Add new GUI widget QgsDatabaseSchemaComboBox for selection of

available schemas for a specific data connection

(providers must implement the connections API)

python/gui/auto_generated/qgsdatabaseschemacombobox.sip.in

@@ -0,0 +1,95 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/gui/qgsdatabaseschemacombobox.h                                  *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+
+class QgsDatabaseSchemaComboBox : QWidget
+{
+%Docstring
+The QgsDatabaseSchemaComboBox class is a combo box which displays the list of schemas for a specific database connection.
+
+.. warning::
+
+   The provider must support the connection API methods in its QgsProviderMetadata implementation
+   in order for the combobox to work correctly.
+
+.. versionadded:: 3.14
+%End
+
+%TypeHeaderCode
+#include "qgsdatabaseschemacombobox.h"
+%End
+  public:
+
+    explicit QgsDatabaseSchemaComboBox( const QString &provider, const QString &connection, QWidget *parent /TransferThis/ = 0 );
+%Docstring
+Constructor for QgsDatabaseSchemaComboBox, for the specified ``provider`` and ``connection``.
+
+.. warning::
+
+   The provider must support the connection API methods in its QgsProviderMetadata implementation
+   in order for the model to work correctly.
+%End
+
+    explicit QgsDatabaseSchemaComboBox( QgsAbstractDatabaseProviderConnection *connection /Transfer/, QWidget *parent /TransferThis/ = 0 );
+%Docstring
+Constructor for QgsDatabaseSchemaComboBox, for the specified ``connection``.
+
+Ownership of ``connection`` is transferred to the combobox.
+%End
+
+    QString currentSchema() const;
+%Docstring
+Returns the name of the current schema selected in the combo box.
+%End
+
+    QComboBox *comboBox();
+%Docstring
+Returns the combobox portion of the widget.
+%End
+
+  public slots:
+
+    void setSchema( const QString &schema );
+%Docstring
+Sets the current schema selected in the combo box.
+%End
+
+    void setConnectionName( const QString &connection, const QString &provider = QString() );
+%Docstring
+Sets the database connection name from which to retrieve the available schemas.
+
+Optionally the ``provider`` can be reset too.
+%End
+
+    void refreshSchemas();
+%Docstring
+Refreshes the list of available schemas.
+%End
+
+  signals:
+    void schemaChanged( const QString &schema );
+%Docstring
+Emitted whenever the currently selected schema changes.
+%End
+
+  protected slots:
+    void indexChanged( int i );
+    void rowsChanged();
+
+};
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/gui/qgsdatabaseschemacombobox.h                                  *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/

python/gui/gui_auto.sip

@@ -54,6 +54,7 @@
 %Include auto_generated/qgscredentialdialog.sip
 %Include auto_generated/qgscurveeditorwidget.sip
 %Include auto_generated/qgscustomdrophandler.sip
+%Include auto_generated/qgsdatabaseschemacombobox.sip
 %Include auto_generated/qgsdataitemguiprovider.sip
 %Include auto_generated/qgsdataitemguiproviderregistry.sip
 %Include auto_generated/qgsdatasourceselectdialog.sip

src/gui/CMakeLists.txt

@@ -321,6 +321,7 @@ SET(QGIS_GUI_SRCS
   qgscredentialdialog.cpp
   qgscustomdrophandler.cpp
   qgscurveeditorwidget.cpp
+  qgsdatabaseschemacombobox.cpp
   qgsdataitemguiprovider.cpp
   qgsdataitemguiproviderregistry.cpp
   qgsdatumtransformdialog.cpp
@@ -525,6 +526,7 @@ SET(QGIS_GUI_HDRS
   qgscredentialdialog.h
   qgscurveeditorwidget.h
   qgscustomdrophandler.h
+  qgsdatabaseschemacombobox.h
   qgsdataitemguiprovider.h
   qgsdataitemguiproviderregistry.h
   qgsdatasourcemanagerdialog.h

