From 2deadc6cfbf71e06908963fb1bae628cfe370f9d Mon Sep 17 00:00:00 2001
From: jaseg <git-bigdata-wsl-arch@jaseg.de>
Date: Sun, 16 Aug 2020 17:04:32 +0200
Subject: Basic model/view action works

---
 numberator.cpp        |  14 +++-
 numberator.h          |   2 +
 numberator.ui         |  68 ++++++++++++++++-
 sqlitebackend.cpp     | 200 +++++++++++++++++++++++++++++++++++++-------------
 sqlitebackend.h       |  10 ++-
 tagitem.cpp           |  67 ++++++++++++++++-
 tagitem.h             |   7 +-
 taglistmodel.cpp      |   6 +-
 taglistmodel.h        |   2 +
 tagproptablemodel.cpp |  52 +++++++------
 tagproptablemodel.h   |   6 +-
 tagscene.cpp          |  51 +++++++++----
 tagscene.h            |  12 ++-
 tagview.cpp           |  59 +++++++++++----
 tagview.h             |  14 +++-
 15 files changed, 438 insertions(+), 132 deletions(-)

diff --git a/numberator.cpp b/numberator.cpp
index 912c5e3..29c0d6b 100644
--- a/numberator.cpp
+++ b/numberator.cpp
@@ -29,6 +29,8 @@ Numberator::Numberator(QWidget *parent)
     connect(ui->actionReload_Image, &QAction::triggered,
             &proj, &SQLiteSaveFile::reloadImageFromDisk);
 
+    ui->graphicsView->setProject(&proj);
+
     tagsDockUi->tagList->setModel(&tagListModel);
     tagsDockUi->propertyTable->setModel(&tagPropTableModel);
 
@@ -78,11 +80,15 @@ Numberator::Numberator(QWidget *parent)
     });
     connect(ui->actionAbout, &QAction::triggered, &aboutDialog, &AboutDialog::open);
 
-    connect(tagsDockUi->tagList->selectionModel(), &QItemSelectionModel::currentChanged,
-            [=](const QModelIndex &current, const QModelIndex &previous) {
-        Q_UNUSED(previous);
-        tagPropTableModel.showTag(tagListModel.getTag(current));
+    connect(tagsDockUi->tagList->selectionModel(), &QItemSelectionModel::selectionChanged,
+            [=](const QItemSelection &selected, const QItemSelection &deselected) {
+        Q_UNUSED(deselected);
+        tagPropTableModel.showTag(tagListModel.getTag(selected.indexes().first()));
     });
+
+    connect(ui->actionZoom_to_fit, &QAction::triggered, ui->graphicsView, &TagView::zoomToFit);
+    connect(ui->actionZoom_in, &QAction::triggered, ui->graphicsView, &TagView::zoomIn);
+    connect(ui->actionZoom_out, &QAction::triggered, ui->graphicsView, &TagView::zoomOut);
 }
 
 Numberator::~Numberator()
diff --git a/numberator.h b/numberator.h
index bf661db..4192196 100644
--- a/numberator.h
+++ b/numberator.h
@@ -5,6 +5,7 @@
 #include "sqlitebackend.h"
 #include "taglistmodel.h"
 #include "tagproptablemodel.h"
+#include "tagview.h"
 
 #include <QFileDialog>
 #include <QMainWindow>
@@ -41,5 +42,6 @@ private:
     SQLiteSaveFile proj;
     TagListModel tagListModel;
     TagPropTableModel tagPropTableModel;
+    TagView m_tagView;
 };
 #endif // NUMBERATOR_H
diff --git a/numberator.ui b/numberator.ui
index 8bf3371..70b9e14 100644
--- a/numberator.ui
+++ b/numberator.ui
@@ -16,7 +16,7 @@
   <widget class="QWidget" name="centralwidget">
    <layout class="QVBoxLayout" name="verticalLayout">
     <item>
-     <widget class="QGraphicsView" name="graphicsView"/>
+     <widget class="TagView" name="graphicsView"/>
     </item>
    </layout>
   </widget>
@@ -69,6 +69,9 @@
     <property name="title">
      <string>View</string>
     </property>
+    <addaction name="actionZoom_to_fit"/>
+    <addaction name="actionZoom_in"/>
+    <addaction name="actionZoom_out"/>
    </widget>
    <addaction name="menuFile"/>
    <addaction name="menuEdit"/>
@@ -85,11 +88,17 @@
    <property name="text">
     <string>Undo</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+Z</string>
+   </property>
   </action>
   <action name="actionRedo">
    <property name="text">
     <string>Redo</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+R</string>
+   </property>
   </action>
   <action name="actionCopy">
    <property name="text">
@@ -100,46 +109,73 @@
    <property name="text">
     <string>Cut</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+X</string>
+   </property>
   </action>
   <action name="actionPaste">
    <property name="text">
     <string>Paste</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+V</string>
+   </property>
   </action>
   <action name="actionNew_Tag">
    <property name="text">
     <string>New Tag</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+A</string>
+   </property>
   </action>
   <action name="actionNew_Project">
    <property name="text">
     <string>New Project</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+N</string>
+   </property>
   </action>
   <action name="actionOpen_Project">
    <property name="text">
     <string>Open Project</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+O</string>
+   </property>
   </action>
   <action name="actionImport_Image">
    <property name="text">
     <string>Import Image</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+I</string>
+   </property>
   </action>
   <action name="actionReload_Image">
    <property name="text">
     <string>Reload Image</string>
    </property>
+   <property name="shortcut">
+    <string>F5</string>
+   </property>
   </action>
   <action name="actionSave_Project">
    <property name="text">
-    <string>Save Project</string>
+    <string>Save Project as...</string>
+   </property>
+   <property name="shortcut">
+    <string>Ctrl+Shift+S</string>
    </property>
   </action>
   <action name="actionExport_PDF">
    <property name="text">
     <string>Export PDF</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+E</string>
+   </property>
   </action>
   <action name="actionExport_PNG">
    <property name="text">
@@ -150,8 +186,36 @@
    <property name="text">
     <string>Exit</string>
    </property>
+   <property name="shortcut">
+    <string>Ctrl+Q</string>
+   </property>
+  </action>
+  <action name="actionZoom_to_fit">
+   <property name="text">
+    <string>Zoom to fit</string>
+   </property>
+   <property name="shortcut">
+    <string>Ctrl+0</string>
+   </property>
+  </action>
+  <action name="actionZoom_in">
+   <property name="text">
+    <string>Zoom in</string>
+   </property>
+  </action>
+  <action name="actionZoom_out">
+   <property name="text">
+    <string>Zoom out</string>
+   </property>
   </action>
  </widget>
+ <customwidgets>
+  <customwidget>
+   <class>TagView</class>
+   <extends>QGraphicsView</extends>
+   <header>tagview.h</header>
+  </customwidget>
+ </customwidgets>
  <resources/>
  <connections/>
 </ui>
diff --git a/sqlitebackend.cpp b/sqlitebackend.cpp
index 89b7b07..4a9f8b9 100644
--- a/sqlitebackend.cpp
+++ b/sqlitebackend.cpp
@@ -14,8 +14,8 @@ SQLiteSaveFile::SQLiteSaveFile(QObject *parent) :
 
