Hook up snapping for QgsLayoutViewTools

Tools can now indicate (via setFlags()) if they desire snapping to be active for the tool. When a tool has the flag set, any QgsLayoutViewMouseEvents it receives will have a snappedPoint() available which returns the mouse event point snapped using the layout's snapping settings.
qgis · Aug 7, 2017 · f57212e · f57212e
1 parent 5be237f
commit f57212e
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Showing 8 changed files with 116 additions and 16 deletions.
diff --git a/python/gui/layout/qgslayoutviewmouseevent.sip b/python/gui/layout/qgslayoutviewmouseevent.sip
@@ -32,12 +32,12 @@ class QgsLayoutViewMouseEvent : QMouseEvent
 %End
   public:
 
-    QgsLayoutViewMouseEvent( QgsLayoutView *view, QMouseEvent *event );
+    QgsLayoutViewMouseEvent( QgsLayoutView *view, QMouseEvent *event, bool snap = false );
 %Docstring
  Constructor for QgsLayoutViewMouseEvent. Should only be required to be called from the QgsLayoutView.
-
  \param view The view in which the event occurred.
  \param event The original mouse event
+ \param snap set to true to snap the point using the layout's snapping settings
 %End
 
     QPointF layoutPoint() const;
@@ -47,6 +47,22 @@ class QgsLayoutViewMouseEvent : QMouseEvent
  :rtype: QPointF
 %End
 
+    QPointF snappedPoint() const;
+%Docstring
+ Returns the snapped event point location in layout coordinates. The snapped point will consider
+ all possible snapping methods, such as snapping to grid or guide lines.
+.. seealso:: isSnapped()
+.. seealso:: pos()
+ :rtype: QPointF
+%End
+
+    bool isSnapped() const;
+%Docstring
+ Returns true if point was snapped, e.g. to grid or guide lines.
+.. seealso:: snappedPoint()
+ :rtype: bool
+%End
+
 };
 
 /************************************************************************

diff --git a/python/gui/layout/qgslayoutviewtool.sip b/python/gui/layout/qgslayoutviewtool.sip
@@ -34,8 +34,22 @@ class QgsLayoutViewTool : QObject
 %End
   public:
 
+    enum Flag
+    {
+      FlagSnaps,
+    };
+    typedef QFlags<QgsLayoutViewTool::Flag> Flags;
+
+
     virtual ~QgsLayoutViewTool();
 
+    QgsLayoutViewTool::Flags flags() const;
+%Docstring
+ Returns the current combination of flags set for the tool.
+.. seealso:: setFlags()
+ :rtype: QgsLayoutViewTool.Flags
+%End
+
     virtual void layoutMoveEvent( QgsLayoutViewMouseEvent *event );
 %Docstring
  Mouse move event for overriding. Default implementation does nothing.
@@ -147,6 +161,12 @@ class QgsLayoutViewTool : QObject
 
   protected:
 
+    void setFlags( const QgsLayoutViewTool::Flags flags );
+%Docstring
+ Sets the combination of ``flags`` that will be used for the tool.
+.. seealso:: flags()
+%End
+
     QgsLayoutViewTool( QgsLayoutView *view /TransferThis/, const QString &name );
 %Docstring
  Constructor for QgsLayoutViewTool, taking a layout ``view`` and

diff --git a/src/gui/layout/qgslayoutview.cpp b/src/gui/layout/qgslayoutview.cpp
@@ -209,7 +209,7 @@ void QgsLayoutView::mousePressEvent( QMouseEvent *event )
 {
   if ( mTool )
   {
-    std::unique_ptr<QgsLayoutViewMouseEvent> me( new QgsLayoutViewMouseEvent( this, event ) );
+    std::unique_ptr<QgsLayoutViewMouseEvent> me( new QgsLayoutViewMouseEvent( this, event, mTool->flags() & QgsLayoutViewTool::FlagSnaps ) );
     mTool->layoutPressEvent( me.get() );
     event->setAccepted( me->isAccepted() );
   }
@@ -246,7 +246,7 @@ void QgsLayoutView::mouseReleaseEvent( QMouseEvent *event )
 {
   if ( mTool )
   {
-    std::unique_ptr<QgsLayoutViewMouseEvent> me( new QgsLayoutViewMouseEvent( this, event ) );
+    std::unique_ptr<QgsLayoutViewMouseEvent> me( new QgsLayoutViewMouseEvent( this, event, mTool->flags() & QgsLayoutViewTool::FlagSnaps ) );
     mTool->layoutReleaseEvent( me.get() );
     event->setAccepted( me->isAccepted() );
   }
@@ -264,7 +264,12 @@ void QgsLayoutView::mouseMoveEvent( QMouseEvent *event )
 
