Merge lp:~osomon/webbrowser-app/webview-capture into lp:webbrowser-app

[Olivier Tilloy]

Take captures of live webviews and cache them on disk, to use them as tab previews.

[PS Jenkins bot (ps-jenkins)]

FAILED: Continuous integration, rev:829
http://jenkins.qa.ubuntu.com/job/webbrowser-app-ci/1314/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/generic-deb-autopilot-vivid-touch/395
    UNSTABLE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-vivid/243
    SUCCESS: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-amd64-ci/72
    SUCCESS: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-armhf-ci/72
        deb: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-armhf-ci/72/artifact/work/output/*zip*/output.zip
    FAILURE: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-i386-ci/72/console
    SUCCESS: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-armhf/395
        deb: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-armhf/395/artifact/work/output/*zip*/output.zip
    UNSTABLE: http://jenkins.qa.ubuntu.com/job/autopilot-testrunner-otto-vivid/215
    SUCCESS: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-amd64/248
        deb: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-amd64/248/artifact/work/output/*zip*/output.zip

Click here to trigger a rebuild:
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review: Needs Fixing (continuous-integration)

[PS Jenkins bot (ps-jenkins)]

FAILED: Continuous integration, rev:830
http://jenkins.qa.ubuntu.com/job/webbrowser-app-ci/1315/
Executed test runs:
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-deb-autopilot-vivid-touch/407/console
    UNSTABLE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-vivid/249
    SUCCESS: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-amd64-ci/73
    FAILURE: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-armhf-ci/73/console
    SUCCESS: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-i386-ci/73
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-armhf/407/console
    UNSTABLE: http://jenkins.qa.ubuntu.com/job/autopilot-testrunner-otto-vivid/220
    SUCCESS: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-amd64/254
        deb: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-amd64/254/artifact/work/output/*zip*/output.zip

Click here to trigger a rebuild:
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review: Needs Fixing (continuous-integration)

[PS Jenkins bot (ps-jenkins)]

FAILED: Continuous integration, rev:831
http://jenkins.qa.ubuntu.com/job/webbrowser-app-ci/1317/
Executed test runs:
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-deb-autopilot-vivid-touch/413/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-vivid/255/console
    SUCCESS: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-amd64-ci/75
    FAILURE: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-armhf-ci/75/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-i386-ci/75/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-armhf/413/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-amd64/260/console

Click here to trigger a rebuild:
http://s-jenkins.ubuntu-ci:8080/job/webbrowser-app-ci/1317/rebuild

review: Needs Fixing (continuous-integration)

[PS Jenkins bot (ps-jenkins)]

FAILED: Continuous integration, rev:831
http://jenkins.qa.ubuntu.com/job/webbrowser-app-ci/1325/
Executed test runs:
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-deb-autopilot-vivid-touch/484/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-vivid/273/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-amd64-ci/83/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-armhf-ci/83/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-i386-ci/83/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-armhf/484/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-amd64/279/console

Click here to trigger a rebuild:
http://s-jenkins.ubuntu-ci:8080/job/webbrowser-app-ci/1325/rebuild

review: Needs Fixing (continuous-integration)

[PS Jenkins bot (ps-jenkins)]

FAILED: Continuous integration, rev:832
http://jenkins.qa.ubuntu.com/job/webbrowser-app-ci/1326/
Executed test runs:
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-deb-autopilot-vivid-touch/488/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-vivid/276/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-amd64-ci/84/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-armhf-ci/84/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-i386-ci/84/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-armhf/488/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-amd64/282/console

Click here to trigger a rebuild:
http://s-jenkins.ubuntu-ci:8080/job/webbrowser-app-ci/1326/rebuild

review: Needs Fixing (continuous-integration)

[PS Jenkins bot (ps-jenkins)]

