Add API to show empty entries in QgsDatabaseTableComboBox

qgis · Mar 14, 2020 · 30fbf24 · 30fbf24
1 parent 513966c
commit 30fbf24
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Showing 8 changed files with 363 additions and 9 deletions.
diff --git a/python/core/auto_generated/qgsdatabasetablemodel.sip.in b/python/core/auto_generated/qgsdatabasetablemodel.sip.in
@@ -36,6 +36,7 @@ called.
       RoleCustomInfo,
       RoleWkbType,
       RoleCrs,
+      RoleEmpty,
     };
 
     explicit QgsDatabaseTableModel( const QString &provider, const QString &connection, const QString &schema = QString(), QObject *parent /TransferThis/ = 0 );
@@ -70,6 +71,20 @@ Ownership of ``connection`` is transferred to the model.
     virtual QModelIndex index( int row, int column, const QModelIndex &parent ) const;
 
 
+    void setAllowEmptyTable( bool allowEmpty );
+%Docstring
+Sets whether an optional empty table ("not set") option is present in the model.
+
+.. seealso:: :py:func:`allowEmptyTable`
+%End
+
+    bool allowEmptyTable() const;
+%Docstring
+Returns ``True`` if the model allows the empty table ("not set") choice.
+
+.. seealso:: :py:func:`setAllowEmptyTable`
+%End
+
   public slots:
 
     void refresh();

diff --git a/python/gui/auto_generated/qgsdatabasetablecombobox.sip.in b/python/gui/auto_generated/qgsdatabasetablecombobox.sip.in
@@ -10,6 +10,7 @@
 
 
 
+
 class QgsDatabaseTableComboBox : QWidget
 {
 %Docstring
@@ -47,6 +48,20 @@ Constructor for QgsDatabaseTableComboBox, for the specified ``connection``.
 The optional ``schema`` argument can be used to restrict the listed tables to a specific schema.
 
 Ownership of ``connection`` is transferred to the combobox.
+%End
+
+    void setAllowEmptyTable( bool allowEmpty );
+%Docstring
+Sets whether an optional empty table ("not set") option is present in the combobox.
+
+.. seealso:: :py:func:`allowEmptyTable`
+%End
+
+    bool allowEmptyTable() const;
+%Docstring
+Returns ``True`` if the combobox allows the empty table ("not set") choice.
+
+.. seealso:: :py:func:`setAllowEmptyTable`
 %End
 
     QString currentTable() const;

diff --git a/src/core/qgsdatabasetablemodel.cpp b/src/core/qgsdatabasetablemodel.cpp
@@ -57,7 +57,7 @@ int QgsDatabaseTableModel::rowCount( const QModelIndex &parent ) const
   if ( parent.isValid() )
     return 0;
 
-  return mTables.count();
+  return mTables.count() + ( mAllowEmpty ? 1 : 0 );
 }
 
 int QgsDatabaseTableModel::columnCount( const QModelIndex &parent ) const
@@ -72,14 +72,26 @@ QVariant QgsDatabaseTableModel::data( const QModelIndex &index, int role ) const
   if ( !index.isValid() )
     return QVariant();
 
-  if ( index.row() >= mTables.count() )
+  if ( index.row() == 0 && mAllowEmpty )
+  {
+    if ( role == RoleEmpty )
+      return true;
+
     return QVariant();
+  }
 
-  const QgsAbstractDatabaseProviderConnection::TableProperty &table = mTables[ index.row() ];
+  if ( index.row() - ( mAllowEmpty ? 1 : 0 ) >= mTables.count() )
+    return QVariant();
+
+  const QgsAbstractDatabaseProviderConnection::TableProperty &table = mTables[ index.row() - ( mAllowEmpty ? 1 : 0 ) ];
   switch ( role )
   {
+    case RoleEmpty:
+      return false;
+
     case Qt::DisplayRole:
     case Qt::ToolTipRole:
+    case Qt::EditRole:
     {
       return mSchema.isEmpty() && !table.schema().isEmpty() ? QStringLiteral( "%1.%2" ).arg( table.schema(), table.tableName() ) : table.tableName();
     }
@@ -158,6 +170,25 @@ QModelIndex QgsDatabaseTableModel::index( int row, int column, const QModelIndex
   return QModelIndex();
 }
 