 bool SQLiteSaveFile::open(const QString &filename)
 {
-    qDebug() << "open";
-    {
+    auto dbg = qDebug() << "open";
+    { /* Emit signals only after unlocking mutex to allow accesses by receivers */
         QMutexLocker l(&m_dbMut);
         QFile f(filename);
         if (!f.exists()) {
@@ -44,15 +44,16 @@ bool SQLiteSaveFile::open(const QString &filename)
         m_dirty = false;
         m_open = true;
         m_image = q.value(0).toByteArray();
+        dbg << QString("Loaded %1 byte image").arg(m_image.size());
     }
-    fileReload(); /* Call after unlocking mutex to allow accesses by receivers */
+    fileReload();
     return true;
 }
 
 bool SQLiteSaveFile::clearNew()
 {
     qDebug() << "clearNew";
-    {
+    { /* Emit signals only after unlocking mutex to allow accesses by receivers */
         QMutexLocker l(&m_dbMut);
 
         QSqlDatabase new_db(QSqlDatabase::addDatabase("QSQLITE", QUuid::createUuid().toString()));
@@ -148,7 +149,7 @@ bool SQLiteSaveFile::saveAs(const QString &filename)
 
 QList<Tag> SQLiteSaveFile::getAllTags()
 {
-    qDebug() << "getAllTags";
+    auto dbg = qDebug() << "getAllTags()";
     QMutexLocker l(&m_dbMut);
     resetError();
     QList<Tag> rv;
@@ -170,56 +171,134 @@ QList<Tag> SQLiteSaveFile::getAllTags()
     if (!setDatabaseError(q))
         return QList<Tag>();
 
+    dbg << QString("%1 tags").arg(rv.size());
     return rv;
 }
 
 bool SQLiteSaveFile::updateTag(Tag tag)
 {
-    QMutexLocker l(&m_dbMut);
-    if (!runSql("UPDATE tags SET name=?, anchor_x=?, anchor_y=?, meta=? WHERE id=?", {
-               tag.name, tag.anchor.x(), tag.anchor.y(), QJsonDocument::fromVariant(tag.metadata).toJson(), tag.id
-           }))
-        return false;
+    auto dbg = qDebug() << "updating tag" << tag.id << tag.name;
+    {
+        QMutexLocker l(&m_dbMut);
+        QSqlQuery q(m_db);
+        q.prepare("SELECT 1 FROM tags WHERE id=? AND name=?");
+        q.addBindValue(tag.id);
+        q.addBindValue(tag.name);
+        if (!q.exec()) {
+            setDatabaseError(q);
+            return false;
+        }
+        bool nameChanged = !q.next();
+        if (!setDatabaseError(q))
+                return false;
 
-    m_dirty = true;
+        if (nameChanged)
+            setMetaLocked("lastTagName", tag.name);
+
+        if (!runSql("UPDATE tags SET name=?, anchor_x=?, anchor_y=?, meta=? WHERE id=?", {
+                   tag.name, tag.anchor.x(), tag.anchor.y(), QJsonDocument::fromVariant(tag.metadata).toJson(), tag.id
+               })) {
+            return false;
+        }
+
+        m_dirty = true;
+    }
+    dbg << "calling handlers";
     tagChange(TagChange::CHANGED, tag);
     return true;
 }
 
 bool SQLiteSaveFile::deleteTag(Tag tag)
 {
-    QMutexLocker l(&m_dbMut);
-    if (!runSql("DELETE FROM tags WHERE id=?", {tag.id}))
-        return false;
+    {
+        QMutexLocker l(&m_dbMut);
+        if (!runSql("DELETE FROM tags WHERE id=?", {tag.id}))
+            return false;
 