FAILED: Continuous integration, rev:836
http://jenkins.qa.ubuntu.com/job/webbrowser-app-ci/1330/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/generic-deb-autopilot-vivid-touch/524
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-vivid/292/console
    FAILURE: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-amd64-ci/88/console
    SUCCESS: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-armhf-ci/88
        deb: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-armhf-ci/88/artifact/work/output/*zip*/output.zip
    FAILURE: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-i386-ci/88/console
    SUCCESS: http://jenkins.qa.ubuntu.com/job/generic-deb-autopilot-runner-vivid-mako/456
    SUCCESS: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-armhf/522
        deb: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-armhf/522/artifact/work/output/*zip*/output.zip
    SUCCESS: http://s-jenkins.ubuntu-ci:8080/job/touch-flash-device/16507
    FAILURE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-amd64/298/console

Click here to trigger a rebuild:
http://s-jenkins.ubuntu-ci:8080/job/webbrowser-app-ci/1330/rebuild

review: Needs Fixing (continuous-integration)

[lp:~osomon/webbrowser-app/webview-capture]

842. By Olivier Tilloy on 2014-12-11

Remove an unnecessary mutex, when updatePainNode() is called, the GUI thread is blocked.

843. By Olivier Tilloy on 2014-12-11

Remove the superfluous onCaptureFinished wrapper.

[PS Jenkins bot (ps-jenkins)]

FAILED: Continuous integration, rev:841
http://jenkins.qa.ubuntu.com/job/webbrowser-app-ci/1332/
Executed test runs:
    UNSTABLE: http://jenkins.qa.ubuntu.com/job/generic-deb-autopilot-vivid-touch/538
    UNSTABLE: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-vivid/299
    FAILURE: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-amd64-ci/90/console
    SUCCESS: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-armhf-ci/90
        deb: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-armhf-ci/90/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/webbrowser-app-vivid-i386-ci/90
    UNSTABLE: http://jenkins.qa.ubuntu.com/job/generic-deb-autopilot-runner-vivid-mako/469
    SUCCESS: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-armhf/536
        deb: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-armhf/536/artifact/work/output/*zip*/output.zip
    SUCCESS: http://s-jenkins.ubuntu-ci:8080/job/touch-flash-device/16533
    UNSTABLE: http://jenkins.qa.ubuntu.com/job/autopilot-testrunner-otto-vivid/255
    SUCCESS: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-amd64/305
        deb: http://jenkins.qa.ubuntu.com/job/generic-mediumtests-builder-vivid-amd64/305/artifact/work/output/*zip*/output.zip

Click here to trigger a rebuild:
http://s-jenkins.ubuntu-ci:8080/job/webbrowser-app-ci/1332/rebuild

review: Needs Fixing (continuous-integration)

=== modified file 'src/app/webbrowser/Browser.qml'
--- src/app/webbrowser/Browser.qml	2014-11-11 18:30:38 +0000
+++ src/app/webbrowser/Browser.qml	2014-12-11 18:51:44 +0000
@@ -76,37 +76,6 @@
     ]
 
     Item {
-        id: previewsContainer
-
-        width: tabContainer.width
-        height: tabContainer.height
-        y: tabContainer.y
-
-        Component {
-            id: previewComponent
-
-            ShaderEffectSource {
-                id: preview
-
-                property var tab
-
-                width: parent.width
-                height: parent.height
-
-                sourceItem: tab ? tab.webview : null
-
-                onTabChanged: {
-                    if (!tab) {
-                        this.destroy()
-                    }
-                }
-
-                live: mainView.visible && (browser.currentWebview === sourceItem)
-            }
-        }
-    }
-
-    Item {
         id: mainView
 
         anchors.fill: parent
@@ -363,6 +332,7 @@
         id: tabComponent
 
         FocusScope {
+            property string uniqueId: this.toString() + "-" + Date.now()
             property url initialUrl
             property string initialTitle
             property var request
@@ -370,7 +340,7 @@
             readonly property url url: webview ? webview.url : initialUrl
             readonly property string title: webview ? webview.title : initialTitle
             readonly property url icon: webview ? webview.icon : ""
-            property var preview
+            property url preview
 