+void QgsDatabaseTableModel::setAllowEmptyTable( bool allowEmpty )
+{
+  if ( allowEmpty == mAllowEmpty )
+    return;
+
+  if ( allowEmpty )
+  {
+    beginInsertRows( QModelIndex(), 0, 0 );
+    mAllowEmpty = true;
+    endInsertRows();
+  }
+  else
+  {
+    beginRemoveRows( QModelIndex(), 0, 0 );
+    mAllowEmpty = false;
+    endRemoveRows();
+  }
+}
+
 void QgsDatabaseTableModel::refresh()
 {
   const QList< QgsAbstractDatabaseProviderConnection::TableProperty > newTables = mConnection->tables( mSchema );
@@ -168,7 +199,7 @@ void QgsDatabaseTableModel::refresh()
     if ( !newTables.contains( oldTable ) )
     {
       int r = mTables.indexOf( oldTable );
-      beginRemoveRows( QModelIndex(), r, r );
+      beginRemoveRows( QModelIndex(), r + ( mAllowEmpty ? 1 : 0 ), r + ( mAllowEmpty ? 1 : 0 ) );
       mTables.removeAt( r );
       endRemoveRows();
     }
@@ -178,7 +209,7 @@ void QgsDatabaseTableModel::refresh()
   {
     if ( !mTables.contains( newTable ) )
     {
-      beginInsertRows( QModelIndex(), mTables.count(), mTables.count() );
+      beginInsertRows( QModelIndex(), mTables.count() + ( mAllowEmpty ? 1 : 0 ), mTables.count() + ( mAllowEmpty ? 1 : 0 ) );
       mTables.append( newTable );
       endInsertRows();
     }

diff --git a/src/core/qgsdatabasetablemodel.h b/src/core/qgsdatabasetablemodel.h
@@ -52,6 +52,7 @@ class CORE_EXPORT QgsDatabaseTableModel : public QAbstractItemModel
       RoleCustomInfo, //!< Custom info variant map role
       RoleWkbType, //!< WKB type for primary (first) geometry column in table
       RoleCrs, //!< CRS for primary (first) geometry column in table
+      RoleEmpty, //!< Entry is an empty entry
     };
 
     /**
@@ -80,6 +81,18 @@ class CORE_EXPORT QgsDatabaseTableModel : public QAbstractItemModel
     QVariant data( const QModelIndex &index, int role = Qt::DisplayRole ) const override;
     QModelIndex index( int row, int column, const QModelIndex &parent ) const override;
 
+    /**
+     * Sets whether an optional empty table ("not set") option is present in the model.
+     * \see allowEmptyTable()
+     */
+    void setAllowEmptyTable( bool allowEmpty );
+
+    /**
+     * Returns TRUE if the model allows the empty table ("not set") choice.
+     * \see setAllowEmptyTable()
+     */
+    bool allowEmptyTable() const { return mAllowEmpty; }
+
   public slots:
 
     /**
@@ -92,6 +105,7 @@ class CORE_EXPORT QgsDatabaseTableModel : public QAbstractItemModel
     std::unique_ptr< QgsAbstractDatabaseProviderConnection > mConnection;
     QString mSchema;
     QList<QgsAbstractDatabaseProviderConnection::TableProperty> mTables;
+    bool mAllowEmpty = false;
 };
 
 #endif // QGSDATABASETABLEMODEL_H
diff --git a/src/gui/qgsdatabasetablecombobox.cpp b/src/gui/qgsdatabasetablecombobox.cpp
@@ -38,11 +38,21 @@ QgsDatabaseTableComboBox::QgsDatabaseTableComboBox( QgsAbstractDatabaseProviderC
   init();
 }
 
+void QgsDatabaseTableComboBox::setAllowEmptyTable( bool allowEmpty )
+{
+  mModel->setAllowEmptyTable( allowEmpty );
+}
+
+bool QgsDatabaseTableComboBox::allowEmptyTable() const
+{
+  return mModel->allowEmptyTable();
+}
+
 void QgsDatabaseTableComboBox::init()
 {
   mComboBox = new QComboBox();
 
