TreeModel: (Partially) separate header data from root item

Full separation does not seem possible as QTreeView assumes
all items to have equal column count.

Change-Id: Ia260924fe13ea62789923af8484f9838295355b6
Reviewed-by: Christian Stenger <christian.stenger@theqtcompany.com>

src/libs/extensionsystem/pluginview.cpp

@@ -285,8 +285,7 @@ PluginView::PluginView(QWidget *parent)
     m_categoryView->setSelectionBehavior(QAbstractItemView::SelectRows);
 
     m_model = new TreeModel(this);
-    m_model->setRootItem(new TreeItem(QStringList()
-        << tr("Name") << tr("Load") << tr("Version") << tr("Vendor")));
+    m_model->setHeader(QStringList() << tr("Name") << tr("Load") << tr("Version") << tr("Vendor"));
     m_categoryView->setModel(m_model);
 
     QGridLayout *gridLayout = new QGridLayout(this);

src/libs/utils/treemodel.cpp

@@ -640,11 +640,6 @@ bool TreeItem::isLazy() const
     return m_lazy;
 }
 
-int TreeItem::columnCount() const
-{
-    return m_displays ? m_displays->size() : 1;
-}
-
 int TreeItem::rowCount() const
 {
     ensurePopulated();
@@ -680,8 +675,9 @@ void TreeItem::prependChild(TreeItem *item)
 {
     QTC_CHECK(!item->parent());
 
-    if (m_model) {
+    if (m_model && !m_lazy) {
         QModelIndex idx = index();
+        item->propagateModel(m_model);
         m_model->beginInsertRows(idx, 0, 0);
         item->m_parent = this;
         item->m_model = m_model;
@@ -696,9 +692,10 @@ void TreeItem::appendChild(TreeItem *item)
 {
     QTC_CHECK(!item->parent());
 
-    if (m_model) {
+    if (m_model && !m_lazy) {
         const int n = rowCount();
         QModelIndex idx = index();
+        item->propagateModel(m_model);
         m_model->beginInsertRows(idx, n, n);
         item->m_parent = this;
         item->m_model = m_model;
@@ -728,7 +725,7 @@ void TreeItem::update()
 {
     if (m_model) {
         QModelIndex idx = index();
-        m_model->dataChanged(idx.sibling(idx.row(), 0), idx.sibling(idx.row(), columnCount() - 1));
+        m_model->dataChanged(idx.sibling(idx.row(), 0), idx.sibling(idx.row(), m_model->m_columnCount - 1));
     }
 }
 
@@ -799,6 +796,17 @@ void TreeItem::ensurePopulated() const
     }
 }
 
+void TreeItem::propagateModel(TreeModel *m)
+{
+    QTC_ASSERT(m, return);
+    QTC_ASSERT(m_model == 0 || m_model == m, return);
+    if (m && !m_model) {
+        m_model = m;
+        foreach (TreeItem *item, m_children)
+            item->propagateModel(m);
+    }
+}
+
 /*!
     \class Utils::TreeModel
 
@@ -807,13 +815,24 @@ void TreeItem::ensurePopulated() const
 */
 
 TreeModel::TreeModel(QObject *parent)
-    : QAbstractItemModel(parent), m_root(new TreeItem)
+    : QAbstractItemModel(parent),
+      m_root(new TreeItem)
 {
+    m_columnCount = 1;
+    m_root->m_model = this;
 #if USE_MODEL_TEST
     new ModelTest(this, this);
 #endif
 }
 
+TreeModel::TreeModel(TreeItem *root, QObject *parent)
+    : QAbstractItemModel(parent),
+      m_root(root)
+{
+    m_columnCount = 1;
+    m_root->m_model = this;
+}
+
 TreeModel::~TreeModel()
 {
     delete m_root;
@@ -854,11 +873,9 @@ int TreeModel::rowCount(const QModelIndex &idx) const
 int TreeModel::columnCount(const QModelIndex &idx) const
 {
     CHECK_INDEX(idx);
-    if (!idx.isValid())
-        return m_root->columnCount();
     if (idx.column() > 0)
         return 0;
-    return itemFromIndex(idx)->columnCount();
+    return m_columnCount;
 }
 
 bool TreeModel::setData(const QModelIndex &idx, const QVariant &data, int role)
@@ -879,8 +896,8 @@ QVariant TreeModel::data(const QModelIndex &idx, int role) const
 QVariant TreeModel::headerData(int section, Qt::Orientation orientation,
                                int role) const
 {
-    if (orientation == Qt::Horizontal)
-        return m_root->data(section, role);
+    if (orientation == Qt::Horizontal && role == Qt::DisplayRole && section < m_header.size())
+        return m_header.at(section);
     return QVariant();
 }
 
@@ -898,11 +915,15 @@ TreeItem *TreeModel::rootItem() const
     return m_root;
 }
 
-void TreeModel::setRootItem(TreeItem *item)
+void TreeModel::setHeader(const QStringList &displays)
 {
-    delete m_root;
-    m_root = item;
-    m_root->setModel(this);
+    m_header = displays;
+    m_columnCount = displays.size();
+}
+
+void TreeModel::setColumnCount(int columnCount)
+{
+    m_columnCount = columnCount;
 }
 
