Change canCommitChanges to allowCommit flag

qgis · Sep 26, 2018 · cda4950 · cda4950
1 parent d2bb3d6
commit cda4950
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Showing 3 changed files with 106 additions and 6 deletions.
diff --git a/python/core/auto_generated/qgsvectorlayer.sip.in b/python/core/auto_generated/qgsvectorlayer.sip.in
@@ -2236,6 +2236,44 @@ Test if an edit command is active
 %Docstring
 Configuration and logic to apply automatically on any edit happening on this layer.
 
+.. versionadded:: 3.4
+%End
+
+    bool allowCommit()() const;
+%Docstring
+Controls, if the layer is allowed to commit changes. If this is set to false
+it will not be possible to commit changes on this layer. This can be used to
+define checks on a layer that need to be pass before the layer can be saved.
+If you use this API, make sure that:
+
+- the user is visibly informed that his changes were not saved and what he needs
+to do in order to be able to save the changes.
+
+- to set the property back to true, once the user has fixed his data.
+
+When calling :py:func:`commitChanges`, this flag is checked just after the
+
+.. seealso:: :py:func:`beforeCommitChanges`
+
+.. versionadded:: 3.4
+%End
+
+    void setAllowCommit()( bool allowCommit() );
+%Docstring
+Controls, if the layer is allowed to commit changes. If this is set to false
+it will not be possible to commit changes on this layer. This can be used to
+define checks on a layer that need to be pass before the layer can be saved.
+If you use this API, make sure that:
+
+- the user is visibly informed that his changes were not saved and what he needs
+to do in order to be able to save the changes.
+
+- to set the property back to true, once the user has fixed his data.
+
+When calling :py:func:`commitChanges`, this flag is checked just after the
+
+.. seealso:: :py:func:`beforeCommitChanges`
+
 .. versionadded:: 3.4
 %End
 
@@ -2332,6 +2370,13 @@ This signal is emitted when selection was changed
     void layerModified();
 %Docstring
 This signal is emitted when modifications has been done on layer
+%End
+
+    void allowCommitChanged();
+%Docstring
+Emitted whenever the allowCommitChanged() property of this layer changes.
+
+.. versionadded:: 3.4
 %End
 
     void beforeModifiedCheck() const;

diff --git a/src/core/qgsvectorlayer.cpp b/src/core/qgsvectorlayer.cpp
@@ -2924,15 +2924,11 @@ bool QgsVectorLayer::commitChanges()
     return false;
   }
 
-  bool canCommit = true;
-
-  emit canCommitChanges( &canCommit );
+  emit beforeCommitChanges();
 
-  if ( !canCommit )
+  if ( !mAllowCommit )
     return false;
 
-  emit beforeCommitChanges();
-
   bool success = mEditBuffer->commitChanges( mCommitErrors );
 
   if ( success )
@@ -4853,6 +4849,20 @@ QgsAbstractVectorLayerLabeling *QgsVectorLayer::readLabelingFromCustomProperties
   return labeling;
 }
 
+bool QgsVectorLayer::allowCommit() const
+{
+  return mAllowCommit;
+}
+
+void QgsVectorLayer::setAllowCommit( bool allowCommit )
+{
+  if ( mAllowCommit == allowCommit )
+    return;
+
+  mAllowCommit = allowCommit;
+  emit allowCommitChanged();
+}
+
 QgsGeometryOptions *QgsVectorLayer::geometryOptions() const
 {
   return mGeometryOptions.get();

diff --git a/src/core/qgsvectorlayer.h b/src/core/qgsvectorlayer.h
@@ -2010,6 +2010,42 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer, public QgsExpressionConte
      */
     QgsGeometryOptions *geometryOptions() const;
 
+    /**
+     * Controls, if the layer is allowed to commit changes. If this is set to false
+     * it will not be possible to commit changes on this layer. This can be used to
+     * define checks on a layer that need to be pass before the layer can be saved.
+     * If you use this API, make sure that:
+     *
+     *  - the user is visibly informed that his changes were not saved and what he needs
+     *    to do in order to be able to save the changes.
+     *
+     *  - to set the property back to true, once the user has fixed his data.
+     *
+     * When calling \see commitChanges(), this flag is checked just after the
+     * \see beforeCommitChanges() signal is emitted, so it's possible to adjust it from there.
+     *
+     * \since QGIS 3.4
+     */
+    bool allowCommit()() const;
+
+    /**
+     * Controls, if the layer is allowed to commit changes. If this is set to false
+     * it will not be possible to commit changes on this layer. This can be used to
+     * define checks on a layer that need to be pass before the layer can be saved.
+     * If you use this API, make sure that:
+     *
+     *  - the user is visibly informed that his changes were not saved and what he needs
+     *    to do in order to be able to save the changes.
+     *
+     *  - to set the property back to true, once the user has fixed his data.
+     *
+     * When calling \see commitChanges(), this flag is checked just after the
+     * \see beforeCommitChanges() signal is emitted, so it's possible to adjust it from there.
+     *
+     * \since QGIS 3.4
+     */
+    void setAllowCommit()( bool allowCommit() );
+
   public slots:
 
     /**
@@ -2102,6 +2138,13 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer, public QgsExpressionConte
     //! This signal is emitted when modifications has been done on layer
     void layerModified();
 
+    /**
+     * Emitted whenever the allowCommitChanged() property of this layer changes.
+     *
+     * \since QGIS 3.4
+     */
+    void allowCommitChanged();
+
     //! Is emitted, when layer is checked for modifications. Use for last-minute additions
     void beforeModifiedCheck() const;
 
@@ -2512,6 +2555,8 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer, public QgsExpressionConte
 
     std::unique_ptr<QgsGeometryOptions> mGeometryOptions;
 
+    bool mAllowCommit = true;
+
     friend class QgsVectorLayerFeatureSource;
 };