[api] Allow the text and icon for the 'empty layer' option in QgsMapL…

…ayerComboBox to be customised
qgis · Mar 30, 2021 · f0aafd2 · f0aafd2
1 parent f488a6c
commit f0aafd2
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Showing 7 changed files with 34 additions and 10 deletions.
diff --git a/python/core/auto_generated/qgsmaplayermodel.sip.in b/python/core/auto_generated/qgsmaplayermodel.sip.in
@@ -79,10 +79,12 @@ Returns ``True`` if items in the model can be reordered via drag and drop.
 checkAll changes the checkstate for all the layers
 %End
 
-    void setAllowEmptyLayer( bool allowEmpty );
+    void setAllowEmptyLayer( bool allowEmpty, const QString &text = QString(), const QIcon &icon = QIcon() );
 %Docstring
 Sets whether an optional empty layer ("not set") option is present in the model.
 
+Since QGIS 3.20, the optional ``text`` and ``icon`` arguments allows the text and icon for the empty layer item to be set.
+
 .. seealso:: :py:func:`allowEmptyLayer`
 
 .. versionadded:: 3.0

diff --git a/python/gui/auto_generated/qgsmaplayercombobox.sip.in b/python/gui/auto_generated/qgsmaplayercombobox.sip.in
@@ -68,10 +68,12 @@ Returns the list of data providers which are excluded from the combobox.
 .. versionadded:: 3.0
 %End
 
-    void setAllowEmptyLayer( bool allowEmpty );
+    void setAllowEmptyLayer( bool allowEmpty, const QString &text = QString(), const QIcon &icon = QIcon() );
 %Docstring
 Sets whether an optional empty layer ("not set") option is shown in the combo box.
 
+Since QGIS 3.20, the optional ``text`` and ``icon`` arguments allows the text and icon for the empty layer item to be set.
+
 .. seealso:: :py:func:`allowEmptyLayer`
 
 .. versionadded:: 3.0

diff --git a/src/core/qgsmaplayermodel.cpp b/src/core/qgsmaplayermodel.cpp
@@ -63,8 +63,10 @@ void QgsMapLayerModel::checkAll( Qt::CheckState checkState )
   emit dataChanged( index( 0, 0 ), index( rowCount() - 1, 0 ) );
 }
 
-void QgsMapLayerModel::setAllowEmptyLayer( bool allowEmpty )
+void QgsMapLayerModel::setAllowEmptyLayer( bool allowEmpty, const QString &text, const QIcon &icon )
 {
+  mEmptyText = text;
+  mEmptyIcon = icon;
   if ( allowEmpty == mAllowEmpty )
     return;
 
@@ -252,7 +254,7 @@ QVariant QgsMapLayerModel::data( const QModelIndex &index, int role ) const
     case Qt::EditRole:
     {
       if ( index.row() == 0 && mAllowEmpty )
-        return QVariant();
+        return mEmptyText;
 
       if ( additionalIndex >= 0 )
         return mAdditionalItems.at( additionalIndex );
@@ -337,7 +339,10 @@ QVariant QgsMapLayerModel::data( const QModelIndex &index, int role ) const
 
     case Qt::DecorationRole:
     {
-      if ( isEmpty || additionalIndex >= 0 )
+      if ( isEmpty )
+        return mEmptyIcon.isNull() ? QVariant() : mEmptyIcon;
+
+      if ( additionalIndex >= 0 )
         return QVariant();
 
       QgsMapLayer *layer = mLayers.value( index.row() - ( mAllowEmpty ? 1 : 0 ) );

diff --git a/src/core/qgsmaplayermodel.h b/src/core/qgsmaplayermodel.h
@@ -19,6 +19,7 @@
 #include <QAbstractItemModel>
 #include <QSortFilterProxyModel>
 #include <QStringList>
+#include <QIcon>
 
 #include "qgis_core.h"
 #include "qgis_sip.h"
@@ -98,10 +99,13 @@ class CORE_EXPORT QgsMapLayerModel : public QAbstractItemModel
 
