Add new selection style : free selection.

Use like normal selection + hold the ctrl key.
The code made in this commit are largely inspired by the the rubber band of QGraphicsView.


git-svn-id: svn+ssh://svn.tuxfamily.org/svnroot/qet/qet/trunk@5716 bfdf4180-ca20-0410-9c96-a3a8aa849046

ChangeLog

@@ -46,6 +46,7 @@ This commit fix it : When element is removed one or several conductors are creat
 * Diagram properties, Element properties, Independent text item can be changed (and mass changed) through the search and replace widget.
 * Added 4 tools for edit the depth (Z value) of items.
 * Element panel : elements can be searched by their name but also with by all their informations.
+* New free selection style.
 
 
 * Title block editor :

sources/diagramview.cpp

@@ -409,9 +409,16 @@ void DiagramView::mousePressEvent(QMouseEvent *e)
 		//Start drag view when hold the middle button
 	if (e->button() == Qt::MidButton)
 	{
-		m_rubber_band_origin = e->pos();
+		m_drag_last_pos = e->pos();
 		viewport()->setCursor(Qt::ClosedHandCursor);
 	}
+	else if (e->button() == Qt::LeftButton &&
+			 e->modifiers() == Qt::CTRL)
+	{
+		m_free_rubberbanding = true;
+		m_free_rubberband = QPolygon();
+		QGraphicsView::mousePressEvent(e);
+	}
 
 	else QGraphicsView::mousePressEvent(e);
 }
@@ -429,12 +436,50 @@ void DiagramView::mouseMoveEvent(QMouseEvent *e)
 	{
 		QScrollBar *h = horizontalScrollBar();
 		QScrollBar *v = verticalScrollBar();
-		QPointF pos = m_rubber_band_origin - e -> pos();
-		m_rubber_band_origin = e -> pos();
+		QPointF pos = m_drag_last_pos - e -> pos();
+		m_drag_last_pos = e -> pos();
 		h -> setValue(h -> value() + pos.x());
 		v -> setValue(v -> value() + pos.y());
 		adjustSceneRect();
 	}
+	else if (m_free_rubberbanding)
+	{
+			//Update old free rubberband
+		if (viewportUpdateMode() != QGraphicsView::NoViewportUpdate && !m_free_rubberband.isEmpty())
+		{
+			if (viewportUpdateMode() != QGraphicsView::FullViewportUpdate) {
+				viewport()->update(m_free_rubberband.boundingRect().toRect());
+			}
+			else {
+				update();
+			}
+		}
+		
+			//Stop polygon rubberbanding if user has let go of all buttons (even
+			//if we didn't get the release events)
+		if (!e->buttons()) {
+			m_free_rubberbanding = false;
+			m_free_rubberband = QPolygon();
+			return;
+		}
+		m_free_rubberband.append(mapToScene(e->pos()));
+		emit freeRubberBandChanged(m_free_rubberband);
+		
+		if (viewportUpdateMode() != QGraphicsView::NoViewportUpdate)
+		{
+			if (viewportUpdateMode() != QGraphicsView::FullViewportUpdate) {
+				viewport()->update(mapFromScene(m_free_rubberband.boundingRect()));
+			}
+			else {
+				update();
+			}
+		}
+		
+			//Set the new selection area
+		QPainterPath selection_area;
+		selection_area.addPolygon(m_free_rubberband);
+		m_diagram->setSelectionArea(selection_area);
+	}
 
 	else QGraphicsView::mouseMoveEvent(e);
 }
@@ -448,9 +493,27 @@ void DiagramView::mouseReleaseEvent(QMouseEvent *e)
 	if (m_event_interface && m_event_interface->mouseReleaseEvent(e)) return;
 
