Add API for favicon database

[ChangeLog][QtWebEngineCore][QWebEngineProfile] Add new API
to access icon database asynchronously.
[ChangeLog][QtWebEngineQuick] image:/favicon/ URLs now can be used to access
icon database.

Task-number: QTBUG-51184
Change-Id: I6096ad9a4210670ed59458c4fa099a02595e8a1e
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
(cherry picked from commit 2ad450018e8ae22f4c426a421fa5c0995feb1e16)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

6 files changed, 250 insertions, 34 deletions

diff --git a/src/webenginequick/api/qquickwebenginefaviconprovider.cpp b/src/webenginequick/api/qquickwebenginefaviconprovider.cpp
index 23397003e..d19954620 100644
--- a/src/webenginequick/api/qquickwebenginefaviconprovider.cpp
+++ b/src/webenginequick/api/qquickwebenginefaviconprovider.cpp
@@ -39,10 +39,13 @@
 
 #include "qquickwebenginefaviconprovider_p_p.h"
 
-#include "qquickwebengineview_p.h"
+#include "profile_adapter.h"
+#include "qquickwebenginesettings_p.h"
 #include "qquickwebengineview_p_p.h"
 #include "web_contents_adapter.h"
 
+#include <QtCore/QMimeDatabase>
+#include <QtCore/QTimer>
 #include <QtGui/QIcon>
 #include <QtGui/QPixmap>
 
@@ -95,14 +98,155 @@ static QPixmap extractPixmap(const QIcon &icon, const QSize &requestedSize)
     return iconPixmap.scaled(requestedSize, Qt::KeepAspectRatio, Qt::SmoothTransformation).copy();
 }
 
+static bool isIconURL(const QUrl &url)
+{
+    QMimeType mimeType = QMimeDatabase().mimeTypeForFile(url.path(), QMimeDatabase::MatchExtension);
+
+    // Check file extension.
+    if (mimeType.name().startsWith(QLatin1String("image")))
+        return true;
+
+    // Check if it is an image data: URL.
+    if (url.scheme() == QLatin1String("data") && url.path().startsWith(QLatin1String("image")))
+        return true;
+
+    return false;
+}
+
 static QQuickWebEngineView *findViewById(const QString &id, QList<QQuickWebEngineView *> *views)
 {
+    QQuickWebEngineView *result = nullptr;
     for (QQuickWebEngineView *view : *views) {
-        if (view->icon() == QQuickWebEngineFaviconProvider::faviconProviderUrl(QUrl(id)))
-            return view;
+        if (isIconURL(QUrl(id))) {
+            if (view->icon() == QQuickWebEngineFaviconProvider::faviconProviderUrl(QUrl(id))) {
+                result = view;
+                break;
+            }
+        } else if (view->url() == QUrl(id)) {
+            result = view;
+            break;
+        }
+    }
+
+    return result;
+}
+
+FaviconImageResponseRunnable::FaviconImageResponseRunnable(const QString &id,
+                                                           const QSize &requestedSize,
+                                                           QList<QQuickWebEngineView *> *views)
+    : m_id(id), m_requestedSize(requestedSize), m_views(views)
+{
+}
+
+void FaviconImageResponseRunnable::run()
+{
+    if (tryNextView() == -1) {
+        // There is no non-otr view to access icon database.
+        Q_EMIT done(QPixmap());
+    }
+}
+
+void FaviconImageResponseRunnable::iconRequestDone(const QIcon &icon)
+{
+    if (icon.isNull()) {
+        if (tryNextView() == -1) {
+            // Ran out of views.
+            Q_EMIT done(QPixmap());
+        }
+        return;
+    }
+
+    Q_EMIT done(extractPixmap(icon, m_requestedSize).copy());
+}
+
+int FaviconImageResponseRunnable::tryNextView()
+{
+    for (; m_nextViewIndex < m_views->size(); ++m_nextViewIndex) {
+        QQuickWebEngineView *view = m_views->at(m_nextViewIndex);
+        if (view->profile()->isOffTheRecord())
+            continue;
+
+        requestIconOnUIThread(view);
+
+        return m_nextViewIndex++;
     }
 
