Refactor QQuickIconLoader.

Instead using a QObject with a single icon member variable
that needs to be instantiated for each task bar button, introduce a static
load function that takes a member function pointer accepting a QVariant.
For synchronous requests, invoke it immediately; connect it to a slot
for network requests.

Task-number: QTBUG-36730
Change-Id: Ic70422d98d0bc3d486b32fb3534400b9fff8d324
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

6 files changed, 178 insertions, 108 deletions

diff --git a/src/imports/winextras/qquickiconloader.cpp b/src/imports/winextras/qquickiconloader.cpp
index e1b7506..5ed7445 100644
--- a/src/imports/winextras/qquickiconloader.cpp
+++ b/src/imports/winextras/qquickiconloader.cpp
@@ -1,7 +1,7 @@
 /****************************************************************************
  **
  ** Copyright (C) 2013 Ivan Vizir <define-true-false@yandex.com>
- ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+ ** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
  ** Contact: http://www.qt-project.org/legal
  **
  ** This file is part of the QtWinExtras module of the Qt Toolkit.
@@ -42,105 +42,110 @@
 
 #include "qquickiconloader_p.h"
 
-#include <QUrl>
 #include <QQmlEngine>
 #include <QNetworkAccessManager>
 #include <QFileInfo>
 #include <QNetworkRequest>
 #include <QNetworkReply>
-#include <QPixmap>
 #include <QQuickImageProvider>
 #include <QQmlFile>
 #include <qt_windows.h>
-#include <QDebug>
 
 QT_BEGIN_NAMESPACE
 
-QQuickIconLoader::QQuickIconLoader(QObject *parent) :
-    QObject(parent)
+QVariant QQuickIconLoader::loadFromFile(const QUrl &url, QVariant::Type type)
 {
-}
-
-void QQuickIconLoader::load(const QUrl &url, QQmlEngine *engine)
-{
-    m_icon = QIcon();
-    QString scheme = url.scheme();
-    if (scheme == QLatin1String("qrc") || scheme == QLatin1String("file"))
-        loadFromFile(url);
-    else if (scheme == QLatin1String("http") || scheme == QLatin1String("https"))
-        loadFromNetwork(url, engine);
-    else if (scheme == QLatin1String("image"))
-        loadFromImageProvider(url, engine);
-}
-
-QIcon QQuickIconLoader::icon() const
-{
-    return m_icon;
-}
-
-void QQuickIconLoader::onRequestFinished(QNetworkReply *reply)
-{
-    disconnect(reply->manager(), 0, this, 0);
-    if (reply->error() == QNetworkReply::NoError) {
-        QByteArray data = reply->readAll();
-        QPixmap pixmap;
-        if (pixmap.loadFromData(data)) {
-            m_icon = QIcon(pixmap);
-            emit finished();
-        }
-    } else {
-        qWarning().nospace() << "Cannot load " << reply->url().toString() << " (" << qPrintable(reply->errorString()) << ")";
-    }
-    reply->deleteLater();
-}
-
-void QQuickIconLoader::loadFromFile(const QUrl &url)
-{
-    QString path = QQmlFile::urlToLocalFileOrQrc(url);
+    const QString path = QQmlFile::urlToLocalFileOrQrc(url);
     if (QFileInfo(path).exists()) {
-        m_icon = QIcon(path);
-        emit finished();
+        switch (type) {
+        case QMetaType::QIcon:
+            return QVariant(QIcon(path));
+        case QMetaType::QPixmap:
+            return QVariant(QPixmap(path));
+        default:
+            qWarning("%s: Unsupported type: %d", Q_FUNC_INFO, int(type));
+            break;
+        }
     }
+    return QVariant();
 }
 
-void QQuickIconLoader::loadFromNetwork(const QUrl &url, QQmlEngine *engine)
+QNetworkReply *QQuickIconLoader::loadFromNetwork(const QUrl &url, const QQmlEngine *engine)
 {
-    QNetworkRequest request(url);
-    QNetworkAccessManager *manager = engine->networkAccessManager();
-    connect(manager, SIGNAL(finished(QNetworkReply*)), SLOT(onRequestFinished(QNetworkReply*)));
-    manager->get(request);
+    return engine->networkAccessManager()->get(QNetworkRequest(url));
 }
 