             anchors.fill: parent
 
@@ -388,6 +358,56 @@
                 }
             }
 
+            function close() {
+                unload()
+                if (preview) {
+                    FileOperations.remove(preview)
+                }
+                destroy()
+            }
+
+            property var captureTaker
+            Component {
+                id: captureComponent
+                ItemCapture {
+                    quality: 50
+                    onCaptureFinished: {
+                        if ((request == uniqueId) && capture.toString()) {
+                            if (preview == capture) {
+                                // Ensure that the preview URL actually changes,
+                                // for the image to be reloaded
+                                preview = ""
+                            }
+                            preview = capture
+                        }
+                        if (!webview.visible) {
+                            captureTaker.destroy()
+                        }
+                    }
+                }
+            }
+            function createCaptureTakerIfNeeded() {
+                if (!captureTaker) {
+                    captureTaker = captureComponent.createObject(webview)
+                }
+            }
+            onWebviewChanged: {
+                if (webview) {
+                    createCaptureTakerIfNeeded()
+                }
+            }
+
+            Connections {
+                target: webview
+                onVisibleChanged: {
+                    if (webview.visible) {
+                        createCaptureTakerIfNeeded()
+                    } else {
+                        captureTaker.requestCapture(uniqueId)
+                    }
+                }
+            }
+
             Component.onCompleted: {
                 if (request) {
                     // Instantiating the webview cannot be delayed because the request
@@ -502,7 +522,6 @@
                 tabsModel.setCurrent(index)
                 chrome.requestedUrl = tab.initialUrl
             }
-            tab.preview = previewComponent.createObject(previewsContainer, {tab: tab})
         }
 
         function focusAddressBar() {
@@ -568,13 +587,21 @@
         // history, current scroll offset and form data. See http://pad.lv/1353143.
         function serializeTabState(tab) {
             var state = {}
+            state.uniqueId = tab.uniqueId
             state.url = tab.url.toString()
             state.title = tab.title
+            state.preview = tab.preview.toString()
             return state
         }
 
         function createTabFromState(state) {
             var properties = {"initialUrl": state.url, "initialTitle": state.title}
+            if ('uniqueId' in state) {
+                properties["uniqueId"] = state.uniqueId
+            }
+            if ('preview' in state) {
+                properties["preview"] = state.preview
+            }
             return tabComponent.createObject(tabContainer, properties)
         }
     }

=== modified file 'src/app/webbrowser/CMakeLists.txt'
--- src/app/webbrowser/CMakeLists.txt	2014-10-15 09:57:35 +0000
+++ src/app/webbrowser/CMakeLists.txt	2014-12-11 18:51:44 +0000
@@ -25,7 +25,11 @@
 
 qt5_use_modules(${WEBBROWSER_APP_MODELS} Core Sql)
 
+include_directories(${Qt5Quick_PRIVATE_INCLUDE_DIRS})
+
 set(WEBBROWSER_APP_SRC
+    file-operations.cpp
+    item-capture.cpp
     searchengine.cpp
     settings.cpp
     webbrowser-app.cpp
@@ -37,7 +41,7 @@
 
 target_link_libraries(${WEBBROWSER_APP} ${COMMONLIB} ${WEBBROWSER_APP_MODELS})
 
-qt5_use_modules(${WEBBROWSER_APP} Core Gui Qml Quick)
+qt5_use_modules(${WEBBROWSER_APP} Concurrent Core Gui Qml Quick)
 
 install(TARGETS ${WEBBROWSER_APP}
         RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})

=== modified file 'src/app/webbrowser/TabPreview.qml'
--- src/app/webbrowser/TabPreview.qml	2014-08-21 08:02:42 +0000
+++ src/app/webbrowser/TabPreview.qml	2014-12-11 18:51:44 +0000
@@ -146,6 +146,7 @@
         Image {
             visible: !previewContainer.visible
             source: "assets/tab-artwork.png"
+            asynchronous: true
             fillMode: Image.PreserveAspectFit
             height: Math.min(parent.height / 1.6, units.gu(28))
             width: height
@@ -166,11 +167,25 @@
             }
         }
 