 QModelIndex TreeModel::index(int row, int column, const QModelIndex &parent) const

src/libs/utils/treemodel.h

@@ -55,7 +55,6 @@ public:
     virtual TreeItem *parent() const { return m_parent; }
     virtual TreeItem *child(int pos) const;
     virtual bool isLazy() const;
-    virtual int columnCount() const;
     virtual int rowCount() const;
     virtual void populate();
 
@@ -87,6 +86,7 @@ private:
 
     void clear();
     void ensurePopulated() const;
+    void propagateModel(TreeModel *m);
 
     TreeItem *m_parent; // Not owned.
     TreeModel *m_model; // Not owned.
@@ -229,6 +229,7 @@ class QTCREATOR_UTILS_EXPORT TreeModel : public QAbstractItemModel
 
 public:
     explicit TreeModel(QObject *parent = 0);
+    explicit TreeModel(TreeItem *root, QObject *parent = 0);
     virtual ~TreeModel();
 
     int rowCount(const QModelIndex &idx = QModelIndex()) const;
@@ -242,11 +243,13 @@ public:
     QVariant headerData(int section, Qt::Orientation orientation, int role) const;
 
     TreeItem *rootItem() const;
-    void setRootItem(TreeItem *item);
     TreeItem *itemFromIndex(const QModelIndex &) const;
     QModelIndex indexFromItem(const TreeItem *needle) const;
     void removeItems();
 
+    void setHeader(const QStringList &displays);
+    void setColumnCount(int columnCount);
+
     UntypedTreeLevelItems untypedLevelItems(int level = 0, TreeItem *start = 0) const;
     UntypedTreeLevelItems untypedLevelItems(TreeItem *start) const;
 
@@ -277,6 +280,8 @@ private:
     friend class TreeItem;
 
     TreeItem *m_root; // Owned.
+    QStringList m_header;
+    int m_columnCount;
 };
 
 } // namespace Utils

src/plugins/debugger/breakhandler.cpp

@@ -56,8 +56,6 @@ namespace Internal {
 
 struct LocationItem : public TreeItem
 {
-    int columnCount() const { return 8; }
-
     QVariant data(int column, int role) const
     {
         if (role == Qt::DisplayRole) {
@@ -86,7 +84,6 @@ class BreakpointItem : public QObject, public TreeItem
 public:
     ~BreakpointItem();
 
-    int columnCount() const { return 8; }
     QVariant data(int column, int role) const;
 
     QIcon icon() const;
@@ -251,10 +248,9 @@ BreakHandler::BreakHandler()
 #if USE_BREAK_MODEL_TEST
     new ModelTest(this, 0);
 #endif
-    auto root = new TreeItem(QStringList()
+    setHeader(QStringList()
         << tr("Number") <<  tr("Function") << tr("File") << tr("Line")
         << tr("Address") << tr("Condition") << tr("Ignore") << tr("Threads"));
-    setRootItem(root);
 }
 
 QIcon BreakHandler::breakpointIcon()

src/plugins/debugger/debuggeroptionspage.cpp

@@ -65,8 +65,6 @@ class DebuggerTreeItem : public TreeItem
 public:
     DebuggerTreeItem(const DebuggerItem &item, bool changed) : m_item(item), m_changed(changed) {}
 
-    int columnCount() const { return 3; }
-
     QVariant data(int column, int role) const
     {
         switch (role) {
@@ -119,10 +117,9 @@ private:
 DebuggerItemModel::DebuggerItemModel()
     : m_currentTreeItem(0)
 {
-    auto root = new TreeItem(QStringList() << tr("Name") << tr("Location") << tr("Type"));
-    root->appendChild(new TreeItem(QStringList() << tr("Auto-detected") << QString() << QString()));
-    root->appendChild(new TreeItem(QStringList() << tr("Manual") << QString() << QString()));
-    setRootItem(root);
+    setHeader(QStringList() << tr("Name") << tr("Location") << tr("Type"));
+    rootItem()->appendChild(new TreeItem(QStringList() << tr("Auto-detected") << QString() << QString()));
+    rootItem()->appendChild(new TreeItem(QStringList() << tr("Manual") << QString() << QString()));
 
     foreach (const DebuggerItem &item, DebuggerItemManager::debuggers())
         addDebugger(item, false);

src/plugins/debugger/moduleshandler.cpp

@@ -177,14 +177,13 @@ ModulesHandler::ModulesHandler(DebuggerEngine *engine)
     QString pad = QLatin1String("        ");
     m_model = new TreeModel(this);
     m_model->setObjectName(QLatin1String("ModulesModel"));
-    auto root = new TreeItem(QStringList()
+    m_model->setHeader(QStringList()
         << ModulesHandler::tr("Module Name") + pad
         << ModulesHandler::tr("Module Path") + pad
         << ModulesHandler::tr("Symbols Read") + pad
         << ModulesHandler::tr("Symbols Type") + pad
         << ModulesHandler::tr("Start Address") + pad
         << ModulesHandler::tr("End Address") + pad);
-    m_model->setRootItem(root);
 
     m_proxyModel = new QSortFilterProxyModel(this);
     m_proxyModel->setObjectName(QLatin1String("ModulesProxyModel"));

src/plugins/debugger/registerhandler.cpp

@@ -371,7 +371,6 @@ public:
         : m_subKind(subKind), m_subSize(subSize), m_count(count), m_changed(false)
     {}
 
