Implemented history (position stack)

Allows the user to return back after selecting a cross-page link

app/app.pro

@@ -109,6 +109,7 @@ SOURCES += \
   src/BooksImportModel.cpp \
   src/BooksListWatcher.cpp \
   src/BooksLoadingProperty.cpp \
+  src/BooksPageStack.cpp \
   src/BooksPageWidget.cpp \
   src/BooksPaintContext.cpp \
   src/BooksPathModel.cpp \
@@ -150,6 +151,7 @@ HEADERS += \
   src/BooksItem.h \
   src/BooksListWatcher.h \
   src/BooksLoadingProperty.h \
+  src/BooksPageStack.h \
   src/BooksPageWidget.h \
   src/BooksPaintContext.h \
   src/BooksPathModel.h \

app/qml/BooksBookView.qml

@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2015-2016 Jolla Ltd.
+  Copyright (C) 2015-2017 Jolla Ltd.
   Contact: Slava Monich <slava.monich@jolla.com>
 
   You may use this file under the terms of BSD license as follows:
@@ -43,8 +43,8 @@ SilicaFlickable {
     signal pageClicked(var page)
 
     property int orientation: Orientation.Portrait
-    property int _currentPage: bookListWatcher.currentIndex
+    property alias stackModel: bookModel.pageStack
-    property bool _loading: minLoadingDelay.running || bookModel.loading
+    property bool loading: bookModel.loading
     property var _currentState: _visibilityStates[Settings.pageDetails % _visibilityStates.length]
     readonly property var _visibilityStates: [
         { pager: false, page: false, title: false, tools: false },
@@ -52,18 +52,6 @@ SilicaFlickable {
         { pager: true,  page: true,  title: true,  tools: true  }
     ]
 
-    // NOTE: These have to match ResetReason in BooksBookModel
-    readonly property var _loadingTextLabel: [
-        //% "Formatting..."
-        qsTrId("harbour-books-book-view-formatting"),
-        //% "Loading..."
-        qsTrId("harbour-books-book-view-loading"),
-        //% "Applying larger fonts..."
-        qsTrId("harbour-books-book-view-applying_larger_fonts"),
-        //% "Applying smaller fonts..."
-        qsTrId("harbour-books-book-view-applying_smaller_fonts")
-    ]
-
     interactive: (!linkMenu || !linkMenu.visible) &&
         (!imageView || !imageView.visible) &&
         (!footnoteView || !footnoteView.visible)
@@ -101,49 +89,14 @@ SilicaFlickable {
         }
     }
 
-    Timer {
-        id: minLoadingDelay
-        interval: 1000
-    }
-
-    Timer {
-        id: resetPager
-        interval: 0
-        onTriggered: {
-            if (_currentPage >= 0) {
-                console.log("resetting pager to", _currentPage)
-                pager.currentPage = _currentPage
-            }
-        }
-    }
-
     BookModel {
         id: bookModel
         book: root.book ? root.book : null
-        size: bookListWatcher.size
+        size: bookViewWatcher.size
-        currentPage: _currentPage
         leftMargin: Theme.horizontalPageMargin
         rightMargin: Theme.horizontalPageMargin
         topMargin: Theme.itemSizeSmall
         bottomMargin: Theme.itemSizeSmall
-        onJumpToPage: bookView.jumpTo(index)
-        onCurrentPageChanged: {
-            if (linkMenu) linkMenu.hide()
-            if (currentPage >= 0 && bookView._jumpingTo < 0) {
-                pager.currentPage = currentPage
-            }
-        }
-        onLoadingChanged: {
-            if (loading && !pageCount) {
-                minLoadingDelay.start()
-                bookView._jumpingTo = -1
-            }
-        }
-    }
-
-    ListWatcher {
-        id: bookListWatcher
-        listView: bookView
     }
 
     SilicaListView {
@@ -154,9 +107,50 @@ SilicaFlickable {
         orientation: ListView.Horizontal
         snapMode: ListView.SnapOneItem
         spacing: Theme.paddingMedium
-        opacity: _loading ? 0 : 1
+        opacity: loading ? 0 : 1
         visible: opacity > 0
         interactive: root.interactive
+        readonly property int currentPage: stackModel.currentPage
+        property bool completed
+
+        Component.onCompleted: {
+            //console.log(currentPage)
+            bookViewWatcher.positionViewAtIndex(currentPage)
+            completed = true
+        }
+
+        onCurrentPageChanged: {
+            //console.log(currentPage, completed, flicking)
+            if (completed && !flicking) {
+                bookViewWatcher.positionViewAtIndex(currentPage)
+            }
+        }
+
+        onFlickingChanged: {
+            if (!flicking) {
+                bookViewWatcher.updateModel()
+            }
+        }
+
+        ListWatcher {
+            id: bookViewWatcher
+            listView: bookView
+            onCurrentIndexChanged: {
+                if (listView.completed && !listView.flicking && currentIndex >= 0) {
+                    //console.log(currentIndex, listView.completed, listView.flicking)
+                    updateModel()
+                }
+            }
+            function updateModel() {
+                if (linkMenu) linkMenu.hide()
+                //console.trace()
+                stackModel.currentPage = currentIndex
+                if (!pager.pressed) {
+                    pager.currentPage = currentIndex
+                }
+            }
+        }
+
         delegate: BooksPageView {
             width: bookView.width
             height: bookView.height
@@ -172,12 +166,13 @@ SilicaFlickable {
             pageNumberVisible: _currentState.page
             title: bookModel.title
             onJumpToPage: bookView.jumpTo(page)
+            onPushPosition: stackModel.pushPosition(position) // bookView.jumpTo(page)
             onPageClicked: {
                 root.pageClicked(index)
-                Settings.pageDetails = (Settings.pageDetails+ 1) % _visibilityStates.length
+                Settings.pageDetails = (Settings.pageDetails + 1) % _visibilityStates.length
             }
             onImagePressed: {
-                if (_currentPage == index) {
+                if (bookViewWatcher.currentIndex == index) {
                     if (!imageView) {
                         imageView = imageViewComponent.createObject(root)
                     }
@@ -185,7 +180,7 @@ SilicaFlickable {
                 }
             }
             onBrowserLinkPressed: {
-                if (_currentPage == index) {
+                if (bookViewWatcher.currentIndex == index) {
                     if (!linkMenu) {
                         linkMenu = linkMenuComponent.createObject(root)
                     }
@@ -193,7 +188,7 @@ SilicaFlickable {
                 }
             }
             onFootnotePressed: {
-                if (_currentPage == index) {
+                if (bookViewWatcher.currentIndex == index) {
                     if (!footnoteView) {
                         footnoteView = footnoteViewComponent.createObject(root)
                     }
@@ -202,15 +197,15 @@ SilicaFlickable {
             }
         }
 
-        property int _jumpingTo: -1
+        property int jumpingTo: -1
         function jumpTo(page) {
-            if (page >=0 && page !== _currentPage) {
+            if (page >=0 && page !== bookViewWatcher.currentIndex) {
-                _jumpingTo = page
+                jumpingTo = page
-                positionViewAtIndex(page, ListView.Center)
+                bookViewWatcher.positionViewAtIndex(page)
                 pager.currentPage = page
-                _jumpingTo = -1
+                jumpingTo = -1
-                if (_currentPage !== page) {
+                if (bookViewWatcher.currentIndex !== page) {
-                    console.log("oops, still at", _currentPage)
+                    console.log("oops, still at", currentPage)
                     resetPager.restart()
                 }
             }
@@ -218,6 +213,15 @@ SilicaFlickable {
 
         Behavior on opacity { FadeAnimation {} }
 
+        Timer {
+            id: resetPager
+            interval: 0
+            onTriggered: {
+                console.log("resetting pager to", bookViewWatcher.currentIndex)
+                pager.currentPage = bookViewWatcher.currentIndex
+            }
+        }
+
         BooksPageTools {
             id: pageTools
             anchors {
@@ -228,7 +232,7 @@ SilicaFlickable {
             leftMargin: bookModel.leftMargin
             rightMargin: bookModel.rightMargin
             opacity: _currentState.tools ? 1 : 0
-            visible: opacity > 0 && book && bookModel.pageCount && !_loading
+            visible: opacity > 0 && book && bookModel.pageCount && !loading
             Behavior on opacity { FadeAnimation {} }
             onIncreaseFontSize: bookModel.increaseFontSize()
             onDecreaseFontSize: bookModel.decreaseFontSize()
@@ -237,9 +241,14 @@ SilicaFlickable {
         BooksPager {
             id: pager
             anchors {
+                left: parent.left
+                right: parent.right
                 bottom: parent.bottom
                 bottomMargin: (Theme.itemSizeExtraSmall + 2*(bookModel.bottomMargin - height))/4
             }
+            leftMargin: bookModel.leftMargin
+            rightMargin: bookModel.rightMargin
+            stack: stackModel
             pageCount: bookModel.pageCount
             width: parent.width
             opacity: (_currentState.pager && book && bookModel.pageCount) ? 0.75 : 0
@@ -261,20 +270,20 @@ SilicaFlickable {
         text: bookModel.title
         height: Theme.itemSizeExtraSmall
         color: Theme.highlightColor
-        opacity: _loading ? 0.6 : 0
+        opacity: loading ? 0.6 : 0
     }
 
     BusyIndicator {
         id: busyIndicator
         anchors.centerIn: parent
         size: BusyIndicatorSize.Large
-        running: _loading
+        running: loading
     }
 
     BooksFitLabel {
         anchors.fill: busyIndicator
         text: bookModel.progress > 0 ? bookModel.progress : ""
-        opacity: (_loading && bookModel.progress > 0) ? 1 : 0
+        opacity: (loading && bookModel.progress > 0) ? 1 : 0
     }
 