-        Item {
+        Image {
             id: previewContainer
-            visible: tabPreview.tab ? tabPreview.tab.webview : false
-            anchors.fill: parent
-            clip: true
+            visible: source.toString() && (status == Image.Ready)
+            anchors {
+                left: parent.left
+                right: parent.right
+                top: parent.top
+            }
+            height: sourceSize.height
+            fillMode: Image.Pad
+            source: tabPreview.tab ? tabPreview.tab.preview : ""
+            asynchronous: true
+            cache: false
+            onStatusChanged: {
+                if (status == Image.Error) {
+                    // The cached preview doesn’t exist any longer
+                    tabPreview.tab.preview = ""
+                }
+            }
         }
 
         MouseArea {
@@ -189,25 +204,4 @@
             opacity: 0.3
         }
     }
-
-    QtObject {
-        id: internal
-        property var previewParent
-    }
-
-    Component.onCompleted: {
-        var preview = tabPreview.tab.preview
-        internal.previewParent = preview.parent
-        preview.parent = previewContainer
-        preview.width = internal.previewParent.width
-        preview.height = internal.previewParent.height
-    }
-    Component.onDestruction: {
-        if (tabPreview.tab) {
-            var preview = tabPreview.tab.preview
-            preview.parent = internal.previewParent
-            preview.width = preview.parent.width
-            preview.height = preview.parent.height
-        }
-    }
 }

=== modified file 'src/app/webbrowser/TabsView.qml'
--- src/app/webbrowser/TabsView.qml	2014-11-12 11:04:34 +0000
+++ src/app/webbrowser/TabsView.qml	2014-12-11 18:51:44 +0000
@@ -66,8 +66,7 @@
             onCloseRequested: {
                 var tab = tabsview.model.remove(index)
                 if (tab) {
-                    tab.unload()
-                    tab.destroy()
+                    tab.close()
                 }
                 if (tabsview.model.count === 0) {
                     tabsview.newTabRequested()

=== added file 'src/app/webbrowser/file-operations.cpp'
--- src/app/webbrowser/file-operations.cpp	1970-01-01 00:00:00 +0000
+++ src/app/webbrowser/file-operations.cpp	2014-12-11 18:51:44 +0000
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2014 Canonical Ltd.
+ *
+ * This file is part of webbrowser-app.
+ *
+ * webbrowser-app is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 3.
+ *
+ * webbrowser-app is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "file-operations.h"
+
+#include <QtCore/QFile>
+#include <QtCore/QUrl>
+
+FileOperations::FileOperations(QObject* parent)
+    : QObject(parent)
+{
+}
+
+bool FileOperations::remove(const QUrl& file) const
+{
+    return QFile::remove(file.toLocalFile());
+}

=== added file 'src/app/webbrowser/file-operations.h'
--- src/app/webbrowser/file-operations.h	1970-01-01 00:00:00 +0000
+++ src/app/webbrowser/file-operations.h	2014-12-11 18:51:44 +0000
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2014 Canonical Ltd.
+ *
+ * This file is part of webbrowser-app.
+ *
+ * webbrowser-app is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 3.
+ *
+ * webbrowser-app is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __FILE_OPERATIONS_H__
+#define __FILE_OPERATIONS_H__
+
+#include <QtCore/QObject>
+
+class QUrl;
+
+class FileOperations : public QObject
+{
+    Q_OBJECT
+
+public:
+    explicit FileOperations(QObject* parent=0);
+
+    Q_INVOKABLE bool remove(const QUrl& file) const;
+};
+
+#endif // __FILE_OPERATIONS_H__

