Qt.labs.sharedimage: Make plugin optional

This moves the sharedimage types into a new library and is meant to make
them availabe to the QML compiler at some point in the future.

Task-number: QTBUG-90487
Change-Id: If79425a43cb8c1831422631791d35c1f329c7e80
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

6 files changed, 5 insertions, 578 deletions

diff --git a/src/imports/sharedimage/CMakeLists.txt b/src/imports/sharedimage/CMakeLists.txt
index 90020be7ee..70f3abb76e 100644
--- a/src/imports/sharedimage/CMakeLists.txt
+++ b/src/imports/sharedimage/CMakeLists.txt
@@ -9,19 +9,13 @@ qt_internal_add_qml_module(sharedimageplugin
     VERSION "${CMAKE_PROJECT_VERSION}"
     CLASSNAME QtQuickSharedImagePlugin
     SKIP_TYPE_REGISTRATION
-    GENERATE_QMLTYPES
-    INSTALL_QMLTYPES
+    PLUGIN_OPTIONAL
     SOURCES
         plugin.cpp
-        qsharedimageloader.cpp qsharedimageloader_p.h
-        sharedimageprovider.cpp sharedimageprovider.h
     PUBLIC_LIBRARIES
         Qt::Core
-        Qt::CorePrivate
-        Qt::Gui
-        Qt::GuiPrivate
         Qt::Qml
-        Qt::QuickPrivate
+        Qt::LabsSharedImagePrivate
 )
 
 #### Keys ignored in scope 1:.:.:sharedimage.pro:<TRUE>:
diff --git a/src/imports/sharedimage/plugin.cpp b/src/imports/sharedimage/plugin.cpp
index 3245635b2d..dab04efd92 100644
--- a/src/imports/sharedimage/plugin.cpp
+++ b/src/imports/sharedimage/plugin.cpp
@@ -37,10 +37,11 @@
 **
 ****************************************************************************/
 
+#include <QtLabsSharedImage/private/qtlabssharedimageglobal_p.h>
+#include <QtLabsSharedImage/private/qsharedimageprovider_p.h>
+
 #include <qqmlextensionplugin.h>
 #include <qqmlengine.h>
-#include <sharedimageprovider.h>
-
 
 /*!
     \qmlmodule Qt.labs.sharedimage 1
@@ -99,8 +100,6 @@
     The shared image module does not provide any directly usable QML types.
 */
 
