0.114 * b * b);
-            ++count;
-        }
-    }
-
-    return count == 0 ? 0.0 : totalLuminance / count;
-}
-
 QString CUtils::toLocalFile(const QUrl& url) const {
     if (!url.isLocalFile()) {
         qWarning() << "CUtils::toLocalFile: given url is not a local file" << url;
diff --git a/plugin/src/Caelestia/cutils.hpp b/plugin/src/Caelestia/cutils.hpp
index 57ece14..027226d 100644
--- a/plugin/src/Caelestia/cutils.hpp
+++ b/plugin/src/Caelestia/cutils.hpp
@@ -23,22 +23,7 @@ public:
 
     Q_INVOKABLE bool copyFile(const QUrl& source, const QUrl& target, bool overwrite = true) const;
     Q_INVOKABLE bool deleteFile(const QUrl& path) const;
-
-    Q_INVOKABLE void getDominantColour(QQuickItem* item, QJSValue callback);
-    Q_INVOKABLE void getDominantColour(QQuickItem* item, int rescaleSize, QJSValue callback);
-    Q_INVOKABLE void getDominantColour(const QString& path, QJSValue callback);
-    Q_INVOKABLE void getDominantColour(const QString& path, int rescaleSize, QJSValue callback);
-
-    Q_INVOKABLE void getAverageLuminance(QQuickItem* item, QJSValue callback);
-    Q_INVOKABLE void getAverageLuminance(QQuickItem* item, int rescaleSize, QJSValue callback);
-    Q_INVOKABLE void getAverageLuminance(const QString& path, QJSValue callback);
-    Q_INVOKABLE void getAverageLuminance(const QString& path, int rescaleSize, QJSValue callback);
-
     Q_INVOKABLE QString toLocalFile(const QUrl& url) const;
-
-private:
-    QColor findDominantColour(const QImage& image, int rescaleSize) const;
-    qreal findAverageLuminance(const QImage& image, int rescaleSize) const;
 };
 
 } // namespace caelestia
diff --git a/plugin/src/Caelestia/imageanalyser.cpp b/plugin/src/Caelestia/imageanalyser.cpp
new file mode 100644
index 0000000..31fe839
--- /dev/null
+++ b/plugin/src/Caelestia/imageanalyser.cpp
@@ -0,0 +1,223 @@
+#include "imageanalyser.hpp"
+
+#include <QtConcurrent/qtconcurrentrun.h>
+#include <QtQuick/qquickitemgrabresult.h>
+#include <qfuturewatcher.h>
+#include <qimage.h>
+#include <qquickwindow.h>
+
+namespace caelestia {
+
+ImageAnalyser::ImageAnalyser(QObject* parent)
+    : QObject(parent)
+    , m_futureWatcher(new QFutureWatcher<AnalyseResult>(this))
+    , m_source("")
+    , m_sourceItem(nullptr)
+    , m_rescaleSize(128)
+    , m_dominantColour(0, 0, 0)
+    , m_luminance(0) {
+    QObject::connect(m_futureWatcher, &QFutureWatcher<AnalyseResult>::finished, this, [this]() {
+        if (!m_futureWatcher->future().isResultReadyAt(0)) {
+            return;
+        }
+
+        const auto result = m_futureWatcher->result();
+        if (m_dominantColour != result.first) {
+            m_dominantColour = result.first;
+            emit dominantColourChanged();
+        }
+        if (qFuzzyCompare(m_luminance + 1.0, result.second + 1.0)) {
+            m_luminance = result.second;
+            emit luminanceChanged();
+        }
+    });
+}
+
+QString ImageAnalyser::source() const {
+    return m_source;
+}
+
+void ImageAnalyser::setSource(const QString& source) {
+    if (m_source == source) {
+        return;
+    }
+
+    m_source = source;
+    emit sourceChanged();
+
+    if (m_sourceItem) {
+        m_sourceItem = nullptr;
+        emit sourceItemChanged();
+    }
+
+    requestUpdate();
+}
+
+QQuickItem* ImageAnalyser::sourceItem() const {
+    return m_sourceItem;
+}
+
+void ImageAnalyser::setSourceItem(QQuickItem* sourceItem) {
+    if (m_sourceItem == sourceItem) {
