diff --git a/hurricane/src/viewer/CellWidget.cpp b/hurricane/src/viewer/CellWidget.cpp
index bcbeb770..210c7cd8 100644
--- a/hurricane/src/viewer/CellWidget.cpp
+++ b/hurricane/src/viewer/CellWidget.cpp
@@ -2,6 +2,7 @@
 
 #include <QPaintEvent>
 #include <QPainter>
+#include <QPen>
 
 #include "DataBase.h"
 #include "Technology.h"
@@ -20,35 +21,128 @@ Technology* getTechnology() {
     return NULL;
 }
 
+}
+
 CellWidget::CellWidget(Cell* c, QWidget* parent)
     : QAbstractScrollArea(parent),
-    cell(c) {
+    cell(c),
+    invalidRegion(),
+    clipBox(),
+    painter(NULL),
+    scale(1),
+    screenDx(0),
+    screenDy(0) {
+        painter = new QPainter();
 }
 
 void CellWidget::paintEvent(QPaintEvent* event) {
-    //invalidate(event->rect());
-    redraw();
+    invalidate(event->rect());
+
+    if (!invalidRegion.isEmpty()) {
+        QRect invalidRect = invalidRegion.boundingRect();
+
+        H::Box area = getBox(invalidRect).inflate(getSize(1));
+        cerr << "akecoucou3" << endl;
+
+        //QPaintDevice* device = this;
+
+	//QPainter newPainter(device);
+	//QPainter* oldPainter = painter;
+	//painter = &newPainter;
+
+        painter->setPen(QPen(QColor(255, 255, 255)));
+	painter->fillRect(QRectF(0, 0, 100, 100), QBrush(QColor(255, 255, 255)));
+
+
+        drawPhantoms(cell, area, Transformation());
+        drawBoundaries(cell, area, Transformation());
+        for_each_layer(layer, getTechnology()->GetLayers()) {
+            drawCell(cell, layer, area, Transformation());
+            end_for;
+        }
+
+        invalidRegion = QRegion();
+    }
 }
 
+void CellWidget::invalidate() {
+    invalidRegion = QRegion(rect());
+}
+
+
+void CellWidget::invalidate(const QRect& screenRect) {
+    QRect visibleScreenRect = screenRect.intersect(rect());
+
+    if (!visibleScreenRect.isEmpty()) {
+        invalidRegion = invalidRegion.unite(QRegion(visibleScreenRect));
+    }
+}
+
+
+
 void CellWidget::redraw() {
-    drawPhantoms(cell);
-    drawBoundaries(cell);
-    for_each_layer(layer, getTechnology()->GetLayers()) {
-        drawCell(cell, layer);
+    if (!invalidRegion.isEmpty()) {
+        QRect invalidRect = invalidRegion.boundingRect();
+
+        H::Box area = getBox(invalidRect).inflate(getSize(1));
+        cerr << "akecoucou2" << endl;
+
+        QPaintDevice* device = this;
+
+	QPainter newPainter(device);
+	QPainter* oldPainter = painter;
+	painter = &newPainter;
+
+	//painter->fillRect(QRectF(0, 0, 100, 100), QBrush(QColor(255, 255, 255)));
+
+        //painter->setPen(QPen(QColor(255, 255, 255)));
+
+        //drawPhantoms(cell, area, Transformation());
+        //drawBoundaries(cell, area, Transformation());
+        //for_each_layer(layer, getTechnology()->GetLayers()) {
+        //    drawCell(cell, layer, area, Transformation());
+        //    end_for;
+        //}
+
+        invalidRegion = QRegion();
+    }
+}
+
+void CellWidget::drawCell(const Cell* cell, const Layer* layer, const H::Box& updateArea, const Transformation& transformation) const {
+}
+
+void CellWidget::drawPhantoms(const Cell* cell, const H::Box& updateArea, const Transformation& transformation) const {
+    for_each_instance(instance, cell->GetInstancesUnder(updateArea)) {
+        drawPhantoms(instance, updateArea, transformation);
         end_for;
     }
 }
 
-void CellWidget::drawCell(const Cell* cell, const Layer* layer) const {
+void CellWidget::drawPhantoms(const Instance* instance, const H::Box& updateArea, const Transformation& transformation) const {
+    H::Box masterArea = updateArea;
+    Transformation masterTransformation = instance->GetTransformation();
+    instance->GetTransformation().GetInvert().ApplyOn(masterArea);
+    transformation.ApplyOn(masterTransformation);
+    drawPhantoms(instance->GetMasterCell(), masterArea, masterTransformation);
 }
 