-extern void qml_register_types_Qt_labs_sharedimage();
-
 QT_BEGIN_NAMESPACE
 
 class QtQuickSharedImagePlugin : public QQmlEngineExtensionPlugin
diff --git a/src/imports/sharedimage/qsharedimageloader.cpp b/src/imports/sharedimage/qsharedimageloader.cpp
deleted file mode 100644
index c9e3ef3eb3..0000000000
--- a/src/imports/sharedimage/qsharedimageloader.cpp
+++ /dev/null
@@ -1,266 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2017 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the plugins of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include "qsharedimageloader_p.h"
-#include <private/qobject_p.h>
-#include <private/qimage_p.h>
-#include <QSharedMemory>
-
-
-QT_BEGIN_NAMESPACE
-
-Q_LOGGING_CATEGORY(lcSharedImage, "qt.quick.sharedimage");
-
-struct SharedImageHeader {
-    quint8 magic;
-    quint8 version;
-    quint16 offset;
-    qint32 width;
-    qint32 height;
-    qint32 bpl;
-    QImage::Format format;
-};
-Q_STATIC_ASSERT(sizeof(SharedImageHeader) % 4 == 0);
-
-#if QT_CONFIG(sharedmemory)
-struct SharedImageInfo {
-    QString path;
-    QPointer<QSharedMemory> shmp;
-};
-
-void cleanupSharedImage(void *cleanupInfo)
-{
-    if (!cleanupInfo)
-        return;
-    SharedImageInfo *sii = static_cast<SharedImageInfo *>(cleanupInfo);
-    qCDebug(lcSharedImage) << "Cleanup called for" << sii->path;
-    if (sii->shmp.isNull()) {
-        qCDebug(lcSharedImage) << "shm is 0 for" << sii->path;
-        return;
-    }
-    QSharedMemory *shm = sii->shmp.data();
-    sii->shmp.clear();
-    delete shm;    // destructor detaches
-    delete sii;
-}
-#else
-void cleanupSharedImage(void *) {}
-#endif
-
-class QSharedImageLoaderPrivate : public QObjectPrivate
-{
-    Q_DECLARE_PUBLIC(QSharedImageLoader)
-
-public:
-    QSharedImageLoaderPrivate() {}
-
-    QImage load(const QString &path, QSharedImageLoader::ImageParameters *params);
-
-    void storeImageToMem(void *data, const QImage &img);
-
-    bool verifyMem(const void *data, int size);
-
-    QImage createImageFromMem(const void *data, void *cleanupInfo);
-
-};
-
-
-void QSharedImageLoaderPrivate::storeImageToMem(void *data, const QImage &img)
-{
-    Q_ASSERT(data && !img.isNull());
-
-    SharedImageHeader *h = static_cast<SharedImageHeader *>(data);
-    h->magic = 'Q';
-    h->version = 1;
-    h->offset = sizeof(SharedImageHeader);
-    h->width = img.width();
-    h->height = img.height();
-    h->bpl = img.bytesPerLine();
-    h->format = img.format();
-
-    uchar *p = static_cast<uchar *>(data) + sizeof(SharedImageHeader);
-    memcpy(p, img.constBits(), img.sizeInBytes());
-}
-
-
-bool QSharedImageLoaderPrivate::verifyMem(const void *data, int size)
-{
-    if (!data || size < int(sizeof(SharedImageHeader)))
-        return false;
-
-    const SharedImageHeader *h = static_cast<const SharedImageHeader *>(data);
-    if ((h->magic != 'Q')
-        || (h->version < 1)
-        || (h->offset < sizeof(SharedImageHeader))
-        || (h->width <= 0)
-        || (h->height <= 0)
-        || (h->bpl <= 0)
-        || (h->format <= QImage::Format_Invalid)
-        || (h->format >= QImage::NImageFormats)) {
-        return false;
-    }
-
-    int availSize = size - h->offset;
-    if (h->height * h->bpl > availSize)
-        return false;
-    if ((qt_depthForFormat(h->format) * h->width * h->height) > (8 * availSize))
-        return false;
-
-    return true;
-}
-
-
-QImage QSharedImageLoaderPrivate::createImageFromMem(const void *data, void *cleanupInfo)
-{
-    const SharedImageHeader *h = static_cast<const SharedImageHeader *>(data);
-    const uchar *p = static_cast<const uchar *>(data) + h->offset;
-
-    QImage img(p, h->width, h->height, h->bpl, h->format, cleanupSharedImage, cleanupInfo);
-    return img;
-}
-
-
-QImage QSharedImageLoaderPrivate::load(const QString &path, QSharedImageLoader::ImageParameters *params)
-{
-#if QT_CONFIG(sharedmemory)
-    Q_Q(QSharedImageLoader);
-
-    QImage nil;
-    if (path.isEmpty())
-        return nil;
-
-    QScopedPointer<QSharedMemory> shm(new QSharedMemory(q->key(path, params)));
-    bool locked = false;
-
-    if (!shm->attach(QSharedMemory::ReadOnly)) {
-        QImage img = q->loadFile(path, params);
-        if (img.isNull())
-            return nil;
-        size_t size = sizeof(SharedImageHeader) + img.sizeInBytes();
-        if (size > size_t(std::numeric_limits<int>::max())) {
-            qCDebug(lcSharedImage) << "Image" << path << "to large to load";
-            return nil;
-        } else if (shm->create(int(size))) {
-            qCDebug(lcSharedImage) << "Created new shm segment of size" << size << "for image" << path;
-            if (!shm->lock()) {
