Use standard map layer and field combo boxes in relation add dialog

src/app/qgsrelationadddlg.cpp

@@ -16,6 +16,7 @@
 
 #include "qgsrelationadddlg.h"
 #include "qgsvectorlayer.h"
+#include "qgsmaplayerproxymodel.h"
 
 #include <QPushButton>
 
@@ -24,45 +25,41 @@ QgsRelationAddDlg::QgsRelationAddDlg( QWidget *parent )
 {
   setupUi( this );
 
-  mTxtRelationId->setPlaceholderText( tr( "[Generated automatically]" ) );
-  checkDefinitionValid();
+  connect( mCbxReferencingLayer, &QgsMapLayerComboBox::layerChanged, this, [=]( QgsMapLayer * layer ) { mCbxReferencingField->setLayer( layer ); }
+         );
+  connect( mCbxReferencedLayer, &QgsMapLayerComboBox::layerChanged, this, [=]( QgsMapLayer * layer ) { mCbxReferencedField->setLayer( layer ); }
+         );
 
-  connect( mCbxReferencingLayer, SIGNAL( currentIndexChanged( int ) ), this, SLOT( checkDefinitionValid() ) );
-  connect( mCbxReferencingField, SIGNAL( currentIndexChanged( int ) ), this, SLOT( checkDefinitionValid() ) );
-  connect( mCbxReferencedLayer, SIGNAL( currentIndexChanged( int ) ), this, SLOT( checkDefinitionValid() ) );
-  connect( mCbxReferencedField, SIGNAL( currentIndexChanged( int ) ), this, SLOT( checkDefinitionValid() ) );
-}
-
-void QgsRelationAddDlg::addLayers( const QList< QgsVectorLayer* >& layers )
-{
-  mCbxReferencingLayer->addItem( QLatin1String( "" ), "" );
-  mCbxReferencedLayer->addItem( QLatin1String( "" ), "" );
+  mCbxReferencingLayer->setFilters( QgsMapLayerProxyModel::VectorLayer );
+  mCbxReferencingField->setLayer( mCbxReferencingLayer->currentLayer() );
+  mCbxReferencedLayer->setFilters( QgsMapLayerProxyModel::VectorLayer );
+  mCbxReferencedField->setLayer( mCbxReferencedLayer->currentLayer() );
 
-  Q_FOREACH ( QgsVectorLayer* layer, layers )
-  {
-    mCbxReferencingLayer->addItem( layer->name(), layer->id() );
-    mCbxReferencedLayer->addItem( layer->name(), layer->id() );
+  mTxtRelationId->setPlaceholderText( tr( "[Generated automatically]" ) );
+  checkDefinitionValid();
 
-    mLayers.insert( layer->id(), layer );
-  }
+  connect( mCbxReferencingLayer, &QgsMapLayerComboBox::layerChanged, this, &QgsRelationAddDlg::checkDefinitionValid );
+  connect( mCbxReferencingField, &QgsFieldComboBox::fieldChanged, this, &QgsRelationAddDlg::checkDefinitionValid );
+  connect( mCbxReferencedLayer, &QgsMapLayerComboBox::layerChanged, this, &QgsRelationAddDlg::checkDefinitionValid );
+  connect( mCbxReferencedField, &QgsFieldComboBox::fieldChanged, this, &QgsRelationAddDlg::checkDefinitionValid );
 }
 
 QString QgsRelationAddDlg::referencingLayerId()
 {
-  return mCbxReferencingLayer->currentData().toString();
+  return mCbxReferencingLayer->currentLayer()->id();
 }
 
 QString QgsRelationAddDlg::referencedLayerId()
 {
-  return mCbxReferencedLayer->currentData().toString();
+  return mCbxReferencedLayer->currentLayer()->id();
 }
 
 QList< QPair< QString, QString > > QgsRelationAddDlg::references()
 {
   QList< QPair< QString, QString > > references;
 
-  QString referencingField = mCbxReferencingField->currentData().toString();
-  QString referencedField = mCbxReferencedField->currentData().toString();
+  QString referencingField = mCbxReferencingField->currentField();
+  QString referencedField = mCbxReferencedField->currentField();
 
   references.append( QPair<QString, QString> ( referencingField, referencedField ) );
 
@@ -79,15 +76,6 @@ QString QgsRelationAddDlg::relationName()
   return mTxtRelationName->text();
 }
 
