[FEATURE] Add undo and redo on transaction groups (#4765)

* [FEATURE] adds undo/redo for transaction groups

[needs-docs] the undo/redo now works with transcation groups. Just check
that there is no restriction in the transaction groups doc concerning
undo.

related to #14799

The undo/redo is implemented using SAVEPOINT.

The QgsTransaction interface has been enlarged to allow savepoints
creation and management. The savepoint is destroyed on
rollbackToSavepoint to have the same behavior has the sql ROLLBACK TO
SAVEPPOINT.

To avoid the creation of a savepoint for each feature modified in bulk
editing (e.g. paste, field calculator) the logic is a bit complicated: the
savepoint is created on QgsVectorLayer::editCommandStarted and the first
actual undo command (QgsVectorLayerUndoPassthroughCommand) is
responsible for the re-creation of the savepoint in case of undo-redo.
Since the behavior must be different in case edition doesn't take place
inside an edit command, a member function has been added to
QgsVectorLayer to expose the mEditCommandActive state.

Another (commented) tricky bit is the modification of the database
structure on add/delete attributes. On undo, the attribute is removed
before the rollback to savepoint, i.e. there is a useless ALTER TABLE
issued to restore the structure just before restoring it with the
ROLLBACK TO SAVEPOINT. This is necessary to make the provider
aware of the change of structure. It could be nicer/cleaner to have a way
to reload providers metadata.

The editPaste function has also been modified to use addFeatures instead of
addFeature (plural/singular), this is at the expense of an additional "cpy"
of the clipboard in memory, but it should improve perf with postgis provider.

* fixup operator aliases

python/core/core_auto.sip

@@ -120,6 +120,7 @@
 %Include qgsvectorlayerjoininfo.sip
 %Include qgsvectorlayerlabeling.sip
 %Include qgsvectorlayerundocommand.sip
+%Include qgsvectorlayerundopassthroughcommand.sip
 %Include qgsvectorlayerutils.sip
 %Include qgsvectorsimplifymethod.sip
 %Include qgsvirtuallayerdefinition.sip

python/core/qgstransaction.sip

@@ -110,6 +110,50 @@ class QgsTransaction : QObject /Abstract/
  :rtype: bool
 %End
 
+    QString createSavepoint( QString &error /Out/ );
+%Docstring
+ creates a save point
+ returns empty string on error
+ returns the last created savepoint if it's not dirty
+.. versionadded:: 3.0
+ :rtype: str
+%End
+
+    QString createSavepoint( const QString &savePointId, QString &error /Out/ );
+%Docstring
+ creates a save point
+ returns empty string on error
+.. versionadded:: 3.0
+ :rtype: str
+%End
+
+    bool rollbackToSavepoint( const QString &name, QString &error /Out/ );
+%Docstring
+ rollback to save point, the save point is maintained and is "undertied"
+.. versionadded:: 3.0
+ :rtype: bool
+%End
+
+    void dirtyLastSavePoint();
+%Docstring
+ dirty save point such that next call to createSavepoint will create a new one
+.. versionadded:: 3.0
+%End
+
+    QList< QString > savePoints() const;
+%Docstring
+ returns savepoints
+.. versionadded:: 3.0
+ :rtype: list of str
+%End
+
+    bool lastSavePointIsDirty() const;
+%Docstring
+ returns the last created savepoint
+.. versionadded:: 3.0
+ :rtype: bool
+%End
+
   signals:
 
     void afterRollback();

python/core/qgsvectorlayer.sip

@@ -1804,6 +1804,14 @@ Returns the current blending mode for features
  :rtype: bool
 %End
 
+    bool isEditCommandActive() const;
+%Docstring
+ Test if an edit command is active
+
+.. versionadded:: 3.0
+ :rtype: bool
+%End
+
   signals:
 
     void selectionChanged( const QgsFeatureIds &selected, const QgsFeatureIds &deselected, const bool clearAndSelect );

python/core/qgsvectorlayereditbuffer.sip

@@ -289,6 +289,7 @@ Updates an index in an attribute map to a new value (for updates of changed attr
 
 
 
+
 };
 
 /************************************************************************

python/core/qgsvectorlayerundocommand.sip

@@ -221,7 +221,6 @@ class QgsVectorLayerUndoCommandRenameAttribute : QgsVectorLayerUndoCommand
 
 };
 