=== added file 'src/app/webbrowser/item-capture.cpp'
--- src/app/webbrowser/item-capture.cpp	1970-01-01 00:00:00 +0000
+++ src/app/webbrowser/item-capture.cpp	2014-12-11 18:51:44 +0000
@@ -0,0 +1,123 @@
+/*
+ * Copyright 2014 Canonical Ltd.
+ *
+ * This file is part of webbrowser-app.
+ *
+ * webbrowser-app is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 3.
+ *
+ * webbrowser-app is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+// local
+#include "item-capture.h"
+
+// Qt
+#include <QtConcurrent/QtConcurrent>
+#include <QtCore/QDebug>
+#include <QtCore/QDir>
+#include <QtCore/QMetaObject>
+#include <QtCore/QStandardPaths>
+#include <QtGui/QImage>
+#include <QtQuick/private/qquickitem_p.h>
+
+ItemCapture::ItemCapture(QQuickItem* parent)
+    : QQuickShaderEffectSource(parent)
+    , m_quality(-1)
+{
+    connect(this, SIGNAL(parentChanged(QQuickItem*)), SLOT(onParentChanged(QQuickItem*)));
+
+    setScale(0);
+
+    QDir cacheLocation(QStandardPaths::writableLocation(QStandardPaths::CacheLocation) + "/captures");
+    m_cacheLocation = cacheLocation.absolutePath();
+    if (!cacheLocation.exists()) {
+        QDir::root().mkpath(m_cacheLocation);
+    }
+}
+
+const int ItemCapture::quality() const
+{
+    return m_quality;
+}
+
+void ItemCapture::setQuality(const int quality)
+{
+    if (quality != m_quality) {
+        if ((quality >= -1) && (quality <= 100)) {
+            m_quality = quality;
+            Q_EMIT qualityChanged();
+        } else {
+            qWarning() << "Invalid value for quality, must be between 0 and 100 (or -1 for default)";
+        }
+    }
+}
+
+void ItemCapture::onParentChanged(QQuickItem* parent)
+{
+    if (sourceItem()) {
+        sourceItem()->disconnect(this);
+    }
+    QQuickItemPrivate::get(this)->anchors()->setFill(parent);
+    setSourceItem(parent);
+    if (parent) {
+        connect(parent, SIGNAL(visibleChanged()), SLOT(onParentVisibleChanged()));
+    }
+}
+
+void ItemCapture::onParentVisibleChanged()
+{
+    setLive(parentItem()->isVisible());
+}
+
+QSGNode* ItemCapture::updatePaintNode(QSGNode* oldNode, UpdatePaintNodeData* updatePaintNodeData)
+{
+    QSGNode* newNode = QQuickShaderEffectSource::updatePaintNode(oldNode, updatePaintNodeData);
+    if (!m_request.isEmpty()) {
+        QString request = m_request;
+        m_request.clear();
+        QQuickShaderEffectTexture* texture =
+            qobject_cast<QQuickShaderEffectTexture*>(textureProvider()->texture());
+        QOpenGLContext* ctx =
+            QQuickItemPrivate::get(this)->sceneGraphRenderContext()->openglContext();
+        if (ctx->makeCurrent(ctx->surface())) {
+            QImage image = texture->toImage().mirrored();
+            if (!image.isNull()) {
+                QString filePath = m_cacheLocation + "/" + request + ".jpg";
+                QtConcurrent::run(this, &ItemCapture::saveImage, image, filePath, m_quality, request);
+                return newNode;
+            }
+        }
+        QMetaObject::invokeMethod(this, "captureFinished", Qt::QueuedConnection,
+                                  Q_ARG(QString, request), Q_ARG(QUrl, QUrl()));
+    }
+    return newNode;
+}
+
+void ItemCapture::requestCapture(const QString& id)
+{
+    if (id.contains("/")) {
+        qWarning() << "Invalid ID (contains slashes)";
+        Q_EMIT captureFinished(id, QUrl());
+    }
+    m_request = id;
+    scheduleUpdate();
+}
+
+void ItemCapture::saveImage(const QImage& image, const QString& filePath,
+                            const int quality, const QString& request)
+{
+    QUrl capture;
+    if (image.save(filePath, 0, quality)) {
+        capture = QUrl::fromLocalFile(filePath);
+    }
+    QMetaObject::invokeMethod(this, "captureFinished", Qt::QueuedConnection,
+                              Q_ARG(QString, request), Q_ARG(QUrl, capture));
+}

