diff --git a/DRAMSys/traceAnalyzer/businessObjects/phases/phase.cpp b/DRAMSys/traceAnalyzer/businessObjects/phases/phase.cpp
index 869b20b3..a785d319 100644
--- a/DRAMSys/traceAnalyzer/businessObjects/phases/phase.cpp
+++ b/DRAMSys/traceAnalyzer/businessObjects/phases/phase.cpp
@@ -64,13 +64,11 @@ void Phase::draw(QPainter *painter, const QwtScaleMap &xMap,
         painter->setPen(pen);
     }
 
-    if (!isCollapsed(drawingProperties))
+    for (auto line : getTracePlotLines(drawingProperties))
     {
-        for (auto line : getTracePlotLines(drawingProperties))
-        {
+        if (!line->isCollapsed())
             drawPhaseSymbol(span.Begin(), span.End(), line->getYVal(),
                             drawingProperties.drawText, getPhaseSymbol(), painter, xMap, yMap);
-        }
     }
 
     for (Timespan span : spansOnCommandBus)
@@ -148,7 +146,7 @@ bool Phase::isSelected(traceTime time, double yVal,
     {
         for (auto line : getTracePlotLines(drawingProperties))
         {
-            if (fabs(yVal - line->getYVal()) <= hexagonHeight)
+            if (!line->isCollapsed() && fabs(yVal - line->getYVal()) <= hexagonHeight)
                 return true;
         }
     }
@@ -201,12 +199,3 @@ std::vector<std::shared_ptr<TracePlotLine>> Phase::getTracePlotLines(const Trace
                                               % drawingProperties.banksPerGroup);
     }
 }
-
-bool Phase::isCollapsed(const TraceDrawingProperties &drawingProperties) const
-{
-    // Never discard REQ and RESP phases
-    if (dynamic_cast<const REQ *>(this) != nullptr || dynamic_cast<const RESP *>(this) != nullptr)
-        return false;
-
-    return drawingProperties.getRankCollapsedState(transaction->rank);
-}
diff --git a/DRAMSys/traceAnalyzer/businessObjects/phases/phase.h b/DRAMSys/traceAnalyzer/businessObjects/phases/phase.h
index b5fb6815..b540ce98 100644
--- a/DRAMSys/traceAnalyzer/businessObjects/phases/phase.h
+++ b/DRAMSys/traceAnalyzer/businessObjects/phases/phase.h
@@ -104,8 +104,6 @@ protected:
     {
         return Granularity::Bankwise;
     }
-
-    bool isCollapsed(const TraceDrawingProperties &drawingProperties) const;
 };
 
 class REQ : public Phase
diff --git a/DRAMSys/traceAnalyzer/presentation/tracedrawingproperties.cpp b/DRAMSys/traceAnalyzer/presentation/tracedrawingproperties.cpp
index c57bbc6b..c6fd577f 100644
--- a/DRAMSys/traceAnalyzer/presentation/tracedrawingproperties.cpp
+++ b/DRAMSys/traceAnalyzer/presentation/tracedrawingproperties.cpp
@@ -34,6 +34,8 @@
  */
 
 #include "tracedrawingproperties.h"
+#include "util/customlabelscaledraw.h"
+#include "traceplot.h"
 
 TraceDrawingProperties::TraceDrawingProperties(bool drawText, bool drawBorder,
                                                ColorGrouping colorGrouping) :
@@ -43,45 +45,52 @@ TraceDrawingProperties::TraceDrawingProperties(bool drawText, bool drawBorder,
 {
 }
 
-void TraceDrawingProperties::init(std::shared_ptr<TracePlotLineVector> tracePlotLines,
-                                  std::shared_ptr<QHash<int, bool>> collapsedRanks)
+void TraceDrawingProperties::init(std::shared_ptr<TracePlotLineVector> tracePlotLines)
 {
     this->tracePlotLines = tracePlotLines;
-    this->collapsedRanks = collapsedRanks;
+}
+
+void TraceDrawingProperties::init(std::shared_ptr<TracePlotLineVector> tracePlotLines,
+                                  TracePlot *tracePlot)
+{
+    this->tracePlotLines = tracePlotLines;
+    this->tracePlot = tracePlot;
 }
 
 void TraceDrawingProperties::setUpTracePlotLines()
 {
-    tracePlotLines->push_back(std::make_shared<TracePlotRequestLine>("REQ", collapsedRanks));
-    tracePlotLines->push_back(std::make_shared<TracePlotResponseLine>("RESP", collapsedRanks));
+    tracePlotLines->push_back(std::make_shared<TracePlotRequestLine>("REQ"));
+    tracePlotLines->push_back(std::make_shared<TracePlotResponseLine>("RESP"));
 