     Button {
@@ -286,7 +295,7 @@ SilicaFlickable {
             horizontalCenter: parent.horizontalCenter
         }
         onClicked: root.closeBook()
-        enabled: _loading && bookModel.resetReason === BookModel.ReasonLoading
+        enabled: loading && bookModel.resetReason === BookModel.ReasonLoading
         visible: opacity > 0
         opacity: enabled ? 1.0 : 0.0
         Behavior on opacity { FadeAnimation { } }
@@ -301,9 +310,19 @@ SilicaFlickable {
         }
         horizontalAlignment: Text.AlignHCenter
         color: Theme.highlightColor
-        opacity: _loading ? 1 : 0
+        opacity: loading ? 1 : 0
         visible: opacity > 0
         Behavior on opacity { FadeAnimation {} }
-        text: bookModel ? _loadingTextLabel[bookModel.resetReason] : ""
+        text: bookModel ? (bookModel.resetReason == BookModel.ReasonLoading ?
+            //% "Loading..."
+            qsTrId("harbour-books-book-view-loading") :
+            bookModel.resetReason == BookModel.ReasonIncreasingFontSize ?
+            //% "Applying larger fonts..."
+            qsTrId("harbour-books-book-view-applying_larger_fonts") :
+            bookModel.resetReason == BookModel.ReasonDecreasingFontSize ?
+            //% "Applying smaller fonts..."
+            qsTrId("harbour-books-book-view-applying_smaller_fonts") :
+            //% "Formatting..."
+            qsTrId("harbour-books-book-view-formatting")) : ""
     }
 }

app/qml/BooksPageView.qml

@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2015-2016 Jolla Ltd.
+  Copyright (C) 2015-2017 Jolla Ltd.
   Contact: Slava Monich <slava.monich@jolla.com>
 
   You may use this file under the terms of BSD license as follows:
@@ -54,6 +54,7 @@ Item {
     signal footnotePressed(var touchX, var touchY, var text, var url)
     signal browserLinkPressed(var url)
     signal jumpToPage(var page)
+    signal pushPosition(var position)
 
     PageWidget {
         id: widget
@@ -63,6 +64,7 @@ Item {
         onImagePressed: view.imagePressed(imageId, rect)
         onActiveTouch: pressImage.animate(touchX, touchY)
         onJumpToPage: view.jumpToPage(page)
+        onPushPosition: view.pushPosition(position)
         onShowFootnote: view.footnotePressed(touchX,touchY,text,imageId)
     }
 

app/qml/BooksPager.qml

@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 2015-2016 Jolla Ltd.
+  Copyright (C) 2015-2017 Jolla Ltd.
   Contact: Slava Monich <slava.monich@jolla.com>
 
   You may use this file under the terms of BSD license as follows:
@@ -38,29 +38,82 @@ Item {
     id: root
     height: slider.height
 
-    property alias pageCount: slider.maximumValue
+    property var stack
+    property int pageCount
+    property real leftMargin: Theme.horizontalPageMargin
+    property real rightMargin: Theme.horizontalPageMargin
     property alias currentPage: slider.value
     property alias pressed: slider.pressed
-    property alias leftMargin: slider.leftMargin
-    property alias rightMargin: slider.rightMargin
 
     signal pageChanged(var page)
 
+    MouseArea {
+        id: navigateBackArea
+        property bool down: pressed && containsMouse
+        width: navigateBack.width + root.leftMargin
+        height: navigateBack.height
+        anchors {
+            left: parent.left
+            verticalCenter: parent.verticalCenter
+        }
+        onClicked: stack.back()
+    }
+
+
+    IconButton {
+        id: navigateBack
+        icon.source: "image://theme/icon-m-left?" + Settings.primaryPageToolColor
+        down: navigateBackArea.down || (pressed && containsMouse)
+        anchors {
+            left: parent.left
+            leftMargin: root.leftMargin
+            verticalCenter: parent.verticalCenter
+        }
+        onClicked: stack.back()
+    }
+
     BooksPageSlider {
         id: slider
         anchors {
-            left: parent.left
+            left: navigateBack.right
-            right: parent.right
+            right: navigateForwardArea.left
             bottom: parent.bottom
         }
         stepSize: 1
         minimumValue: 0
+        maximumValue: pageCount > 0 ? pageCount - 1 : 0
         valueText: ""
         label: ""
+        leftMargin: Theme.horizontalPageMargin
+        rightMargin: Theme.horizontalPageMargin
         primaryColor: Settings.primaryPageToolColor
         secondaryColor: Settings.primaryPageToolColor
         highlightColor: Settings.highlightPageToolColor
         secondaryHighlightColor: Settings.highlightPageToolColor
         onSliderValueChanged: root.pageChanged(value)
     }
+
+    MouseArea {
+        id: navigateForwardArea
+        property bool down: pressed && containsMouse
+        width: navigateForward.width + root.rightMargin
+        height: navigateForward.height
+        anchors {
+            right: parent.right
+            verticalCenter: parent.verticalCenter
+        }
+        onClicked: stack.forward()
+    }
+
+    IconButton {
+        id: navigateForward
+        icon.source: "image://theme/icon-m-right?" + Settings.primaryPageToolColor
+        down: navigateForwardArea.down || (pressed && containsMouse)
+        anchors {
+            right: parent.right
+            rightMargin: root.rightMargin
+            verticalCenter: parent.verticalCenter
+        }
+        onClicked: stack.forward()
+    }
 }

app/src/BooksBook.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015 Jolla Ltd.
+ * Copyright (C) 2015-2017 Jolla Ltd.
  * Contact: Slava Monich <slava.monich@jolla.com>
  *
  * You may use this file under the terms of the BSD license as follows:
@@ -14,7 +14,7 @@
  *     notice, this list of conditions and the following disclaimer in
  *     the documentation and/or other materials provided with the
  *     distribution.
- *   * Neither the name of Nemo Mobile nor the names of its contributors
+ *   * Neither the name of Jolla Ltd nor the names of its contributors
  *     may be used to endorse or promote products derived from this
  *     software without specific prior written permission.
  *
@@ -58,6 +58,7 @@
 #include <unistd.h>
 #include <errno.h>
 
+#define BOOK_STATE_PAGE_STACK_INDEX "pageStackIndex"
 #define BOOK_STATE_FONT_SIZE_ADJUST "fontSizeAdjust"
 #define BOOK_STATE_POSITION         "position"
 #define BOOK_COVER_SUFFIX           ".cover."
@@ -328,10 +329,40 @@ BooksBook::BooksBook(const BooksStorage& aStorage, QString aRelativePath,
         // Load the state
         QVariantMap state;
         if (HarbourJson::load(iStateFilePath, state)) {
-            iLastPos = BooksPos::fromVariant(state.value(BOOK_STATE_POSITION));
             iFontSizeAdjust = state.value(BOOK_STATE_FONT_SIZE_ADJUST).toInt();
+#ifdef BOOK_STATE_PAGE_STACK_INDEX
+            iPageStackPos = state.value(BOOK_STATE_PAGE_STACK_INDEX).toInt();
+#endif
+            // Current position can be stored in two formats - a single
+            // position (older format) or a list of position (newer one).
+            // We have to detect which one we are dealing with
+            QVariant position(state.value(BOOK_STATE_POSITION));
+            BooksPos bookPos(BooksPos::fromVariant(position));
+            if (bookPos.valid()) {
+                // Old format (single position)
+                iPageStack.append(bookPos);
+            } else {
+                // New format (list of positions)
+                QVariantList list(position.toList());
+                const int count = list.count();
+                for (int k=0; k<count; k++) {
+                    bookPos = BooksPos::fromVariant(list.at(k));
+                    if (bookPos.valid()) {
+                        iPageStack.append(bookPos);
+                    }
+                }
+            }
         }
     }
+    // Validate the state
+    if (iPageStack.isEmpty()) {
+        iPageStack.append(BooksPos(0,0,0));
+    }
+    if (iPageStackPos < 0) {
+        iPageStackPos = 0;
+    } else if (iPageStackPos >= iPageStack.count()) {
+        iPageStackPos = iPageStack.count() - 1;
+    }
     // Refcounted BooksBook objects are managed by C++ code
     QQmlEngine::setObjectOwnership(this, QQmlEngine::CppOwnership);
 }
@@ -339,6 +370,7 @@ BooksBook::BooksBook(const BooksStorage& aStorage, QString aRelativePath,
 void BooksBook::init()
 {
     iFontSizeAdjust = 0;
+    iPageStackPos = 0;
     iCoverTask = NULL;
     iCoverTasksDone = false;
     iCopyingOut = false;
@@ -419,10 +451,23 @@ bool BooksBook::setFontSizeAdjust(int aFontSizeAdjust)
     }
 }
 
-void BooksBook::setLastPos(const BooksPos& aPos)
+void BooksBook::setPageStack(BooksPos::List aStack, int aStackPos)
 {
-    if (iLastPos != aPos) {
+    if (aStackPos < 0) {
-        iLastPos = aPos;
+        aStackPos = 0;
+    } else if (aStackPos >= aStack.count()) {
+        aStackPos = aStack.count() - 1;
+    }
+    bool changed = false;
+    if (iPageStack != aStack) {
+        iPageStack = aStack;
+        changed = true;
+    }
+    if (iPageStackPos != aStackPos) {
+        iPageStackPos = aStackPos;
+        changed = true;
+    }
+    if (changed) {
         requestSave();
     }
 }
@@ -536,8 +581,14 @@ void BooksBook::saveState()
     if (!iStateFilePath.isEmpty()) {
         QVariantMap state;
         HarbourJson::load(iStateFilePath, state);
-        state.insert(BOOK_STATE_POSITION, iLastPos.toVariant());
+        QVariantList positions;
+        const int n = iPageStack.count();
+        for (int i=0; i<n; i++) positions.append(iPageStack.at(i).toVariant());
+        state.insert(BOOK_STATE_POSITION, positions);
         state.insert(BOOK_STATE_FONT_SIZE_ADJUST, iFontSizeAdjust);
+#ifdef BOOK_STATE_PAGE_STACK_INDEX
+        state.insert(BOOK_STATE_PAGE_STACK_INDEX, iPageStackPos);
+#endif
         if (HarbourJson::save(iStateFilePath, state)) {
             HDEBUG("wrote" << iStateFilePath);
         }

app/src/BooksBook.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015 Jolla Ltd.
+ * Copyright (C) 2015-2017 Jolla Ltd.
  * Contact: Slava Monich <slava.monich@jolla.com>
  *
  * You may use this file under the terms of the BSD license as follows:
@@ -14,7 +14,7 @@
  *     notice, this list of conditions and the following disclaimer in
  *     the documentation and/or other materials provided with the
  *     distribution.
- *   * Neither the name of Nemo Mobile nor the names of its contributors
+ *   * Neither the name of Jolla Ltd nor the names of its contributors
  *     may be used to endorse or promote products derived from this
  *     software without specific prior written permission.
  *
@@ -74,16 +74,17 @@ public:
     static BooksBook* newBook(const BooksStorage& aStorage, QString aRelPath,
         QString aFileName);
 