-static inline QString imageProviderId(const QUrl &url)
-{
-    return url.host();
-}
-
-static inline QString imageId(const QUrl &url)
-{
-    return url.toString(QUrl::RemoveScheme | QUrl::RemoveAuthority).mid(1);
-}
-
-void QQuickIconLoader::loadFromImageProvider(const QUrl &url, QQmlEngine *engine)
+QVariant QQuickIconLoader::loadFromImageProvider(const QUrl &url, const QQmlEngine *engine,
+                                                  QVariant::Type type, QSize requestedSize)
 {
     const QString providerId = url.host();
     const QString imageId = url.toString(QUrl::RemoveScheme | QUrl::RemoveAuthority).mid(1);
     QQuickImageProvider::ImageType imageType = QQuickImageProvider::Invalid;
     QQuickImageProvider *provider = static_cast<QQuickImageProvider *>(engine->imageProvider(providerId));
     QSize size;
-    QSize requestSize(GetSystemMetrics(SM_CXICON), GetSystemMetrics(SM_CYICON));
+    if (!requestedSize.isValid())
+        requestedSize = QSize(GetSystemMetrics(SM_CXICON), GetSystemMetrics(SM_CYICON));
     if (provider)
         imageType = provider->imageType();
-    if (imageType == QQuickImageProvider::Image) {
-        QImage image = provider->requestImage(imageId, &size, requestSize);
+    QPixmap pixmap;
+    switch (imageType) {
+    case QQuickImageProvider::Image: {
+        QImage image = provider->requestImage(imageId, &size, requestedSize);
         if (!image.isNull())
-            m_icon = QIcon(QPixmap::fromImage(image));
-    } else if (imageType == QQuickImageProvider::Pixmap) {
-        QPixmap pixmap = provider->requestPixmap(imageId, &size, requestSize);
-        if (!pixmap.isNull())
-            m_icon = QIcon(pixmap);
+            pixmap = QPixmap::fromImage(image);
+    }
+        break;
+    case QQuickImageProvider::Pixmap:
+        pixmap = provider->requestPixmap(imageId, &size, requestedSize);
+        break;
+    default:
+        break;
     }
-    emit finished();
+    if (!pixmap.isNull()) {
+        switch (type) {
+        case QMetaType::QIcon:
+            return QVariant(QIcon(pixmap));
+        case QMetaType::QPixmap:
+            return QVariant(pixmap);
+        default:
+            qWarning("%s: Unsupported type: %d", Q_FUNC_INFO, int(type));
+            break;
+        }
+    }
+    return QVariant();
+}
+
+QQuickIconLoaderNetworkReplyHandler::QQuickIconLoaderNetworkReplyHandler(QNetworkReply *reply, QVariant::Type type)
+    : QObject(reply)
+    , m_type(type)
+{
+    connect(reply, &QNetworkReply::finished, this, &QQuickIconLoaderNetworkReplyHandler::onRequestFinished);
+}
+
+void QQuickIconLoaderNetworkReplyHandler::onRequestFinished()
+{
+    QNetworkReply *reply = qobject_cast<QNetworkReply *>(sender());
+    Q_ASSERT(reply);
+    if (reply->error() != QNetworkReply::NoError) {
+        qWarning() << Q_FUNC_INFO << reply->url() << "failed:" << reply->errorString();
+        return;
+    }
+    const QByteArray data = reply->readAll();
+    QPixmap pixmap;
+    if (pixmap.loadFromData(data)) {
+        switch (m_type) {
+        case QMetaType::QIcon:
+            emit finished(QVariant(QIcon(pixmap)));
+            break;
+        case QMetaType::QPixmap:
+            emit finished(QVariant(pixmap));
+            break;
+        default:
+            qWarning("%s: Unsupported type: %d", Q_FUNC_INFO, int(m_type));
+            break;
+        }
+    }
+    reply->deleteLater();
 }
 
