Update TODO example

The example gathered a bit of dust. Especially in terms of role names
handling

Task-number: QTBUG-35024
Change-Id: Ie2309c654fc8f2cc5d14705ab03616af713f02f6
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>

4 files changed, 15 insertions, 36 deletions

diff --git a/examples/widgets/todos-cpp/doc/src/todos-cpp.qdoc b/examples/widgets/todos-cpp/doc/src/todos-cpp.qdoc
index 449ceda..7d0b689 100644
--- a/examples/widgets/todos-cpp/doc/src/todos-cpp.qdoc
+++ b/examples/widgets/todos-cpp/doc/src/todos-cpp.qdoc
@@ -53,17 +53,23 @@
     and the \c completed information we need to define these two roles.
     \snippet todos-cpp/todosmodel.h definition
 
-    The newly created model is empty and define basic roles. Most roles are created dynamically,
-    based on the json data-structure.  They have no predefined value in the \l Qt::ItemDataRole enum.
+    By default views (for example \l QListView) use the \l{Qt::ItemDataRole} role to display or edit the content.
+    The newly created \l{EnginioModelCpp}{EnginioModel} is empty and defines basic roles. Most roles are created
+    dynamically, based on the json data-structure.  They have no predefined value in the \l Qt::ItemDataRole enum.
     \l{EnginioModelCpp}{EnginioModel} automatically populates itself as soon as the
     \l{EnginioModel::query}{query} and \l{EnginioModel::enginio}{enginio} properties have been set.
     When the data is downloaded, the model resets itself, and sets up the internal data cache and roles names.
     \l{EnginioModelCpp}{EnginioModel} guesses the role names based on heuristics and it may be wrong if not all
     objects received from the backend have exactly the same structure, for example a property can be missing
-    in certain objects. To protect against such cases we overload \l{EnginioModel::roleNames}{roleNames()}
+    in certain objects. To protect against such cases we overload \l{EnginioModel::roleNames}{roleNames()}.
+    Overriding \l{EnginioModel::roleNames}{roleNames()} can also be used to match default Qt roles to the named
+    ones.
 
     \snippet todos-cpp/todosmodel.cpp roleNames
 
+    In this example we map the \l Qt::DisplayRole and \l Qt::EditRole to the "title" property in the JSON.
+    This way the right string is shown by default and editing works as expected.
+
     Remember to always call the base class implementation to avoid situations in which the internal cache is not in sync.
 
     By default \l {EnginioModelCpp}{EnginioModel} operates on \l{QJsonValue}, and that is
@@ -87,15 +93,6 @@
 
     \snippet todos-cpp/mainwindow.cpp assignModel
 
-    At this point we are supposed to have a working read only View / Model setup.  To be able
-    to modify the model, we also need to reimplement the EnginioModel::setData function.
-    By default \l QListView uses \l{Qt::ItemDataRole} when a user decides to edit
-    a data content. We need to map that role to our "title" role, and call
-    \l {EnginioModel::setData}{EnginioModel::setData()}
-    to update the data, like in the following code snippet:
-
-    \snippet todos-cpp/todosmodel.cpp setData
-
     To make the application fully functional, a way to add and remove "To Dos" is needed.
     To do so, we need to connect correct buttons to slots for adding a new item:
 
diff --git a/examples/widgets/todos-cpp/todosmodel.cpp b/examples/widgets/todos-cpp/todosmodel.cpp
index 196eb59..f44c1e5 100644
--- a/examples/widgets/todos-cpp/todosmodel.cpp
+++ b/examples/widgets/todos-cpp/todosmodel.cpp
@@ -47,11 +47,9 @@
 
 #include <Enginio/enginioreply.h>
 
-//![resetRoles]
 TodosModel::TodosModel(QObject *parent)
     : EnginioModel(parent)
 {}
-//![resetRoles]
 
