Start porting mouse handles to layout

python/core/layout/qgslayout.sip

@@ -26,6 +26,7 @@ class QgsLayout : QGraphicsScene, QgsExpressionContextGenerator, QgsLayoutUndoOb
       ZItem,
       ZGrid,
       ZGuide,
+      ZMouseHandles,
       ZMapTool,
       ZSnapIndicator,
     };

src/core/layout/qgslayout.h

@@ -47,8 +47,9 @@ class CORE_EXPORT QgsLayout : public QGraphicsScene, public QgsExpressionContext
       ZItem = 1, //!< Minimum z value for items
       ZGrid = 9998, //!< Z-value for page grids
       ZGuide = 9999, //!< Z-value for page guides
-      ZMapTool = 10000, //!< Z-value for temporary map tool items
-      ZSnapIndicator = 10001, //!< Z-value for snapping indicator
+      ZMouseHandles = 10000, //!< Z-value for mouse handles
+      ZMapTool = 10001, //!< Z-value for temporary map tool items
+      ZSnapIndicator = 10002, //!< Z-value for snapping indicator
     };
 
     /**

src/gui/CMakeLists.txt

@@ -161,6 +161,7 @@ SET(QGIS_GUI_SRCS
 
   layout/qgslayoutitemguiregistry.cpp
   layout/qgslayoutitemwidget.cpp
+  layout/qgslayoutmousehandles.cpp
   layout/qgslayoutnewitempropertiesdialog.cpp
   layout/qgslayoutruler.cpp
   layout/qgslayoutunitscombobox.cpp
@@ -657,6 +658,7 @@ SET(QGIS_GUI_MOC_HDRS
   layout/qgslayoutdesignerinterface.h
   layout/qgslayoutitemguiregistry.h
   layout/qgslayoutitemwidget.h
+  layout/qgslayoutmousehandles.h
   layout/qgslayoutnewitempropertiesdialog.h
   layout/qgslayoutruler.h
   layout/qgslayoutunitscombobox.h

