implement date() and time() in QgsDateTimeEdit to handle NULL values

python/gui/auto_generated/editorwidgets/qgsdatetimeedit.sip.in

@@ -31,6 +31,7 @@ The QgsDateTimeEdit class is a QDateTimeEdit with the capability of setting/read
 Constructor for QgsDateTimeEdit
 The current date and time is used by default.
 The widget is allowing null by default.
+If allow null is disabled, you should check allowNull before getting values from the widget.
 %End
 
     void setAllowNull( bool allowNull );
@@ -58,17 +59,31 @@ setDateTime set the date time in the widget and handles null date times.
 
     QDateTime dateTime() const;
 %Docstring
-dateTime returns the date time which can eventually be a null date/time
+dateTime returns the date time which can be a null date/time
 
 .. note::
 
-    You mustn't call date() or time() because they can't return a NULL value.
+   Before QGIS 3.10, you mustn't call date() or time() because they can't return a NULL value.
 
 .. note::
 
    since QDateTimeEdit.dateTime() is not virtual, dateTime must be called for QgsDateTimeEdit
 %End
 
+    QTime time() const;
+%Docstring
+time returns the time which can be a null time.
+
+.. versionadded:: 3.10
+%End
+
+    QDate date() const;
+%Docstring
+date returns the date which can be a null date.
+
+.. versionadded:: 3.10
+%End
+
     virtual void clear();
 
 %Docstring

src/gui/editorwidgets/qgsdatetimeedit.cpp

@@ -275,3 +275,27 @@ QDateTime QgsDateTimeEdit::dateTime() const
     return QDateTimeEdit::dateTime();
   }
 }
+
+QTime QgsDateTimeEdit::time() const
+{
+  if ( mAllowNull && mIsNull )
+  {
+    return QTime();
+  }
+  else
+  {
+    return QDateTimeEdit::time();
+  }
+}
+
+QDate QgsDateTimeEdit::date() const
+{
+  if ( mAllowNull && mIsNull )
+  {
+    return QDate();
+  }
+  else
+  {
+    return QDateTimeEdit::date();
+  }
+}

src/gui/editorwidgets/qgsdatetimeedit.h

@@ -40,6 +40,7 @@ class GUI_EXPORT QgsDateTimeEdit : public QDateTimeEdit
      * Constructor for QgsDateTimeEdit
      * The current date and time is used by default.
      * The widget is allowing null by default.
+     * If allow null is disabled, you should check allowNull before getting values from the widget.
      */
     explicit QgsDateTimeEdit( QWidget *parent SIP_TRANSFERTHIS = nullptr );
 
@@ -62,12 +63,24 @@ class GUI_EXPORT QgsDateTimeEdit : public QDateTimeEdit
     void setDateTime( const QDateTime &dateTime );
 
     /**
-     * \brief dateTime returns the date time which can eventually be a null date/time
+     * \brief dateTime returns the date time which can be a null date/time
-     * \note  You mustn't call date() or time() because they can't return a NULL value.
+     * \note Before QGIS 3.10, you mustn't call date() or time() because they can't return a NULL value.
      * \note since QDateTimeEdit::dateTime() is not virtual, dateTime must be called for QgsDateTimeEdit
      */
     QDateTime dateTime() const;
 
+    /**
+     * \brief time returns the time which can be a null time.
+     * \since QGIS 3.10
+     */
+    QTime time() const;
+
+    /**
+     * \brief date returns the date which can be a null date.
+     * \since QGIS 3.10
+     */
+    QDate date() const;
+
     /**
      * Set the current date as NULL
      * \note if the widget is not configured to accept NULL dates, this will have no effect

tests/src/gui/CMakeLists.txt

@@ -127,6 +127,7 @@ ADD_QGIS_TEST(datumtransformdialog testqgsdatumtransformdialog.cpp)
 ADD_QGIS_TEST(doublespinbox testqgsdoublespinbox.cpp)
 ADD_QGIS_TEST(dualviewtest testqgsdualview.cpp)
 ADD_QGIS_TEST(attributeformtest testqgsattributeform.cpp)
+ADD_QGIS_TEST(datetimedittest testqgsdatetimeedit.cpp)
 ADD_QGIS_TEST(dockwidget testqgsdockwidget.cpp)
 ADD_QGIS_TEST(fieldexpressionwidget testqgsfieldexpressionwidget.cpp)
 ADD_QGIS_TEST(filewidget testqgsfilewidget.cpp)

tests/src/gui/testqgsdatetimeedit.cpp

@@ -0,0 +1,83 @@
+/***************************************************************************
+    testqgsdatetimeedit.cpp
+     --------------------------------------
+    Date                 : September 2019
+    Copyright            : (C) 2019 Etienne Trimaille
+    Email                : etienne dot trimaille 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 "qgstest.h"
+#include "qdatetime.h"
+
+#include <qgsdatetimeedit.h>
+
+class TestQgsDateTimeEdit: public QObject
+{
+    Q_OBJECT
+  private slots:
+    void initTestCase(); // will be called before the first testfunction is executed.
+    void cleanupTestCase(); // will be called after the last testfunction was executed.
+    void init(); // will be called before each testfunction is executed.
+    void cleanup(); // will be called after every testfunction.
+
+    void nullValues();
+
+};
+
+void TestQgsDateTimeEdit::initTestCase()
+{
+}
+
+void TestQgsDateTimeEdit::cleanupTestCase()
+{
+}
+
+void TestQgsDateTimeEdit::init()
+{
+}
+
+void TestQgsDateTimeEdit::cleanup()
+{
+}
+
+void TestQgsDateTimeEdit::nullValues()
+{
+  QgsDateTimeEdit *timeEdit = new QgsDateTimeEdit();
+
+  // Allow null with a null datetime
+  QVERIFY( timeEdit->allowNull() );
+  timeEdit->setDateTime( QDateTime() );
+  QCOMPARE( timeEdit->dateTime(), QDateTime() );
+  QCOMPARE( timeEdit->time(), QTime() );
+  QCOMPARE( timeEdit->date(), QDate() );
+
+  // Not null with not null datetime
+  QDateTime date( QDate( 2019, 7, 6 ), QTime( 8, 30, 0 ) );
+  timeEdit->setAllowNull( false );
+  QVERIFY( !timeEdit->allowNull() );
+  timeEdit->setDateTime( date );
+  QCOMPARE( timeEdit->dateTime(), date );
+  QCOMPARE( timeEdit->time(), date.time() );
+  QCOMPARE( timeEdit->date(), date.date() );
+
+  // Not null with null date
+  timeEdit->setAllowNull( false );
+  QVERIFY( !timeEdit->allowNull() );
+  timeEdit->setDateTime( QDateTime() );
+  QCOMPARE( timeEdit->dateTime(), date );
+  QCOMPARE( timeEdit->time(), date.time() );
+  QCOMPARE( timeEdit->date(), date.date() );
+
+  delete timeEdit;
+}
+
+QGSTEST_MAIN( TestQgsDateTimeEdit )
+#include "testqgsdatetimeedit.moc"