 QVariant TodosModel::headerData(int section, Qt::Orientation orientation, int role) const
 {
@@ -63,9 +61,6 @@ QVariant TodosModel::headerData(int section, Qt::Orientation orientation, int ro
 //![data]
 QVariant TodosModel::data(const QModelIndex &index, int role) const
 {
-    if (role == Qt::DisplayRole)
-        return EnginioModel::data(index, TitleRole).value<QJsonValue>().toString();
-
     if (role == Qt::FontRole) {
         bool completed = EnginioModel::data(index, CompletedRole).value<QJsonValue>().toBool();
         QFont font;
@@ -82,27 +77,17 @@ QVariant TodosModel::data(const QModelIndex &index, int role) const
     if (role == CompletedRole)
         return EnginioModel::data(index, CompletedRole).value<QJsonValue>().toBool();
 
-    if (role == TitleRole)
-        return EnginioModel::data(index, TitleRole).value<QJsonValue>().toString();
-
     // fallback to base class
     return EnginioModel::data(index, role);
 }
 //![data]
-//![setData]
-bool TodosModel::setData(const QModelIndex &index, const QVariant &value, int role)
-{
-    if (role == Qt::EditRole || role == TitleRole)
-        return EnginioModel::setData(index, value, role);
-
-    return false;
-}
-//![setData]
 //![roleNames]
 QHash<int, QByteArray> TodosModel::roleNames() const
 {
     QHash<int, QByteArray> roles = EnginioModel::roleNames();
     roles.insert(TitleRole, "title");
+    roles.insert(Qt::DisplayRole, "title");
+    roles.insert(Qt::EditRole, "title");
     roles.insert(CompletedRole, "completed");
     return roles;
 }
diff --git a/examples/widgets/todos-cpp/todosmodel.h b/examples/widgets/todos-cpp/todosmodel.h
index 0403817..c839753 100644
--- a/examples/widgets/todos-cpp/todosmodel.h
+++ b/examples/widgets/todos-cpp/todosmodel.h
@@ -58,8 +58,6 @@ public:
 
     explicit TodosModel(QObject *parent = 0);
     virtual QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const Q_DECL_OVERRIDE;
-    virtual bool setData(const QModelIndex &index, const QVariant &value, int role = Qt::EditRole) Q_DECL_OVERRIDE;
-
     virtual QVariant headerData(int section, Qt::Orientation orientation, int role) const Q_DECL_OVERRIDE;
 
     virtual QHash<int, QByteArray> roleNames() const Q_DECL_OVERRIDE;
diff --git a/src/enginio_client/enginiomodelbase_p.h b/src/enginio_client/enginiomodelbase_p.h
index b2e104d..e9eae8a 100644
--- a/src/enginio_client/enginiomodelbase_p.h
+++ b/src/enginio_client/enginiomodelbase_p.h
@@ -775,7 +775,7 @@ public:
 
     EnginioReplyBase *setData(const int row, const QVariant &value, int role)
     {
-        if (role > Enginio::SyncedRole) {
+        if (role != Enginio::InvalidRole) {
             QJsonObject oldObject = _data.at(row).toObject();
             QString id = oldObject[EnginioString::id].toString();
             if (id.isEmpty())
@@ -816,8 +816,8 @@ public:
     EnginioReplyBase *setDataNow(const int row, const QVariant &value, int role, const QJsonObject &oldObject, const QString &id)
     {
         Q_ASSERT(!id.isEmpty());
-        Q_ASSERT(role > Enginio::SyncedRole);
         const QString roleName(_roles.value(role));
+        Q_ASSERT(!roleName.isEmpty());
         QJsonObject deltaObject;
         QJsonObject newObject = oldObject;
         deltaObject[roleName] = newObject[roleName] = QJsonValue::fromVariant(value);
@@ -860,14 +860,13 @@ public:
             return _attachedData.isSynced(row);
         }
 
-        if (role == Qt::DisplayRole)
-            return _data.at(row);
-
         const QJsonObject object = _data.at(row).toObject();
         if (!object.isEmpty()) {
             const QString roleName = _roles.value(role);
             if (!roleName.isEmpty())
                 return object[roleName];
+            else if (role == Qt::DisplayRole)
+                return _data.at(row);
         }
 
         return QVariant();