     for (unsigned int rank = numberOfRanks; rank--;)
     {
+        std::shared_ptr<TracePlotFirstRankLine> firstRankLine;
+
         for (unsigned int group = groupsPerRank; group--;)
         {
             for (unsigned int bank = banksPerGroup; bank--;)
             {
-                std::shared_ptr<TracePlotLine> line;
+                std::shared_ptr<TracePlotBankLine> line;
 
                 if (bank == banksPerGroup - 1 && group == groupsPerRank - 1)
-                    line = std::make_shared<TracePlotFirstRankLine>(rank, group, bank, collapsedRanks);
+                {
+                    firstRankLine = createFirstRankLine(rank, group, bank);
+                    line = firstRankLine;
+                }
                 else
-                    line = std::make_shared<TracePlotBankLine>(rank, group, bank, collapsedRanks);
+                {
+                    line = std::make_shared<TracePlotBankLine>(rank, group, bank, firstRankLine);
+                }
 
                 tracePlotLines->push_back(line);
             }
         }
     }
 
-    tracePlotLines->push_back(std::make_shared<TracePlotCommandBusLine>("Command Bus", collapsedRanks));
-    tracePlotLines->push_back(std::make_shared<TracePlotDataBusLine>("Data Bus", collapsedRanks));
+    tracePlotLines->push_back(std::make_shared<TracePlotCommandBusLine>("Command Bus"));
+    tracePlotLines->push_back(std::make_shared<TracePlotDataBusLine>("Data Bus"));
 
-    // Collapse all ranks except the first one by default.
-    for (int i = 0; i < numberOfRanks; i++)
-        if (i == 0)
-            setRankCollapsedState(i, false);
-        else
-            setRankCollapsedState(i, true);
+    updateLabels();
 }
 
 void TraceDrawingProperties::updateLabels()
@@ -97,20 +106,40 @@ void TraceDrawingProperties::updateLabels()
         // Don't add collapsed ranks, but always add the first rank line.
         auto bankLine = std::dynamic_pointer_cast<TracePlotBankLine>(*it);
         auto firstRankLine = std::dynamic_pointer_cast<TracePlotFirstRankLine>(*it);
-        if (!firstRankLine && bankLine && (*collapsedRanks)[bankLine->rank])
+        if (!firstRankLine && bankLine && bankLine->isCollapsed())
             continue;
 
         (*labels)[i] = (*it)->getLabel();
 
         (*it)->setYVal(i);
 
-        if (std::dynamic_pointer_cast<TracePlotCommandBusLine>(*it)) {
-            // Add two spaces.
-            i += 2;
-        }
+//      Another solution has to be found for this.
+//      if (std::dynamic_pointer_cast<TracePlotCommandBusLine>(*it)) {
+//          // Add two spaces.
+//          i += 2;
+//      }
 
         i++;
     }
+
+    Q_EMIT tracePlot->tracePlotLinesChanged();
+}
+
+std::shared_ptr<TracePlotFirstRankLine> TraceDrawingProperties::createFirstRankLine(unsigned int rank, unsigned int group,
+                                                                                    unsigned int bank) const
+{
+    auto firstRankLine = std::make_shared<TracePlotFirstRankLine>(rank, group, bank, tracePlot);
+
+    QObject::connect(firstRankLine.get(), &TracePlotFirstRankLine::collapsedStateChanged,
+                        this, &TraceDrawingProperties::updateLabels);
+
+    QObject::connect(firstRankLine.get(), &TracePlotFirstRankLine::collapsedStateChanged,
+                        tracePlot, &TracePlot::updateScrollbar);
+
+    QObject::connect(tracePlot->getCustomLabelScaleDraw(), &CustomLabelScaleDraw::scaleRedraw,
+                        firstRankLine.get(), &TracePlotFirstRankLine::updateButtonPosition);
+
+    return firstRankLine;
 }
 
 const std::shared_ptr<QHash<int, QString>> TraceDrawingProperties::getLabels() const
@@ -123,22 +152,11 @@ const TracePlotLineVector &TraceDrawingProperties::getTracePlotLines() const
     return *tracePlotLines;
 }
 