-    QString title() const { return iTitle; }
+    QString title() const;
-    QString authors() const { return iAuthors; }
+    QString authors() const;
-    int fontSizeAdjust() const { return iFontSizeAdjust; }
+    int fontSizeAdjust() const;
     bool setFontSizeAdjust(int aFontSizeAdjust);
-    BooksPos lastPos() const { return iLastPos; }
+    int pageStackPos() const;
-    void setLastPos(const BooksPos& aPos);
+    BooksPos::List pageStack() const;
-    shared_ptr<Book> bookRef() const { return iBook; }
+    void setPageStack(BooksPos::List aStack, int aStackPos);
+    shared_ptr<Book> bookRef() const;
 
-    bool copyingOut() const { return iCopyingOut; }
+    bool copyingOut() const;
-    bool loadingCover() const { return !iCoverTasksDone; }
+    bool loadingCover() const;
     bool hasCoverImage() const;
     bool requestCoverImage();
     void cancelCoverRequest();
@@ -129,7 +130,8 @@ private:
 private:
     QAtomicInt iRef;
     int iFontSizeAdjust;
-    BooksPos iLastPos;
+    int iPageStackPos;
+    BooksPos::List iPageStack;
     BooksStorage iStorage;
     shared_ptr<Book> iBook;
     QImage iCoverImage;
@@ -149,6 +151,22 @@ private:
 
 QML_DECLARE_TYPE(BooksBook)
 
+inline QString BooksBook::title() const
+    { return iTitle; }
+inline QString BooksBook::authors() const
+    { return iAuthors; }
+inline int BooksBook::fontSizeAdjust() const
+    { return iFontSizeAdjust; }
+inline int BooksBook::pageStackPos() const
+    { return iPageStackPos; }
+inline BooksPos::List BooksBook::pageStack() const
+    { return iPageStack; }
+inline shared_ptr<Book> BooksBook::bookRef() const
+    { return iBook; }
+inline bool BooksBook::copyingOut() const
+    { return iCopyingOut; }
+inline bool BooksBook::loadingCover() const
+    { return !iCoverTasksDone; }
 inline bool BooksBook::isCanceled(CopyOperation* aObserver)
     { return aObserver && aObserver->isCanceled(); }
 inline QImage BooksBook::coverImage() const

app/src/BooksBookModel.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2016 Jolla Ltd.
+ * Copyright (C) 2015-2017 Jolla Ltd.
  * Contact: Slava Monich <slava.monich@jolla.com>
  *
  * You may use this file under the terms of the BSD license as follows:
@@ -45,10 +45,6 @@ class BooksBookModel::Data {
 public:
     Data(int aWidth, int aHeight) : iWidth(aWidth), iHeight(aHeight) {}
 
-    int pickPage(const BooksPos& aPagePos) const;
-    int pickPage(const BooksPos& aPagePos, const BooksPos& aNextPagePos,
-        int aPageCount) const;
-
 public:
     int iWidth;
     int iHeight;
@@ -56,65 +52,17 @@ public:
     BooksPos::List iPageMarks;
 };
 
-int BooksBookModel::Data::pickPage(const BooksPos& aPagePos) const
-{
-    int page = 0;
-    if (aPagePos.valid()) {
-        BooksPos::ConstIterator it = qFind(iPageMarks, aPagePos);
-        if (it == iPageMarks.end()) {
-            it = qUpperBound(iPageMarks, aPagePos);
-            page = (int)(it - iPageMarks.begin()) - 1;
-            HDEBUG("using page" << page << "for" << aPagePos);
-        } else {
-            page = it - iPageMarks.begin();
-            HDEBUG("found" << aPagePos << "at page" << page);
-        }
-    }
-    return page;
-}
-
-int BooksBookModel::Data::pickPage(const BooksPos& aPagePos,
-    const BooksPos& aNextPagePos, int aPageCount) const
-{
-    int page = 0;
-    if (aPagePos.valid()) {
-        if (!aNextPagePos.valid()) {
-            // Last page stays the last
-            page = iPageMarks.count() - 1;
-            HDEBUG("last page" << page);
-        } else {
-            BooksPos::ConstIterator it = qFind(iPageMarks, aPagePos);
-            if (it == iPageMarks.end()) {
-                // Two 90-degrees rotations should return the reader
-                // back to the same page. That's what this is about.
-                const BooksPos& pos = (iPageMarks.count() > aPageCount) ?
-                    aPagePos : aNextPagePos;
-                it = qUpperBound(iPageMarks, pos);
-                page = (int)(it - iPageMarks.begin());
-                if (page > 0) page--;
-                HDEBUG("using page" << page << "for" << pos);
-            } else {
-                page = it - iPageMarks.begin();
-                HDEBUG("found" << aPagePos << "at page" << page);
-            }
-        }
-    }
-    return page;
-}
-
 // ==========================================================================
-// BooksBookModel::Task
+// BooksBookModel::PagingTask
 // ==========================================================================
 
-class BooksBookModel::Task : public BooksTask
+class BooksBookModel::PagingTask : public BooksTask
 {
     Q_OBJECT
 
 public:
-    Task(BooksBookModel* aReceiver, shared_ptr<Book> aBook,
+    PagingTask(BooksBookModel* aReceiver, shared_ptr<Book> aBook);
-        const BooksPos& aPagePos, const BooksPos& aNextPagePos,
+    ~PagingTask();
-        const BooksPos& aLastPos, int aPageCount);
-    ~Task();
 
     void performTask();
 
@@ -127,38 +75,27 @@ public:
     BooksMargins iMargins;
     BooksPaintContext iPaint;
     BooksBookModel::Data* iData;
-    BooksPos iPagePos;
-    BooksPos iNextPagePos;
-    BooksPos iLastPos;
-    int iOldPageCount;
-    int iPage;
 };
 
-BooksBookModel::Task::Task(BooksBookModel* aModel,
+BooksBookModel::PagingTask::PagingTask(BooksBookModel* aModel,
-    shared_ptr<Book> aBook, const BooksPos& aPagePos,
+    shared_ptr<Book> aBook) :
-    const BooksPos& aNextPagePos, const BooksPos& aLastPos, int aPageCount) :
     iBook(aBook),
     iTextStyle(aModel->textStyle()),
     iMargins(aModel->margins()),
     iPaint(aModel->width(), aModel->height()),
-    iData(NULL),
+    iData(NULL)
-    iPagePos(aPagePos),
-    iNextPagePos(aNextPagePos),
-    iLastPos(aLastPos),
-    iOldPageCount(aPageCount),
-    iPage(-1)
 {
     aModel->connect(this, SIGNAL(done()), SLOT(onResetDone()));
     aModel->connect(this, SIGNAL(progress(int)), SLOT(onResetProgress(int)),
         Qt::QueuedConnection);
 }
 
-BooksBookModel::Task::~Task()
+BooksBookModel::PagingTask::~PagingTask()
 {
     delete iData;
 }
 
-void BooksBookModel::Task::performTask()
+void BooksBookModel::PagingTask::performTask()
 {
     if (!isCanceled()) {
         iData = new BooksBookModel::Data(iPaint.width(), iPaint.height());
@@ -183,9 +120,6 @@ void BooksBookModel::Task::performTask()
     if (!isCanceled()) {
         HDEBUG(iData->iPageMarks.count() << "page(s)" << qPrintable(
             QString("%1x%2").arg(iData->iWidth).arg(iData->iHeight)));
-        iPage = iPagePos.valid() ?
-            iData->pickPage(iPagePos, iNextPagePos, iOldPageCount) :
-            iData->pickPage(iLastPos);
     } else {
         HDEBUG("giving up" << qPrintable(QString("%1x%2").arg(iPaint.width()).
             arg(iPaint.height())) << "paging");
@@ -203,17 +137,19 @@ enum BooksBookModelRole {
 BooksBookModel::BooksBookModel(QObject* aParent) :
     QAbstractListModel(aParent),
     iResetReason(ReasonUnknown),
-    iCurrentPage(-1),
     iProgress(0),
     iBook(NULL),
-    iTask(NULL),
+    iPagingTask(NULL),
     iData(NULL),
     iData2(NULL),
     iSettings(BooksSettings::sharedInstance()),
-    iTaskQueue(BooksTaskQueue::defaultQueue())
+    iTaskQueue(BooksTaskQueue::defaultQueue()),
+    iPageStack(new BooksPageStack(this))
 {
     iTextStyle = iSettings->textStyle(fontSizeAdjust());
     connect(iSettings.data(), SIGNAL(textStyleChanged()), SLOT(onTextStyleChanged()));
+    connect(iPageStack, SIGNAL(changed()), SLOT(onPageStackChanged()));
+    connect(iPageStack, SIGNAL(currentIndexChanged()), SLOT(onPageStackChanged()));
     HDEBUG("created");
 #if QT_VERSION < 0x050000
     setRoleNames(roleNames());
@@ -222,7 +158,7 @@ BooksBookModel::BooksBookModel(QObject* aParent) :
 
 BooksBookModel::~BooksBookModel()
 {
-    if (iTask) iTask->release(this);
+    if (iPagingTask) iPagingTask->release(this);
     if (iBook) {
         iBook->disconnect(this);
         iBook->release();
@@ -235,7 +171,6 @@ BooksBookModel::~BooksBookModel()
 
 void BooksBookModel::setBook(BooksBook* aBook)
 {
-    shared_ptr<Book> oldBook;
     shared_ptr<Book> newBook;
     if (iBook != aBook) {
         const QString oldTitle(iTitle);
@@ -246,14 +181,16 @@ void BooksBookModel::setBook(BooksBook* aBook)
         if (aBook) {
             (iBook = aBook)->retain();
             iBookRef = newBook;
-            iTitle = iBook->title();
+            iTitle = aBook->title();
             iTextStyle = iSettings->textStyle(fontSizeAdjust());
-            connect(iBook, SIGNAL(fontSizeAdjustChanged()), SLOT(onTextStyleChanged()));
+            iPageStack->setStack(aBook->pageStack(), aBook->pageStackPos());
+            connect(aBook, SIGNAL(fontSizeAdjustChanged()), SLOT(onTextStyleChanged()));
             HDEBUG(iTitle);
         } else {
             iBook = NULL;
             iBookRef.reset();
             iTitle = QString();
+            iPageStack->clear();
             HDEBUG("<none>");
         }
         startReset(ReasonLoading, true);
@@ -268,7 +205,7 @@ void BooksBookModel::setBook(BooksBook* aBook)
 
 bool BooksBookModel::loading() const
 {
-    return (iTask != NULL);
+    return (iPagingTask != NULL);
 }
 
 bool BooksBookModel::increaseFontSize()
@@ -281,19 +218,12 @@ bool BooksBookModel::decreaseFontSize()
     return iBook && iBook->setFontSizeAdjust(iBook->fontSizeAdjust()-1);
 }
 