-
 /************************************************************************
  * This file has been generated automatically from                      *
  *                                                                      *

python/core/qgsvectorlayerundopassthroughcommand.sip

@@ -0,0 +1,255 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsvectorlayerundopassthroughcommand.h                      *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+
+
+class QgsVectorLayerUndoPassthroughCommand : QgsVectorLayerUndoCommand
+{
+%Docstring
+ Undo command for vector layer in transaction group mode.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsvectorlayerundopassthroughcommand.h"
+%End
+  public:
+
+    QgsVectorLayerUndoPassthroughCommand( QgsVectorLayerEditBuffer *buffer, const QString &text );
+%Docstring
+ Constructor for QgsVectorLayerUndoPassthroughCommand
+ \param buffer associated edit buffer
+ \param text text associated with command
+%End
+
+    bool hasError() const;
+%Docstring
+ Returns error status
+ :rtype: bool
+%End
+
+  protected:
+
+    bool rollBackToSavePoint();
+%Docstring
+ Rollback command, release savepoint or set error status
+ save point must be set prior to call
+ error satus should be false prior to call
+ :rtype: bool
+%End
+
+    bool setSavePoint();
+%Docstring
+ Set the command savepoint or set error status
+ error satus should be false prior to call
+ :rtype: bool
+%End
+
+    void setError();
+%Docstring
+ Set error flag and append "failed" to text
+%End
+
+};
+
+
+class QgsVectorLayerUndoPassthroughCommandAddFeatures : QgsVectorLayerUndoPassthroughCommand
+{
+%Docstring
+ Undo command for adding a feature to a vector layer in transaction group mode.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsvectorlayerundopassthroughcommand.h"
+%End
+  public:
+
+    QgsVectorLayerUndoPassthroughCommandAddFeatures( QgsVectorLayerEditBuffer *buffer /Transfer/, QgsFeatureList &features );
+%Docstring
+ Constructor for QgsVectorLayerUndoPassthroughCommandAddFeatures
+ \param buffer associated edit buffer
+ \param features features to add to layer
+%End
+
+    virtual void undo();
+    virtual void redo();
+
+    QgsFeatureList features() const;
+%Docstring
+ List of features (added feaures can be modified by default values from database)
+ :rtype: QgsFeatureList
+%End
+
+};
+
+
+
+class QgsVectorLayerUndoPassthroughCommandDeleteFeatures : QgsVectorLayerUndoPassthroughCommand
+{
+%Docstring
+ Undo command for deleting features from a vector layer in transaction group.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsvectorlayerundopassthroughcommand.h"
+%End
+  public:
+
+    QgsVectorLayerUndoPassthroughCommandDeleteFeatures( QgsVectorLayerEditBuffer *buffer /Transfer/, const QgsFeatureIds &fids );
+%Docstring
+ Constructor for QgsVectorLayerUndoPassthroughCommandDeleteFeatures
+ \param buffer associated edit buffer
+ \param fids feature IDs of features to delete from layer
+%End
+
+    virtual void undo();
+    virtual void redo();
+
+};
+
+
+class QgsVectorLayerUndoPassthroughCommandChangeGeometry : QgsVectorLayerUndoPassthroughCommand
+{
+%Docstring
+ Undo command for changing feature geometry from a vector layer in transaction group.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsvectorlayerundopassthroughcommand.h"
+%End
+  public:
+
+    QgsVectorLayerUndoPassthroughCommandChangeGeometry( QgsVectorLayerEditBuffer *buffer /Transfer/, const QgsFeatureId &fid, const QgsGeometry &geom );
+%Docstring
+ Constructor for QgsVectorLayerUndoPassthroughCommandChangeGeometry
+ \param buffer associated edit buffer
+ \param fid feature ID of feature to change
+ \param geom new geometru
+%End
+
+    virtual void undo();
+    virtual void redo();
+
+};
+
+
+class QgsVectorLayerUndoPassthroughCommandChangeAttribute: QgsVectorLayerUndoPassthroughCommand
+{
+%Docstring
+ Undo command for changing attr value from a vector layer in transaction group.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsvectorlayerundopassthroughcommand.h"
+%End
+  public:
+
+    QgsVectorLayerUndoPassthroughCommandChangeAttribute( QgsVectorLayerEditBuffer *buffer /Transfer/, QgsFeatureId fid, int field, const QVariant &newValue );
+%Docstring
+ Constructor for QgsVectorLayerUndoPassthroughCommandChangeAttribute
+ \param buffer associated edit buffer
+ \param fid feature ID of feature
+ \param field
+ \param newValue
+%End
+
+    virtual void undo();
+    virtual void redo();
+
+};
+
+
+class QgsVectorLayerUndoPassthroughCommandAddAttribute : QgsVectorLayerUndoPassthroughCommand
+{
+%Docstring
+ Undo command for adding attri to a vector layer in transaction group.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsvectorlayerundopassthroughcommand.h"
+%End
+  public:
+
+    QgsVectorLayerUndoPassthroughCommandAddAttribute( QgsVectorLayerEditBuffer *buffer /Transfer/, const QgsField &field );
+%Docstring
+ Constructor for QgsVectorLayerUndoPassthroughCommandAddAttribute
+ \param buffer associated edit buffer
+ \param field
+%End
+
+    virtual void undo();
+    virtual void redo();
+
+};
+
+
+class QgsVectorLayerUndoPassthroughCommandDeleteAttribute : QgsVectorLayerUndoPassthroughCommand
+{
+%Docstring
+ Undo command for deleting attri of a vector layer in transaction group.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsvectorlayerundopassthroughcommand.h"
+%End
+  public:
+
+    QgsVectorLayerUndoPassthroughCommandDeleteAttribute( QgsVectorLayerEditBuffer *buffer /Transfer/, int attr );
+%Docstring
+ Constructor for QgsVectorLayerUndoCommandDeleteAttribute
+ \param buffer associated edit buffer
+ \param attr
+%End
+
+    virtual void undo();
+    virtual void redo();
+
+};
+
+
+class QgsVectorLayerUndoPassthroughCommandRenameAttribute : QgsVectorLayerUndoPassthroughCommand
+{
+%Docstring
+ Undo command for deleting attri of a vector layer in transaction group.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgsvectorlayerundopassthroughcommand.h"
+%End
+  public:
+
+    QgsVectorLayerUndoPassthroughCommandRenameAttribute( QgsVectorLayerEditBuffer *buffer /Transfer/, int attr, const QString &newName );
+%Docstring
+ Constructor for QgsVectorLayerUndoCommandRenameAttribute
+ \param buffer associated edit buffer
+ \param attr
+ \param newName
+%End
+
+    virtual void undo();
+    virtual void redo();
+
+};
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/qgsvectorlayerundopassthroughcommand.h                      *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/