-    m_dirty = true;
+        m_dirty = true;
+    }
     tagChange(TagChange::DELETED, tag);
     return true;
 }
 
 bool SQLiteSaveFile::createTag(Tag tag)
 {
-    qDebug() << "createTag";
+    QSqlQuery q(m_db);
+    auto dbg = qDebug() << "createTag";
+    {
+        QMutexLocker l(&m_dbMut);
+        resetError();
+        if (!runSql("INSERT INTO tags(name, anchor_x, anchor_y, meta) VALUES (?, ?, ?, ?)", {
+                   tag.name,
+                   tag.anchor.x(),
+                   tag.anchor.y(),
+                   QJsonDocument::fromVariant(tag.metadata).toJson()
+               })) {
+            return false;
+        }
+        m_dirty = true;
+    }
+    auto id = q.lastInsertId().toLongLong();
+    dbg << "id" << id;
+    tagChange(TagChange::CREATED, Tag(id, tag));
+    return true;
+}
+
+QString SQLiteSaveFile::getNextAutoTagName()
+{
+    QVariant lookupResult = getMeta("lastTagName");
+    QString lastTagName = "U0";
+    if (lookupResult.isValid() && !lookupResult.toString().isNull())
+        lastTagName = lookupResult.toString();
+    QString newName = "U1";
+
+    QRegularExpression name_re("^(.*?)(\\d+)$");
+    auto res = name_re.match(lastTagName);
+    if (res.hasMatch()) {
+        bool ok = false;
+        int numericSuffix = res.captured(2).toInt(&ok);
+        QString stringPrefix = res.captured(1);
+        qDebug() << "Name has match" << stringPrefix << numericSuffix;
+
+        if (ok) {
+            do {
+                numericSuffix ++;
+                newName = QString("%1%2").arg(stringPrefix).arg(numericSuffix);
+            } while (numericSuffix<10000 && !tagNameIsFree(newName));
+        }
+    }
+    return newName;
+}
+
+bool SQLiteSaveFile::createTagAt(const QPointF &anchor)
+{
+    QString newName = getNextAutoTagName();
+    if (!setMeta("lastTagName", newName))
+        return false;
+    return createTag(Tag(newName, anchor));
+}
+
+bool SQLiteSaveFile::tagNameIsFree(const QString &name)
+{
     QMutexLocker l(&m_dbMut);
-    resetError();
     QSqlQuery q(m_db);
-    q.prepare("INSERT INTO tags(name, anchor_x, anchor_y, meta) VALUES (?, ?, ?, ?)");
-    q.addBindValue(tag.name);
-    q.addBindValue(tag.anchor.x());
-    q.addBindValue(tag.anchor.y());
-    q.addBindValue(QJsonDocument::fromVariant(tag.metadata).toJson());
+    q.prepare("SELECT name FROM tags WHERE name=?");
+    q.addBindValue(name);
+    if (!q.exec()) {
+        setDatabaseError(q);
+        return true;
+    }
 
-    if (!setDatabaseError(q))
+    if (q.next())
         return false;
 
-    Tag created_tag(q.lastInsertId().toLongLong(), tag);
-    m_dirty = true;
-    tagChange(TagChange::CREATED, created_tag);
+    setDatabaseError(q);
     return true;
 }
 
 bool SQLiteSaveFile::setMetaLocked(const QString &key, const QVariant &value)
 {
+    qDebug() << QString("setMeta: %1=%2").arg(key).arg(value.toString());
     return runSql("INSERT OR REPLACE INTO metadata(key, value) VALUES (?, ?)", {key, value});
 }
 
@@ -232,15 +311,15 @@ bool SQLiteSaveFile::setMetaLocked(std::initializer_list<QPair<QString, QVariant
     return true;
 }
 
-bool SQLiteSaveFile::setMeta(const QString &key, const QVariant &value) {
+bool SQLiteSaveFile::setMeta(const QString &key, const QVariant &value, bool setDirty) {
     QMutexLocker l(&m_dbMut);
-    m_dirty = true;
+    m_dirty = m_dirty || setDirty;
     return setMetaLocked(key, value);
 }
 
-bool SQLiteSaveFile::setMeta(std::initializer_list<QPair<QString, QVariant>> metas) {
+bool SQLiteSaveFile::setMeta(std::initializer_list<QPair<QString, QVariant>> metas, bool setDirty) {
     QMutexLocker l(&m_dbMut);
-    m_dirty = true;
+    m_dirty = m_dirty || setDirty;
     return setMetaLocked(metas);
 }
 
@@ -251,7 +330,6 @@ const QVariant SQLiteSaveFile::getMeta(const QString &key) const {
 
 const QVariant SQLiteSaveFile::getMetaLocked(const QString &key) const
 {
-    qDebug() << "getMeta " << key;
     resetError();
     QSqlQuery q(m_db);
     q.prepare("SELECT value FROM metadata WHERE key=?");
@@ -267,6 +345,7 @@ const QVariant SQLiteSaveFile::getMetaLocked(const QString &key) const
         return QVariant();
     }
 
+    qDebug() << QString("getMeta: %1=%2").arg(key).arg(q.value(0).toString());
     return q.value(0);
 }
 