-  mSortModel = new QSortFilterProxyModel( this );
+  mSortModel = new QgsDatabaseTableComboBoxSortModel( this );
   mSortModel->setSourceModel( mModel );
   mSortModel->setSortRole( Qt::DisplayRole );
   mSortModel->setSortLocaleAware( true );
@@ -77,7 +87,11 @@ void QgsDatabaseTableComboBox::setTable( const QString &table, const QString &sc
 
   if ( table.isEmpty() )
   {
-    mComboBox->setCurrentIndex( -1 );
+    if ( mModel->allowEmptyTable() )
+      mComboBox->setCurrentIndex( 0 );
+    else
+      mComboBox->setCurrentIndex( -1 );
+
     emit tableChanged( QString() );
     return;
   }
@@ -108,6 +122,7 @@ void QgsDatabaseTableComboBox::setConnectionName( const QString &connection, con
   const QString oldSchema = currentSchema();
   QgsDatabaseTableModel *oldModel = mModel;
   mModel = new QgsDatabaseTableModel( mProvider, mConnection, mSchema, this );
+  mModel->setAllowEmptyTable( oldModel->allowEmptyTable() );
   mSortModel->setSourceModel( mModel );
   oldModel->deleteLater();
   if ( currentTable() != oldTable || currentSchema() != oldSchema )
@@ -163,7 +178,7 @@ void QgsDatabaseTableComboBox::indexChanged( int i )
 
 void QgsDatabaseTableComboBox::rowsChanged()
 {
-  if ( mComboBox->count() == 1 )
+  if ( mComboBox->count() == 1 || ( mModel->allowEmptyTable() && mComboBox->count() == 2 && mComboBox->currentIndex() == 1 ) )
   {
     //currently selected connection item has changed
     emit tableChanged( currentTable(), currentSchema() );
@@ -173,3 +188,26 @@ void QgsDatabaseTableComboBox::rowsChanged()
     emit tableChanged( QString() );
   }
 }
+
+///@cond PRIVATE
+QgsDatabaseTableComboBoxSortModel::QgsDatabaseTableComboBoxSortModel( QObject *parent )
+  : QSortFilterProxyModel( parent )
+{
+
+}
+
+bool QgsDatabaseTableComboBoxSortModel::lessThan( const QModelIndex &left, const QModelIndex &right ) const
+{
+  // empty row is always first
+  if ( sourceModel()->data( left, QgsDatabaseTableModel::RoleEmpty ).toBool() )
+    return true;
+  else if ( sourceModel()->data( right, QgsDatabaseTableModel::RoleEmpty ).toBool() )
+    return false;
+
+  // default mode is alphabetical order
+  QString leftStr = sourceModel()->data( left ).toString();
+  QString rightStr = sourceModel()->data( right ).toString();
+  return QString::localeAwareCompare( leftStr, rightStr ) < 0;
+}
+
+///@endcond
diff --git a/src/gui/qgsdatabasetablecombobox.h b/src/gui/qgsdatabasetablecombobox.h
@@ -20,11 +20,24 @@
 
 #include "qgis_gui.h"
 #include "qgis_sip.h"
+#include <QSortFilterProxyModel>
 
 class QgsDatabaseTableModel;
-class QSortFilterProxyModel;
 class QgsAbstractDatabaseProviderConnection;
 
+///@cond PRIVATE
+#ifndef SIP_RUN
+class GUI_EXPORT QgsDatabaseTableComboBoxSortModel: public QSortFilterProxyModel
+{
+  public:
+    explicit QgsDatabaseTableComboBoxSortModel( QObject *parent = nullptr );
+  protected:
+    bool lessThan( const QModelIndex &source_left, const QModelIndex &source_right ) const override;
+
+};
+#endif
+///@endcond
+
 /**
  * \ingroup gui
  * \brief The QgsDatabaseTableComboBox class is a combo box which displays the list of tables for a specific database connection.
@@ -59,6 +72,18 @@ class GUI_EXPORT QgsDatabaseTableComboBox : public QWidget
      */
     explicit QgsDatabaseTableComboBox( QgsAbstractDatabaseProviderConnection *connection SIP_TRANSFER, const QString &schema = QString(), QWidget *parent SIP_TRANSFERTHIS = nullptr );
 
+    /**
+     * Sets whether an optional empty table ("not set") option is present in the combobox.
+     * \see allowEmptyTable()
+     */
+    void setAllowEmptyTable( bool allowEmpty );
+
+    /**
+     * Returns TRUE if the combobox allows the empty table ("not set") choice.
+     * \see setAllowEmptyTable()
+     */
+    bool allowEmptyTable() const;
+
     /**
      * Returns the name of the current table selected in the combo box.
      */