src/app/qgisapp.cpp

@@ -7862,8 +7862,8 @@ void QgisApp::editPaste( QgsMapLayer *destinationLayer )
 
   QgsExpressionContext context = pasteVectorLayer->createExpressionContext();
 
-  QgsFeatureIds newIds;
 
+  QgsFeatureList newFeatures;
   QgsFeatureList::const_iterator featureIt = features.constBegin();
   while ( featureIt != features.constEnd() )
   {
@@ -7907,13 +7907,18 @@ void QgisApp::editPaste( QgsMapLayer *destinationLayer )
 
     // now create new feature using pasted feature as a template. This automatically handles default
     // values and field constraints
-    QgsFeature newFeature = QgsVectorLayerUtils::createFeature( pasteVectorLayer, geom, dstAttr, &context );
-    pasteVectorLayer->addFeature( newFeature );
-    newIds << newFeature.id();
-
+    newFeatures << QgsVectorLayerUtils::createFeature( pasteVectorLayer, geom, dstAttr, &context );
     ++featureIt;
   }
 
+  pasteVectorLayer->addFeatures( newFeatures );
+  QgsFeatureIds newIds;
+  for ( const QgsFeature &f : qgsAsConst( newFeatures ) )
+  {
+    newIds << f.id();
+  }
+
+
   pasteVectorLayer->selectByIds( newIds );
   pasteVectorLayer->endEditCommand();
   pasteVectorLayer->updateExtents();

src/core/CMakeLists.txt

@@ -301,6 +301,7 @@ SET(QGIS_CORE_SRCS
   qgsvectorlayerrenderer.cpp
   qgsvectorlayertools.cpp
   qgsvectorlayerundocommand.cpp
+  qgsvectorlayerundopassthroughcommand.cpp
   qgsvectorlayerutils.cpp
   qgsvectorsimplifymethod.cpp
   qgsvirtuallayerdefinition.cpp
@@ -906,6 +907,7 @@ SET(QGIS_CORE_HDRS
   qgsvectorlayerlabeling.h
   qgsvectorlayerrenderer.h
   qgsvectorlayerundocommand.h
+  qgsvectorlayerundopassthroughcommand.h
   qgsvectorlayerutils.h
   qgsvectorsimplifymethod.h
   qgsvirtuallayerdefinition.h