-void BooksBookModel::setCurrentPage(int aPage)
+void BooksBookModel::onPageStackChanged()
 {
-    if (iCurrentPage != aPage) {
+    if (iBook) {
-        iCurrentPage = aPage;
+        BooksPos::Stack stack = iPageStack->getStack();
-        if (iData &&
+        HDEBUG(stack.iList << stack.iPos);
-            iCurrentPage >= 0 &&
+        iBook->setPageStack(stack.iList, stack.iPos);
-            iCurrentPage < iData->iPageMarks.count()) {
-            iBook->setLastPos(iData->iPageMarks.at(iCurrentPage));
-            HDEBUG(aPage << iBook->lastPos());
-        } else {
-            HDEBUG(aPage);
-        }
-        Q_EMIT currentPageChanged();
     }
 }
 
@@ -314,24 +244,18 @@ int BooksBookModel::fontSizeAdjust() const
 
 BooksPos BooksBookModel::pageMark(int aPage) const
 {
-    if (aPage >= 0 && iData) {
+    return iData ? BooksPos::posAt(iData->iPageMarks, aPage) : BooksPos();
-        const int n = iData->iPageMarks.count();
-        if (aPage < n) {
-            return iData->iPageMarks.at(aPage);
-        }
-    }
-    return BooksPos();
 }
 
-int BooksBookModel::linkToPage(const std::string& aLink) const
+BooksPos BooksBookModel::linkPosition(const std::string& aLink) const
 {
     if (iData && !iData->iBookModel.isNull()) {
         BookModel::Label label = iData->iBookModel->label(aLink);
         if (label.ParagraphNumber >= 0) {
-            return iData->pickPage(BooksPos(label.ParagraphNumber, 0, 0));
+            return BooksPos(label.ParagraphNumber, 0, 0);
         }
     }
-    return -1;
+    return BooksPos();
 }
 
 shared_ptr<BookModel> BooksBookModel::bookModel() const
@@ -410,6 +334,7 @@ void BooksBookModel::updateModel(int aPrevPageCount)
 {
     const int newPageCount = pageCount();
     if (aPrevPageCount != newPageCount) {
+        HDEBUG(aPrevPageCount << "->" << newPageCount);
         if (newPageCount > aPrevPageCount) {
             beginInsertRows(QModelIndex(), aPrevPageCount, newPageCount-1);
             endInsertRows();
@@ -433,36 +358,20 @@ void BooksBookModel::setSize(QSize aSize)
         } else if (iData2 && iData2->iWidth == w && iData2->iHeight == h) {
             HDEBUG("switching to backup layout");
             const int oldModelPageCount = pageCount();
-            int oldPageCount;
-            BooksPos page1, page2;
-            if (iTask) {
-                // Layout has been switched back before the paging task
-                // has completed
-                HDEBUG("not so fast please...");
-                oldPageCount = iTask->iOldPageCount;
-                page1 = iTask->iPagePos;
-                page2 = iTask->iNextPagePos;
-            } else {
-                oldPageCount = oldModelPageCount;
-                page1 = pageMark(iCurrentPage);
-                page2 = pageMark(iCurrentPage+1);
-            }
             Data* tmp = iData;
             iData = iData2;
             iData2 = tmp;
-            if (iData) {
+            // Cancel unnecessary paging task
-                // Cancel unnecessary paging task
+            BooksLoadingSignalBlocker block(this);
-                if (iTask) {
+            if (iPagingTask) {
-                    BooksLoadingSignalBlocker block(this);
+                HDEBUG("not so fast please...");
-                    iTask->release(this);
+                iPagingTask->release(this);
-                    iTask = NULL;
+                iPagingTask = NULL;
-                }
-                updateModel(oldModelPageCount);
-                Q_EMIT pageMarksChanged();
-                Q_EMIT jumpToPage(iData->pickPage(page1, page2, oldPageCount));
-            } else {
-                startReset(ReasonUnknown, false);
             }
+            updateModel(oldModelPageCount);
+            iPageStack->setPageMarks(iData->iPageMarks);
+            Q_EMIT pageMarksChanged();
+            Q_EMIT jumpToPage(iPageStack->currentPage());
         } else {
             startReset(ReasonUnknown, false);
         }
@@ -487,9 +396,8 @@ void BooksBookModel::onTextStyleChanged()
 
 void BooksBookModel::startReset(ResetReason aResetReason, bool aFullReset)
 {
+    BooksPos dummy;
     BooksLoadingSignalBlocker block(this);
-    const BooksPos thisPage = pageMark(iCurrentPage);
-    const BooksPos nextPage = pageMark(iCurrentPage+1);
     if (aResetReason == ReasonUnknown) {
         if (iResetReason == ReasonUnknown) {
             if (!iData && !iData2) {
@@ -499,9 +407,9 @@ void BooksBookModel::startReset(ResetReason aResetReason, bool aFullReset)
             aResetReason = iResetReason;
         }
     }
-    if (iTask) {
+    if (iPagingTask) {
-        iTask->release(this);
+        iPagingTask->release(this);
-        iTask = NULL;
+        iPagingTask = NULL;
     }
     const int oldPageCount(pageCount());
     if (oldPageCount > 0) {
@@ -520,9 +428,8 @@ void BooksBookModel::startReset(ResetReason aResetReason, bool aFullReset)
     if (iBook && width() > 0 && height() > 0) {
         HDEBUG("starting" << qPrintable(QString("%1x%2").arg(width()).
             arg(height())) << "paging");
-        iTask = new Task(this, iBook->bookRef(), thisPage, nextPage,
+        iPagingTask = new PagingTask(this, iBook->bookRef());
-            iBook->lastPos(), oldPageCount);
+        iTaskQueue->submit(iPagingTask);
-        iTaskQueue->submit(iTask);
     }
 
     if (oldPageCount > 0) {
@@ -531,11 +438,6 @@ void BooksBookModel::startReset(ResetReason aResetReason, bool aFullReset)
         Q_EMIT pageCountChanged();
     }
 
-    if (iCurrentPage != 0) {
-        iCurrentPage = 0;
-        Q_EMIT currentPageChanged();
-    }
-
     if (iProgress != 0) {
         iProgress = 0;
         Q_EMIT progressChanged();
@@ -551,7 +453,7 @@ void BooksBookModel::onResetProgress(int aProgress)
 {
     // progress -> onResetProgress is a queued connection, we may received
     // this event from the task that has already been canceled.
-    if (iTask == sender() && aProgress > iProgress) {
+    if (iPagingTask == sender() && aProgress > iProgress) {
         iProgress = aProgress;
         Q_EMIT progressChanged();
     }
@@ -559,22 +461,22 @@ void BooksBookModel::onResetProgress(int aProgress)
 
 void BooksBookModel::onResetDone()
 {
-    HASSERT(sender() == iTask);
+    HASSERT(sender() == iPagingTask);
-    HASSERT(iTask->iData);
+    HASSERT(iPagingTask->iData);
     HASSERT(!iData);
 
     const int oldPageCount(pageCount());
     shared_ptr<BookModel> oldBookModel(bookModel());
     BooksLoadingSignalBlocker block(this);
-    int page = iTask->iPage;
 
-    iData = iTask->iData;
+    iData = iPagingTask->iData;
-    iTask->iData = NULL;
+    iPagingTask->iData = NULL;
-    iTask->release(this);
+    iPagingTask->release(this);
-    iTask = NULL;
+    iPagingTask = NULL;
 
     updateModel(oldPageCount);
-    Q_EMIT jumpToPage(page);
+    iPageStack->setPageMarks(iData->iPageMarks);
+    Q_EMIT jumpToPage(iPageStack->currentPage());
     Q_EMIT pageMarksChanged();
     if (oldBookModel != bookModel()) {
         Q_EMIT bookModelChanged();

app/src/BooksBookModel.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2016 Jolla Ltd.
+ * Copyright (C) 2015-2017 Jolla Ltd.
  * Contact: Slava Monich <slava.monich@jolla.com>
  *
  * You may use this file under the terms of the BSD license as follows:
@@ -42,6 +42,7 @@
 #include "BooksPos.h"
 #include "BooksPaintContext.h"
 #include "BooksLoadingProperty.h"
+#include "BooksPageStack.h"
 
 #include "ZLTextStyle.h"
 #include "bookmodel/BookModel.h"
@@ -63,11 +64,11 @@ class BooksBookModel: public QAbstractListModel, private BooksLoadingProperty
     Q_PROPERTY(bool loading READ loading NOTIFY loadingChanged)
     Q_PROPERTY(int progress READ progress NOTIFY progressChanged)
     Q_PROPERTY(int pageCount READ pageCount NOTIFY pageCountChanged)
-    Q_PROPERTY(int currentPage READ currentPage WRITE setCurrentPage NOTIFY currentPageChanged)
     Q_PROPERTY(int leftMargin READ leftMargin WRITE setLeftMargin NOTIFY leftMarginChanged)
     Q_PROPERTY(int rightMargin READ rightMargin WRITE setRightMargin NOTIFY rightMarginChanged)
     Q_PROPERTY(int topMargin READ topMargin WRITE setTopMargin NOTIFY topMarginChanged)
     Q_PROPERTY(int bottomMargin READ bottomMargin WRITE setBottomMargin NOTIFY bottomMarginChanged)
+    Q_PROPERTY(BooksPageStack* pageStack READ pageStack CONSTANT)
     Q_PROPERTY(BooksBook* book READ book WRITE setBook NOTIFY bookChanged)
     Q_PROPERTY(ResetReason resetReason READ resetReason NOTIFY resetReasonChanged)
 