-    return nullptr;
+    return -1;
+}
+
+void FaviconImageResponseRunnable::requestIconOnUIThread(QQuickWebEngineView *view)
+{
+    QTimer *timer = new QTimer();
+    timer->moveToThread(qApp->thread());
+    timer->setSingleShot(true);
+    QObject::connect(timer, &QTimer::timeout, [=]() {
+        QtWebEngineCore::ProfileAdapter *profileAdapter = view->d_ptr->profileAdapter();
+        bool touchIconsEnabled = view->profile()->settings()->touchIconsEnabled();
+        if (isIconURL(QUrl(m_id))) {
+            profileAdapter->requestIconForIconURL(QUrl(m_id),
+                                                  qMax(m_requestedSize.width(), m_requestedSize.height()),
+                                                  touchIconsEnabled,
+                                                  [this](const QIcon &icon, const QUrl &) { iconRequestDone(icon); });
+        } else {
+            profileAdapter->requestIconForPageURL(QUrl(m_id),
+                                                  qMax(m_requestedSize.width(), m_requestedSize.height()),
+                                                  touchIconsEnabled,
+                                                  [this](const QIcon &icon, const QUrl &, const QUrl &) { iconRequestDone(icon); });
+        }
+        timer->deleteLater();
+    });
+    QMetaObject::invokeMethod(timer, "start", Qt::QueuedConnection, Q_ARG(int, 0));
+}
+
+FaviconImageResponse::FaviconImageResponse()
+{
+    Q_EMIT finished();
+}
+
+FaviconImageResponse::FaviconImageResponse(const QString &id, const QSize &requestedSize,
+                                           QList<QQuickWebEngineView *> *views, QThreadPool *pool)
+{
+    if (QQuickWebEngineView *view = findViewById(id, views)) {
+        QTimer *timer = new QTimer();
+        timer->moveToThread(qApp->thread());
+        timer->setSingleShot(true);
+        QObject::connect(timer, &QTimer::timeout, [=]() {
+            QIcon icon = view->d_ptr->adapter->icon();
+            if (icon.isNull())
+                startRunnable(id, requestedSize, views, pool);
+            else
+                handleDone(extractPixmap(icon, requestedSize).copy());
+            timer->deleteLater();
+        });
+        QMetaObject::invokeMethod(timer, "start", Qt::QueuedConnection, Q_ARG(int, 0));
+    } else {
+        startRunnable(id, requestedSize, views, pool);
+    }
+}
+
+FaviconImageResponse::~FaviconImageResponse() { }
+
+void FaviconImageResponse::handleDone(QPixmap pixmap)
+{
+    if (m_runnable)
+        delete m_runnable;
+    m_image = pixmap.toImage();
+    Q_EMIT finished();
+}
+
+QQuickTextureFactory *FaviconImageResponse::textureFactory() const
+{
+    return QQuickTextureFactory::textureFactoryForImage(m_image);
+}
+
+void FaviconImageResponse::startRunnable(const QString &id, const QSize &requestedSize,
+                                         QList<QQuickWebEngineView *> *views, QThreadPool *pool)
+{
+    m_runnable = new FaviconImageResponseRunnable(id, requestedSize, views);
+    m_runnable->setAutoDelete(false);
+    connect(m_runnable, &FaviconImageResponseRunnable::done, this,
+            &FaviconImageResponse::handleDone);
+    pool->start(m_runnable);
 }
 
 QString QQuickWebEngineFaviconProvider::identifier()
@@ -128,31 +272,18 @@ QUrl QQuickWebEngineFaviconProvider::faviconProviderUrl(const QUrl &url)
     return providerUrl;
 }
 
-QQuickWebEngineFaviconProvider::QQuickWebEngineFaviconProvider()
-    : QQuickImageProvider(QQuickImageProvider::Pixmap)
-{
-}
+QQuickWebEngineFaviconProvider::QQuickWebEngineFaviconProvider() { }
 
 QQuickWebEngineFaviconProvider::~QQuickWebEngineFaviconProvider() { }
 
-QPixmap QQuickWebEngineFaviconProvider::requestPixmap(const QString &id, QSize *size,
-                                                      const QSize &requestedSize)
+QQuickImageResponse *
+QQuickWebEngineFaviconProvider::requestImageResponse(const QString &id, const QSize &requestedSize)
 {
-    Q_UNUSED(size);
-    Q_UNUSED(requestedSize);
-
-    if (m_views.isEmpty())
-        return QPixmap();
-
-    QQuickWebEngineView *view = findViewById(id, &m_views);
-    if (!view)
-        return QPixmap();
-
-    QIcon icon = view->d_ptr->adapter->icon();
-    if (icon.isNull())
-        return QPixmap();
+    if (m_views.empty())
+        return new FaviconImageResponse;
 