=== added file 'src/app/webbrowser/item-capture.h'
--- src/app/webbrowser/item-capture.h	1970-01-01 00:00:00 +0000
+++ src/app/webbrowser/item-capture.h	2014-12-11 18:51:44 +0000
@@ -0,0 +1,63 @@
+/*
+ * Copyright 2014 Canonical Ltd.
+ *
+ * This file is part of webbrowser-app.
+ *
+ * webbrowser-app is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 3.
+ *
+ * webbrowser-app is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __ITEM_CAPTURE_H__
+#define __ITEM_CAPTURE_H__
+
+// Qt
+#include <QtCore/QString>
+#include <QtCore/QUrl>
+#include <QtQuick/private/qquickshadereffectsource_p.h>
+
+class QImage;
+
+class ItemCapture : public QQuickShaderEffectSource
+{
+    Q_OBJECT
+
+    Q_PROPERTY(int quality READ quality WRITE setQuality NOTIFY qualityChanged)
+
+public:
+    ItemCapture(QQuickItem* parent=0);
+
+    const int quality() const;
+    void setQuality(const int quality);
+
+public Q_SLOTS:
+    void requestCapture(const QString& id);
+
+Q_SIGNALS:
+    void qualityChanged() const;
+    void captureFinished(QString request, QUrl capture) const;
+
+protected:
+    QSGNode* updatePaintNode(QSGNode* oldNode, UpdatePaintNodeData* updatePaintNodeData);
+
+private Q_SLOTS:
+    void onParentChanged(QQuickItem* parent);
+    void onParentVisibleChanged();
+    void saveImage(const QImage& image, const QString& filePath,
+                   const int quality, const QString& request);
+
+private:
+    QString m_cacheLocation;
+    QString m_request;
+    int m_quality;
+};
+
+#endif // __ITEM_CAPTURE_H__

=== modified file 'src/app/webbrowser/webbrowser-app.cpp'
--- src/app/webbrowser/webbrowser-app.cpp	2014-10-22 18:02:03 +0000
+++ src/app/webbrowser/webbrowser-app.cpp	2014-12-11 18:51:44 +0000
@@ -18,12 +18,14 @@
 
 #include "bookmarks-model.h"
 #include "config.h"
+#include "file-operations.h"
 #include "history-model.h"
 #include "history-matches-model.h"
 #include "history-timeframe-model.h"
 #include "history-byvisits-model.h"
 #include "history-domainlist-model.h"
 #include "history-domainlist-chronological-model.h"
+#include "item-capture.h"
 #include "limit-proxy-model.h"
 #include "searchengine.h"
 #include "settings.h"
@@ -49,6 +51,13 @@
 {
 }
 
+static QObject* FileOperations_singleton_factory(QQmlEngine* engine, QJSEngine* scriptEngine)
+{
+    Q_UNUSED(engine);
+    Q_UNUSED(scriptEngine);
+    return new FileOperations();
+}
+
 bool WebbrowserApp::initialize()
 {
     // Re-direct webapps to the dedicated container for backward compatibility
@@ -82,6 +91,8 @@
     qmlRegisterType<LimitProxyModel>(uri, 0 , 1, "LimitProxyModel");
     qmlRegisterType<TabsModel>(uri, 0, 1, "TabsModel");
     qmlRegisterType<BookmarksModel>(uri, 0, 1, "BookmarksModel");
+    qmlRegisterType<ItemCapture>(uri, 0, 1, "ItemCapture");
+    qmlRegisterSingletonType<FileOperations>(uri, 0, 1, "FileOperations", FileOperations_singleton_factory);
 
     if (BrowserApplication::initialize("webbrowser/webbrowser-app.qml")) {
         Settings settings;

=== modified file 'tests/unittests/qml/CMakeLists.txt'
--- tests/unittests/qml/CMakeLists.txt	2014-11-26 11:33:10 +0000
+++ tests/unittests/qml/CMakeLists.txt	2014-12-11 18:51:44 +0000
@@ -9,11 +9,16 @@
 set(TEST tst_QmlTests)
 set(SOURCES
     ${webbrowser-common_SOURCE_DIR}/favicon-fetcher.cpp
+    ${webbrowser-app_SOURCE_DIR}/item-capture.cpp
     tst_QmlTests.cpp
 )
 add_executable(${TEST} ${SOURCES})
-qt5_use_modules(${TEST} Qml QuickTest)
-include_directories(${webbrowser-common_SOURCE_DIR})
+qt5_use_modules(${TEST} Qml Quick QuickTest)
+include_directories(
+    ${webbrowser-common_SOURCE_DIR}
+    ${webbrowser-app_SOURCE_DIR}
+    ${Qt5Quick_PRIVATE_INCLUDE_DIRS}
+)
 add_test(${TEST} ${XVFB_COMMAND} ${CMAKE_CURRENT_BINARY_DIR}/${TEST}
          -input ${CMAKE_CURRENT_SOURCE_DIR}
          -import ${CMAKE_BINARY_DIR}/src)