@@ -88,25 +89,23 @@ public:
 
     bool loading() const;
     int pageCount() const;
-    int progress() const { return iProgress; }
+    int progress() const;
-    QString title() const { return iTitle; }
+    QString title() const;
-    int width() const { return iSize.width(); }
+    int width() const;
-    int height() const { return iSize.height(); }
+    int height() const;
-    ResetReason resetReason() const { return iResetReason; }
+    ResetReason resetReason() const;
+    BooksPageStack* pageStack() const;
 
-    QSize size() const { return iSize; }
+    QSize size() const;
     void setSize(QSize aSize);
 
-    int currentPage() const { return iCurrentPage; }
+    BooksBook* book() const;
-    void setCurrentPage(int aPage);
-
-    BooksBook* book() const { return iBook; }
     void setBook(BooksBook* aBook);
 
-    int leftMargin() const { return iMargins.iLeft; }
+    int leftMargin() const;
-    int rightMargin() const { return iMargins.iRight; }
+    int rightMargin() const;
-    int topMargin() const { return iMargins.iTop; }
+    int topMargin() const;
-    int bottomMargin() const { return iMargins.iBottom; }
+    int bottomMargin() const;
 
     void setLeftMargin(int aMargin);
     void setRightMargin(int aMargin);
@@ -115,14 +114,14 @@ public:
 
     BooksPos::List pageMarks() const;
     BooksPos pageMark(int aPage) const;
-    BooksMargins margins() const { return iMargins; }
+    BooksMargins margins() const;
-    shared_ptr<Book> bookRef() const { return iBookRef; }
+    shared_ptr<Book> bookRef() const;
     shared_ptr<BookModel> bookModel() const;
     shared_ptr<ZLTextModel> bookTextModel() const;
     shared_ptr<ZLTextModel> contentsModel() const;
     shared_ptr<ZLTextModel> footnoteModel(const std::string& aId) const;
-    shared_ptr<ZLTextStyle> textStyle() const { return iTextStyle; }
+    shared_ptr<ZLTextStyle> textStyle() const;
-    int linkToPage(const std::string& aLink) const;
+    BooksPos linkPosition(const std::string& aLink) const;
     int fontSizeAdjust() const;
 
     // QAbstractListModel
@@ -139,6 +138,7 @@ private Q_SLOTS:
     void onResetProgress(int aProgress);
     void onResetDone();
     void onTextStyleChanged();
+    void onPageStackChanged();
 
 Q_SIGNALS:
     void sizeChanged();
@@ -149,7 +149,6 @@ Q_SIGNALS:
     void pageCountChanged();
     void pageMarksChanged();
     void progressChanged();
-    void currentPageChanged();
     void leftMarginChanged();
     void rightMarginChanged();
     void topMarginChanged();
@@ -160,24 +159,55 @@ Q_SIGNALS:
 
 private:
     class Data;
-    class Task;
+    class PagingTask;
 
     ResetReason iResetReason;
-    int iCurrentPage;
     int iProgress;
     QSize iSize;
     QString iTitle;
     BooksMargins iMargins;
     BooksBook* iBook;
     shared_ptr<Book> iBookRef;
-    Task* iTask;
+    PagingTask* iPagingTask;
     Data* iData;
     Data* iData2;
     QSharedPointer<BooksSettings> iSettings;
     shared_ptr<BooksTaskQueue> iTaskQueue;
     shared_ptr<ZLTextStyle> iTextStyle;
+    BooksPageStack* iPageStack;
 };
 
 QML_DECLARE_TYPE(BooksBookModel)
 
+inline int BooksBookModel::progress() const
+    { return iProgress; }
+inline QString BooksBookModel::title() const
+    { return iTitle; }
+inline int BooksBookModel::width() const
+    { return iSize.width(); }
+inline int BooksBookModel::height() const
+    { return iSize.height(); }
+inline BooksBookModel::ResetReason BooksBookModel::resetReason() const
+    { return iResetReason; }
+inline BooksPageStack* BooksBookModel::pageStack() const
+    { return iPageStack; }
+inline QSize BooksBookModel::size() const
+    { return iSize; }
+inline BooksBook* BooksBookModel::book() const
+    { return iBook; }
+inline int BooksBookModel::leftMargin() const
+    { return iMargins.iLeft; }
+inline int BooksBookModel::rightMargin() const
+    { return iMargins.iRight; }
+inline int BooksBookModel::topMargin() const
+    { return iMargins.iTop; }
+inline int BooksBookModel::bottomMargin() const
+    { return iMargins.iBottom; }
+inline BooksMargins BooksBookModel::margins() const
+    { return iMargins; }
+inline shared_ptr<Book> BooksBookModel::bookRef() const
+    { return iBookRef; }
+inline shared_ptr<ZLTextStyle> BooksBookModel::textStyle() const
+    { return iTextStyle; }
+
 #endif // BOOKS_BOOK_MODEL_H

app/src/BooksListWatcher.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2016 Jolla Ltd.
+ * Copyright (C) 2015-2017 Jolla Ltd.
  * Contact: Slava Monich <slava.monich@jolla.com>
  *
  * You may use this file under the terms of the BSD license as follows:
@@ -37,6 +37,8 @@
 
 #define LISTVIEW_CONTENT_X              "contentX"
 #define LISTVIEW_CONTENT_Y              "contentY"
+#define LISTVIEW_CONTENT_WIDTH          "contentWidth"
+#define LISTVIEW_CONTENT_HEIGHT         "contentHeight"
 #define LISTVIEW_INDEX_AT               "indexAt"
 #define LISTVIEW_POSITION_VIEW_AT_INDEX "positionViewAtIndex"
 
@@ -48,7 +50,6 @@ BooksListWatcher::BooksListWatcher(QObject* aParent) :
     iListView(NULL),
     iCenterMode(-1),
     iPositionIsChanging(false),
-    iCanRetry(true),
     iResizeTimer(new QTimer(this))
 {
     iResizeTimer->setSingleShot(true);
@@ -63,7 +64,6 @@ void BooksListWatcher::setListView(QQuickItem* aView)
         if (iListView) iListView->disconnect(this);
         iListView = aView;
         iCenterMode = -1;
-        iCanRetry = true;
         if (iListView) {
             connect(iListView,
                 SIGNAL(widthChanged()),
@@ -120,46 +120,47 @@ void BooksListWatcher::positionViewAtIndex(int aIndex)
 {
     if (iListView) {
         HDEBUG(aIndex);
-        if (iCenterMode < 0) {
+        doPositionViewAtIndex(aIndex);
-            bool ok = false;
+    }
-            const QMetaObject* metaObject = iListView->metaObject();
+}
-            if (metaObject) {
+
-                int index = metaObject->indexOfEnumerator("PositionMode");
+void BooksListWatcher::doPositionViewAtIndex(int aIndex)
-                if (index >= 0) {
+{
-                    QMetaEnum metaEnum = metaObject->enumerator(index);
+    if (iCenterMode < 0) {
-                    int value = metaEnum.keyToValue("Center", &ok);
+        bool ok = false;
-                    if (ok) {
+        const QMetaObject* metaObject = iListView->metaObject();
-                        iCenterMode = value;
+        if (metaObject) {
-                        HDEBUG("Center =" << iCenterMode);
+            int index = metaObject->indexOfEnumerator("PositionMode");
-                    }
+            if (index >= 0) {
+                QMetaEnum metaEnum = metaObject->enumerator(index);
+                int value = metaEnum.keyToValue("Center", &ok);
+                if (ok) {
+                    iCenterMode = value;
+                    HDEBUG("Center =" << iCenterMode);
                 }
             }
-            HASSERT(ok);
-            if (!ok) {
-                // This is what it normally is
-                iCenterMode = 1;
-            }
         }
-        iPositionIsChanging = true;
+        HASSERT(ok);
-        positionViewAtIndex(aIndex, iCenterMode);
+        if (!ok) {
-        if (iCanRetry) {
+            // This is what it normally is
-            // This is probably a bug in QQuickListView - it first calculates
+            iCenterMode = 1;
-            // the item position and then starts instantiating the delegates.
-            // The very first time the item position always turns out to be
-            // zero because the average item size isn't known yet. So if we
-            // are trying to position the list at a non-zero index and instead
-            // we got positioned at zero, try it again. It doesn't make sense
-            // to retry more than once though.
-            if (aIndex > 0 && getCurrentIndex() == 0) {
-                // Didn't work from the first try, give it another go
-                HDEBUG("retrying...");
-                positionViewAtIndex(aIndex, iCenterMode);
-            }
-            iCanRetry = false;
         }
-        iPositionIsChanging = false;
-        updateCurrentIndex();
     }
+    iPositionIsChanging = true;
+    positionViewAtIndex(aIndex, iCenterMode);
+    // This is probably a bug in QQuickListView - it first calculates
+    // the item position and then starts instantiating the delegates.
+    // If there are no delegates yet, then the average item size is zero
+    // and the resulting item position will always turn out to be zero.
+    // So if we are trying to position the list at a non-zero index and
+    // instead we got positioned at zero, try it again.
+    if (aIndex > 0 && getCurrentIndex() == 0) {
+        // Didn't work from the first try, give it another go
+        HDEBUG("retrying...");
+        positionViewAtIndex(aIndex, iCenterMode);
+    }
+    iPositionIsChanging = false;
+    updateCurrentIndex();
 }
 
 void BooksListWatcher::positionViewAtIndex(int aIndex, int aMode)
@@ -181,6 +182,16 @@ qreal BooksListWatcher::contentY()
     return getRealProperty(LISTVIEW_CONTENT_Y);
 }
 
+qreal BooksListWatcher::contentWidth()
+{
+    return getRealProperty(LISTVIEW_CONTENT_WIDTH);
+}
+
+qreal BooksListWatcher::contentHeight()
+{
+    return getRealProperty(LISTVIEW_CONTENT_HEIGHT);
+}
+
 int BooksListWatcher::getCurrentIndex()
 {
     if (iListView) {
@@ -194,13 +205,29 @@ int BooksListWatcher::getCurrentIndex()
     return -1;
 }
 