@@ -288,29 +367,35 @@ bool SQLiteSaveFile::runSql(QString query, std::initializer_list<QVariant> bindi
 
 bool SQLiteSaveFile::loadImageFromDisk(const QString &filename)
 {
-    QMutexLocker l(&m_dbMut);
-    QFile f(filename);
-    resetError();
-
-    if (!f.open(QIODevice::ReadOnly)) {
-        setError(ImageOpenError, QString("Failed to open image: %1").arg(f.errorString()));
-        return false;
-    }
-
-    m_image = f.readAll();
-    if (f.error() != QFileDevice::NoError) {
-        setError(ImageReadError, QString("Failed to read image: %1").arg(f.errorString()));
-        return false;
+    {
+        QMutexLocker l(&m_dbMut);
+        QFile f(filename);
+        resetError();
+    
+        if (!f.open(QIODevice::ReadOnly)) {
+            setError(ImageOpenError, QString("Failed to open image: %1").arg(f.errorString()));
+            return false;
+        }
+    
+        m_image = f.readAll();
+        if (f.error() != QFileDevice::NoError) {
+            setError(ImageReadError, QString("Failed to read image: %1").arg(f.errorString()));
+            return false;
+        }
+    
+        if (!setMetaLocked({
+                     {"imagePathOriginal", f.fileName()},
+                     {"imagePathAbsolute", QFileInfo(f).absoluteFilePath()},
+                     {"imageLoadedTime", QDateTime::currentDateTimeUtc().toMSecsSinceEpoch()}}))
+            return false;
+    
+        m_dirty = true;
+        if (!runSql("INSERT OR REPLACE INTO blobs(name, data) VALUES ('image', ?)", {m_image}))
+            return false;
     }
-
-    if (!setMetaLocked({
-                 {"imagePathOriginal", f.fileName()},
-                 {"imagePathAbsolute", QFileInfo(f).absoluteFilePath()},
-                 {"imageLoadedTime", QDateTime::currentDateTimeUtc().toMSecsSinceEpoch()}}))
-        return false;
-
-    m_dirty = true;
-    return runSql("INSERT OR REPLACE INTO blobs(name, data) VALUES ('image', ?)", {m_image});
+    /* Emit signal with mutex unlocked */
+    imageLoaded(m_image);
+    return true;
 }
 
 bool SQLiteSaveFile::reloadImageFromDisk()
@@ -344,6 +429,15 @@ Tag::Tag(long long id, const Tag &other)
 {
 }
 
+Tag::Tag(QString name, const QPointF &anchor, const QVariantMap metadata)
+    : id(-1)
+    , name(name)
+    , anchor(anchor)
+    , metadata(metadata)
+    , valid(false)
+{
+}
+
 bool SQLiteSaveFile::setDatabaseError(const QSqlQuery &q) const
 {
     if (!q.lastError().isValid())
diff --git a/sqlitebackend.h b/sqlitebackend.h
index 8bfce00..0e7d339 100644
--- a/sqlitebackend.h
+++ b/sqlitebackend.h
@@ -19,6 +19,7 @@ public:
     Tag() : valid(false) {}
     Tag(long long int id, QString name, qreal anchor_x, qreal anchor_y, QByteArray metadata);
     Tag(long long int id, const Tag &other);
+    Tag(QString name, const QPointF &anchor, const QVariantMap metadata=QVariantMap());
 
     bool isValid() { return valid; }
 
@@ -44,13 +45,17 @@ public:
     bool updateTag(Tag tag);
     bool deleteTag(Tag tag);
     bool createTag(Tag tag);
+    bool createTagAt(const QPointF &anchor);
+    QString getNextAutoTagName();
+
+    bool tagNameIsFree(const QString &name);
 
     bool isMemory() { return m_memory; } /* backend db points to temporary memory db */
     bool isDirty() { return m_dirty; } /* backend db was changed since opening */
     bool isOpen() { return m_open; } /* backend db is open */
 
-    bool setMeta(const QString &key, const QVariant &value);
-    bool setMeta(std::initializer_list<QPair<QString, QVariant>> metas);
+    bool setMeta(const QString &key, const QVariant &value, bool setDirty=false);
+    bool setMeta(std::initializer_list<QPair<QString, QVariant>> metas, bool setDirty=false);
     const QVariant getMeta(const QString &key) const;
 
     const QString &errorString() const { return m_lastErrorString; }
@@ -87,6 +92,7 @@ signals:
     void tagChange(TagChange change, const Tag &tag);
     void fileReload();
     void fileIOError(Error e, QString errorName, QString description) const;
+    void imageLoaded(const QByteArray &image);
 
 private:
     bool connect();
diff --git a/tagitem.cpp b/tagitem.cpp
index d251428..e493b81 100644
--- a/tagitem.cpp
+++ b/tagitem.cpp
@@ -1,25 +1,86 @@
 #include "tagitem.h"
 
+#include <QPainter>
+#include <QGuiApplication>
+
 TagItem::TagItem(const Tag &tag)
     : valid(true)
 {
     setFlags(QGraphicsItem::ItemIsMovable
              | QGraphicsItem::ItemIsSelectable
-             | QGraphicsItem::ItemIsFocusable);
-    /* TODO text_it.setFlags(QGraphicsItem::ItemIgnoresTransformations);
-     */
+             | QGraphicsItem::ItemIsFocusable
+             | QGraphicsItem::ItemIgnoresTransformations
+             | QGraphicsItem::ItemSendsGeometryChanges);
+    QFont font(QGuiApplication::font());
+    font.setPointSize(18);
+    setFont(font);
     tagUpdated(tag);
 }
 
 void TagItem::tagUpdated(const Tag &tag)
 {
     m_tag = tag;
+    qDebug() << "TagItem updated" << tag.name << tag.anchor;
     setText(tag.name);
     setPos(tag.anchor);
 }
 