src/gui/qgsdatabaseschemacombobox.cpp

@@ -0,0 +1,135 @@
+/***************************************************************************
+   qgsdatabaseschemacombobox.cpp
+    --------------------------------
+   Date                 : March 2020
+   Copyright            : (C) 2020 Nyall Dawson
+   Email                : nyall dot dawson at gmail dot com
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************/
+
+#include "qgsdatabaseschemacombobox.h"
+#include "qgsdatabaseschemamodel.h"
+#include <QHBoxLayout>
+
+QgsDatabaseSchemaComboBox::QgsDatabaseSchemaComboBox( const QString &provider, const QString &connection, QWidget *parent )
+  : QWidget( parent )
+  , mProvider( provider )
+{
+  mModel = new QgsDatabaseSchemaModel( provider, connection, this );
+  init();
+}
+
+QgsDatabaseSchemaComboBox::QgsDatabaseSchemaComboBox( QgsAbstractDatabaseProviderConnection *connection, QWidget *parent )
+  : QWidget( parent )
+{
+  mModel = new QgsDatabaseSchemaModel( connection, this );
+  init();
+}
+
+void QgsDatabaseSchemaComboBox::init()
+{
+  mComboBox = new QComboBox();
+
+  mSortModel = new QSortFilterProxyModel( this );
+  mSortModel->setSourceModel( mModel );
+  mSortModel->setSortRole( Qt::DisplayRole );
+  mSortModel->setSortLocaleAware( true );
+  mSortModel->setSortCaseSensitivity( Qt::CaseInsensitive );
+  mSortModel->setDynamicSortFilter( true );
+  mSortModel->sort( 0 );
+
+  mComboBox->setModel( mSortModel );
+
+  QHBoxLayout *l = new QHBoxLayout();
+  l->setContentsMargins( 0, 0, 0, 0 );
+  l->addWidget( mComboBox );
+  setLayout( l );
+
+  connect( mComboBox, static_cast < void ( QComboBox::* )( int ) > ( &QComboBox::activated ), this, &QgsDatabaseSchemaComboBox::indexChanged );
+  connect( mSortModel, &QAbstractItemModel::rowsInserted, this, &QgsDatabaseSchemaComboBox::rowsChanged );
+  connect( mSortModel, &QAbstractItemModel::rowsRemoved, this, &QgsDatabaseSchemaComboBox::rowsChanged );
+}
+
+void QgsDatabaseSchemaComboBox::setSchema( const QString &schema )
+{
+  if ( schema == currentSchema() )
+    return;
+
+  if ( schema.isEmpty() )
+  {
+    mComboBox->setCurrentIndex( -1 );
+    emit schemaChanged( QString() );
+    return;
+  }
+
+  QModelIndexList idx = mSortModel->match( mSortModel->index( 0, 0 ), Qt::DisplayRole, schema, Qt::MatchFixedString | Qt::MatchCaseSensitive );
+  if ( !idx.empty() )
+  {
+    QModelIndex proxyIdx = idx.at( 0 );
+    if ( proxyIdx.isValid() )
+    {
+      mComboBox->setCurrentIndex( proxyIdx.row() );
+      emit schemaChanged( currentSchema() );
+      return;
+    }
+  }
+  mComboBox->setCurrentIndex( -1 );
+  emit schemaChanged( QString() );
+}
+
+void QgsDatabaseSchemaComboBox::setConnectionName( const QString &connection, const QString &provider )
+{
+  if ( !provider.isEmpty() )
+    mProvider = provider;
+
+  const QString oldSchema = currentSchema();
+  QgsDatabaseSchemaModel *oldModel = mModel;
+  mModel = new QgsDatabaseSchemaModel( mProvider, connection, this );
+  mSortModel->setSourceModel( mModel );
+  oldModel->deleteLater();
+  if ( currentSchema() != oldSchema )
+    setSchema( oldSchema );
+}
+
+void QgsDatabaseSchemaComboBox::refreshSchemas()
+{
+  const QString oldSchema = currentSchema();
+  mModel->refresh();
+  setSchema( oldSchema );
+}
+
+QString QgsDatabaseSchemaComboBox::currentSchema() const
+{
+  const QModelIndex proxyIndex = mSortModel->index( mComboBox->currentIndex(), 0 );
+  if ( !proxyIndex.isValid() )
+  {
+    return QString();
+  }
+
+  return mSortModel->data( proxyIndex, Qt::DisplayRole ).toString();
+}
+
+void QgsDatabaseSchemaComboBox::indexChanged( int i )
+{
+  Q_UNUSED( i )
+  emit schemaChanged( currentSchema() );
+}
+
+void QgsDatabaseSchemaComboBox::rowsChanged()
+{
+  if ( mComboBox->count() == 1 )
+  {
+    //currently selected connection item has changed
+    emit schemaChanged( currentSchema() );
+  }
+  else if ( mComboBox->count() == 0 )
+  {
+    emit schemaChanged( QString() );
+  }
+}

