fix date/time widget does not handle time zones

issue #16657
manually picked from QGIS3 bdf744e

src/gui/editorwidgets/qgsdatetimeeditconfig.cpp

@@ -21,6 +21,13 @@ QgsDateTimeEditConfig::QgsDateTimeEditConfig( QgsVectorLayer* vl, int fieldIdx,
 {
   setupUi( this );
 
+  mFieldFormatComboBox->clear();
+  mFieldFormatComboBox->addItem( tr( "Date" ), QGSDATETIMEEDIT_DATEFORMAT );
+  mFieldFormatComboBox->addItem( tr( "Time" ), QGSDATETIMEEDIT_TIMEFORMAT );
+  mFieldFormatComboBox->addItem( tr( "Date time" ), QGSDATETIMEEDIT_DATETIMEFORMAT );
+  mFieldFormatComboBox->addItem( tr( "ISO date time" ), QGSDATETIMEEDIT_ISODATETIMEFORMAT );
+  mFieldFormatComboBox->addItem( tr( "Custom" ), QString() );
+
   mDemoDateTimeEdit->setDateTime( QDateTime::currentDateTime() );
 
   connect( mDisplayFormatEdit, SIGNAL( textChanged( QString ) ), this, SLOT( updateDemoWidget() ) );
@@ -53,46 +60,50 @@ void QgsDateTimeEditConfig::updateDemoWidget()
 
 void QgsDateTimeEditConfig::updateFieldFormat( int idx )
 {
-  if ( idx == 0 )
-  {
-    mFieldFormatEdit->setText( QGSDATETIMEEDIT_DATEFORMAT );
-  }
-  else if ( idx == 1 )
-  {
-    mFieldFormatEdit->setText( QGSDATETIMEEDIT_TIMEFORMAT );
-  }
-  else if ( idx == 2 )
+  const QString format = mFieldFormatComboBox->itemData( idx ).toString();
+  bool custom = format.isEmpty();
+  if ( !custom )
   {
-    mFieldFormatEdit->setText( QGSDATETIMEEDIT_DATETIMEFORMAT );
+    mFieldFormatEdit->setText( format );
   }
 
-  mFieldFormatEdit->setVisible( idx == 3 );
-  mFieldHelpToolButton->setVisible( idx == 3 );
+  mFieldFormatEdit->setEnabled( custom );
+  mFieldHelpToolButton->setVisible( custom );
   if ( mFieldHelpToolButton->isHidden() && mDisplayHelpToolButton->isHidden() )
   {
     mHelpScrollArea->setVisible( false );
   }
 }
 
 
+
 void QgsDateTimeEditConfig::updateDisplayFormat( const QString& fieldFormat )
 {
   if ( mDisplayFormatComboBox->currentIndex() == 0 )
   {
-    mDisplayFormatEdit->setText( fieldFormat );
+    // i.e. display format is default
+    if ( mFieldFormatComboBox->itemData( mFieldFormatComboBox->currentIndex() ) == QGSDATETIMEEDIT_ISODATETIMEFORMAT )
+    {
+      mDisplayFormatEdit->setText( QGSDATETIMEEDIT_ISODISPLAYFORMAT );
+    }
+    else
+    {
+      mDisplayFormatEdit->setText( fieldFormat );
+    }
   }
 }
 
 
 void QgsDateTimeEditConfig::displayFormatChanged( int idx )
 {
-  mDisplayFormatEdit->setEnabled( idx == 1 );
-  mDisplayHelpToolButton->setVisible( idx == 1 );
+  const bool custom = idx == 1;
+  mDisplayFormatEdit->setEnabled( custom );
+  mDisplayHelpToolButton->setVisible( custom );
   if ( mFieldHelpToolButton->isHidden() && mDisplayHelpToolButton->isHidden() )
   {
     mHelpScrollArea->setVisible( false );
   }
-  if ( idx == 0 )
+  if ( !custom )
   {
     mDisplayFormatEdit->setText( mFieldFormatEdit->text() );
   }
@@ -110,6 +121,7 @@ QgsEditorWidgetConfig QgsDateTimeEditConfig::config()
 {
   QgsEditorWidgetConfig myConfig;
 
+  myConfig.insert( "field_iso_format", mFieldFormatEdit->text() == QGSDATETIMEEDIT_ISODATETIMEFORMAT );
   myConfig.insert( "field_format", mFieldFormatEdit->text() );
   myConfig.insert( "display_format", mDisplayFormatEdit->text() );
   myConfig.insert( "calendar_popup", mCalendarPopupCheckBox->isChecked() );
@@ -126,14 +138,15 @@ void QgsDateTimeEditConfig::setConfig( const QgsEditorWidgetConfig &config )
     const QString fieldFormat = config[ "field_format" ].toString();
     mFieldFormatEdit->setText( fieldFormat );
 
-    if ( fieldFormat == QGSDATETIMEEDIT_DATEFORMAT )
-      mFieldFormatComboBox->setCurrentIndex( 0 );
-    else if ( fieldFormat == QGSDATETIMEEDIT_TIMEFORMAT )
-      mFieldFormatComboBox->setCurrentIndex( 1 );
-    else if ( fieldFormat == QGSDATETIMEEDIT_DATETIMEFORMAT )
-      mFieldFormatComboBox->setCurrentIndex( 2 );
+    const int idx = mFieldFormatComboBox->findData( fieldFormat );
+    if ( idx >= 0 )
+    {
+      mFieldFormatComboBox->setCurrentIndex( idx );
+    }
     else
-      mFieldFormatComboBox->setCurrentIndex( 3 );
+    {
+      mFieldFormatComboBox->setCurrentIndex( 4 );
+    }
   }
 
   if ( config.contains( "display_format" ) )

src/gui/editorwidgets/qgsdatetimeeditfactory.h

@@ -21,6 +21,9 @@
 #define QGSDATETIMEEDIT_DATEFORMAT "yyyy-MM-dd"
 #define QGSDATETIMEEDIT_TIMEFORMAT "HH:mm:ss"
 #define QGSDATETIMEEDIT_DATETIMEFORMAT "yyyy-MM-dd HH:mm:ss"
+#define QGSDATETIMEEDIT_ISODATETIMEFORMAT "Qt ISO Date"
+#define QGSDATETIMEEDIT_ISODISPLAYFORMAT "yyyy-MM-dd HH:mm:ss+t"
+
 