+QRectF TagItem::boundingRect() const
+{
+    QRectF parentRect(QGraphicsSimpleTextItem::boundingRect());
+    parentRect.translate(-(parentRect.bottomRight() - parentRect.topLeft()) * 0.5);
+    return parentRect.marginsAdded(QMargins(5, 5, 5, 5));
+}
+
+/* For some reason this is not exposed through the public API so we have to copy-paste it here m( */
+static void paintSelectionHighlightBorder(QPainter *painter, const QStyleOptionGraphicsItem *option, TagItem *item)
+{
+        const QRectF mbrect = painter->transform().mapRect(item->boundingRect());
+        if (qMin(mbrect.width(), mbrect.height()) < qreal(1.0))
+            return;
+
+        const qreal pad = item->pen().widthF() / 2;
+        const qreal penWidth = 0; // cosmetic pen
+        const QColor fgcolor = option->palette.windowText().color();
+        const QColor bgcolor( // ensure good contrast against fgcolor
+            fgcolor.red()   > 127 ? 0 : 255,
+            fgcolor.green() > 127 ? 0 : 255,
+            fgcolor.blue()  > 127 ? 0 : 255);
+        painter->setPen(QPen(bgcolor, penWidth, Qt::SolidLine));
+        painter->setBrush(Qt::NoBrush);
+        painter->drawRect(item->boundingRect().adjusted(pad, pad, -pad, -pad));
+        painter->setPen(QPen(option->palette.windowText(), 0, Qt::DashLine));
+        painter->setBrush(Qt::NoBrush);
+        painter->drawRect(item->boundingRect().adjusted(pad, pad, -pad, -pad));
+}
+
+void TagItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
+{
+    painter->setBrush(Qt::white);
+    painter->drawRect(boundingRect());
+
+    QRectF parentRect(QGraphicsSimpleTextItem::boundingRect());
+    QPointF pos = (parentRect.bottomRight() - parentRect.topLeft()) * 0.5;
+    painter->translate(-pos);
+
+    QStyleOptionGraphicsItem newOption(*option);
+    newOption.state = ~(QStyle::State_Selected |QStyle::State_HasFocus);
+    QGraphicsSimpleTextItem::paint(painter, &newOption, widget);
+
+    painter->translate(pos);
+    if (option->state & (QStyle::State_Selected | QStyle::State_HasFocus))
+        paintSelectionHighlightBorder(painter, option, this);
+}
+
+QPainterPath TagItem::shape() const
+{
+    QPainterPath path;
+    return QGraphicsItem::shape();
+}
+
 QVariant TagItem::itemChange(QGraphicsItem::GraphicsItemChange change, const QVariant &value)
 {
+    qDebug() << "itemChange" << m_tag.name << this->boundingRect() << change;
     if (change == ItemPositionChange) {
         /* https://gist.github.com/csukuangfj/c2a06416062bec9ed99eddd705c21275#file-qgraphicsscenetest-cpp-L90
          *
diff --git a/tagitem.h b/tagitem.h
index a248243..3863d40 100644
--- a/tagitem.h
+++ b/tagitem.h
@@ -14,13 +14,14 @@ public:
 
     enum { TagItemType = UserType + 1 };
     int type() const override { return TagItemType; }
-
     bool isValid() { return valid; }
-
     void tagUpdated(const Tag &tag);
-
     Tag tag() { return m_tag; }
 
+    virtual QRectF boundingRect() const override;
+    virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override;
+    virtual QPainterPath shape() const override;
+
 protected:
     QVariant itemChange(QGraphicsItem::GraphicsItemChange change, const QVariant &value) override;
 
diff --git a/taglistmodel.cpp b/taglistmodel.cpp
index e3ba006..d68fc57 100644
--- a/taglistmodel.cpp
+++ b/taglistmodel.cpp
@@ -4,6 +4,7 @@ TagListModel::TagListModel(SQLiteSaveFile &backend)
     : backend(backend)
     , cached_tags(backend.getAllTags())
 {
+    qDebug() << "connecting TagListModel" << &backend;
     connect(&backend, &SQLiteSaveFile::tagChange,
             [=](TagChange change, const Tag &tag) { Q_UNUSED(change); Q_UNUSED(tag); reloadTags(); });
     connect(&backend, &SQLiteSaveFile::fileReload,
@@ -28,10 +29,11 @@ QVariant TagListModel::data(const QModelIndex &index, int role) const
     if (!index.isValid())
         return QVariant();
 
-    if (role != Qt::DisplayRole)
+    if (role != Qt::DisplayRole && role != Qt::EditRole)
         return QVariant();
 
-    return cached_tags.at(index.row()).name;
+    auto rv = cached_tags.at(index.row()).name;
+    return rv;
 }
 
 QVariant TagListModel::headerData(int section, Qt::Orientation orientation, int role) const
diff --git a/taglistmodel.h b/taglistmodel.h
index 41fa520..d4bd5df 100644
--- a/taglistmodel.h
+++ b/taglistmodel.h
@@ -7,6 +7,8 @@
 
 class TagListModel : public QAbstractListModel
 {
+    Q_OBJECT
+
 public:
     TagListModel(SQLiteSaveFile &backend);
 
diff --git a/tagproptablemodel.cpp b/tagproptablemodel.cpp
index 711494d..4dc5e6b 100644
--- a/tagproptablemodel.cpp
+++ b/tagproptablemodel.cpp
@@ -1,26 +1,24 @@
 #include "tagproptablemodel.h"
 