-void BooksListWatcher::updateCurrentIndex()
+void BooksListWatcher::tryToRestoreCurrentIndex()
 {
+    HASSERT(!iPositionIsChanging);
     const int index = getCurrentIndex();
     if (iCurrentIndex != index) {
-        HDEBUG(index);
+        if (iCurrentIndex >= 0) {
-        iCurrentIndex = index;
+            doPositionViewAtIndex(iCurrentIndex);
-        Q_EMIT currentIndexChanged();
+        }
+    }
+}
+
+void BooksListWatcher::updateCurrentIndex()
+{
+    HASSERT(!iPositionIsChanging);
+    if (contentWidth() > 0 || contentHeight() > 0) {
+        const int index = getCurrentIndex();
+        if (iCurrentIndex != index) {
+            iCurrentIndex = index;
+            HDEBUG(index << contentWidth() << "x" << contentHeight());
+            Q_EMIT currentIndexChanged();
+        }
+    } else {
+        HDEBUG(contentWidth() << "x" << contentHeight());
     }
 }
 
@@ -211,6 +238,7 @@ void BooksListWatcher::updateSize()
     if (iSize != size) {
         const QSize oldSize(iSize);
         iSize = size;
+        tryToRestoreCurrentIndex();
         Q_EMIT sizeChanged();
         if (oldSize.width() != iSize.width()) {
             Q_EMIT widthChanged();
@@ -272,6 +300,7 @@ void BooksListWatcher::onContentSizeChanged()
 {
     HASSERT(sender() == iListView);
     if (!iPositionIsChanging) {
+        tryToRestoreCurrentIndex();
         updateCurrentIndex();
     }
 }

app/src/BooksListWatcher.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2016 Jolla Ltd.
+ * Copyright (C) 2015-2017 Jolla Ltd.
  * Contact: Slava Monich <slava.monich@jolla.com>
  *
  * You may use this file under the terms of the BSD license as follows:
@@ -64,10 +64,14 @@ public:
 private:
     qreal contentX();
     qreal contentY();
+    qreal contentWidth();
+    qreal contentHeight();
     qreal getRealProperty(const char *name, qreal defaultValue = 0.0);
     int getCurrentIndex();
+    void doPositionViewAtIndex(int aIndex);
     void positionViewAtIndex(int aIndex, int aMode);
     void updateCurrentIndex();
+    void tryToRestoreCurrentIndex();
     void updateSize();
 
 private Q_SLOTS:
@@ -93,7 +97,6 @@ private:
     QQuickItem* iListView;
     int iCenterMode;
     bool iPositionIsChanging;
-    bool iCanRetry;
     QTimer* iResizeTimer;
 };
 