 QT_END_NAMESPACE
diff --git a/src/imports/winextras/qquickiconloader_p.h b/src/imports/winextras/qquickiconloader_p.h
index 0df9b01..3d4d13d 100644
--- a/src/imports/winextras/qquickiconloader_p.h
+++ b/src/imports/winextras/qquickiconloader_p.h
@@ -1,7 +1,7 @@
 /****************************************************************************
  **
  ** Copyright (C) 2013 Ivan Vizir <define-true-false@yandex.com>
- ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+ ** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
  ** Contact: http://www.qt-project.org/legal
  **
  ** This file is part of the QtWinExtras module of the Qt Toolkit.
@@ -44,7 +44,11 @@
 #define QQUICKICONLOADER_P_H
 
 #include <QObject>
+#include <QVariant>
+#include <QUrl>
 #include <QIcon>
+#include <QPixmap>
+#include <QDebug>
 
 QT_BEGIN_NAMESPACE
 
@@ -52,29 +56,77 @@ class QIcon;
 class QQmlEngine;
 class QNetworkReply;
 
-class QQuickIconLoader : public QObject
+class QQuickIconLoader
+{
+public:
+    enum LoadResult {
+        LoadOk,
+        LoadError,
+        LoadNetworkRequestStarted,
+    };
+
+    // Load a QIcon (pass type = QMetaType::QIcon) or a QPixmap (pass type =
+    // QMetaType::QPixmap) from url. The function takes an object and member
+    // function pointer to a slot accepting a QVariant. For resources that can
+    // loaded synchronously ("file", "qrc" or "image"), the member function pointer
+    // will be invoked immediately with the result. For network resources, it will be
+    // connected to an object handling the network reply and invoked once it finishes.
+    template <typename Object>
+    static LoadResult load(const QUrl &url, const QQmlEngine *engine,
+                           QVariant::Type type, const QSize &requestedSize,
+                           Object *receiver, void (Object::*function)(const QVariant &));
+
+private:
+    QQuickIconLoader() {}
+    static QVariant loadFromFile(const QUrl &url, QVariant::Type type);
+    static QVariant loadFromImageProvider(const QUrl &url, const QQmlEngine *engine,
+                                          QVariant::Type type, QSize requestedSize);
+    static QNetworkReply *loadFromNetwork(const QUrl &url, const QQmlEngine *engine);
+};
+
+// Internal handler which loads the resource once QNetworkReply finishes
+class QQuickIconLoaderNetworkReplyHandler : public QObject
 {
     Q_OBJECT
 
 public:
-    explicit QQuickIconLoader(QObject *parent = 0);
-    void load(const QUrl &url, QQmlEngine *engine);
-    QIcon icon() const;
+    explicit QQuickIconLoaderNetworkReplyHandler(QNetworkReply *reply, QVariant::Type);
 
 Q_SIGNALS:
-    void finished();
+    void finished(const QVariant &);
 
 private Q_SLOTS:
-    void onRequestFinished(QNetworkReply*);
+    void onRequestFinished();
 
 private:
-    void loadFromFile(const QUrl &url);
-    void loadFromNetwork(const QUrl &url, QQmlEngine *engine);
-    void loadFromImageProvider(const QUrl &url, QQmlEngine *engine);
-
-    QIcon m_icon;
+    const QVariant::Type m_type;
 };
 
+template <typename Object>
+QQuickIconLoader::LoadResult
+    QQuickIconLoader::load(const QUrl &url, const QQmlEngine *engine,
+                           QVariant::Type type, const QSize &requestedSize,
+                           Object *receiver, void (Object::*function)(const QVariant &))
+{
+    const QString scheme = url.scheme();
+    if (scheme.startsWith(QLatin1String("http"))) {
+        if (QNetworkReply *reply = QQuickIconLoader::loadFromNetwork(url, engine)) {
+            QQuickIconLoaderNetworkReplyHandler *handler = new QQuickIconLoaderNetworkReplyHandler(reply, type);
+            QObject::connect(handler, &QQuickIconLoaderNetworkReplyHandler::finished, receiver, function);
+            return LoadNetworkRequestStarted;
+        }
+        return LoadError;
+    }
+    const QVariant resource = scheme == QLatin1String("image")
+        ? QQuickIconLoader::loadFromImageProvider(url, engine, type, requestedSize)
+        : QQuickIconLoader::loadFromFile(url, type); // qrc, file
+    if (resource.isValid()) {
+        (receiver->*function)(resource);
+        return LoadOk;
+    }
+    return LoadError;
+}
+
 QT_END_NAMESPACE
 