 TagPropTableModel::TagPropTableModel(SQLiteSaveFile &backend, const Tag tag)
-    : backend(backend)
-    , tag_cached(tag)
-    , tagIsValid(true)
+    : TagPropTableModel(backend, true)
 {
+    tag_cached = tag;
     tag_keys = tag_cached.metadata.keys();
     tag_keys.sort();
-    connect(&backend, &SQLiteSaveFile::tagChange,
-            this, &TagPropTableModel::tagChange);
-    connect(&backend, &SQLiteSaveFile::fileReload,
-            [=]() {
-        beginResetModel();
-        tagIsValid = false;
-        endResetModel();
-    });
+    qDebug() << "connecting TagPropTableModel" << &backend;
 }
 
-TagPropTableModel::TagPropTableModel(SQLiteSaveFile &backend)
+TagPropTableModel::TagPropTableModel(SQLiteSaveFile &backend, bool tagIsValid)
     : backend(backend)
-    , tagIsValid(false)
+    , tagIsValid(tagIsValid)
 {
+    connect(&backend, &SQLiteSaveFile::tagChange, this, &TagPropTableModel::tagChange);
+    connect(&backend, &SQLiteSaveFile::fileReload, [=]() {
+        beginResetModel();
+        this->tagIsValid = false;
+        endResetModel();
+    });
 }
 
 int TagPropTableModel::rowCount(const QModelIndex &parent) const
@@ -42,7 +40,7 @@ QVariant TagPropTableModel::data(const QModelIndex &index, int role) const
     if (!index.isValid())
         return QVariant();
 
-    if (role != Qt::DisplayRole)
+    if (role != Qt::DisplayRole && role != Qt::EditRole)
         return QVariant();
 
     bool label = index.column() == 0;
@@ -50,7 +48,7 @@ QVariant TagPropTableModel::data(const QModelIndex &index, int role) const
     switch (index.row()) {
     case 0: return label ? QVariant("Database ID")    : tag_cached.id;   break;
     case 1: return label ? QVariant("Label")          : tag_cached.name; break;
-    case 2: return label ? QVariant("Anchor")         : tag_cached.anchor; break;
+    case 2: return label ? QVariant("Anchor")         : QString("%1, %2").arg(tag_cached.anchor.x()).arg(tag_cached.anchor.y()); break;
     }
 
     int idx = index.row() - 3;
@@ -100,18 +98,19 @@ bool TagPropTableModel::setData(const QModelIndex &index, const QVariant &value,
     if (role != Qt::EditRole)
         return false;
 
-    if (index.row() == 1)
+    if (index.row() == 1) {
         tag_cached.name = value.toString();
-    else if (index.row() < 3)
+    } else if (index.row() < 3) {
         return false;
-
-    int idx = index.row() - 3;
-    if (index.column() == 0) { /* key changed */
-        /* move value to new key and delete old key */
-        tag_cached.metadata[value.toString()] = tag_cached.metadata[tag_keys[idx]];
-        tag_cached.metadata.remove(tag_keys[idx]);
     } else {
-        tag_cached.metadata[tag_keys[idx]] = value.toString();
+        int idx = index.row() - 3;
+        if (index.column() == 0) { /* key changed */
+            /* move value to new key and delete old key */
+            tag_cached.metadata[value.toString()] = tag_cached.metadata[tag_keys[idx]];
+            tag_cached.metadata.remove(tag_keys[idx]);
+        } else {
+            tag_cached.metadata[tag_keys[idx]] = value.toString();
+        }
     }
 
     backend.updateTag(tag_cached);
@@ -120,13 +119,17 @@ bool TagPropTableModel::setData(const QModelIndex &index, const QVariant &value,
 
 void TagPropTableModel::tagChange(TagChange change, const Tag &tag)
 {
+    auto dbg = qDebug() << QString("TagPropTableModel::tagChange(%1, %2 \"%3\")").arg(change).arg(tag.id).arg(tag.name);
     if (tag.id != tag_cached.id)
         return;
 
     assert(change != TagChange::CREATED);
     if (change == TagChange::CHANGED) {
+        dbg << "changed";
         showTag(tag);
+
     } else if (change == TagChange::DELETED) {
+        dbg << "deleted";
         beginResetModel();
         tagIsValid = false;
         endResetModel();
@@ -140,5 +143,6 @@ void TagPropTableModel::showTag(const Tag &tag)
     tag_cached = tag;
     tag_keys = tag_cached.metadata.keys();
     tag_keys.sort();
+    tagIsValid = true;
     endResetModel();
 }
diff --git a/tagproptablemodel.h b/tagproptablemodel.h
index b127f90..09ab8b4 100644
--- a/tagproptablemodel.h
+++ b/tagproptablemodel.h
@@ -9,8 +9,10 @@
 
 class TagPropTableModel : public QAbstractTableModel
 {
+    Q_OBJECT
+
 public:
-    TagPropTableModel(SQLiteSaveFile &backend);
+    TagPropTableModel(SQLiteSaveFile &backend) : TagPropTableModel(backend, false) {};
     TagPropTableModel(SQLiteSaveFile &backend, const Tag tag);
 
     int rowCount(const QModelIndex &parent=QModelIndex()) const override;
@@ -27,6 +29,8 @@ private slots:
     void tagChange(TagChange change, const Tag &tag);
 
 private:
+    TagPropTableModel(SQLiteSaveFile &backend, bool tagIsValid);
+
     SQLiteSaveFile &backend;
     Tag tag_cached;
     QStringList tag_keys;
diff --git a/tagscene.cpp b/tagscene.cpp
index fb52574..a6efd17 100644
--- a/tagscene.cpp
+++ b/tagscene.cpp
@@ -2,15 +2,16 @@
 