     /**
      * Sets whether an optional empty layer ("not set") option is present in the model.
+     *
+     * Since QGIS 3.20, the optional \a text and \a icon arguments allows the text and icon for the empty layer item to be set.
+     *
      * \see allowEmptyLayer()
      * \since QGIS 3.0
      */
-    void setAllowEmptyLayer( bool allowEmpty );
+    void setAllowEmptyLayer( bool allowEmpty, const QString &text = QString(), const QIcon &icon = QIcon() );
 
     /**
      * Returns TRUE if the model allows the empty layer ("not set") choice.
@@ -210,6 +214,8 @@ class CORE_EXPORT QgsMapLayerModel : public QAbstractItemModel
   private:
 
     bool mAllowEmpty = false;
+    QString mEmptyText;
+    QIcon mEmptyIcon;
     bool mShowCrs = false;
     QStringList mAdditionalItems;
 };

diff --git a/src/gui/qgsmaplayercombobox.cpp b/src/gui/qgsmaplayercombobox.cpp
@@ -44,9 +44,9 @@ QStringList QgsMapLayerComboBox::excludedProviders() const
   return mProxyModel->excludedProviders();
 }
 
-void QgsMapLayerComboBox::setAllowEmptyLayer( bool allowEmpty )
+void QgsMapLayerComboBox::setAllowEmptyLayer( bool allowEmpty, const QString &text, const QIcon &icon )
 {
-  mProxyModel->sourceLayerModel()->setAllowEmptyLayer( allowEmpty );
+  mProxyModel->sourceLayerModel()->setAllowEmptyLayer( allowEmpty, text, icon );
 }
 
 bool QgsMapLayerComboBox::allowEmptyLayer() const

diff --git a/src/gui/qgsmaplayercombobox.h b/src/gui/qgsmaplayercombobox.h
@@ -75,10 +75,13 @@ class GUI_EXPORT QgsMapLayerComboBox : public QComboBox
 
     /**
      * Sets whether an optional empty layer ("not set") option is shown in the combo box.
+     *
+     * Since QGIS 3.20, the optional \a text and \a icon arguments allows the text and icon for the empty layer item to be set.
+     *
      * \see allowEmptyLayer()
      * \since QGIS 3.0
      */
-    void setAllowEmptyLayer( bool allowEmpty );
+    void setAllowEmptyLayer( bool allowEmpty, const QString &text = QString(), const QIcon &icon = QIcon() );
 
     /**
      * Returns TRUE if the combo box allows the empty layer ("not set") choice.

diff --git a/tests/src/python/test_qgsmaplayermodel.py b/tests/src/python/test_qgsmaplayermodel.py
@@ -12,7 +12,7 @@
 
 import qgis  # NOQA
 
-from qgis.core import QgsVectorLayer, QgsProject, QgsMapLayerModel
+from qgis.core import QgsVectorLayer, QgsProject, QgsMapLayerModel, QgsApplication
 from qgis.PyQt.QtCore import Qt, QModelIndex
 
 from qgis.testing import start_app, unittest
@@ -125,6 +125,12 @@ def testAllowEmpty(self):
         self.assertEqual(m.data(m.index(2, 0), Qt.DisplayRole), 'l2')
         self.assertEqual(m.data(m.index(3, 0), Qt.DisplayRole), 'l3')
 
+        self.assertIsNone(m.data(m.index(0, 0), Qt.DecorationRole))
+        # set icon and text for empty item
+        m.setAllowEmptyLayer(True, 'empty', QgsApplication.getThemeIcon('/mItemBookmark.svg'))
+        self.assertEqual(m.data(m.index(0, 0), Qt.DisplayRole), 'empty')
+        self.assertFalse(m.data(m.index(0, 0), Qt.DecorationRole).isNull())
+
         QgsProject.instance().removeMapLayers([l1.id(), l2.id(), l3.id()])
 
     def testAdditionalItems(self):