Start work on undo/redo support for layouts

python/core/core_auto.sip

@@ -156,13 +156,16 @@
 %Include composer/qgspaperitem.sip
 %Include layout/qgslayoutcontext.sip
 %Include layout/qgslayoutgridsettings.sip
+%Include layout/qgslayoutitemundocommand.sip
 %Include layout/qgslayoutmeasurement.sip
 %Include layout/qgslayoutmeasurementconverter.sip
 %Include layout/qgspagesizeregistry.sip
 %Include layout/qgslayoutpoint.sip
 %Include layout/qgslayoutserializableobject.sip
 %Include layout/qgslayoutsize.sip
 %Include layout/qgslayoutsnapper.sip
+%Include layout/qgslayoutundocommand.sip
+%Include layout/qgslayoutundostack.sip
 %Include layout/qgslayoututils.sip
 %Include metadata/qgslayermetadata.sip
 %Include metadata/qgslayermetadatavalidator.sip

python/core/layout/qgslayout.sip

@@ -8,7 +8,7 @@
 
 
 
-class QgsLayout : QGraphicsScene, QgsExpressionContextGenerator
+class QgsLayout : QGraphicsScene, QgsExpressionContextGenerator, QgsLayoutUndoObjectInterface
 {
 %Docstring
  Base class for layouts, which can contain items such as maps, labels, scalebars, etc.
@@ -269,6 +269,17 @@ class QgsLayout : QGraphicsScene, QgsExpressionContextGenerator
  :rtype: bool
 %End
 
+    QgsLayoutUndoStack *undoStack();
+%Docstring
+ Returns a pointer to the layout's undo stack, which manages undo/redo states for the layout
+ and it's associated objects.
+ :rtype: QgsLayoutUndoStack
+%End
+
+
+    virtual QgsAbstractLayoutUndoCommand *createCommand( const QString &text, int id = 0, QUndoCommand *parent = 0 ) /Factory/;
+
+
 
   public slots:
 

python/core/layout/qgslayoutitem.sip

@@ -9,7 +9,7 @@
 
 
 
-class QgsLayoutItem : QgsLayoutObject, QGraphicsRectItem
+class QgsLayoutItem : QgsLayoutObject, QGraphicsRectItem, QgsLayoutUndoObjectInterface
 {
 %Docstring
  Base class for graphical items within a QgsLayout.
@@ -219,6 +219,9 @@ class QgsLayoutItem : QgsLayoutObject, QGraphicsRectItem
  :rtype: bool
 %End
 
+    virtual QgsAbstractLayoutUndoCommand *createCommand( const QString &text, int id, QUndoCommand *parent = 0 ) /Factory/;
+
+
   public slots:
 
     virtual void refresh();

python/core/layout/qgslayoutitempage.sip

@@ -90,6 +90,9 @@ class QgsLayoutItemPage : QgsLayoutItem
     virtual void attemptResize( const QgsLayoutSize &size );
 
 
+    virtual QgsAbstractLayoutUndoCommand *createCommand( const QString &text, int id, QUndoCommand *parent = 0 ) /Factory/;
+
+
   public slots:
 
     virtual void redraw();

python/core/layout/qgslayoutitemundocommand.sip

@@ -0,0 +1,83 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/layout/qgslayoutitemundocommand.h                           *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+
+class QgsLayoutItemUndoCommand: QgsAbstractLayoutUndoCommand
+{
+%Docstring
+*************************************************************************
+                                                                         *
+   This program is free software; you can redistribute it and/or modify  *
+   it under the terms of the GNU General Public License as published by  *
+   the Free Software Foundation; either version 2 of the License, or     *
+   (at your option) any later version.                                   *
+                                                                         *
+**************************************************************************
+%End
+
+%TypeHeaderCode
+#include "qgslayoutitemundocommand.h"
+%End
+  public:
+
+    QgsLayoutItemUndoCommand( QgsLayoutItem *item, const QString &text, int id = 0, QUndoCommand *parent /TransferThis/ = 0 );
+
+    virtual bool mergeWith( const QUndoCommand *command );
+
+
+    QgsLayout *layout() const;
+%Docstring
+ :rtype: QgsLayout
+%End
+
+    QString itemUuid() const;
+%Docstring
+ :rtype: str
+%End
+
+  protected:
+
+    virtual void saveState( QDomDocument &stateDoc ) const;
+
+    virtual void restoreState( QDomDocument &stateDoc );
+
+
+    virtual QgsLayoutItem *recreateItem( int itemType, QgsLayout *layout ) /Factory/;
+%Docstring
+ :rtype: QgsLayoutItem
+%End
+
+};
+
+class QgsLayoutItemDeleteUndoCommand: QgsLayoutItemUndoCommand
+{
+
+%TypeHeaderCode
+#include "qgslayoutitemundocommand.h"
+%End
+  public:
+
+    QgsLayoutItemDeleteUndoCommand( QgsLayoutItem *item, const QString &text, int id = 0, QUndoCommand *parent /TransferThis/ = 0 );
+    virtual bool mergeWith( const QUndoCommand *command );
+
+    virtual void redo();
+
+
+};
+
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/layout/qgslayoutitemundocommand.h                           *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/

python/core/layout/qgslayoutserializableobject.sip

@@ -10,7 +10,7 @@
 
 
 
-class QgsLayoutSerializableObject
+class QgsLayoutSerializableObject : QgsLayoutUndoObjectInterface
 {
 %Docstring
  An interface for layout objects which can be stored and read from DOM elements.
@@ -52,6 +52,9 @@ class QgsLayoutSerializableObject
  :rtype: bool
 %End
 