 #include <QGraphicsSceneMouseEvent>
 
-TagScene::TagScene(SQLiteSaveFile &proj)
-    : proj(proj)
-{
-    reloadPicture();
-    reloadTags();
+void TagScene::setProject(SQLiteSaveFile *proj) {
+    if (m_proj)
+        disconnect(m_proj, nullptr, this, nullptr);
+    m_proj = proj;
+
+    reloadScene();
 
-    connect(&proj, &SQLiteSaveFile::tagChange, this, &TagScene::tagChanged);
-    connect(&proj, &SQLiteSaveFile::fileReload,
-            [=]() { reloadTags(); });
+    connect(m_proj, &SQLiteSaveFile::tagChange, this, &TagScene::tagChanged);
+    connect(m_proj, &SQLiteSaveFile::fileReload, this, &TagScene::reloadScene);
+    connect(m_proj, &SQLiteSaveFile::imageLoaded, this, &TagScene::reloadPicture);
 }
 
 void TagScene::tagChanged(TagChange change, const Tag &tag)
@@ -40,11 +41,22 @@ void TagScene::tagChanged(TagChange change, const Tag &tag)
 
 void TagScene::reloadPicture()
 {
-    pix.loadFromData(proj.getImage());
+    if (!m_proj)
+        return;
+
+    pix.loadFromData(m_proj->getImage());
     if (pix_it)
         removeItem(pix_it);
     pix_it = new QGraphicsPixmapItem(pix);
+    pix_it->setZValue(-1);
     addItem(pix_it);
+    QRectF imgBounds = pix_it->boundingRect();
+    imgBounds = imgBounds.marginsAdded(QMargins(imgBounds.width() * 0.5, imgBounds.height() * 0.5, imgBounds.width() * 0.5, imgBounds.height() * 0.5));
+    setSceneRect(itemsBoundingRect().united(imgBounds));
+    qDebug() << "TagScene: reloadPicture()" << pix_it->boundingRect() << pix_it << pix << pix_it->isActive();
+
+    invalidate();
+    imageLoaded();
 }
 
 void TagScene::addTag(const Tag tag) {
@@ -53,16 +65,20 @@ void TagScene::addTag(const Tag tag) {
     tags[tag.id] = it;
 }
 
-void TagScene::reloadTags()
+void TagScene::reloadScene()
 {
     clear();
-    for (auto *it : tags.values()) {
+    for (auto *it : tags.values())
         delete it;
-    }
+    pix_it = nullptr;
 
-    for (const Tag &tag : proj.getAllTags()) {
+    if (!m_proj)
+        return;
+
+    for (const Tag &tag : m_proj->getAllTags())
         addTag(tag);
-    }
+
+    reloadPicture(); /* calls invalidate() for us */
 }
 
 void TagScene::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event)
@@ -70,11 +86,18 @@ void TagScene::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event)
     QGraphicsItem *it = itemAt(event->scenePos(), QTransform());
     if (!it) {
         QGraphicsScene::mouseDoubleClickEvent(event);
+        return;
+    }
+
+    if (it == pix_it) {
+        m_proj->createTagAt(event->scenePos());
+        return;
     }
 
     TagItem *tagitem = qgraphicsitem_cast<TagItem *>(it);
     if (!tagitem) {
         QGraphicsScene::mouseDoubleClickEvent(event);
+        return;
     }
 
     tagDoubleClicked(tagitem->tag());
diff --git a/tagscene.h b/tagscene.h
index 006fffd..4c81fe5 100644
--- a/tagscene.h
+++ b/tagscene.h
@@ -14,14 +14,18 @@ class TagScene : public QGraphicsScene
     Q_OBJECT
 
 public:
-    TagScene(SQLiteSaveFile &proj);
+    TagScene() {}
+    const QGraphicsPixmapItem *backgroundPixmapItem() const { return pix_it; }
 
 public slots:
     void reloadPicture();
-    void reloadTags();
+    void reloadScene();
+
+    void setProject(SQLiteSaveFile *proj);
 
 signals:
     void tagDoubleClicked(const Tag &tag);
+    void imageLoaded();
 
 protected:
     void mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event) override;
@@ -32,9 +36,9 @@ private slots:
 private:
     void addTag(const Tag tag);
 
-    SQLiteSaveFile &proj;
+    SQLiteSaveFile *m_proj = nullptr;
 
-    QGraphicsPixmapItem *pix_it;
+    QGraphicsPixmapItem *pix_it = nullptr;
     QPixmap pix;
     QMap<long long int, TagItem*> tags;
 };
diff --git a/tagview.cpp b/tagview.cpp
index b4e83dd..9a9c9a0 100644
--- a/tagview.cpp
+++ b/tagview.cpp
@@ -4,34 +4,41 @@
 #include <QScrollBar>
 #include <cmath>
 