src/gui/layout/qgslayoutmousehandles.h

@@ -0,0 +1,203 @@
+/***************************************************************************
+                             qgslayoutmousehandles.h
+                             -----------------------
+    begin                : September 2017
+    copyright            : (C) 2017 by Nyall Dawson
+    email                : nyall.dawson@gmail.com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   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.                                   *
+ *                                                                         *
+ ***************************************************************************/
+#ifndef QGSLAYOUTMOUSEHANDLES_H
+#define QGSLAYOUTMOUSEHANDLES_H
+
+#define SIP_NO_FILE
+
+#include <QGraphicsRectItem>
+#include <QObject>
+#include <QPointer>
+
+#include "qgis_gui.h"
+
+class QgsLayout;
+class QGraphicsView;
+class QgsLayoutView;
+
+///@cond PRIVATE
+
+/**
+ * \ingroup gui
+ * Handles drawing of selection outlines and mouse handles in a QgsLayoutView
+ *
+ * Also is responsible for mouse interactions such as resizing and moving selected items.
+ *
+ * \note not available in Python bindings
+ * \since QGIS 3.0
+ *
+*/
+class GUI_EXPORT QgsLayoutMouseHandles: public QObject, public QGraphicsRectItem
+{
+    Q_OBJECT
+  public:
+
+    //! Describes the action (move or resize in different directon) to be done during mouse move
+    enum MouseAction
+    {
+      MoveItem,
+      ResizeUp,
+      ResizeDown,
+      ResizeLeft,
+      ResizeRight,
+      ResizeLeftUp,
+      ResizeRightUp,
+      ResizeLeftDown,
+      ResizeRightDown,
+      SelectItem,
+      NoAction
+    };
+
+    enum ItemPositionMode
+    {
+      UpperLeft,
+      UpperMiddle,
+      UpperRight,
+      MiddleLeft,
+      Middle,
+      MiddleRight,
+      LowerLeft,
+      LowerMiddle,
+      LowerRight
+    };
+
+    enum SnapGuideMode
+    {
+      Item,
+      Point
+    };
+
+    QgsLayoutMouseHandles( QgsLayout *layout, QgsLayoutView *view );
+
+    /**
+     * Sets the \a layout for the handles.
+     * \see layout()
+     */
+    void setLayout( QgsLayout *layout ) { mLayout = layout; }
+
+    /**
+     * Returns the layout for the handles.
+     * \see setLayout()
+     */
+    QgsLayout *layout() { return mLayout; }
+
+    void paint( QPainter *painter, const QStyleOptionGraphicsItem *itemStyle, QWidget *pWidget ) override;
+
+    //! Finds out which mouse move action to choose depending on the scene cursor position
+    QgsLayoutMouseHandles::MouseAction mouseActionForScenePos( QPointF sceneCoordPos );
+
+    //! Returns true is user is currently dragging the handles
+    bool isDragging() { return mIsDragging; }
+
+    //! Returns true is user is currently resizing with the handles
+    bool isResizing() { return mIsResizing; }
+
+  protected:
+
+    void mouseMoveEvent( QGraphicsSceneMouseEvent *event ) override;
+    void mouseReleaseEvent( QGraphicsSceneMouseEvent *event ) override;
+    void mousePressEvent( QGraphicsSceneMouseEvent *event ) override;
+    void mouseDoubleClickEvent( QGraphicsSceneMouseEvent *event ) override;
+    void hoverMoveEvent( QGraphicsSceneHoverEvent *event ) override;
+    void hoverLeaveEvent( QGraphicsSceneHoverEvent *event ) override;
+
+  public slots:
+
+    //! Sets up listeners to sizeChanged signal for all selected items
+    void selectionChanged();
+
+    //! Redraws handles when selected item size changes
+    void selectedItemSizeChanged();
+
+    //! Redraws handles when selected item rotation changes
+    void selectedItemRotationChanged();
+
+  private:
+
+    QgsLayout *mLayout = nullptr;
+    QPointer< QgsLayoutView > mView;
+
+    MouseAction mCurrentMouseMoveAction = NoAction;
+    //! Start point of the last mouse move action (in scene coordinates)
+    QPointF mMouseMoveStartPos;
+    //! Position of the last mouse move event (in scene coordinates)
+    QPointF mLastMouseEventPos;
+    //! Position of the mouse at beginning of move/resize (in scene coordinates)
+    QPointF mBeginMouseEventPos;
+    //! Position of composer handles at beginning of move/resize (in scene coordinates)
+    QPointF mBeginHandlePos;
+    //! Width and height of composer handles at beginning of resize
+    double mBeginHandleWidth = 0;
+    double mBeginHandleHeight = 0;
+
+    QRectF mResizeRect;
+    double mResizeMoveX = 0;
+    double mResizeMoveY = 0;
+
+    //! True if user is currently dragging items
+    bool mIsDragging = false;
+    //! True is user is currently resizing items
+    bool mIsResizing = false;
+
+    //! Align snap lines
+    QGraphicsLineItem *mHAlignSnapItem = nullptr;
+    QGraphicsLineItem *mVAlignSnapItem = nullptr;
+
+    QSizeF mCursorOffset;
+
+    //! Returns the mouse handle bounds of current selection
+    QRectF selectionBounds() const;
+
+    //! Returns true if all selected items have same rotation, and if so, updates passed rotation variable
+    bool selectionRotation( double &rotation ) const;
+
+    //! Redraws or hides the handles based on the current selection
+    void updateHandles();
+    //! Draws the handles
+    void drawHandles( QPainter *painter, double rectHandlerSize );
+    //! Draw outlines for selected items
+    void drawSelectedItemBounds( QPainter *painter );
+
+    /** Returns the current (zoom level dependent) tolerance to decide if mouse position is close enough to the
+    item border for resizing*/
+    double rectHandlerBorderTolerance();
+
+    //! Finds out the appropriate cursor for the current mouse position in the widget (e.g. move in the middle, resize at border)
+    Qt::CursorShape cursorForPosition( QPointF itemCoordPos );
+
+    //! Finds out which mouse move action to choose depending on the cursor position inside the widget
+    MouseAction mouseActionForPosition( QPointF itemCoordPos );
+
+    //! Handles dragging of items during mouse move
+    void dragMouseMove( QPointF currentPosition, bool lockMovement, bool preventSnap );
+
+    //! Calculates the distance of the mouse cursor from thed edge of the mouse handles
+    QSizeF calcCursorEdgeOffset( QPointF cursorPos );
+
+    //! Handles resizing of items during mouse move
+    void resizeMouseMove( QPointF currentPosition, bool lockAspect, bool fromCenter );
+
+    //sets the mouse cursor for the QGraphicsView attached to the composition (workaround qt bug #3732)
+    void setViewportCursor( Qt::CursorShape cursor );
+
+    //resets the composer window status bar to the default message
+    void resetStatusBar();
+};
+
+///@endcond PRIVATE
+
+#endif // QGSLAYOUTMOUSEHANDLES_H

src/gui/layout/qgslayoutview.cpp

@@ -22,6 +22,7 @@
 #include "qgslayoutviewtooltemporarykeypan.h"
 #include "qgslayoutviewtooltemporarykeyzoom.h"
 #include "qgslayoutviewtooltemporarymousepan.h"
+#include "qgslayoutmousehandles.h"
 #include "qgslayoutruler.h"
 #include "qgssettings.h"
 #include "qgsrectangle.h"
@@ -88,6 +89,12 @@ void QgsLayoutView::setCurrentLayout( QgsLayout *layout )
     connect( &layout->guides(), &QAbstractItemModel::modelReset, mVerticalRuler, [ = ] { mVerticalRuler->update(); } );
   }
 
+  //add mouse selection handles to layout, and initially hide
+  mMouseHandles = new QgsLayoutMouseHandles( layout, this );
+  mMouseHandles->hide();
+  mMouseHandles->setZValue( QgsLayout::ZMouseHandles );
+  layout->addItem( mMouseHandles );
+
   //emit layoutSet, so that designer dialogs can update for the new layout
   emit layoutSet( layout );
 }

src/gui/layout/qgslayoutview.h

@@ -35,6 +35,7 @@ class QgsLayoutViewToolTemporaryMousePan;
 class QgsLayoutRuler;
 class QgsLayoutViewMenuProvider;
 class QgsLayoutViewSnapMarker;
+class QgsLayoutMouseHandles;
 
 /**
  * \ingroup gui
@@ -300,6 +301,8 @@ class GUI_EXPORT QgsLayoutView: public QGraphicsView
 
     std::unique_ptr< QgsLayoutViewSnapMarker > mSnapMarker;
 
+    QgsLayoutMouseHandles *mMouseHandles = nullptr; //owned by scene
+
     int mCurrentPage = 0;
 
     friend class TestQgsLayoutView;