 #endif // QQUICKICONLOADER_P_H
diff --git a/src/imports/winextras/qquicktaskbarbutton.cpp b/src/imports/winextras/qquicktaskbarbutton.cpp
index 97e0765..b644b78 100644
--- a/src/imports/winextras/qquicktaskbarbutton.cpp
+++ b/src/imports/winextras/qquicktaskbarbutton.cpp
@@ -1,7 +1,7 @@
 /****************************************************************************
  **
  ** Copyright (C) 2013 Ivan Vizir <define-true-false@yandex.com>
- ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+ ** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
  ** Contact: http://www.qt-project.org/legal
  **
  ** This file is part of the QtWinExtras module of the Qt Toolkit.
@@ -41,7 +41,10 @@
  ****************************************************************************/
 
 #include "qquicktaskbarbutton_p.h"
+#include "qquickiconloader_p.h"
+
 #include <QQuickWindow>
+#include <QVariant>
 
 QT_BEGIN_NAMESPACE
 
@@ -73,7 +76,6 @@ QT_BEGIN_NAMESPACE
 QQuickTaskbarOverlay::QQuickTaskbarOverlay(QWinTaskbarButton *button, QObject *parent) :
     QObject(parent), m_button(button)
 {
-    connect(&m_loader, SIGNAL(finished()), SLOT(iconLoaded()));
 }
 
 QUrl QQuickTaskbarOverlay::iconSource() const
@@ -83,10 +85,20 @@ QUrl QQuickTaskbarOverlay::iconSource() const
 
 void QQuickTaskbarOverlay::setIconSource(const QUrl &iconSource)
 {
-    if (m_iconSource != iconSource) {
+    if (m_iconSource == iconSource)
+        return;
+
+    if (iconSource.isEmpty()) {
+        m_button->clearOverlayIcon();
+        m_iconSource = iconSource;
+        emit iconSourceChanged();
+        return;
+    }
+
+    if (QQuickIconLoader::load(iconSource, qmlEngine(parent()), QVariant::Icon, QSize(),
+                               this, &QQuickTaskbarOverlay::iconLoaded) != QQuickIconLoader::LoadError) {
         m_iconSource = iconSource;
         emit iconSourceChanged();
-        m_loader.load(m_iconSource, qmlEngine(parent()));
     }
 }
 
@@ -103,11 +115,9 @@ void QQuickTaskbarOverlay::setAccessibleDescription(const QString &description)
     }
 }
 
-void QQuickTaskbarOverlay::iconLoaded()
+void QQuickTaskbarOverlay::iconLoaded(const QVariant &value)
 {
-    QIcon icon = m_loader.icon();
-    if (!icon.isNull())
-        m_button->setOverlayIcon(icon);
+    m_button->setOverlayIcon(value.value<QIcon>());
 }
 
 QQuickTaskbarButton::QQuickTaskbarButton(QQuickItem *parent) : QQuickItem(parent),
diff --git a/src/imports/winextras/qquicktaskbarbutton_p.h b/src/imports/winextras/qquicktaskbarbutton_p.h
index d24947d..2849dab 100644
--- a/src/imports/winextras/qquicktaskbarbutton_p.h
+++ b/src/imports/winextras/qquicktaskbarbutton_p.h
@@ -47,10 +47,9 @@
 #include <QWinTaskbarButton>
 #include <QWinTaskbarProgress>
 