src/gui/qgsdatabaseschemacombobox.h

@@ -0,0 +1,104 @@
+/***************************************************************************
+   qgsdatabaseschemacombobox.h
+    --------------------------------
+   Date                 : March 2020
+   Copyright            : (C) 2020 Nyall Dawson
+   Email                : nyall dot dawson at gmail dot com
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************/
+
+#ifndef QGSDATABASESCHEMACOMBOBOX_H
+#define QGSDATABASESCHEMACOMBOBOX_H
+
+#include <QComboBox>
+
+#include "qgis_gui.h"
+#include "qgis_sip.h"
+
+class QgsDatabaseSchemaModel;
+class QSortFilterProxyModel;
+class QgsAbstractDatabaseProviderConnection;
+
+/**
+ * \ingroup gui
+ * \brief The QgsDatabaseSchemaComboBox class is a combo box which displays the list of schemas for a specific database connection.
+ *
+ * \warning The provider must support the connection API methods in its QgsProviderMetadata implementation
+ * in order for the combobox to work correctly.
+ *
+ * \since QGIS 3.14
+ */
+class GUI_EXPORT QgsDatabaseSchemaComboBox : public QWidget
+{
+    Q_OBJECT
+
+  public:
+
+    /**
+     * Constructor for QgsDatabaseSchemaComboBox, for the specified \a provider and \a connection.
+     *
+    * \warning The provider must support the connection API methods in its QgsProviderMetadata implementation
+    * in order for the model to work correctly.
+     */
+    explicit QgsDatabaseSchemaComboBox( const QString &provider, const QString &connection, QWidget *parent SIP_TRANSFERTHIS = nullptr );
+
+    /**
+     * Constructor for QgsDatabaseSchemaComboBox, for the specified \a connection.
+     *
+     * Ownership of \a connection is transferred to the combobox.
+     */
+    explicit QgsDatabaseSchemaComboBox( QgsAbstractDatabaseProviderConnection *connection SIP_TRANSFER, QWidget *parent SIP_TRANSFERTHIS = nullptr );
+
+    /**
+     * Returns the name of the current schema selected in the combo box.
+     */
+    QString currentSchema() const;
+
+    /**
+     * Returns the combobox portion of the widget.
+     */
+    QComboBox *comboBox() { return mComboBox; }
+
+  public slots:
+
+    /**
+     * Sets the current schema selected in the combo box.
+     */
+    void setSchema( const QString &schema );
+
+    /**
+     * Sets the database connection name from which to retrieve the available schemas.
+     *
+     * Optionally the \a provider can be reset too.
+     */
+    void setConnectionName( const QString &connection, const QString &provider = QString() );
+
+    /**
+     * Refreshes the list of available schemas.
+     */
+    void refreshSchemas();
+
+  signals:
+    //! Emitted whenever the currently selected schema changes.
+    void schemaChanged( const QString &schema );
+
+  protected slots:
+    void indexChanged( int i );
+    void rowsChanged();
+
+  private:
+    void init();
+
+    QString mProvider;
+    QgsDatabaseSchemaModel *mModel = nullptr;
+    QSortFilterProxyModel *mSortModel = nullptr;
+    QComboBox *mComboBox = nullptr;
+};
+
+#endif // QGSDATABASESCHEMACOMBOBOX_H

tests/src/python/CMakeLists.txt

@@ -306,6 +306,7 @@ IF (ENABLE_PGTEST)
   ADD_PYTHON_TEST(PyQgsDbManagerPostgis test_db_manager_postgis.py)
   ADD_PYTHON_TEST(PyQgsDatabaseSchemaModel test_qgsdatabaseschemamodel.py)
   ADD_PYTHON_TEST(PyQgsDatabaseTableModel test_qgsdatabasetablemodel.py)
+  ADD_PYTHON_TEST(PyQgsDatabaseSchemaComboBox test_qgsdatabaseschemacombobox.py)
   ADD_PYTHON_TEST(PyQgsProviderConnectionPostgres test_qgsproviderconnection_postgres.py)
 ENDIF (ENABLE_PGTEST)
 