-                qCDebug(lcSharedImage) << "Lock1 failed!?" << shm->errorString();
-                return nil;
-            }
-            locked = true;
-            storeImageToMem(shm->data(), img);
-        } else if (shm->error() == QSharedMemory::AlreadyExists) {
-            // race handling: other process may have created the share while
-            // we loaded the image, so try again to just attach
-            if (!shm->attach(QSharedMemory::ReadOnly)) {
-                qCDebug(lcSharedImage) << "Attach to existing failed?" << shm->errorString();
-                return nil;
-            }
-        } else {
-            qCDebug(lcSharedImage) << "Create failed?" << shm->errorString();
-            return nil;
-        }
-    }
-
-    Q_ASSERT(shm->isAttached());
-
-    if (!locked) {
-        if (!shm->lock()) {
-            qCDebug(lcSharedImage) << "Lock2 failed!?" << shm->errorString();
-            return nil;
-        }
-        locked = true;
-    }
-
-    if (!verifyMem(shm->constData(), shm->size())) {
-        qCDebug(lcSharedImage) << "Verifymem failed!?";
-        shm->unlock();
-        return nil;
-    }
-
-    QSharedMemory *shmp = shm.take();
-    SharedImageInfo *sii = new SharedImageInfo;
-    sii->path = path;
-    sii->shmp = shmp;
-    QImage shImg = createImageFromMem(shmp->constData(), sii);
-
-    if (!shmp->unlock()) {
-        qCDebug(lcSharedImage) << "UnLock failed!?";
-    }
-
-    return shImg;
-#else
-    Q_UNUSED(path);
-    Q_UNUSED(params);
-    return QImage();
-#endif
-}
-
-
-QSharedImageLoader::QSharedImageLoader(QObject *parent)
-    : QObject(*new QSharedImageLoaderPrivate, parent)
-{
-}
-
-QSharedImageLoader::~QSharedImageLoader()
-{
-}
-
-QImage QSharedImageLoader::load(const QString &path, ImageParameters *params)
-{
-    Q_D(QSharedImageLoader);
-
-    return d->load(path, params);
-}
-
-QImage QSharedImageLoader::loadFile(const QString &path, ImageParameters *params)
-{
-    Q_UNUSED(params);
-
-    return QImage(path);
-}
-
-QString QSharedImageLoader::key(const QString &path, ImageParameters *params)
-{
-    Q_UNUSED(params);
-
-    return path;
-}
-
-
-QT_END_NAMESPACE
diff --git a/src/imports/sharedimage/qsharedimageloader_p.h b/src/imports/sharedimage/qsharedimageloader_p.h
deleted file mode 100644
index ce10d0d72c..0000000000
--- a/src/imports/sharedimage/qsharedimageloader_p.h
+++ /dev/null
@@ -1,81 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2017 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the plugins of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QSHAREDIMAGELOADER_H
-#define QSHAREDIMAGELOADER_H
-
-#include <QImage>
-#include <QVariant>
-#include <QLoggingCategory>
-#include <qqml.h>
-
-QT_BEGIN_NAMESPACE
-
-Q_DECLARE_LOGGING_CATEGORY(lcSharedImage);
-
-class QSharedImageLoaderPrivate;
-
-class QSharedImageLoader : public QObject
-{
-    Q_OBJECT
-    Q_DECLARE_PRIVATE(QSharedImageLoader)
-
-    // We need to provide some type, in order to mention the 1.0 version.
-    QML_ANONYMOUS
-    QML_ADDED_IN_VERSION(1, 0)
-
-public:
-    typedef QVector<QVariant> ImageParameters;
-
-    QSharedImageLoader(QObject *parent = nullptr);
-    ~QSharedImageLoader();
-
-    QImage load(const QString &path, ImageParameters *params = nullptr);
-
-protected:
-    virtual QImage loadFile(const QString &path, ImageParameters *params);
-    virtual QString key(const QString &path, ImageParameters *params);
-
-private:
-    Q_DISABLE_COPY(QSharedImageLoader)
-};
-
-QT_END_NAMESPACE
-
-#endif // QSHAREDIMAGELOADER_H
diff --git a/src/imports/sharedimage/sharedimageprovider.cpp b/src/imports/sharedimage/sharedimageprovider.cpp
deleted file mode 100644
index aad6ea3b78..0000000000
--- a/src/imports/sharedimage/sharedimageprovider.cpp
+++ /dev/null
@@ -1,160 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2017 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the plugins of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include <sharedimageprovider.h>
-#include <qsharedimageloader_p.h>
-#include <private/qquickpixmapcache_p.h>
-#include <private/qimage_p.h>
-#include <QImageReader>
-#include <QFileInfo>
-#include <QDir>
-
-Q_DECLARE_METATYPE(QQuickImageProviderOptions)
-
-class QuickSharedImageLoader : public QSharedImageLoader
-{
-    Q_OBJECT
-    friend class SharedImageProvider;
-
-public:
-    enum ImageParameter {
-        OriginalSize = 0,
-        RequestedSize,
-        ProviderOptions,
-        NumImageParameters
-    };
-
-    QuickSharedImageLoader(QObject *parent = nullptr)
-        : QSharedImageLoader(parent)
-    {
-    }
-
-protected:
-    QImage loadFile(const QString &path, ImageParameters *params) override
-    {