-    int columnCount() const { return 2; }
     QVariant data(int column, int role) const;
 
     Qt::ItemFlags flags(int column) const
@@ -393,7 +392,6 @@ class RegisterItem : public Utils::TreeItem
 public:
     explicit RegisterItem(const Register &reg);
 
-    int columnCount() const { return 2; }
     QVariant data(int column, int role) const;
     Qt::ItemFlags flags(int column) const;
 
@@ -524,26 +522,11 @@ QVariant RegisterSubItem::data(int column, int role) const
 //
 //////////////////////////////////////////////////////////////////
 
-class RegisterRootItem : public Utils::TreeItem
-{
-public:
-    int columnCount() const { return 2; }
-    QVariant data(int section, int role) const
-    {
-        if (role == Qt::DisplayRole) {
-            switch (section) {
-            case 0: return RegisterHandler::tr("Name");
-            case 1: return RegisterHandler::tr("Value");
-            };
-        }
-        return QVariant();
-    }
-};
-
 RegisterHandler::RegisterHandler()
 {
     setObjectName(QLatin1String("RegisterModel"));
-    setRootItem(new RegisterRootItem); // Needed to get two columns.
+    setHeader(QStringList() << tr("Name") << tr("Value"));
+
 #if USE_REGISTER_MODEL_TEST
     new ModelTest(this, 0);
 #endif

src/plugins/projectexplorer/kitmodel.cpp

@@ -112,12 +112,11 @@ KitModel::KitModel(QBoxLayout *parentLayout, QObject *parent) :
     m_defaultNode(0),
     m_keepUnique(true)
 {
-    auto root = new TreeItem(QStringList(tr("Name")));
+    setHeader(QStringList(tr("Name")));
     m_autoRoot = new TreeItem(QStringList(tr("Auto-detected")));
     m_manualRoot = new TreeItem(QStringList(tr("Manual")));
-    root->appendChild(m_autoRoot);
-    root->appendChild(m_manualRoot);
-    setRootItem(root);
+    rootItem()->appendChild(m_autoRoot);
+    rootItem()->appendChild(m_manualRoot);
 
     foreach (Kit *k, KitManager::sortedKits())
         addKit(k);

src/plugins/projectexplorer/projectwizardpage.cpp

@@ -491,8 +491,7 @@ void ProjectWizardPage::initializeProjectTree(Node *context, const QStringList &
 
     setAdditionalInfo(selector.deployingProjects());
 
-    TreeModel *model = new TreeModel;
-    model->setRootItem(tree);
+    TreeModel *model = new TreeModel(tree);
     setModel(model);
     setBestNode(selector.bestChoice());
     setAddingSubProject(action == AddSubProject);

src/plugins/projectexplorer/toolchainoptionspage.cpp

@@ -78,8 +78,6 @@ public:
         }
     }
 
-    int columnCount() const { return 2; }
-
     QVariant data(int column, int role) const
     {
         switch (role) {
@@ -119,23 +117,22 @@ public:
         m_factories = ExtensionSystem::PluginManager::getObjects<ToolChainFactory>(
                     [](ToolChainFactory *factory) { return factory->canCreate();});
 
-        auto root = new TreeItem(QStringList() << tr("Name") << tr("Type"));
+        m_model.setHeader(QStringList() << tr("Name") << tr("Type"));
         m_autoRoot = new TreeItem(QStringList() << tr("Auto-detected") << QString());
         m_manualRoot = new TreeItem(QStringList() << tr("Manual") << QString());
-        root->appendChild(m_autoRoot);
-        root->appendChild(m_manualRoot);
+        m_model.rootItem()->appendChild(m_autoRoot);
+        m_model.rootItem()->appendChild(m_manualRoot);
         foreach (ToolChain *tc, ToolChainManager::toolChains()) {
             TreeItem *parent = tc->isAutoDetected() ? m_autoRoot : m_manualRoot;
             parent->appendChild(new ToolChainTreeItem(tc, false));
         }
-        m_model.setRootItem(root);
 
         m_toolChainView = new QTreeView(this);
         m_toolChainView->setUniformRowHeights(true);
-        m_toolChainView->header()->setStretchLastSection(false);
         m_toolChainView->setSelectionMode(QAbstractItemView::SingleSelection);
         m_toolChainView->setSelectionBehavior(QAbstractItemView::SelectRows);
         m_toolChainView->setModel(&m_model);
+        m_toolChainView->header()->setStretchLastSection(false);
         m_toolChainView->header()->setSectionResizeMode(0, QHeaderView::ResizeToContents);
         m_toolChainView->header()->setSectionResizeMode(1, QHeaderView::Stretch);
         m_toolChainView->expandAll();