app/src/BooksPageStack.cpp

@@ -0,0 +1,633 @@
+/*
+ * Copyright (C) 2016-2017 Jolla Ltd.
+ * Contact: Slava Monich <slava.monich@jolla.com>
+ *
+ * You may use this file under the terms of the BSD license as follows:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in
+ *     the documentation and/or other materials provided with the
+ *     distribution.
+ *   * Neither the name of Jolla Ltd nor the names of its contributors
+ *     may be used to endorse or promote products derived from this
+ *     software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "BooksPageStack.h"
+
+#include "HarbourDebug.h"
+
+#define SignalModelChanged          (1 << 0)
+#define SignalCountChanged          (1 << 1)
+#define SignalCurrentIndexChanged   (1 << 2)
+#define SignalCurrentPageChanged    (1 << 3)
+
+// ==========================================================================
+// BooksPageStack::Entry
+// ==========================================================================
+
+class BooksPageStack::Entry {
+public:
+    BooksPos iPos;
+    int iPage;
+
+public:
+    Entry() : iPos(0, 0, 0), iPage(0) {}
+    Entry(const BooksPos& aPos, int aPage) : iPos(aPos), iPage(aPage) {}
+    Entry(const Entry& aEntry) : iPos(aEntry.iPos), iPage(aEntry.iPage) {}
+
+    const Entry& operator = (const Entry& Entry)
+    {
+        iPage = Entry.iPage;
+        iPos = Entry.iPos;
+        return *this;
+    }
+
+    bool operator == (const Entry& aEntry) const
+    {
+        return iPage == aEntry.iPage && iPos == aEntry.iPos;
+    }
+
+    bool operator != (const Entry& aEntry) const
+    {
+        return iPage != aEntry.iPage || iPos != aEntry.iPos;
+    }
+};
+
+// ==========================================================================
+// BooksPageStack::Private
+// ==========================================================================
+
+class BooksPageStack::Private : public QObject {
+    Q_OBJECT
+public:
+    QList<Entry> iEntries;
+    int iCurrentIndex;
+    int iQueuedSignals;
+
+    enum {
+        MAX_DEPTH = 10
+    };
+
+private:
+    BooksPos::List iPageMarks;
+    BooksPageStack* iModel;
+
+public:
+    Private(BooksPageStack* aModel);
+
+    BooksPos::Stack getStack() const;
+    bool isValidIndex(int aIndex) const;
+    void setCurrentIndex(int aIndex);
+    int currentPage() const;
+    int pageAt(int aIndex) const;
+    void setCurrentPage(int aPage);
+    void setPageAt(int aIndex, int aPage);
+    void setStack(BooksPos::List aStack, int aCurrentPos);
+    void setPageMarks(BooksPos::List aPageMarks);
+    void push(BooksPos aPos, int aPage);
+    void push(BooksPos);
+    void push(int aPage);
+    void pop();
+    void clear();
+    void emitQueuedSignals();
+
+private Q_SLOTS:
+    void onModelChanged();
+
+private:
+    BooksPos getPosAt(int aIndex) const;
+    int findPage(BooksPos aPos) const;
+    int makeIndexValid(int aIndex) const;
+    void pageChanged(int aIndex);
+    void checkCurrentIndex(int aLastIndex);
+    void checkCurrentPage(int aLastCurrentPage);
+    void checkCount(int aLastCount);
+    int validateCurrentIndex();
+    void queueSignals(int aSignals);
+};
+
+BooksPageStack::Private::Private(BooksPageStack* aModel) :
+    QObject(aModel),
+    iCurrentIndex(0),
+    iQueuedSignals(0),
+    iModel(aModel)
+{
+    iEntries.append(Entry());
+    connect(aModel,
+        SIGNAL(dataChanged(QModelIndex,QModelIndex,QVector<int>)),
+        SLOT(onModelChanged()));
+    connect(aModel,
+        SIGNAL(rowsInserted(QModelIndex,int,int)),
+        SLOT(onModelChanged()));
+    connect(aModel,
+        SIGNAL(rowsRemoved(QModelIndex,int,int)),
+        SLOT(onModelChanged()));
+    connect(aModel,
+        SIGNAL(modelReset()),
+        SLOT(onModelChanged()));
+}
+
+void BooksPageStack::Private::emitQueuedSignals()
+{
+    static const struct SignalInfo {
+        int signal;
+        void (BooksPageStack::*fn)();
+    } signalInfo [] = {
+        { SignalModelChanged, &BooksPageStack::changed },
+        { SignalCountChanged, &BooksPageStack::countChanged },
+        { SignalCurrentIndexChanged, &BooksPageStack::currentIndexChanged },
+        { SignalCurrentPageChanged, &BooksPageStack::currentPageChanged}
+    };
+    const uint n = sizeof(signalInfo)/sizeof(signalInfo[0]);
+    for (uint i=0; i<n && iQueuedSignals; i++) {
+        if (iQueuedSignals & signalInfo[i].signal) {
+            iQueuedSignals &= ~signalInfo[i].signal;
+            Q_EMIT (iModel->*(signalInfo[i].fn))();
+        }
+    }
+}
+
+void BooksPageStack::Private::onModelChanged()
+{
+    queueSignals(SignalModelChanged);
+}
+
+inline void BooksPageStack::Private::queueSignals(int aSignals)
+{
+    iQueuedSignals |= aSignals;
+}
+
+int BooksPageStack::Private::makeIndexValid(int aIndex) const
+{
+    if (aIndex < 0) {
+        return 0;
+    } else if (aIndex >= iEntries.count()) {
+        return iEntries.count() - 1;
+    }
+    return aIndex;
+}
+
+inline bool BooksPageStack::Private::isValidIndex(int aIndex) const
+{
+    return aIndex >= 0 && aIndex < iEntries.count();
+}
+
+inline void BooksPageStack::Private::checkCurrentIndex(int aLastIndex)
+{
+    if (validateCurrentIndex() != aLastIndex) {
+        queueSignals(SignalCurrentIndexChanged);
+    }
+}
+
+inline void BooksPageStack::Private::checkCurrentPage(int aLastCurrentPage)
+{
+    if (currentPage() != aLastCurrentPage) {
+        queueSignals(SignalCurrentPageChanged);
+    }
+}
+
+inline void BooksPageStack::Private::checkCount(int aLastCount)
+{
+    if (iEntries.count() != aLastCount) {
+        queueSignals(SignalCountChanged);
+    }
+}
+
+int BooksPageStack::Private::validateCurrentIndex()
+{
+    const int validIndex = makeIndexValid(iCurrentIndex);
+    if (iCurrentIndex != validIndex) {
+        iCurrentIndex = validIndex;
+        queueSignals(SignalCurrentIndexChanged);
+    }
+    return iCurrentIndex;
+}
+
+inline int BooksPageStack::Private::currentPage() const
+{
+    return iEntries.at(iCurrentIndex).iPage;
+}
+
+int BooksPageStack::Private::pageAt(int aIndex) const
+{
+    if (isValidIndex(aIndex)) {
+        return iEntries.at(aIndex).iPage;
+    }
+    return 0;
+}
+
+void BooksPageStack::Private::setCurrentIndex(int aIndex)
+{
+    const int newIndex = makeIndexValid(aIndex);
+    if (iCurrentIndex != newIndex) {
+        const int oldCurrentPage = currentPage();
+        iCurrentIndex = newIndex;
+        HDEBUG(iCurrentIndex);
+        checkCurrentPage(oldCurrentPage);
+        queueSignals(SignalCurrentIndexChanged);
+    }
+}
+
+void BooksPageStack::Private::setPageAt(int aIndex, int aPage)
+{
+    Entry entry = iEntries.at(aIndex);
+    if (entry.iPage != aPage) {
+        entry.iPage = aPage;
+        const int np = iPageMarks.count();
+        if (np > 0) {
+            entry.iPos = (aPage < 0) ? iPageMarks.at(0) :
+                (aPage >= np) ? iPageMarks.at(np-1) :
+                iPageMarks.at(aPage);
+        } else {
+            entry.iPos.set(0, 0, 0);
+        }
+        iEntries[aIndex] = entry;
+        pageChanged(aIndex);
+    }
+}
+
+inline void BooksPageStack::Private::setCurrentPage(int aPage)
+{
+    setPageAt(iCurrentIndex, aPage);
+}
+
+void BooksPageStack::Private::pageChanged(int aIndex)
+{
+    QVector<int> roles;
+    roles.append(PageRole);
+    QModelIndex modelIndex(iModel->createIndex(aIndex, 0));
+    Q_EMIT iModel->dataChanged(modelIndex, modelIndex, roles);
+}
+
+void BooksPageStack::Private::setStack(BooksPos::List aStack, int aStackPos)
+{
+    if (aStack.isEmpty()) {
+        aStack = BooksPos::List();
+        aStack.append(BooksPos(0, 0, 0));
+    }
+
+    // First entry (always exists)
+    BooksPos pos = aStack.at(0);
+    Entry lastEntry(pos, findPage(pos));
+    if (iEntries.at(0) != lastEntry) {
+        iEntries[0] = lastEntry;
+        pageChanged(0);
+    } else {
+        iEntries[0] = lastEntry;
+    }
+
+    // Update other entries
+    int entryIndex = 1, stackIndex = 1;
+    const int oldEntryCount = iEntries.count();
+    while (entryIndex < oldEntryCount && stackIndex < aStack.count()) {
+        pos = aStack.at(stackIndex++);
+        Entry entry(pos, findPage(pos));
+        if (iEntries.at(entryIndex) != entry) {
+            iEntries[entryIndex] = entry;
+            pageChanged(entryIndex);
+        } else {
+            iEntries[entryIndex] = entry;
+        }
+        lastEntry = entry;
+        entryIndex++;
+    }
+
+    if (entryIndex < oldEntryCount) {
+        // We have run out of stack entries, remove remainig rows
+        iModel->beginRemoveRows(QModelIndex(), entryIndex, oldEntryCount-1);
+        while (iEntries.count() > entryIndex) {
+            iEntries.removeLast();
+        }
+        iModel->endRemoveRows();
+        Q_EMIT iModel->countChanged();
+    } else {
+        // Add new entries if necessary
+        while (stackIndex < aStack.count()) {
+            pos = aStack.at(stackIndex++);
+            Entry entry(pos, findPage(pos));
+            if (entry != lastEntry) {
+                iEntries.append(entry);
+                lastEntry = entry;
+            }
+        }
+        const int n = iEntries.count();
+        if (n > oldEntryCount) {
+            // We have added some entries, update the model
+            iModel->beginInsertRows(QModelIndex(), oldEntryCount, n-1);
+            iModel->endInsertRows();
+            Q_EMIT iModel->countChanged();
+        }
+    }
+
+    setCurrentIndex(aStackPos);
+    validateCurrentIndex();
+}
+
+void BooksPageStack::Private::setPageMarks(BooksPos::List aPageMarks)
+{
+    if (iPageMarks != aPageMarks) {
+        iPageMarks = aPageMarks;
+        const int prevCurrentPage = currentPage();
+        HDEBUG(iPageMarks);
+        const int n = iEntries.count();
+        for (int i=0; i<n; i++) {
+            Entry entry = iEntries.at(i);
+            const int page = findPage(entry.iPos);
+            if (entry.iPage != page) {
+                entry.iPage = page;
+                iEntries[i] = entry;
+                pageChanged(i);
+            }
+        }
+        checkCurrentPage(prevCurrentPage);
+    }
+}
+
+int BooksPageStack::Private::findPage(BooksPos aPos) const
+{
+    BooksPos::ConstIterator it = qBinaryFind(iPageMarks, aPos);
+    if (it == iPageMarks.end()) {
+        it = qLowerBound(iPageMarks, aPos);
+        if (it == iPageMarks.end()) {
+            return iPageMarks.count() - 1;
+        } else if (it == iPageMarks.begin()) {
+            return 0;
+        } else {
+            return (it - iPageMarks.begin()) - 1;
+        }
+    } else {
+        return it - iPageMarks.begin();
+    }
+}
+
+BooksPos BooksPageStack::Private::getPosAt(int aIndex) const
+{
+    if (iPageMarks.isEmpty()) {
+        return BooksPos(0, 0, 0);
+    } else if (aIndex < 0) {
+        return iPageMarks.first();
+    } else if (aIndex >= iPageMarks.count()) {
+        return iPageMarks.last();
+    } else {
+        return iPageMarks.at(aIndex);
+    }
+}
+
+void BooksPageStack::Private::push(BooksPos aPos, int aPage)
+{
+    Entry last = iEntries.last();
+    if (last.iPos != aPos || last.iPage != aPage) {
+        // We push on top of the current position. If we have reached
+        // the depth limit, we push the entire stack down
+        const int n = iEntries.count();
+        if (n >= MAX_DEPTH) {
+            for (int i=1; i<n; i++) {
+                iEntries[i-1] = iEntries[i];
+                pageChanged(i-1);
+            }
+            iEntries[n-1] = Entry(aPos, aPage);
+            pageChanged(n-1);
+        } else {
+            if (n >= iCurrentIndex+2) {
+                if (n > iCurrentIndex+2) {
+                    // Drop unnecessary entries
+                    iModel->beginRemoveRows(QModelIndex(), iCurrentIndex+2, n-1);
+                    while (iEntries.count() > iCurrentIndex+2) {
+                        iEntries.removeLast();
+                    }
+                    iModel->endRemoveRows();
+                    Q_EMIT iModel->countChanged();
+                    queueSignals(SignalCountChanged);
+                }
+                // And replace the next one
+                setPageAt(iCurrentIndex+1, aPage);
+            } else {
+                // Just push the new one
+                const int i = iCurrentIndex+1;
+                iModel->beginInsertRows(QModelIndex(), i, i);
+                iEntries.append(Entry(aPos, aPage));
+                iModel->endInsertRows();
+                queueSignals(SignalCountChanged);
+            }
+            // Move the current index
+            setCurrentIndex(iCurrentIndex+1);
+        }
+    }
+}
+
+void BooksPageStack::Private::push(BooksPos aPos)
+{
+    if (iEntries.last().iPos != aPos) {
+        push(aPos, findPage(aPos));
+    }
+}
+
+void BooksPageStack::Private::push(int aPage)
+{
+    if (iEntries.last().iPage != aPage) {
+        push(getPosAt(aPage), aPage);
+    }
+}
+
+void BooksPageStack::Private::pop()
+{
+    const int n = iEntries.count();
+    if (n > 1) {
+        iModel->beginRemoveRows(QModelIndex(), n-1, n-1);
+        iEntries.removeLast();
+        validateCurrentIndex();
+        iModel->endRemoveRows();
+        queueSignals(SignalCountChanged);
+    }
+}
+
+void BooksPageStack::Private::clear()
+{
+    const int n = iEntries.count();
+    if (n > 1) {
+        Entry currentEntry = iEntries.at(iCurrentIndex);
+        iModel->beginRemoveRows(QModelIndex(), 1, n-1);
+        while (iEntries.count() > 1) {
+            iEntries.removeLast();
+        }
+        validateCurrentIndex();
+        iModel->endRemoveRows();
+        if (iEntries.at(0) != currentEntry) {
+            iEntries[0] = currentEntry;
+            pageChanged(0);
+        }
+        queueSignals(SignalCountChanged);
+    }
+}
+
+BooksPos::Stack BooksPageStack::Private::getStack() const
+{
+    const int n = iEntries.count();
+    BooksPos::Stack stack;
+    stack.iList.reserve(n);
+    for (int i=0; i<n; i++) {
+        stack.iList.append(iEntries.at(i).iPos);
+    }
+    stack.iPos = iCurrentIndex;
+    return stack;
+}
+
+// ==========================================================================
+// BooksPageStack
+// ==========================================================================
+
+BooksPageStack::BooksPageStack(QObject* aParent) :
+    QAbstractListModel(aParent),
+    iPrivate(new Private(this))
+{
+#if QT_VERSION < 0x050000
+    setRoleNames(roleNames());
+#endif
+}
+
+int BooksPageStack::count() const
+{
+    return iPrivate->iEntries.count();
+}
+
+int BooksPageStack::currentIndex() const
+{
+    return iPrivate->iCurrentIndex;
+}
+
+int BooksPageStack::currentPage() const
+{
+    return iPrivate->currentPage();
+}
+
+void BooksPageStack::setCurrentIndex(int aIndex)
+{
+    iPrivate->setCurrentIndex(aIndex);
+    iPrivate->emitQueuedSignals();
+}
+
+void BooksPageStack::setCurrentPage(int aPage)
+{
+    iPrivate->setCurrentPage(aPage);
+    iPrivate->emitQueuedSignals();
+}
+
+void BooksPageStack::back()
+{
+    iPrivate->setCurrentIndex(iPrivate->iCurrentIndex - 1);
+    iPrivate->emitQueuedSignals();
+}
+
+void BooksPageStack::forward()
+{
+    iPrivate->setCurrentIndex(iPrivate->iCurrentIndex + 1);
+    iPrivate->emitQueuedSignals();
+}
+
+BooksPos::Stack BooksPageStack::getStack() const
+{
+    return iPrivate->getStack();
+}
+
+void BooksPageStack::setStack(BooksPos::List aStack, int aCurrentPos)
+{
+    iPrivate->setStack(aStack, aCurrentPos);
+    iPrivate->emitQueuedSignals();
+}
+
+void BooksPageStack::setPageMarks(BooksPos::List aPageMarks)
+{
+    iPrivate->setPageMarks(aPageMarks);
+    iPrivate->emitQueuedSignals();
+}
+
+int BooksPageStack::pageAt(int aIndex)
+{
+    return iPrivate->pageAt(aIndex);
+}
+
+void BooksPageStack::pushPage(int aPage)
+{
+    HDEBUG(aPage);
+    iPrivate->push(aPage);
+    iPrivate->emitQueuedSignals();
+}
+
+void BooksPageStack::pushPosition(BooksPos aPos)
+{
+    HDEBUG("" << aPos);
+    iPrivate->push(aPos);
+    iPrivate->emitQueuedSignals();
+}
+
+void BooksPageStack::pop()
+{
+    HDEBUG("");
+    iPrivate->pop();
+    iPrivate->emitQueuedSignals();
+}
+
+void BooksPageStack::clear()
+{
+    HDEBUG("");
+    iPrivate->clear();
+    iPrivate->emitQueuedSignals();
+}
+
+QHash<int,QByteArray> BooksPageStack::roleNames() const
+{
+    QHash<int, QByteArray> roles;
+    roles.insert(PageRole, "page");
+    return roles;
+}
+
+int BooksPageStack::rowCount(const QModelIndex&) const
+{
+    return iPrivate->iEntries.count();
+}
+
+QVariant BooksPageStack::data(const QModelIndex& aIndex, int aRole) const
+{
+    const int row = aIndex.row();
+    if (iPrivate->isValidIndex(row) && aRole == PageRole) {
+        return iPrivate->iEntries.at(row).iPage;
+    }
+    return QVariant();
+}
+
+bool BooksPageStack::setData(const QModelIndex& aIndex, const QVariant& aValue,
+    int aRole)
+{
+    const int row = aIndex.row();
+    if (iPrivate->isValidIndex(row) && aRole == PageRole) {
+        bool ok = false;
+        const int page = aValue.toInt(&ok);
+        if (page >= 0 && ok) {
+            iPrivate->setPageAt(row, page);
+            iPrivate->emitQueuedSignals();
+            return true;
+        }
+    }
+    return false;
+}
+
+#include "BooksPageStack.moc"