   if ( mTool )
   {
-    std::unique_ptr<QgsLayoutViewMouseEvent> me( new QgsLayoutViewMouseEvent( this, event ) );
+    if ( !event->buttons() && mTool->flags() & QgsLayoutViewTool::FlagSnaps )
+    {
+      //draw snapping point indicator
+
+    }
+    std::unique_ptr<QgsLayoutViewMouseEvent> me( new QgsLayoutViewMouseEvent( this, event, mTool->flags() & QgsLayoutViewTool::FlagSnaps ) );
     mTool->layoutMoveEvent( me.get() );
     event->setAccepted( me->isAccepted() );
   }
@@ -277,7 +282,7 @@ void QgsLayoutView::mouseDoubleClickEvent( QMouseEvent *event )
 {
   if ( mTool )
   {
-    std::unique_ptr<QgsLayoutViewMouseEvent> me( new QgsLayoutViewMouseEvent( this, event ) );
+    std::unique_ptr<QgsLayoutViewMouseEvent> me( new QgsLayoutViewMouseEvent( this, event, mTool->flags() & QgsLayoutViewTool::FlagSnaps ) );
     mTool->layoutDoubleClickEvent( me.get() );
     event->setAccepted( me->isAccepted() );
   }

diff --git a/src/gui/layout/qgslayoutviewmouseevent.cpp b/src/gui/layout/qgslayoutviewmouseevent.cpp
@@ -16,16 +16,24 @@
 
 #include "qgslayoutviewmouseevent.h"
 #include "qgslayoutview.h"
+#include "qgslayout.h"
 
-
-QgsLayoutViewMouseEvent::QgsLayoutViewMouseEvent( QgsLayoutView *view, QMouseEvent *event )
+QgsLayoutViewMouseEvent::QgsLayoutViewMouseEvent( QgsLayoutView *view, QMouseEvent *event, bool snap )
   : QMouseEvent( event->type(), event->pos(), event->button(), event->buttons(), event->modifiers() )
   , mView( view )
 {
-
+  mLayoutPoint = mView->mapToScene( x(), y() );
+  if ( snap && mView->currentLayout() )
+  {
+    mSnappedPoint = mView->currentLayout()->snapper().snapPoint( mLayoutPoint, mView->transform().m11(), mSnapped );
+  }
+  else
+  {
+    mSnappedPoint = mLayoutPoint;
+  }
 }
 
 QPointF QgsLayoutViewMouseEvent::layoutPoint() const
 {
-  return mView->mapToScene( x(), y() );
+  return mLayoutPoint;
 }
diff --git a/src/gui/layout/qgslayoutviewmouseevent.h b/src/gui/layout/qgslayoutviewmouseevent.h
@@ -46,23 +46,41 @@ class GUI_EXPORT QgsLayoutViewMouseEvent : public QMouseEvent
 
     /**
      * Constructor for QgsLayoutViewMouseEvent. Should only be required to be called from the QgsLayoutView.
-     *
      * \param view The view in which the event occurred.
      * \param event The original mouse event
+     * \param snap set to true to snap the point using the layout's snapping settings
      */
-    QgsLayoutViewMouseEvent( QgsLayoutView *view, QMouseEvent *event );
+    QgsLayoutViewMouseEvent( QgsLayoutView *view, QMouseEvent *event, bool snap = false );
 
     /**
      * Returns the event point location in layout coordinates.
      * \see pos()
      */
     QPointF layoutPoint() const;
 
+    /**
+     * Returns the snapped event point location in layout coordinates. The snapped point will consider
+     * all possible snapping methods, such as snapping to grid or guide lines.
+     * \see isSnapped()
+     * \see pos()
+     */
+    QPointF snappedPoint() const { return mSnappedPoint; }
+
+    /**
+     * Returns true if point was snapped, e.g. to grid or guide lines.
+     * \see snappedPoint()
+     */
+    bool isSnapped() const { return mSnapped; }
+
   private:
 
     //! The view in which the event was triggered.
     QgsLayoutView *mView = nullptr;
 
+    bool mSnapped = false;
+    QPointF mLayoutPoint;
+    QPointF mSnappedPoint;
+
 };
 
 #endif // QGSLAYOUTVIEWMOUSEEVENT_H
diff --git a/src/gui/layout/qgslayoutviewtool.cpp b/src/gui/layout/qgslayoutviewtool.cpp
@@ -20,6 +20,7 @@
 QgsLayoutViewTool::QgsLayoutViewTool( QgsLayoutView *view, const QString &name )
   : QObject( view )
   , mView( view )
+  , mFlags( 0 )
   , mCursor( Qt::ArrowCursor )
   , mToolName( name )
 {
@@ -52,6 +53,16 @@ QgsLayoutViewTool::~QgsLayoutViewTool()
   mView->unsetTool( this );
 }
 