=== added file 'tests/unittests/qml/tst_ItemCapture.qml'
--- tests/unittests/qml/tst_ItemCapture.qml	1970-01-01 00:00:00 +0000
+++ tests/unittests/qml/tst_ItemCapture.qml	2014-12-11 18:51:44 +0000
@@ -0,0 +1,108 @@
+/*
+ * Copyright 2014 Canonical Ltd.
+ *
+ * This file is part of webbrowser-app.
+ *
+ * webbrowser-app is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 3.
+ *
+ * webbrowser-app is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import QtQuick 2.0
+import QtTest 1.0
+import webbrowserapp.private 0.1
+
+Item {
+    width: 200
+    height: 200
+
+    Rectangle {
+        id: rect
+
+        width: 123
+        height: 157
+        color: "red"
+        anchors.centerIn: parent
+
+        ItemCapture {
+            id: capture
+            onCaptureFinished: image.source = capture
+        }
+
+        SignalSpy {
+            id: spyReady
+            target: capture
+            signalName: "scheduledUpdateCompleted"
+        }
+
+        SignalSpy {
+            id: spyCaptured
+            target: capture
+            signalName: "captureFinished"
+        }
+    }
+
+    Image {
+        id: image
+    }
+
+    TestCase {
+        name: "ItemCapture"
+        when: windowShown
+
+        function test_quality_data() {
+            return [
+                {get: -1},
+                {set: 58, get: 58},
+                {set: 122},
+                {set: -39},
+                {set: -1, get: -1},
+                {set: 0, get: 0},
+                {set: 100, get: 100}
+            ]
+        }
+
+        function test_quality(data) {
+            var quality = capture.quality
+            if ('set' in data) {
+                capture.quality = data.set
+            }
+            if ('get' in data) {
+                compare(capture.quality, data.get)
+            } else {
+                compare(capture.quality, quality)
+            }
+        }
+
+        function test_capture() {
+            spyReady.wait()
+            spyCaptured.clear()
+            var id = "test"
+            capture.requestCapture(id)
+            spyCaptured.wait()
+            compare(spyCaptured.signalArguments[0][0], id)
+            verify(image.source.toString())
+            compare(image.status, Image.Ready)
+            compare(image.sourceSize.width, rect.width)
+            compare(image.sourceSize.height, rect.height)
+        }
+
+        function test_capture_invalid_id() {
+            spyReady.wait()
+            spyCaptured.clear()
+            var invalid = "foo/bar"
+            capture.requestCapture(invalid)
+            spyCaptured.wait()
+            compare(spyCaptured.signalArguments[0][0], invalid)
+            verify(!spyCaptured.signalArguments[0][1].toString())
+        }
+    }
+}

=== modified file 'tests/unittests/qml/tst_QmlTests.cpp'
--- tests/unittests/qml/tst_QmlTests.cpp	2014-11-26 11:33:10 +0000
+++ tests/unittests/qml/tst_QmlTests.cpp	2014-12-11 18:51:44 +0000
@@ -22,11 +22,15 @@
 
 // local
 #include "favicon-fetcher.h"
+#include "item-capture.h"
 
 int main(int argc, char** argv)
 {
-    const char* uri = "webbrowsercommon.private";
-    qmlRegisterType<FaviconFetcher>(uri, 0, 1, "FaviconFetcher");
+    const char* commonUri = "webbrowsercommon.private";
+    qmlRegisterType<FaviconFetcher>(commonUri, 0, 1, "FaviconFetcher");
+
+    const char* browserUri = "webbrowserapp.private";
+    qmlRegisterType<ItemCapture>(browserUri, 0, 1, "ItemCapture");
 
     return quick_test_main(argc, argv, "QmlTests", 0);
 }