-void QgsRelationAddDlg::on_mCbxReferencingLayer_currentIndexChanged( int index )
-{
-  loadLayerAttributes( mCbxReferencingField, mLayers[mCbxReferencingLayer->itemData( index ).toString()] );
-}
-
-void QgsRelationAddDlg::on_mCbxReferencedLayer_currentIndexChanged( int index )
-{
-  loadLayerAttributes( mCbxReferencedField, mLayers[mCbxReferencedLayer->itemData( index ).toString()] );
-}
 
 void QgsRelationAddDlg::checkDefinitionValid()
 {
@@ -96,18 +84,3 @@ void QgsRelationAddDlg::checkDefinitionValid()
       && mCbxReferencingLayer->currentIndex() != -1
       && mCbxReferencingField->currentIndex() != -1 );
 }
-
-void QgsRelationAddDlg::loadLayerAttributes( QComboBox* cbx, QgsVectorLayer* layer )
-{
-  cbx->clear();
-
-  if ( !layer )
-  {
-    return;
-  }
-
-  Q_FOREACH ( const QgsField& fld, layer->fields().toList() )
-  {
-    cbx->addItem( fld.name(), fld.name() );
-  }
-}

src/app/qgsrelationadddlg.h

@@ -27,8 +27,6 @@ class APP_EXPORT QgsRelationAddDlg : public QDialog, private Ui::QgsRelationAddD
   public:
     explicit QgsRelationAddDlg( QWidget *parent = nullptr );
 
-    void addLayers( const QList<QgsVectorLayer*>& layers );
-
     QString referencingLayerId();
     QString referencedLayerId();
     QList< QPair< QString, QString > > references();
@@ -37,16 +35,9 @@ class APP_EXPORT QgsRelationAddDlg : public QDialog, private Ui::QgsRelationAddD
 
 
   private slots:
-    void on_mCbxReferencingLayer_currentIndexChanged( int index );
-    void on_mCbxReferencedLayer_currentIndexChanged( int index );
 
     void checkDefinitionValid();
 
-  private:
-    void loadLayerAttributes( QComboBox* cbx, QgsVectorLayer* layer );
-
-    QMap< QString, QgsVectorLayer* > mLayers;
-
 };
 
 #endif // QGSRELATIONADDDLG_H

src/app/qgsrelationmanagerdialog.cpp

@@ -84,7 +84,6 @@ void QgsRelationManagerDialog::addRelation( const QgsRelation &rel )
 void QgsRelationManagerDialog::on_mBtnAddRelation_clicked()
 {
   QgsRelationAddDlg addDlg;
-  addDlg.addLayers( mLayers );
 
   if ( addDlg.exec() )
   {
@@ -164,4 +163,4 @@ QList< QgsRelation > QgsRelationManagerDialog::relations()
 void QgsRelationManagerDialog::onSelectionChanged()
 {
   mBtnRemoveRelation->setEnabled( mRelationsTable->selectionModel()->hasSelection() );
-}
+}

src/ui/qgsrelationadddlgbase.ui

@@ -22,7 +22,7 @@
     </widget>
    </item>
    <item row="4" column="1" colspan="2">
-    <widget class="QComboBox" name="mCbxReferencingLayer"/>
+    <widget class="QgsMapLayerComboBox" name="mCbxReferencingLayer"/>
    </item>
    <item row="9" column="0">
     <widget class="QLabel" name="label_5">
@@ -49,7 +49,7 @@
     </widget>
    </item>
    <item row="5" column="1" colspan="2">
-    <widget class="QComboBox" name="mCbxReferencingField"/>
+    <widget class="QgsFieldComboBox" name="mCbxReferencingField"/>
    </item>
    <item row="5" column="0">
     <widget class="QLabel" name="label_2">
@@ -73,19 +73,31 @@
     </widget>
    </item>
    <item row="3" column="1" colspan="2">
-    <widget class="QComboBox" name="mCbxReferencedField"/>
+    <widget class="QgsFieldComboBox" name="mCbxReferencedField"/>
    </item>
    <item row="9" column="1" colspan="2">
     <widget class="QLineEdit" name="mTxtRelationId"/>
    </item>
    <item row="2" column="1" colspan="2">
-    <widget class="QComboBox" name="mCbxReferencedLayer"/>
+    <widget class="QgsMapLayerComboBox" name="mCbxReferencedLayer"/>
    </item>
    <item row="1" column="1" colspan="2">
     <widget class="QLineEdit" name="mTxtRelationName"/>
    </item>
   </layout>
  </widget>
+ <customwidgets>
+  <customwidget>
+   <class>QgsMapLayerComboBox</class>
+   <extends>QComboBox</extends>
+   <header location="global">qgsmaplayercombobox.h</header>
+  </customwidget>
+  <customwidget>
+   <class>QgsFieldComboBox</class>
+   <extends>QComboBox</extends>
+   <header location="global">qgsfieldcombobox.h</header>
+  </customwidget>
+ </customwidgets>
  <tabstops>
   <tabstop>mTxtRelationName</tabstop>
   <tabstop>mCbxReferencedLayer</tabstop>