From 507dca8c3260c87f1ba243c15703dc6712fe4458 Mon Sep 17 00:00:00 2001
From: ouv <ouv@opencascade.com>
Date: Fri, 19 Nov 2010 14:05:58 +0000
Subject: [PATCH] Added possibility of displaying name of view inside viewport
 itself

---
 src/GraphicsView/GraphicsView_ViewPort.cxx | 67 ++++++++++++++++++++++
 src/GraphicsView/GraphicsView_ViewPort.h   | 10 ++++
 2 files changed, 77 insertions(+)

diff --git a/src/GraphicsView/GraphicsView_ViewPort.cxx b/src/GraphicsView/GraphicsView_ViewPort.cxx
index 8db01df0b..6559b44a9 100644
--- a/src/GraphicsView/GraphicsView_ViewPort.cxx
+++ b/src/GraphicsView/GraphicsView_ViewPort.cxx
@@ -31,9 +31,12 @@
 
 #include <QCursor>
 #include <QGraphicsSceneMouseEvent>
+#include <QLabel>
+#include <QMoveEvent>
 #include <QRectF>
 #include <QRubberBand>
 #include <QScrollBar>
+#include <QVBoxLayout>
 
 #include <math.h>
 
@@ -44,6 +47,40 @@ QCursor* GraphicsView_ViewPort::panCursor = 0;
 QCursor* GraphicsView_ViewPort::panglCursor = 0;
 QCursor* GraphicsView_ViewPort::zoomCursor = 0;
 
+//=======================================================================
+// Name    : GraphicsView_ViewPort::NameLabel
+// Purpose : Wrapper for label, which can ignore move events sent from
+//           QGraphicsView::scrollContentsBy() method, which,
+//           in its turn, called from GraphicsView_ViewPort::pan()
+//=======================================================================
+class GraphicsView_ViewPort::NameLabel : public QLabel
+{
+public:
+  NameLabel( QWidget* theParent ) : QLabel( theParent ) {}
+  ~NameLabel() {}
+
+  void setAcceptMoveEvents( bool theFlag )
+  {
+    myAcceptMoveEvents = theFlag;
+  }
+
+protected:
+  virtual void moveEvent( QMoveEvent* theEvent )
+  {
+    if( myAcceptMoveEvents )
+      QLabel::moveEvent( theEvent );
+    else // return the label to the initial position
+    {
+      myAcceptMoveEvents = true;
+      move( theEvent->oldPos() );
+      myAcceptMoveEvents = false;
+    }
+  }
+
+private:
+  bool myAcceptMoveEvents;
+};
+
 //================================================================
 // Function : createCursors
 // Purpose  : 
@@ -95,6 +132,14 @@ GraphicsView_ViewPort::GraphicsView_ViewPort( QWidget* theParent )
   myScene = new GraphicsView_Scene( this );
   setScene( myScene );
 
+  // view name
+  myNameLabel = new NameLabel( viewport() );
+  myNameLabel->setVisible( false );
+
+  QBoxLayout* aLayout = new QVBoxLayout( viewport() );
+  aLayout->addStretch();
+  aLayout->addWidget( myNameLabel );
+
   // background
   setBackgroundBrush( QBrush( Qt::white ) );
 
@@ -258,6 +303,24 @@ QImage GraphicsView_ViewPort::dumpView( bool theWholeScene )
   return anImage;
 }
 
+//================================================================
+// Function : setViewName
+// Purpose  : 
+//================================================================
+void GraphicsView_ViewPort::setViewName( const QString& theName )
+{
+  myNameLabel->setText( theName );
+}
+
+//================================================================
+// Function : setViewNameEnabled
+// Purpose  : 
+//================================================================
+void GraphicsView_ViewPort::setViewNameEnabled( bool theState )
+{
+  myNameLabel->setVisible( theState );
+}
+
 //================================================================
 // Function : backgroundColor
 // Purpose  : 
@@ -384,11 +447,15 @@ void GraphicsView_ViewPort::pan( double theDX, double theDY )
 {
   myIsTransforming = true;
 
+  myNameLabel->setAcceptMoveEvents( false );
+
   if( QScrollBar* aHBar = horizontalScrollBar() )
     aHBar->setValue( aHBar->value() - theDX );
   if( QScrollBar* aVBar = verticalScrollBar() )
     aVBar->setValue( aVBar->value() + theDY );
 
+  myNameLabel->setAcceptMoveEvents( true );
+
   myIsTransforming = false;
 }
 
diff --git a/src/GraphicsView/GraphicsView_ViewPort.h b/src/GraphicsView/GraphicsView_ViewPort.h
index a20583892..93ea6f62c 100644
--- a/src/GraphicsView/GraphicsView_ViewPort.h
+++ b/src/GraphicsView/GraphicsView_ViewPort.h
@@ -43,6 +43,8 @@ class GRAPHICSVIEW_API GraphicsView_ViewPort : public QGraphicsView
   Q_OBJECT
 
 public:
+  class NameLabel;
+
   enum BlockStatus
   {
     BS_NoBlock   = 0x0000,
@@ -64,6 +66,10 @@ public:
   QImage                           dumpView( bool theWholeScene = false );
 
 public:
+  // view name
+  void                             setViewName( const QString& theName );
+  void                             setViewNameEnabled( bool theState );
+
   // background / foreground
   QColor                           backgroundColor() const;
   void                             setBackgroundColor( const QColor& theColor );
@@ -171,8 +177,12 @@ private:
   static QCursor*                  zoomCursor;
 
 private:
+  // scene
   GraphicsView_Scene*              myScene;
 
+  // view name
+  NameLabel*                       myNameLabel;
+
   // foreground
   bool                             myIsForegroundEnabled;
   QSizeF                           myForegroundSize;
-- 
2.39.2