-        QImageReader imgio(path);
-        QSize realSize = imgio.size();
-        QSize requestSize;
-        QQuickImageProviderOptions options;
-        if (params) {
-            requestSize = params->value(RequestedSize).toSize();
-            options = params->value(ProviderOptions).value<QQuickImageProviderOptions>();
-        }
-
-        QSize scSize = QQuickImageProviderWithOptions::loadSize(imgio.size(), requestSize, imgio.format(), options);
-
-        if (scSize.isValid())
-            imgio.setScaledSize(scSize);
-
-        QImage image;
-        if (imgio.read(&image)) {
-            if (realSize.isEmpty())
-                realSize = image.size();
-            // Make sure we have acceptable format for texture uploader, or it will convert & lose sharing
-            // This mimics the testing & conversion normally done by the quick pixmapcache & texturefactory
-            if (image.format() != QImage::Format_RGB32 && image.format() != QImage::Format_ARGB32_Premultiplied) {
-                QImage::Format newFmt = QImage::Format_RGB32;
-                if (image.hasAlphaChannel() && image.data_ptr()->checkForAlphaPixels())
-                    newFmt = QImage::Format_ARGB32_Premultiplied;
-                qCDebug(lcSharedImage) << "Convert on load from format" << image.format() << "to" << newFmt;
-                image = image.convertToFormat(newFmt);
-            }
-        }
-
-        if (params && params->count() > OriginalSize)
-            params->replace(OriginalSize, realSize);
-
-        return image;
-    }
-
-    QString key(const QString &path, ImageParameters *params) override
-    {
-        QSize reqSz;
-        QQuickImageProviderOptions opts;
-        if (params) {
-            reqSz = params->value(RequestedSize).toSize();
-            opts = params->value(ProviderOptions).value<QQuickImageProviderOptions>();
-        }
-        if (!reqSz.isValid())
-            return path;
-        int aspect = opts.preserveAspectRatioCrop() || opts.preserveAspectRatioFit() ? 1 : 0;
-
-        QString key = path + QStringLiteral("_%1x%2_%3").arg(reqSz.width()).arg(reqSz.height()).arg(aspect);
-        qCDebug(lcSharedImage) << "KEY:" << key;
-        return key;
-    }
-};
-
-
-SharedImageProvider::SharedImageProvider()
-    : QQuickImageProviderWithOptions(QQuickImageProvider::Image), loader(new QuickSharedImageLoader)
-{
-}
-
-QImage SharedImageProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize, const QQuickImageProviderOptions &options)
-{
-    QFileInfo fi(QDir::root(), id);
-    QString path = fi.canonicalFilePath();
-    if (path.isEmpty())
-        return QImage();
-
-    QSharedImageLoader::ImageParameters params(QuickSharedImageLoader::NumImageParameters);
-    params[QuickSharedImageLoader::RequestedSize].setValue(requestedSize);
-    params[QuickSharedImageLoader::ProviderOptions].setValue(options);
-
-    QImage img = loader->load(path, &params);
-    if (img.isNull()) {
-        // May be sharing problem, fall back to normal local load
-        img = loader->loadFile(path, &params);
-        if (!img.isNull())
-            qCWarning(lcSharedImage) << "Sharing problem; loading" << id << "unshared";
-    }
-
-    //... QSize realSize = params.value(QSharedImageLoader::OriginalSize).toSize();
-    // quickpixmapcache's readImage() reports back the original size, prior to requestedSize scaling, in the *size
-    // parameter. That value is currently ignored by quick however, which only cares about the present size of the
-    // returned image. So handling and sharing of info on pre-scaled size is currently not implemented.
-    if (size) {
-        *size = img.size();
-    }
-
-    return img;
-}
-
-#include "sharedimageprovider.moc"
diff --git a/src/imports/sharedimage/sharedimageprovider.h b/src/imports/sharedimage/sharedimageprovider.h
deleted file mode 100644
index e6b6c77134..0000000000
--- a/src/imports/sharedimage/sharedimageprovider.h
+++ /dev/null
@@ -1,59 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2017 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the plugins of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef SHAREDIMAGEPROVIDER_H
-#define SHAREDIMAGEPROVIDER_H
-
-#include <QQuickImageProvider>
-#include <private/qquickpixmapcache_p.h>
-#include <QScopedPointer>
-
-class QuickSharedImageLoader;
-
-class SharedImageProvider : public QQuickImageProviderWithOptions
-{
-public:
-    SharedImageProvider();
-
-    QImage requestImage(const QString &id, QSize *size, const QSize &requestedSize, const QQuickImageProviderOptions &options) override;
-
-protected:
-    QScopedPointer<QuickSharedImageLoader> loader;
-};
-#endif // SHAREDIMAGEPROVIDER_H