-void TraceDrawingProperties::setRankCollapsedState(unsigned int rank, bool collapse)
-{
-    Q_ASSERT(rank <= numberOfRanks - 1);
-
-    (*collapsedRanks)[rank] = collapse;
-
-    updateLabels();
-}
-
-bool TraceDrawingProperties::getRankCollapsedState(unsigned int rank) const
-{
-    return (*collapsedRanks)[rank];
-}
-
 unsigned int TraceDrawingProperties::getNumberOfDisplayedLines() const
 {
+    if (!tracePlotLines)
+        return 0;
+
     unsigned int max = 0;
 
     for (auto line : *tracePlotLines)
@@ -150,7 +168,7 @@ unsigned int TraceDrawingProperties::getNumberOfDisplayedLines() const
     return max;
 }
 
-std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getCommandBusLines() const
+TracePlotLineVector TraceDrawingProperties::getCommandBusLines() const
 {
     if (commandBusLinesCache.size() != 0)
         return commandBusLinesCache;
@@ -168,7 +186,7 @@ std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getCommandBu
     return commandBusLines;
 }
 
-std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getDataBusLines() const
+TracePlotLineVector TraceDrawingProperties::getDataBusLines() const
 {
     if (dataBusLinesCache.size() != 0)
         return dataBusLinesCache;
@@ -186,7 +204,7 @@ std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getDataBusLi
     return dataBusLines;
 }
 
-std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getRequestLines() const
+TracePlotLineVector TraceDrawingProperties::getRequestLines() const
 {
     if (requestLinesCache.size() != 0)
         return requestLinesCache;
@@ -204,7 +222,7 @@ std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getRequestLi
     return requestLines;
 }
 
-std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getResponseLines() const
+TracePlotLineVector TraceDrawingProperties::getResponseLines() const
 {
     if (responseLinesCache.size() != 0)
         return responseLinesCache;
@@ -222,7 +240,7 @@ std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getResponseL
     return responseLines;
 }
 
-std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getFirstRankLines(unsigned int rank) const
+TracePlotLineVector TraceDrawingProperties::getFirstRankLines(unsigned int rank) const
 {
     Q_ASSERT(rank <= numberOfRanks - 1);
 
@@ -243,7 +261,7 @@ std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getFirstRank
     return firstRankLines;
 }
 
-std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getBankLinesFromRank(unsigned int rank) const
+TracePlotLineVector TraceDrawingProperties::getBankLinesFromRank(unsigned int rank) const
 {
     Q_ASSERT(rank <= numberOfRanks - 1);
 
@@ -264,7 +282,7 @@ std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getBankLines
     return bankLines;
 }
 
-std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getBankLinesFromGroup(unsigned int rank, unsigned int group) const
+TracePlotLineVector TraceDrawingProperties::getBankLinesFromGroup(unsigned int rank, unsigned int group) const
 {
     Q_ASSERT(rank <= numberOfRanks - 1);
     Q_ASSERT(group <= groupsPerRank - 1);
@@ -289,8 +307,8 @@ std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getBankLines
     return bankLines;
 }
 
-std::vector<std::shared_ptr<TracePlotLine>> TraceDrawingProperties::getBankLines(unsigned int rank, unsigned int group,
-                                                                                 unsigned int bank) const
+TracePlotLineVector TraceDrawingProperties::getBankLines(unsigned int rank, unsigned int group,
+                                                         unsigned int bank) const
 {
     Q_ASSERT(rank <= numberOfRanks - 1);
     Q_ASSERT(group <= groupsPerRank - 1);
diff --git a/DRAMSys/traceAnalyzer/presentation/tracedrawingproperties.h b/DRAMSys/traceAnalyzer/presentation/tracedrawingproperties.h
index 5dc40a3f..63e8c585 100644
--- a/DRAMSys/traceAnalyzer/presentation/tracedrawingproperties.h
+++ b/DRAMSys/traceAnalyzer/presentation/tracedrawingproperties.h
@@ -39,6 +39,7 @@
 #ifndef TRACECOLLECTIONDRAWINGPROPERTIES_H
 #define TRACECOLLECTIONDRAWINGPROPERTIES_H
 
+#include <QObject>
 #include <QString>
 #include <QColor>
 #include <map>
@@ -51,7 +52,13 @@ enum class ColorGrouping {PhaseType, Transaction, Thread};
 
 using TracePlotLineVector = std::vector<std::shared_ptr<TracePlotLine>>;
 
-struct TraceDrawingProperties {
+class TracePlot;
+
+class TraceDrawingProperties : public QObject
+{
+    Q_OBJECT
+
+public:
     bool drawText;
     bool drawBorder;
     ColorGrouping colorGrouping;
@@ -67,34 +74,37 @@ struct TraceDrawingProperties {
                            bool drawBorder = true,
                            ColorGrouping colorGrouping = ColorGrouping::PhaseType);
 