-TagView::TagView(SQLiteSaveFile &proj)
-    : scene(proj)
-    , proj(proj)
-    , saveCenterTimer()
+TagView::TagView(QWidget *parent)
+    : QGraphicsView(parent)
+    , saveCenterTimer(this)
 {
     setDragMode(QGraphicsView::ScrollHandDrag);
-    setScene(&scene);
-    connect(&scene, &TagScene::tagDoubleClicked, this, &TagView::tagDoubleClicked);
+    setScene(&m_scene);
+    connect(&m_scene, &TagScene::tagDoubleClicked, this, &TagView::tagDoubleClicked);
+    connect(&m_scene, &TagScene::imageLoaded, this, &TagView::zoomToFit);
 
     saveCenterTimer.setSingleShot(true);
     saveCenterTimer.setInterval(500);
-    connect(&saveCenterTimer, &QTimer::timeout,
-            this, &TagView::saveCenter);
+    connect(&saveCenterTimer, &QTimer::timeout, this, &TagView::saveCenter);
+}
+
+TagView::~TagView()
+{
+    were_done = true;
 }
 
 void TagView::zoomToFit()
 {
     QTransform tx = QTransform().rotate(-rotation);
-    QRectF rect = tx.mapRect(scene.itemsBoundingRect());
+    QRectF rect = tx.mapRect(m_scene.itemsBoundingRect());
     QRectF vp = viewport()->rect();
 
     setZoom(qMin(vp.width()/rect.width(), vp.height()/rect.height()));
+    centerOn(m_scene.backgroundPixmapItem());
+    qDebug() << "TagView::zoomToFit():" << sceneRect() << rect << viewport()->rect();
 }
 
 void TagView::setZoom(qreal zoom)
 {
     this->zoom = zoom;
-    proj.setMeta("view_zoom", zoom);
+    if (m_proj)
+        m_proj->setMeta("view_zoom", zoom);
     setTransform(QTransform::fromScale(zoom, zoom).rotate(rotation));
 }
 
@@ -47,7 +54,15 @@ void TagView::rotate(int angle)
     if (tmp < 0)
         tmp += 360;
     rotation = tmp;
-    proj.setMeta("view_rotation", rotation);
+    if (m_proj)
+        m_proj->setMeta("view_rotation", rotation);
+}
+
+void TagView::setProject(SQLiteSaveFile *proj)
+{
+    m_proj = proj;
+    m_scene.setProject(m_proj);
+    restoreViewport();
 }
 
 void TagView::wheelEvent(QWheelEvent *evt)
@@ -63,22 +78,34 @@ void TagView::wheelEvent(QWheelEvent *evt)
     }
 }
 
+void TagView::scrollContentsBy(int dx, int dy)
+{
+    QGraphicsView::scrollContentsBy(dx, dy);
+    /* Hackety hack: On object destruction this method is called downstream in the destructor chain. Prevent segfaults from calling an uninitialized timer. */
+    if (!were_done)
+        saveCenterTimer.start();
+}
+
 void TagView::saveCenter()
 {
     QPointF p = mapToScene(viewport()->rect().center());
-    proj.setMeta("view_center", QJsonDocument(QJsonArray({p.x(), p.y()})).toJson());
+    if (m_proj)
+        m_proj->setMeta("view_center", QJsonDocument(QJsonArray({p.x(), p.y()})).toJson());
 }
 
 void TagView::restoreViewport()
 {
-    QVariant v_rot = proj.getMeta("view_rotation");
+    if (!m_proj)
+        return;
+
+    QVariant v_rot = m_proj->getMeta("view_rotation");
     if (v_rot.isValid()) {
         rotation = v_rot.toInt();
     } else {
         rotation = 0;
     }
 
-    QVariant v_zoom = proj.getMeta("view_zoom");
+    QVariant v_zoom = m_proj->getMeta("view_zoom");
     if (v_zoom.isValid()) {
         zoom = v_zoom.toDouble();
         setTransform(QTransform::fromScale(zoom, zoom).rotate(rotation));
@@ -86,13 +113,13 @@ void TagView::restoreViewport()
         zoomToFit();
     }
 
-    QVariant v_center = proj.getMeta("view_center");
+    QVariant v_center = m_proj->getMeta("view_center");
     if (v_center.isValid()) {
         QJsonArray arr = QJsonDocument::fromJson(v_center.toByteArray()).toVariant().toJsonArray();
         assert(arr.size() == 2);
         assert(arr[0].isDouble() && arr[1].isDouble());
         centerOn(QPointF(arr[0].toDouble(), arr[1].toDouble()));
     } else {
-        centerOn(scene.itemsBoundingRect().center());
+        centerOn(m_scene.itemsBoundingRect().center());
     }
 }
diff --git a/tagview.h b/tagview.h
index 71b418c..edafcf4 100644
--- a/tagview.h
+++ b/tagview.h
@@ -13,19 +13,24 @@ class TagView : public QGraphicsView
     Q_OBJECT
 
 public:
-    TagView(SQLiteSaveFile &proj);
+    TagView(QWidget *parent=nullptr);
+    virtual ~TagView();
 
 public slots:
     void zoomToFit();
     void setZoom(qreal zoom);
-    void zoomIn(qreal delta);
+    void zoomIn(qreal delta=120);
+    void zoomOut(qreal delta=120) { zoomIn(-delta); }
     void rotate(int angle);
 
+    void setProject(SQLiteSaveFile *proj);
+
 signals:
     void tagDoubleClicked(const Tag &tag);
 
 protected:
     void wheelEvent(QWheelEvent *evt) override;
+    void scrollContentsBy(int dx, int dy) override;
 
 private slots:
     void saveCenter();
@@ -33,9 +38,10 @@ private slots:
 private:
     void restoreViewport();
 
-    TagScene scene;
-    SQLiteSaveFile &proj;
     QTimer saveCenterTimer;
+    bool were_done = false;
+    TagScene m_scene;
+    SQLiteSaveFile *m_proj = nullptr;
     int rotation;
     double zoom;
 };
-- 
cgit