-    return extractPixmap(icon, requestedSize).copy();
+    FaviconImageResponse *response = new FaviconImageResponse(id, requestedSize, &m_views, &m_pool);
+    return response;
 }
 
 QT_END_NAMESPACE
diff --git a/src/webenginequick/api/qquickwebenginefaviconprovider_p_p.h b/src/webenginequick/api/qquickwebenginefaviconprovider_p_p.h
index 922f8b3ac..68e23fbcf 100644
--- a/src/webenginequick/api/qquickwebenginefaviconprovider_p_p.h
+++ b/src/webenginequick/api/qquickwebenginefaviconprovider_p_p.h
@@ -53,13 +53,57 @@
 
 #include <QtWebEngineQuick/private/qtwebenginequickglobal_p.h>
 #include <QtCore/QList>
+#include <QtCore/QRunnable>
+#include <QtCore/QThreadPool>
+#include <QtGui/QImage>
 #include <QtQuick/QQuickImageProvider>
 
 QT_BEGIN_NAMESPACE
 
 class QQuickWebEngineView;
 
-class Q_WEBENGINE_PRIVATE_EXPORT QQuickWebEngineFaviconProvider : public QQuickImageProvider
+class FaviconImageResponseRunnable : public QObject, public QRunnable
+{
+    Q_OBJECT
+
+public:
+    FaviconImageResponseRunnable(const QString &id, const QSize &requestedSize,
+                                 QList<QQuickWebEngineView *> *views);
+    void run() override;
+    void iconRequestDone(const QIcon &icon);
+
+signals:
+    void done(QPixmap pixmap);
+
+private:
+    int tryNextView();
+    void requestIconOnUIThread(QQuickWebEngineView *view);
+
+    QString m_id;
+    QSize m_requestedSize;
+    QList<QQuickWebEngineView *> *m_views;
+    int m_nextViewIndex = 0;
+};
+
+class FaviconImageResponse : public QQuickImageResponse
+{
+public:
+    FaviconImageResponse();
+    FaviconImageResponse(const QString &id, const QSize &requestedSize,
+                         QList<QQuickWebEngineView *> *views, QThreadPool *pool);
+    ~FaviconImageResponse();
+    void handleDone(QPixmap pixmap);
+    QQuickTextureFactory *textureFactory() const override;
+
+private:
+    void startRunnable(const QString &id, const QSize &requestedSize,
+                       QList<QQuickWebEngineView *> *views, QThreadPool *pool);
+
+    FaviconImageResponseRunnable *m_runnable = nullptr;
+    QImage m_image;
+};
+
+class Q_WEBENGINE_PRIVATE_EXPORT QQuickWebEngineFaviconProvider : public QQuickAsyncImageProvider
 {
 public:
     static QString identifier();
@@ -71,9 +115,11 @@ public:
     void attach(QQuickWebEngineView *view) { m_views.append(view); }
     void detach(QQuickWebEngineView *view) { m_views.removeAll(view); }
 
-    QPixmap requestPixmap(const QString &, QSize *, const QSize &) override;
+    QQuickImageResponse *requestImageResponse(const QString &id,
+                                              const QSize &requestedSize) override;
 
 private:
+    QThreadPool m_pool;
     QList<QQuickWebEngineView *> m_views;
 };
 
diff --git a/src/webenginequick/api/qquickwebengineprofile.h b/src/webenginequick/api/qquickwebengineprofile.h
index f93c3a5d4..8147f0432 100644
--- a/src/webenginequick/api/qquickwebengineprofile.h
+++ b/src/webenginequick/api/qquickwebengineprofile.h
@@ -177,6 +177,7 @@ private:
     QQuickWebEngineProfile(QQuickWebEngineProfilePrivate *, QObject *parent = nullptr);
     QQuickWebEngineSettings *settings() const;
 