 /** \ingroup gui
  * \class QgsDateTimeEditFactory

src/gui/editorwidgets/qgsdatetimeeditwrapper.cpp

@@ -113,8 +113,16 @@ void QgsDateTimeEditWrapper::showIndeterminateState()
 
 void QgsDateTimeEditWrapper::dateTimeChanged( const QDateTime& dateTime )
 {
-  const QString fieldFormat = config( "field_format", QGSDATETIMEEDIT_DATEFORMAT ).toString();
-  emit valueChanged( dateTime.toString( fieldFormat ) );
+  const bool fieldIsoFormat = config( "field_iso_format" , false ).toBool();
+  const QString fieldFormat = config( "field_format" , QGSDATETIMEEDIT_DATEFORMAT ).toString();
+  if ( fieldIsoFormat )
+  {
+    emit valueChanged( dateTime.toString( Qt::ISODate ) );
+  }
+  else
+  {
+    emit valueChanged( dateTime.toString( fieldFormat ) );
+  }
 }
 
 QVariant QgsDateTimeEditWrapper::value() const
@@ -134,15 +142,25 @@ QVariant QgsDateTimeEditWrapper::value() const
     }
   }
 
+  const bool fieldIsoFormat = config( "field_iso_format", false ).toBool();
   const QString fieldFormat = config( "field_format", QGSDATETIMEEDIT_DATEFORMAT ).toString();
 
+  QDateTime date;
   if ( mQgsDateTimeEdit )
   {
-    return mQgsDateTimeEdit->dateTime().toString( fieldFormat );
+    date = mQgsDateTimeEdit->dateTime();
   }
   else
   {
-    return mQDateTimeEdit->dateTime().toString( fieldFormat );
+    date = mQDateTimeEdit->dateTime();
+  }
+  if ( fieldIsoFormat )
+  {
+    return date.toString( Qt::ISODate );
+  }
+  else
+  {
+    return date.toString( fieldFormat );
   }
 }
 
@@ -151,8 +169,25 @@ void QgsDateTimeEditWrapper::setValue( const QVariant &value )
   if ( !mQDateTimeEdit )
     return;
 
+  const bool fieldIsoFormat = config( "field_iso_format", false ).toBool();
   const QString fieldFormat = config( "field_format", QGSDATETIMEEDIT_DATEFORMAT ).toString();
-  const QDateTime date = field().type() == QVariant::DateTime ? value.toDateTime() : QDateTime::fromString( value.toString(), fieldFormat );
+
+  QDateTime date;
+  if ( field().type() == QVariant::DateTime )
+  {
+    date = value.toDateTime();
+  }
+  else
+  {
+    if ( fieldIsoFormat )
+    {
+      date = QDateTime::fromString( value.toString(), Qt::ISODate );
+    }
+    else
+    {
+      date = QDateTime::fromString( value.toString(), fieldFormat );
+    }
+  }
 
   if ( mQgsDateTimeEdit )
   {

src/gui/editorwidgets/qgsdatetimesearchwidgetwrapper.cpp

@@ -45,8 +45,17 @@ QVariant QgsDateTimeSearchWidgetWrapper::value() const
   if ( ! mDateTimeEdit )
     return QDateTime();
 
+  const bool fieldIsoFormat = config( "field_iso_format", false ).toBool();
   const QString fieldFormat = config( "field_format", QGSDATETIMEEDIT_DATEFORMAT ).toString();
-  return mDateTimeEdit->dateTime().toString( fieldFormat );
+
+  if ( fieldIsoFormat )
+  {
+    return mDateTimeEdit->dateTime().toString( Qt::ISODate );
+  }
+  else
+  {
+    return mDateTimeEdit->dateTime().toString( fieldFormat );
+  }
 }
 
 QgsSearchWidgetWrapper::FilterFlags QgsDateTimeSearchWidgetWrapper::supportedFlags() const

src/ui/editorwidgets/qgsdatetimeeditconfig.ui

@@ -24,8 +24,8 @@
        <rect>
         <x>0</x>
         <y>0</y>
-        <width>468</width>
-        <height>1033</height>
+        <width>478</width>
+        <height>971</height>
        </rect>
       </property>
       <layout class="QGridLayout" name="gridLayout_5">
@@ -80,26 +80,6 @@
           <height>0</height>
          </size>
         </property>
-        <item>
-         <property name="text">
-          <string>Date</string>
-         </property>
-        </item>
-        <item>
-         <property name="text">
-          <string>Time</string>
-         </property>
-        </item>
-        <item>
-         <property name="text">
-          <string>Date &amp; time</string>
-         </property>
-        </item>
-        <item>
-         <property name="text">
-          <string>Custom format</string>
-         </property>
-        </item>
        </widget>
       </item>
       <item row="0" column="1">
@@ -250,6 +230,9 @@
  </widget>
  <resources>
   <include location="../../../images/images.qrc"/>
+  <include location="../../../images/images.qrc"/>
+  <include location="../../../images/images.qrc"/>
+  <include location="../../../images/images.qrc"/>
  </resources>
  <connections/>
 </ui>