+QgsLayoutViewTool::Flags QgsLayoutViewTool::flags() const
+{
+  return mFlags;
+}
+
+void QgsLayoutViewTool::setFlags( QgsLayoutViewTool::Flags flags )
+{
+  mFlags = flags;
+}
+
 void QgsLayoutViewTool::layoutMoveEvent( QgsLayoutViewMouseEvent *event )
 {
   event->ignore();

diff --git a/src/gui/layout/qgslayoutviewtool.h b/src/gui/layout/qgslayoutviewtool.h
@@ -58,8 +58,21 @@ class GUI_EXPORT QgsLayoutViewTool : public QObject
 
   public:
 
+    //! Flags for controlling how a tool behaves
+    enum Flag
+    {
+      FlagSnaps = 1 << 1,  //!< Tool utilizes snapped coordinates.
+    };
+    Q_DECLARE_FLAGS( Flags, Flag )
+
     virtual ~QgsLayoutViewTool();
 
+    /**
+     * Returns the current combination of flags set for the tool.
+     * \see setFlags()
+     */
+    QgsLayoutViewTool::Flags flags() const;
+
     /**
      * Mouse move event for overriding. Default implementation does nothing.
      */
@@ -167,6 +180,12 @@ class GUI_EXPORT QgsLayoutViewTool : public QObject
 
   protected:
 
+    /**
+     * Sets the combination of \a flags that will be used for the tool.
+     * \see flags()
+     */
+    void setFlags( const QgsLayoutViewTool::Flags flags );
+
     /**
      * Constructor for QgsLayoutViewTool, taking a layout \a view and
      * tool \a name as parameters.
@@ -186,6 +205,8 @@ class GUI_EXPORT QgsLayoutViewTool : public QObject
     //! Pointer to layout view.
     QgsLayoutView *mView = nullptr;
 
+    QgsLayoutViewTool::Flags mFlags;
+
     //! Cursor used by tool
     QCursor mCursor;
 

diff --git a/src/gui/layout/qgslayoutviewtooladditem.cpp b/src/gui/layout/qgslayoutviewtooladditem.cpp
@@ -34,6 +34,7 @@
 QgsLayoutViewToolAddItem::QgsLayoutViewToolAddItem( QgsLayoutView *view )
   : QgsLayoutViewTool( view, tr( "Add item" ) )
 {
+  setFlags( QgsLayoutViewTool::FlagSnaps );
   QPixmap crosshairQPixmap = QPixmap( ( const char ** )( cross_hair_cursor ) );
   setCursor( QCursor( crosshairQPixmap, 8, 8 ) );
 }
@@ -56,15 +57,15 @@ void QgsLayoutViewToolAddItem::layoutPressEvent( QgsLayoutViewMouseEvent *event
   mRubberBand.reset( QgsGui::layoutItemGuiRegistry()->createItemRubberBand( mItemType, view() ) );
   if ( mRubberBand )
   {
-    mRubberBand->start( event->layoutPoint(), event->modifiers() );
+    mRubberBand->start( event->snappedPoint(), event->modifiers() );
   }
 }
 
 void QgsLayoutViewToolAddItem::layoutMoveEvent( QgsLayoutViewMouseEvent *event )
 {
   if ( mDrawing && mRubberBand )
   {
-    mRubberBand->update( event->layoutPoint(), event->modifiers() );
+    mRubberBand->update( event->snappedPoint(), event->modifiers() );
   }
   else
   {
@@ -81,7 +82,7 @@ void QgsLayoutViewToolAddItem::layoutReleaseEvent( QgsLayoutViewMouseEvent *even
   }
   mDrawing = false;
 
-  QRectF rect = mRubberBand->finish( event->layoutPoint(), event->modifiers() );
+  QRectF rect = mRubberBand->finish( event->snappedPoint(), event->modifiers() );
 
   QgsLayoutItem *item = QgsApplication::layoutItemRegistry()->createItem( mItemType, layout() );
 
@@ -91,7 +92,7 @@ void QgsLayoutViewToolAddItem::layoutReleaseEvent( QgsLayoutViewMouseEvent *even
   {
     QgsLayoutItemPropertiesDialog dlg( view() );
     dlg.setLayout( layout() );
-    dlg.setItemPosition( QgsLayoutPoint( event->layoutPoint(), layout()->units() ) );
+    dlg.setItemPosition( QgsLayoutPoint( event->snappedPoint(), layout()->units() ) );
     if ( dlg.exec() )
     {
       item->setReferencePoint( dlg.referencePoint() );