+    virtual QgsAbstractLayoutUndoCommand *createCommand( const QString &text, int id, QUndoCommand *parent = 0 ) /Factory/;
+
+
 };
 
 /************************************************************************

python/core/layout/qgslayoutundocommand.sip

@@ -0,0 +1,132 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/layout/qgslayoutundocommand.h                               *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+
+
+class QgsAbstractLayoutUndoCommand: QUndoCommand
+{
+%Docstring
+ Base class for commands to undo/redo layout and layout object changes.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgslayoutundocommand.h"
+%End
+  public:
+
+    QgsAbstractLayoutUndoCommand( const QString &text, int id = 0, QUndoCommand *parent /TransferThis/ = 0 );
+%Docstring
+ Constructor for QgsLayoutUndoCommand.
+ The ``id`` argument can be used to specify an id number for the source event - this is used to determine whether QUndoCommand
+ command compression can apply to the command.
+%End
+
+    virtual void undo();
+
+    virtual void redo();
+
+    virtual int id() const;
+
+    void saveBeforeState();
+%Docstring
+ Saves current layout state as before state.
+.. seealso:: beforeState()
+.. seealso:: saveAfterState()
+%End
+
+    void saveAfterState();
+%Docstring
+ Saves current layout state as after state.
+.. seealso:: afterState()
+.. seealso:: saveBeforeState()
+%End
+
+    QDomDocument beforeState() const;
+%Docstring
+ Returns the before state for the layout.
+.. seealso:: saveBeforeState()
+.. seealso:: afterState()
+ :rtype: QDomDocument
+%End
+
+    QDomDocument afterState() const;
+%Docstring
+ Returns the after state for the layout.
+.. seealso:: saveAfterState()
+.. seealso:: beforeState()
+ :rtype: QDomDocument
+%End
+
+    virtual bool containsChange() const;
+%Docstring
+ Returns true if both the before and after states are valid and different.
+ :rtype: bool
+%End
+
+  protected:
+
+    virtual void saveState( QDomDocument &stateDoc ) const = 0;
+%Docstring
+ Saves the state of the object to the specified ``stateDoc``.
+
+ Subclasses must implement this to handle encapsulating their current state into a DOM document.
+
+.. seealso:: restoreState()
+%End
+
+    virtual void restoreState( QDomDocument &stateDoc ) = 0;
+%Docstring
+ Restores the state of the object from the specified ``stateDoc``.
+
+ Subclasses must implement this to handle restoring their current state from the encapsulated state.
+
+.. seealso:: saveState()
+%End
+
+    void setAfterState( const QDomDocument &stateDoc );
+%Docstring
+ Manually sets the after state for the command. Generally this should not be called directly.
+%End
+
+
+};
+
+class QgsLayoutUndoObjectInterface
+{
+%Docstring
+ Interface for layout objects which support undo/redo commands.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgslayoutundocommand.h"
+%End
+  public:
+
+    virtual QgsAbstractLayoutUndoCommand *createCommand( const QString &text, int id = 0, QUndoCommand *parent = 0 ) = 0 /Factory/;
+%Docstring
+ Creates a new layout undo command with the specified ``text`` and ``parent``.
+
+ The ``id`` argument can be used to specify an id number for the source event - this is used to determine whether QUndoCommand
+ command compression can apply to the command.
+ :rtype: QgsAbstractLayoutUndoCommand
+%End
+};
+
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/layout/qgslayoutundocommand.h                               *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/

python/core/layout/qgslayoutundostack.sip

@@ -0,0 +1,78 @@
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/layout/qgslayoutundostack.h                                 *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/
+
+
+
+
+
+class QgsLayoutUndoStack
+{
+%Docstring
+ An undo stack for QgsLayouts.
+.. versionadded:: 3.0
+%End
+
+%TypeHeaderCode
+#include "qgslayoutundostack.h"
+%End
+  public:
+
+    QgsLayoutUndoStack( QgsLayout *layout );
+%Docstring
+ Constructor for QgsLayoutUndoStack, for the specified parent ``layout``.
+%End
+
+    void beginMacro( const QString &commandText );
+
+    void endMacro();
+
+    void beginCommand( QgsLayoutUndoObjectInterface *object, const QString &commandText, int id = 0 );
+%Docstring
+ Begins a new undo command for the specified ``object``.
+
+ This must be followed by a call to endCommand() or cancelCommand() after the desired changes
+ have been made to ``object``.
+
+ The ``id`` argument can be used to specify an id number for the source event - this is used to determine whether QUndoCommand
+ command compression can apply to the command.
+
+.. seealso:: endCommand()
+.. seealso:: cancelCommand()
+%End
+
+    void endCommand();
+%Docstring
+ Saves final state of an object and pushes the active command to the undo history.
+.. seealso:: beginCommand()
+.. seealso:: cancelCommand()
+%End
+
+    void cancelCommand();
+%Docstring
+ Cancels the active command, discarding it without pushing to the undo history.
+.. seealso:: endCommand()
+.. seealso:: cancelCommand()
+%End
+
+    QUndoStack *stack();
+%Docstring
+ Returns a pointer to the internal QUndoStack.
+ :rtype: QUndoStack
+%End
+
+  private:
+    QgsLayoutUndoStack( const QgsLayoutUndoStack &other );
+};
+
+/************************************************************************
+ * This file has been generated automatically from                      *
+ *                                                                      *
+ * src/core/layout/qgslayoutundostack.h                                 *
+ *                                                                      *
+ * Do not edit manually ! Edit header and run scripts/sipify.pl again   *
+ ************************************************************************/