+        return;
+    }
+
+    m_sourceItem = sourceItem;
+    emit sourceItemChanged();
+
+    if (!m_source.isEmpty()) {
+        m_source = "";
+        emit sourceChanged();
+    }
+
+    requestUpdate();
+}
+
+int ImageAnalyser::rescaleSize() const {
+    return m_rescaleSize;
+}
+
+void ImageAnalyser::setRescaleSize(int rescaleSize) {
+    if (m_rescaleSize == rescaleSize) {
+        return;
+    }
+
+    m_rescaleSize = rescaleSize;
+    emit rescaleSizeChanged();
+
+    requestUpdate();
+}
+
+QColor ImageAnalyser::dominantColour() const {
+    return m_dominantColour;
+}
+
+qreal ImageAnalyser::luminance() const {
+    return m_luminance;
+}
+
+void ImageAnalyser::requestUpdate() {
+    if (m_source.isEmpty() && !m_sourceItem) {
+        return;
+    }
+
+    if (!m_sourceItem || (m_sourceItem->window() && m_sourceItem->window()->isVisible() && m_sourceItem->width() > 0 &&
+                             m_sourceItem->height() > 0)) {
+        update();
+    } else if (m_sourceItem) {
+        if (!m_sourceItem->window()) {
+            QObject::connect(m_sourceItem, &QQuickItem::windowChanged, this, &ImageAnalyser::requestUpdate,
+                Qt::SingleShotConnection);
+        } else if (!m_sourceItem->window()->isVisible()) {
+            QObject::connect(m_sourceItem->window(), &QQuickWindow::visibleChanged, this, &ImageAnalyser::requestUpdate,
+                Qt::SingleShotConnection);
+        }
+        if (m_sourceItem->width() <= 0) {
+            QObject::connect(
+                m_sourceItem, &QQuickItem::widthChanged, this, &ImageAnalyser::requestUpdate, Qt::SingleShotConnection);
+        }
+        if (m_sourceItem->height() <= 0) {
+            QObject::connect(m_sourceItem, &QQuickItem::heightChanged, this, &ImageAnalyser::requestUpdate,
+                Qt::SingleShotConnection);
+        }
+    }
+}
+
+void ImageAnalyser::update() {
+    if (m_source.isEmpty() && !m_sourceItem) {
+        return;
+    }
+
+    if (m_futureWatcher->isRunning()) {
+        m_futureWatcher->cancel();
+    }
+
+    if (m_sourceItem) {
+        const QSharedPointer<const QQuickItemGrabResult> grabResult = m_sourceItem->grabToImage();
+        QObject::connect(grabResult.data(), &QQuickItemGrabResult::ready, this, [grabResult, this]() {
+            m_futureWatcher->setFuture(QtConcurrent::run(&ImageAnalyser::analyse, grabResult->image(), m_rescaleSize));
+        });
+    } else {
+        m_futureWatcher->setFuture(QtConcurrent::run([=, this](QPromise<AnalyseResult>& promise) {
+            const QImage image(m_source);
+            analyse(promise, image, m_rescaleSize);
+        }));
+    }
+}
+
+void ImageAnalyser::analyse(QPromise<AnalyseResult>& promise, const QImage& image, int rescaleSize) {
+    if (image.isNull()) {
+        qWarning() << "ImageAnalyser::analyse: image is null";
+        return;
+    }
+
+    QImage img = image;
+
+    if (rescaleSize > 0 && (img.width() > rescaleSize || img.height() > rescaleSize)) {
+        img = img.scaled(rescaleSize, rescaleSize, Qt::KeepAspectRatio, Qt::FastTransformation);
+    }
+
+    if (promise.isCanceled()) {
+        return;
+    }
+
+    if (img.format() != QImage::Format_ARGB32) {
+        img = img.convertToFormat(QImage::Format_ARGB32);
+    }
+
+    if (promise.isCanceled()) {
+        return;
+    }
+
+    const uchar* data = img.bits();
+    const int width = img.width();
+    const int height = img.height();