 		//Stop drag view
-	if (e -> button() == Qt::MidButton) viewport()->setCursor(Qt::ArrowCursor);
-
-	else QGraphicsView::mouseReleaseEvent(e);
+	if (e -> button() == Qt::MidButton) {
+		viewport()->setCursor(Qt::ArrowCursor);
+	}
+	else if (m_free_rubberbanding && !e->buttons())
+	{
+		if (viewportUpdateMode() != QGraphicsView::NoViewportUpdate)
+		{
+			if (viewportUpdateMode() != QGraphicsView::FullViewportUpdate) {
+				QRectF r(mapFromScene(m_free_rubberband).boundingRect());
+				r.adjust(-5, -5, 5, 5);
+				viewport()->update(r.toRect());
+			} else {
+				update();
+			}
+		}
+		m_free_rubberbanding = false;
+		m_free_rubberband = QPolygon();
+		emit freeRubberBandChanged(m_free_rubberband);
+	}
+	else
+		QGraphicsView::mouseReleaseEvent(e);
 }
 
 /**
@@ -921,6 +984,25 @@ bool DiagramView::event(QEvent *e) {
 	return(QGraphicsView::event(e));
 }
 
+void DiagramView::paintEvent(QPaintEvent *event)
+{
+	QGraphicsView::paintEvent(event);
+	
+	if (m_free_rubberbanding && m_free_rubberband.count() >= 3)
+	{
+		QPainter painter(viewport());
+		painter.setRenderHint(QPainter::Antialiasing);
+		QPen pen(Qt::darkGreen);
+		pen.setWidth(1);
+		painter.setPen(pen);
+		QColor color(Qt::darkGreen);
+		color.setAlpha(50);
+		QBrush brush(color);
+		painter.setBrush(brush);
+		painter.drawPolygon(mapFromScene(m_free_rubberband));
+	}
+}
+
 /**
 	Switch to visualisation mode if the user is pressing Ctrl and Shift.
 	@return true if the view was switched to visualisation mode, false

sources/diagramview.h

@@ -53,10 +53,14 @@ class DiagramView : public QGraphicsView
 		QAction          *m_paste_here = nullptr;
 		QAction			 *m_multi_paste = nullptr;
 		QPoint            m_paste_here_pos;
-		QPointF           m_rubber_band_origin;
+		QPointF           m_drag_last_pos;
 		bool              m_fresh_focus_in,
 						  m_first_activation = true;
 		QList<QAction *>  m_separators;
+		QPolygonF m_free_rubberband;
+		bool m_free_rubberbanding = false;
+		
+		
 	public:
 		QString title() const;
 		void editDiagramProperties();
@@ -74,18 +78,20 @@ class DiagramView : public QGraphicsView
 		void keyPressEvent(QKeyEvent *) override;
 		void keyReleaseEvent(QKeyEvent *) override;
 		bool event(QEvent *) override;
-		virtual bool switchToVisualisationModeIfNeeded(QInputEvent *e);
-		virtual bool switchToSelectionModeIfNeeded(QInputEvent *e);
-		virtual bool isCtrlShifting(QInputEvent *);
-		virtual bool selectedItemHasFocus();
-	
-	private:
+		void paintEvent(QPaintEvent *event) override;
 		void mousePressEvent(QMouseEvent *) override;
 		void mouseMoveEvent(QMouseEvent *) override;
 		void mouseReleaseEvent(QMouseEvent *) override;
 		void dragEnterEvent(QDragEnterEvent *) override;
 		void dragMoveEvent(QDragMoveEvent *) override;
 		void dropEvent(QDropEvent *) override;
+		
+		virtual bool switchToVisualisationModeIfNeeded(QInputEvent *e);
+		virtual bool switchToSelectionModeIfNeeded(QInputEvent *e);
+		virtual bool isCtrlShifting(QInputEvent *);
+		virtual bool selectedItemHasFocus();
+	
+	private:
 		void handleElementDrop(QDropEvent *);
 		void handleTitleBlockDrop(QDropEvent *);
 		void handleTextDrop(QDropEvent *);
@@ -108,6 +114,9 @@ class DiagramView : public QGraphicsView
 		void editElementRequired(const ElementsLocation &);
 			/// Signal emmitted when diagram must be show
 		void showDiagram (Diagram *);
+			/// Signal emmtted when free rubberband changed.
+			/// When free rubberband selection ends this signal will be emitted with null value.
+		void freeRubberBandChanged(QPolygonF polygon);
 	
 	public slots:
 		void selectNothing();