tests/src/python/test_qgsdatabaseschemacombobox.py

@@ -0,0 +1,122 @@
+# -*- coding: utf-8 -*-
+"""QGIS Unit tests for QgsDatabaseSchemaComboBox
+
+.. note:: This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+"""
+__author__ = 'Nyall Dawson'
+__date__ = '8/03/2020'
+__copyright__ = 'Copyright 2020, The QGIS Project'
+
+import qgis  # NOQA
+
+import tempfile
+import shutil
+import os
+
+from qgis.core import (
+    QgsVectorLayer,
+    QgsProviderRegistry
+)
+from qgis.gui import QgsDatabaseSchemaComboBox
+from qgis.PyQt.QtCore import QCoreApplication
+from qgis.PyQt.QtTest import QSignalSpy
+
+from qgis.testing import unittest
+from utilities import unitTestDataPath, start_app
+
+start_app()
+
+TEST_DATA_DIR = unitTestDataPath()
+
+
+class TestQgsDatabaseSchemaComboBox(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        """Run before all tests"""
+
+        QCoreApplication.setOrganizationName("QGIS_Test")
+        QCoreApplication.setOrganizationDomain(cls.__name__)
+        QCoreApplication.setApplicationName(cls.__name__)
+        start_app()
+        cls.postgres_conn = "service='qgis_test'"
+        if 'QGIS_PGTEST_DB' in os.environ:
+            cls.postgres_conn = os.environ['QGIS_PGTEST_DB']
+        cls.uri = cls.postgres_conn + ' sslmode=disable'
+
+    def testCombo(self):
+        """ test combobox functionality """
+        conn = QgsProviderRegistry.instance().providerMetadata('postgres').createConnection(self.uri, {})
+        self.assertTrue(conn)
+
+        m = QgsDatabaseSchemaComboBox(conn)
+        spy = QSignalSpy(m.schemaChanged)
+        self.assertGreaterEqual(m.comboBox().count(), 3)
+
+        text = [m.comboBox().itemText(i) for i in range(m.comboBox().count())]
+        self.assertIn('CamelCaseSchema', text)
+        self.assertIn('qgis_test', text)
+        self.assertLess(text.index('CamelCaseSchema'), text.index('qgis_test'))
+        self.assertEqual(m.currentSchema(), 'CamelCaseSchema')
+
+        m.setSchema('qgis_test')
+        self.assertEqual(m.currentSchema(), 'qgis_test')
+        self.assertEqual(len(spy), 1)
+        self.assertEqual(spy[-1][0], 'qgis_test')
+
+        m.setSchema('')
+        self.assertFalse(m.currentSchema())
+        self.assertEqual(len(spy), 2)
+        self.assertFalse(spy[-1][0])
+        m.setSchema('')
+        self.assertEqual(len(spy), 2)
+        self.assertFalse(m.currentSchema())
+
+        m.setSchema('qgis_test')
+        self.assertEqual(len(spy), 3)
+        self.assertEqual(m.currentSchema(), 'qgis_test')
+        self.assertEqual(spy[-1][0], 'qgis_test')
+
+        conn.createSchema('myNewSchema')
+        text2 = [m.comboBox().itemText(i) for i in range(m.comboBox().count())]
+        # schemas are not automatically refreshed
+        self.assertEqual(text2, text)
+
+        # but setting a new connection should fix this!
+        md = QgsProviderRegistry.instance().providerMetadata('postgres')
+        conn2 = md.createConnection(self.uri, {})
+        md.saveConnection(conn2, 'another')
+        m.setConnectionName('another', 'postgres')
+        # ideally there'd be no extra signal here, but it's a minor issue...
+        self.assertEqual(len(spy), 4)
+        self.assertEqual(m.currentSchema(), 'qgis_test')
+        self.assertEqual(spy[-1][0], 'qgis_test')
+
+        text2 = [m.comboBox().itemText(i) for i in range(m.comboBox().count())]
+        self.assertNotEqual(text2, text)
+        self.assertIn('myNewSchema', text2)
+
+        m.setSchema('myNewSchema')
+        self.assertEqual(len(spy), 5)
+        self.assertEqual(m.currentSchema(), 'myNewSchema')
+        self.assertEqual(spy[-1][0], 'myNewSchema')
+
+        # no auto drop
+        conn.dropSchema('myNewSchema')
+        self.assertEqual(len(spy), 5)
+        self.assertEqual(m.currentSchema(), 'myNewSchema')
+        self.assertEqual(spy[-1][0], 'myNewSchema')
+
+        m.refreshSchemas()
+        text2 = [m.comboBox().itemText(i) for i in range(m.comboBox().count())]
+        self.assertNotIn('myNewSchema', text2)
+        self.assertEqual(len(spy), 6)
+        self.assertFalse(m.currentSchema())
+        self.assertFalse(spy[-1][0])
+
+
+if __name__ == '__main__':
+    unittest.main()

tests/src/python/test_qgsproviderconnectioncombobox.py

@@ -32,7 +32,7 @@ start_app()
 TEST_DATA_DIR = unitTestDataPath()
 
 
-class TestQgsMapLayerComboBox(unittest.TestCase):
+class TestQgsProviderConnectionComboBox(unittest.TestCase):
 
     @classmethod
     def setUpClass(cls):