+    const qsizetype bytesPerLine = img.bytesPerLine();
+
+    std::unordered_map<quint32, int> colours;
+    qreal totalLuminance = 0.0;
+    int count = 0;
+
+    for (int y = 0; y < height; ++y) {
+        const uchar* line = data + y * bytesPerLine;
+        for (int x = 0; x < width; ++x) {
+            if (promise.isCanceled()) {
+                return;
+            }
+
+            const uchar* pixel = line + x * 4;
+
+            if (pixel[3] == 0) {
+                continue;
+            }
+
+            const quint32 mr = static_cast<quint32>(pixel[0] & 0xF8);
+            const quint32 mg = static_cast<quint32>(pixel[1] & 0xF8);
+            const quint32 mb = static_cast<quint32>(pixel[2] & 0xF8);
+            ++colours[(mr << 16) | (mg << 8) | mb];
+
+            const qreal r = pixel[0] / 255.0;
+            const qreal g = pixel[1] / 255.0;
+            const qreal b = pixel[2] / 255.0;
+            totalLuminance += std::sqrt(0.299 * r * r + 0.587 * g * g + 0.114 * b * b);
+            ++count;
+        }
+    }
+
+    quint32 dominantColour = 0;
+    int maxCount = 0;
+    for (const auto& [colour, colourCount] : colours) {
+        if (promise.isCanceled()) {
+            return;
+        }
+
+        if (colourCount > maxCount) {
+            dominantColour = colour;
+            maxCount = colourCount;
+        }
+    }
+
+    promise.addResult(qMakePair(QColor((0xFFu << 24) | dominantColour), count == 0 ? 0.0 : totalLuminance / count));
+}
+
+} // namespace caelestia
diff --git a/plugin/src/Caelestia/imageanalyser.hpp b/plugin/src/Caelestia/imageanalyser.hpp
new file mode 100644
index 0000000..bbea2b3
--- /dev/null
+++ b/plugin/src/Caelestia/imageanalyser.hpp
@@ -0,0 +1,61 @@
+#pragma once
+
+#include <QtQuick/qquickitem.h>
+#include <qfuture.h>
+#include <qfuturewatcher.h>
+#include <qobject.h>
+#include <qqmlintegration.h>
+
+namespace caelestia {
+
+class ImageAnalyser : public QObject {
+    Q_OBJECT
+    QML_ELEMENT
+
+    Q_PROPERTY(QString source READ source WRITE setSource NOTIFY sourceChanged)
+    Q_PROPERTY(QQuickItem* sourceItem READ sourceItem WRITE setSourceItem NOTIFY sourceItemChanged)
+    Q_PROPERTY(int rescaleSize READ rescaleSize WRITE setRescaleSize NOTIFY rescaleSizeChanged)
+    Q_PROPERTY(QColor dominantColour READ dominantColour NOTIFY dominantColourChanged)
+    Q_PROPERTY(qreal luminance READ luminance NOTIFY luminanceChanged)
+
+public:
+    explicit ImageAnalyser(QObject* parent = nullptr);
+
+    [[nodiscard]] QString source() const;
+    void setSource(const QString& source);
+
+    [[nodiscard]] QQuickItem* sourceItem() const;
+    void setSourceItem(QQuickItem* sourceItem);
+
+    [[nodiscard]] int rescaleSize() const;
+    void setRescaleSize(int rescaleSize);
+
+    [[nodiscard]] QColor dominantColour() const;
+    [[nodiscard]] qreal luminance() const;
+
+    Q_INVOKABLE void requestUpdate();
+
+signals:
+    void sourceChanged();
+    void sourceItemChanged();
+    void rescaleSizeChanged();
+    void dominantColourChanged();
+    void luminanceChanged();
+
+private:
+    using AnalyseResult = QPair<QColor, qreal>;
+
+    QFutureWatcher<AnalyseResult>* const m_futureWatcher;
+
+    QString m_source;
+    QQuickItem* m_sourceItem;
+    int m_rescaleSize;
+
+    QColor m_dominantColour;
+    qreal m_luminance;
+
+    void update();
+    static void analyse(QPromise<AnalyseResult>& promise, const QImage& image, int rescaleSize);
+};
+
+} // namespace caelestia