-void CellWidget::drawPhantoms(const Cell* cell) const {
+void CellWidget::drawBoundaries(const Cell* cell, const H::Box& updateArea, const Transformation& transformation) const {
+    drawRectangle(cell->GetAbutmentBox());
+    for_each_instance(instance, cell->GetInstances()) {
+        drawBoundaries(instance, updateArea, transformation);
+        end_for;
+    }
 }
 
-void CellWidget::drawBoundaries(const Cell* cell) const {
+void CellWidget::drawBoundaries(const Instance* instance, const H::Box& updateArea, const Transformation& transformation) const {
+    H::Box masterArea = updateArea;
+    Transformation masterTransformation = instance->GetTransformation();
+    instance->GetTransformation().GetInvert().ApplyOn(masterArea);
+    transformation.ApplyOn(masterTransformation);
+    drawBoundaries(instance->GetMasterCell(), masterArea, masterTransformation);
 }
 
-void CellWidget::drawRectangle(const H::Box& box) {
+void CellWidget::drawRectangle(const H::Box& box) const {
     if (painter) {
         H::Box ibox = box.getIntersection(clipBox);
         if (!ibox.isEmpty()) {
@@ -62,6 +156,29 @@ void CellWidget::drawRectangle(const H::Box& box) {
     }
 }
 
+Unit CellWidget::getX(int screenX) const {
+    return GetUnit((screenX - screenDx) / scale);
+}
+
+Unit CellWidget::getY(int screenY) const {
+    return GetUnit(((height() - screenY) - screenDy) / scale);
+}
+
+Unit CellWidget::getSize(int screenSize) const {
+    return GetUnit(screenSize / scale);
+}
+
+H::Box CellWidget::getBox(const QRect& screenRect) const {
+    if (screenRect.isEmpty()) {
+        return H::Box();
+    }
+
+    return H::Box(getX(screenRect.left()),
+            getY(screenRect.bottom()),
+            getX(screenRect.right()),
+            getY(screenRect.top()));
+}
+
 int CellWidget::getScreenX(const Unit& x) const {
     return screenDx + (int)rint(GetValue(x) * scale);
 }
@@ -69,5 +186,3 @@ int CellWidget::getScreenX(const Unit& x) const {
 int CellWidget::getScreenY(const Unit& y) const {
     return height() - (int)rint(screenDy + (GetValue(y) * scale));
 }
-
-}
diff --git a/hurricane/src/viewer/CellWidget.h b/hurricane/src/viewer/CellWidget.h
index 9e9f637f..ab272e1d 100644
--- a/hurricane/src/viewer/CellWidget.h
+++ b/hurricane/src/viewer/CellWidget.h
@@ -16,18 +16,27 @@ class CellWidget : public QAbstractScrollArea {
         void paintEvent(QPaintEvent* event);
     private:
         Cell* cell;
-        QPainter* painter;
+        QRegion invalidRegion;
         H::Box clipBox;
+        QPainter* painter;
         double scale;
         int screenDx;
 	int screenDy;
 
-        void drawCell(const Cell* cell, const Layer* layer) const;
-        void drawPhantoms(const Cell* cell) const;
-        void drawBoundaries(const Cell* cell) const;
-        void drawRectangle(const H::Box& box);
+        void drawCell(const Cell* cell, const Layer* layer, const H::Box& updateArea, const Transformation& transformation) const;
+        void drawPhantoms(const Cell* cell, const H::Box& updateArea, const Transformation& transformation) const;
+        void drawPhantoms(const Instance* instance, const H::Box& updateArea, const Transformation& transformation) const;
+        void drawBoundaries(const Cell* cell, const H::Box& updateArea, const Transformation& transformation) const;
+        void drawBoundaries(const Instance* instance, const H::Box& updateArea, const Transformation& transformation) const;
+        void drawRectangle(const H::Box& box) const;
+        Unit getX(int screenX) const;
+        Unit getY(int screenY) const;
+        Unit getSize(int screenSize) const;
+        H::Box getBox(const QRect& screenRect) const;
         int getScreenX(const Unit& x) const;
         int getScreenY(const Unit& y) const;
+        void invalidate();
+        void invalidate(const QRect& screenRect);
 };