-#include "qquickiconloader_p.h"
-
 QT_BEGIN_NAMESPACE
 
+class QVariant;
 class QQuickTaskbarButtonPrivate;
 
 class QQuickTaskbarOverlay : public QObject
@@ -73,11 +72,10 @@ Q_SIGNALS:
     void accessibleDescriptionChanged();
 
 private Q_SLOTS:
-    void iconLoaded();
+    void iconLoaded(const QVariant &);
 
 private:
     QUrl m_iconSource;
-    QQuickIconLoader m_loader;
     QWinTaskbarButton *m_button;
 };
 
diff --git a/src/imports/winextras/qquickthumbnailtoolbutton.cpp b/src/imports/winextras/qquickthumbnailtoolbutton.cpp
index 7f84988..31875e7 100644
--- a/src/imports/winextras/qquickthumbnailtoolbutton.cpp
+++ b/src/imports/winextras/qquickthumbnailtoolbutton.cpp
@@ -1,7 +1,7 @@
 /****************************************************************************
  **
  ** Copyright (C) 2013 Ivan Vizir <define-true-false@yandex.com>
- ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+ ** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
  ** Contact: http://www.qt-project.org/legal
  **
  ** This file is part of the QtWinExtras module of the Qt Toolkit.
@@ -41,6 +41,7 @@
  ****************************************************************************/
 
 #include "qquickthumbnailtoolbutton_p.h"
+#include "qquickiconloader_p.h"
 
 #include <QWinThumbnailToolButton>
 
@@ -66,7 +67,6 @@ QQuickThumbnailToolButton::QQuickThumbnailToolButton(QObject *parent) :
     QObject(parent), m_button(new QWinThumbnailToolButton(this))
 {
     connect(m_button, SIGNAL(clicked()), SIGNAL(clicked()));
-    connect(&m_loader, SIGNAL(finished()), SLOT(iconLoaded()));
 }
 
 QQuickThumbnailToolButton::~QQuickThumbnailToolButton()
@@ -80,10 +80,19 @@ QQuickThumbnailToolButton::~QQuickThumbnailToolButton()
  */
 void QQuickThumbnailToolButton::setIconSource(const QUrl &iconSource)
 {
-    if (m_iconSource != iconSource) {
+    if (m_iconSource == iconSource)
+        return;
+
+    if (iconSource.isEmpty()) {
+        m_button->setIcon(QIcon());
+        m_iconSource = iconSource;
+        emit iconSourceChanged();
+    }
+
+    if (QQuickIconLoader::load(iconSource, qmlEngine(this), QVariant::Icon, QSize(),
+                               this, &QQuickThumbnailToolButton::iconLoaded) != QQuickIconLoader::LoadError) {
         m_iconSource = iconSource;
         emit iconSourceChanged();
-        m_loader.load(m_iconSource, qmlEngine(this));
     }
 }
 
@@ -213,11 +222,10 @@ bool QQuickThumbnailToolButton::isFlat() const
     return m_button->isFlat();
 }
 
-void QQuickThumbnailToolButton::iconLoaded()
+void QQuickThumbnailToolButton::iconLoaded(const QVariant &value)
 {
-    QIcon icon = m_loader.icon();
-    if (!icon.isNull())
-        m_button->setIcon(icon);
+    if (value.isValid())
+        m_button->setIcon(value.value<QIcon>());
 }
 
 QT_END_NAMESPACE
diff --git a/src/imports/winextras/qquickthumbnailtoolbutton_p.h b/src/imports/winextras/qquickthumbnailtoolbutton_p.h
index 82fcdae..8235206 100644
--- a/src/imports/winextras/qquickthumbnailtoolbutton_p.h
+++ b/src/imports/winextras/qquickthumbnailtoolbutton_p.h
@@ -1,7 +1,7 @@
 /****************************************************************************
  **
  ** Copyright (C) 2013 Ivan Vizir <define-true-false@yandex.com>
- ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+ ** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
  ** Contact: http://www.qt-project.org/legal
  **
  ** This file is part of the QtWinExtras module of the Qt Toolkit.
@@ -47,8 +47,6 @@
 #include <QWinThumbnailToolBar>
 #include <QUrl>
 
-#include "qquickiconloader_p.h"
-
 QT_BEGIN_NAMESPACE
 
 class QQuickThumbnailToolButton : public QObject
@@ -92,12 +90,11 @@ Q_SIGNALS:
     void flatChanged();
 
 private Q_SLOTS:
-    void iconLoaded();
+    void iconLoaded(const QVariant &);
 
 private:
     QUrl m_iconSource;
     QWinThumbnailToolButton *m_button;
-    QQuickIconLoader m_loader;
 
     friend class QQuickThumbnailToolBar;
 };