+    friend class FaviconImageResponseRunnable;
     friend class QQuickWebEngineSettings;
     friend class QQuickWebEngineSingleton;
     friend class QQuickWebEngineViewPrivate;
diff --git a/src/webenginequick/api/qquickwebengineview_p.h b/src/webenginequick/api/qquickwebengineview_p.h
index b3c092856..2719fa448 100644
--- a/src/webenginequick/api/qquickwebengineview_p.h
+++ b/src/webenginequick/api/qquickwebengineview_p.h
@@ -563,7 +563,8 @@ private:
 
     friend class QtWebEngineCore::RenderWidgetHostViewQtDelegateQuick;
     friend class QQuickContextMenuBuilder;
-    friend class QQuickWebEngineFaviconProvider;
+    friend class FaviconImageResponse;
+    friend class FaviconImageResponseRunnable;
 #ifndef QT_NO_ACCESSIBILITY
     friend class QQuickWebEngineViewAccessible;
 #endif // QT_NO_ACCESSIBILITY
diff --git a/src/webenginequick/doc/src/qtwebengine-features.qdoc b/src/webenginequick/doc/src/qtwebengine-features.qdoc
index 431367765..24bc9d7aa 100644
--- a/src/webenginequick/doc/src/qtwebengine-features.qdoc
+++ b/src/webenginequick/doc/src/qtwebengine-features.qdoc
@@ -54,6 +54,7 @@
         \li \l{View Source}
         \li \l{webrtc_feature}{WebRTC}
         \li \l{Web Notifications}
+        \li \l{Favicon Handling}
     \endlist
 
     \section1 Audio and Video Codecs
@@ -641,4 +642,42 @@
     {WebEngineView.Notifications}.
 
     Support for this feature was added in Qt 5.13.0.
+
+    \section1 Favicon Handling
+
+    For accessing icons a \c QQuickImageProvider is registered. This provider can be
+    accessed by a special URL where the scheme is "image:" and the host is "favicon".
+    For example,
+    \qml
+    Image {
+        source: "image://favicon/url"
+    }
+    \endqml
+
+    The \c url can be  the URL of the favicon. For example,
+    \qml
+    Image {
+        source: "image://favicon/https://www.qt.io/hubfs/2016_Qt_Logo/qt_logo_green_rgb_16x16.png"
+    }
+    \endqml
+
+    The \c url also can be a page URL to access its icon. For example,
+    \qml
+    Image {
+        source: "image://favicon/https://www.qt.io/"
+    }
+    \endqml
+
+    If more than one icon is available, the \l {Image::sourceSize} property can be
+    specified to choose the icon with the desired size. If \l {Image::sourceSize}
+    is not specified or 0, the largest available icon will be chosen.
+
+    The image provider looks up the requested icon in the existing \l {WebEngineView}
+    instances. First, it tries to match the currently displayed icons. If no match
+    has been found it requests the icon from the database. Each profile has its
+    own icon database and it is stored in the persistent storage thus the stored icons
+    can be accessed without network connection too. The icon must be previously loaded
+    to be stored in the database.
+
+    \note The icon database is not available for off-the-record profiles.
 */
diff --git a/src/webenginequick/doc/src/webengineview_lgpl.qdoc b/src/webenginequick/doc/src/webengineview_lgpl.qdoc
index 1ea484703..11dceae69 100644
--- a/src/webenginequick/doc/src/webengineview_lgpl.qdoc
+++ b/src/webenginequick/doc/src/webengineview_lgpl.qdoc
@@ -212,8 +212,7 @@
     \readonly
 
     An internal URL for accessing the currently displayed web site icon,
-    also known as favicon or shortcut icon. The icon is already downloaded
-    and stored by the \QWE's favicon manager.
+    also known as favicon or shortcut icon.
     This read-only URL corresponds to the image used within a mobile browser
     application to represent a bookmarked page on the device's home screen.
 
@@ -229,11 +228,10 @@
     }
     \endqml
 
-    Specifying the \c{sourceSize} property of the \c{Image} element informs
-    the \QWE's favicon provider about the requested size. The
-    favicon provider tries to find the best fit among the web page candidate
-    icons. If \c{sourceSize} property is not specified, the provider provides
-    the icon with the largest resolution.
+    Specifying the \l {Image::sourceSize} property informs
+    the \QWE's favicon provider about the requested size and resizes the
+    icon to it. If \l {Image::sourceSize} property is not specified,
+    the provider provides the icon with the largest available resolution.
 */
 
 /*!