app/src/BooksPageStack.h

@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2016-2017 Jolla Ltd.
+ * Contact: Slava Monich <slava.monich@jolla.com>
+ *
+ * You may use this file under the terms of the BSD license as follows:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in
+ *     the documentation and/or other materials provided with the
+ *     distribution.
+ *   * Neither the name of Jolla Ltd nor the names of its contributors
+ *     may be used to endorse or promote products derived from this
+ *     software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef BOOKS_STACK_MODEL_H
+#define BOOKS_STACK_MODEL_H
+
+#include "BooksTypes.h"
+#include "BooksPos.h"
+
+#include <QAbstractListModel>
+#include <QtQml>
+
+class BooksPageStack: public QAbstractListModel
+{
+    Q_OBJECT
+    Q_PROPERTY(int count READ count NOTIFY countChanged)
+    Q_PROPERTY(int currentPage READ currentPage WRITE setCurrentPage NOTIFY currentPageChanged)
+    Q_PROPERTY(int currentIndex READ currentIndex WRITE setCurrentIndex NOTIFY currentIndexChanged)
+
+    enum Role {
+        PageRole = Qt::UserRole // "page"
+    };
+
+public:
+    explicit BooksPageStack(QObject* aParent = NULL);
+
+    int count() const;
+
+    int currentIndex() const;
+    void setCurrentIndex(int aIndex);
+
+    int currentPage() const;
+    void setCurrentPage(int aPage);
+
+    BooksPos::Stack getStack() const;
+    void setStack(BooksPos::List aStack, int aCurrentPos);
+    void setPageMarks(BooksPos::List aPageMarks);
+
+    // QAbstractListModel
+    QHash<int,QByteArray> roleNames() const;
+    int rowCount(const QModelIndex& aParent) const;
+    QVariant data(const QModelIndex& aIndex, int aRole) const;
+    bool setData(const QModelIndex& aIndex, const QVariant& aValue, int aRole);
+
+    Q_INVOKABLE int pageAt(int aIndex);
+    Q_INVOKABLE void pushPage(int aPage);
+    Q_INVOKABLE void pushPosition(BooksPos aPos);
+    Q_INVOKABLE void pop();
+    Q_INVOKABLE void clear();
+    Q_INVOKABLE void back();
+    Q_INVOKABLE void forward();
+
+Q_SIGNALS:
+    void changed();
+    void countChanged();
+    void currentIndexChanged();
+    void currentPageChanged();
+
+private:
+    class Entry;
+    class Private;
+    Private* iPrivate;
+};
+
+QML_DECLARE_TYPE(BooksPageStack)
+
+#endif // BOOKS_STACK_MODEL_H

app/src/BooksPageWidget.cpp

@@ -723,10 +723,10 @@ void BooksPageWidget::onLongPressTaskDone()
         }
     } else if (task->iKind == INTERNAL_HYPERLINK) {
         if (iModel) {
-            int page = iModel->linkToPage(task->iLink);
+            BooksPos pos = iModel->linkPosition(task->iLink);
-            if (page >= 0) {
+            if (pos.valid()) {
-                HDEBUG("link to page" << page);
+                HDEBUG("link to" << pos);
-                Q_EMIT jumpToPage(page);
+                Q_EMIT pushPosition(pos);
             }
         }
     } else if (task->iKind == FOOTNOTE) {

app/src/BooksPageWidget.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2016 Jolla Ltd.
+ * Copyright (C) 2015-2017 Jolla Ltd.
  * Contact: Slava Monich <slava.monich@jolla.com>
  *
  * You may use this file under the terms of the BSD license as follows:
@@ -101,6 +101,7 @@ Q_SIGNALS:
     void activeTouch(int touchX, int touchY);
     void jumpToPage(int page);
     void showFootnote(int touchX, int touchY, QString text, QString imageId);
+    void pushPosition(BooksPos position);
 
 private Q_SLOTS:
     void onWidthChanged();

app/src/BooksPos.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2016 Jolla Ltd.
+ * Copyright (C) 2015-2017 Jolla Ltd.
  * Contact: Slava Monich <slava.monich@jolla.com>
  *
  * You may use this file under the terms of the BSD license as follows:
@@ -34,6 +34,7 @@
 #ifndef BOOKS_POSITION_H
 #define BOOKS_POSITION_H
 
+#include <QMetaType>
 #include <QVariant>
 #include <QDebug>
 #include <QList>
@@ -46,6 +47,7 @@ struct BooksPos {
     typedef QList<BooksPos> List;
     typedef QList<BooksPos>::iterator Iterator;
     typedef QList<BooksPos>::const_iterator ConstIterator;
+    struct Stack { List iList; int iPos; };
 
     BooksPos() :
         iParagraphIndex(-1),
@@ -80,6 +82,13 @@ struct BooksPos {
         return iParagraphIndex >= 0 && iElementIndex >= 0 && iCharIndex >= 0;
     }
 
+    void set(int aParagraphIndex, int aElementIndex, int aCharIndex)
+    {
+        iParagraphIndex = aParagraphIndex;
+        iElementIndex = aElementIndex;
+        iCharIndex = aCharIndex;
+    }
+
     QVariant toVariant() const
     {
         QVariantList list;
@@ -124,8 +133,7 @@ struct BooksPos {
                (iParagraphIndex > aPos.iParagraphIndex) ?  false :
                (iElementIndex < aPos.iElementIndex) ? true :
                (iElementIndex > aPos.iElementIndex) ? false :
-               (iCharIndex < aPos.iCharIndex) ?  true :
+               (iCharIndex < aPos.iCharIndex);
-               (iCharIndex > aPos.iCharIndex) ?  false : true;
     }
 
     bool operator > (const BooksPos& aPos) const
@@ -159,7 +167,7 @@ struct BooksPos {
 
     QString toString() const
     {
-        return QString("BooksPos(%1,%2,%3)").arg(iParagraphIndex).
+        return QString("(%1,%2,%3)").arg(iParagraphIndex).
             arg(iElementIndex).arg(iCharIndex);
     }
 
@@ -173,4 +181,6 @@ struct BooksPos {
 inline QDebug& operator<<(QDebug& aDebug, const BooksPos& aPos)
     { aDebug << qPrintable(aPos.toString()); return aDebug; }
 
+Q_DECLARE_METATYPE(BooksPos)
+
 #endif /* BOOKS_POSITION_H */

app/src/BooksShelf.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2016 Jolla Ltd.
+ * Copyright (C) 2015-2017 Jolla Ltd.
  * Contact: Slava Monich <slava.monich@jolla.com>
  *
  * You may use this file under the terms of the BSD license as follows:
@@ -1119,7 +1119,7 @@ void BooksShelf::onCopyTaskDone()
                 copy = task->iDestItem->book();
                 if (copy) {
                     copy->retain();
-                    copy->setLastPos(src->lastPos());
+                    copy->setPageStack(src->pageStack(), src->pageStackPos());
                     copy->setCoverImage(src->coverImage());
                     copy->requestCoverImage();
                 } else {

app/src/main.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015-2016 Jolla Ltd.
+ * Copyright (C) 2015-2017 Jolla Ltd.
  * Contact: Slava Monich <slava.monich@jolla.com>
  *
  * You may use this file under the terms of the BSD license as follows:
@@ -32,6 +32,7 @@
  */
 
 #include "BooksDefs.h"
+#include "BooksPos.h"
 #include "BooksShelf.h"
 #include "BooksBook.h"
 #include "BooksBookModel.h"
@@ -39,6 +40,7 @@
 #include "BooksConfig.h"
 #include "BooksImportModel.h"
 #include "BooksPathModel.h"
+#include "BooksPageStack.h"
 #include "BooksStorageModel.h"
 #include "BooksPageWidget.h"
 #include "BooksListWatcher.h"
@@ -68,12 +70,14 @@
 Q_DECL_EXPORT int main(int argc, char **argv)
 {
     QGuiApplication* app = SailfishApp::application(argc, argv);
+    qRegisterMetaType<BooksPos>();
     BOOKS_QML_REGISTER(BooksShelf, "Shelf");
     BOOKS_QML_REGISTER(BooksBook, "Book");
     BOOKS_QML_REGISTER(BooksBookModel, "BookModel");
     BOOKS_QML_REGISTER(BooksCoverModel, "CoverModel");
     BOOKS_QML_REGISTER(BooksImportModel, "BooksImportModel");
     BOOKS_QML_REGISTER(BooksPathModel, "BooksPathModel");
+    BOOKS_QML_REGISTER(BooksPageStack, "BooksPageStack");
     BOOKS_QML_REGISTER(BooksStorageModel, "BookStorage");
     BOOKS_QML_REGISTER(BooksPageWidget, "PageWidget");
     BOOKS_QML_REGISTER(BooksListWatcher, "ListWatcher");