-    void init(std::shared_ptr<TracePlotLineVector> tracePlotLines, std::shared_ptr<QHash<int, bool>> collapsedRanks);
+    void init(std::shared_ptr<TracePlotLineVector> tracePlotLines);
+    void init(std::shared_ptr<TracePlotLineVector> tracePlotLines, TracePlot *tracePlot);
 
     void setUpTracePlotLines();
 
-    void setRankCollapsedState(unsigned int rank, bool collapse);
-    bool getRankCollapsedState(unsigned int rank) const;
-
     unsigned int getNumberOfDisplayedLines() const;
 
-    std::vector<std::shared_ptr<TracePlotLine>> getRequestLines() const;
-    std::vector<std::shared_ptr<TracePlotLine>> getResponseLines() const;
-    std::vector<std::shared_ptr<TracePlotLine>> getCommandBusLines() const;
-    std::vector<std::shared_ptr<TracePlotLine>> getDataBusLines() const;
-    std::vector<std::shared_ptr<TracePlotLine>> getFirstRankLines(unsigned int rank) const;
-    std::vector<std::shared_ptr<TracePlotLine>> getBankLines(unsigned int rank, unsigned int group, unsigned int bank) const;
-    std::vector<std::shared_ptr<TracePlotLine>> getBankLinesFromGroup(unsigned int rank, unsigned int group) const;
-    std::vector<std::shared_ptr<TracePlotLine>> getBankLinesFromRank(unsigned int rank) const;
+    TracePlotLineVector getRequestLines() const;
+    TracePlotLineVector getResponseLines() const;
+    TracePlotLineVector getCommandBusLines() const;
+    TracePlotLineVector getDataBusLines() const;
+    TracePlotLineVector getFirstRankLines(unsigned int rank) const;
+    TracePlotLineVector getBankLines(unsigned int rank, unsigned int group, unsigned int bank) const;
+    TracePlotLineVector getBankLinesFromGroup(unsigned int rank, unsigned int group) const;
+    TracePlotLineVector getBankLinesFromRank(unsigned int rank) const;
 
     const TracePlotLineVector &getTracePlotLines() const;
 
-    void updateLabels();
     const std::shared_ptr<QHash<int, QString>> getLabels() const;
 
+private Q_SLOTS:
+    void updateLabels();
+
 private:
+    std::shared_ptr<TracePlotFirstRankLine> createFirstRankLine(unsigned int rank, unsigned int group,
+                                                                unsigned int bank) const;
+
     std::shared_ptr<QHash<int, QString>> labels = std::make_shared<QHash<int, QString>>();
 
-    std::shared_ptr<QHash<int, bool>> collapsedRanks;
     std::shared_ptr<TracePlotLineVector> tracePlotLines;
+    TracePlot *tracePlot;
 
     // Caches
     mutable std::map<std::tuple<int, int, int>, std::vector<std::shared_ptr<TracePlotLine>>> bankLinesCache;
diff --git a/DRAMSys/traceAnalyzer/presentation/tracenavigator.cpp b/DRAMSys/traceAnalyzer/presentation/tracenavigator.cpp
index b7f44ded..0a85cda8 100644
--- a/DRAMSys/traceAnalyzer/presentation/tracenavigator.cpp
+++ b/DRAMSys/traceAnalyzer/presentation/tracenavigator.cpp
@@ -318,11 +318,6 @@ Timespan TraceNavigator::getSpanCoveredBySelectedTransaction()
     return Timespan(begin, end);
 }
 
-std::shared_ptr<QHash<int, bool>> TraceNavigator::getCollapsedRanks()
-{
-    return collapsedRanks;
-}
-
 std::shared_ptr<TracePlotLineVector> TraceNavigator::getTracePlotLines()
 {
     return tracePlotLines;
diff --git a/DRAMSys/traceAnalyzer/presentation/tracenavigator.h b/DRAMSys/traceAnalyzer/presentation/tracenavigator.h
index e390a8e1..56566625 100644
--- a/DRAMSys/traceAnalyzer/presentation/tracenavigator.h
+++ b/DRAMSys/traceAnalyzer/presentation/tracenavigator.h
@@ -117,7 +117,6 @@ public:
     void commitChangesToDB();
     void refreshData();
 
-    std::shared_ptr<QHash<int, bool>> getCollapsedRanks();
     std::shared_ptr<TracePlotLineVector> getTracePlotLines();
 
 Q_SIGNALS:
@@ -136,7 +135,6 @@ private:
     void getCommentsFromDB();
     bool changesToCommitExist;
 
-    std::shared_ptr<QHash<int, bool>> collapsedRanks = std::make_shared<QHash<int, bool>>();
     std::shared_ptr<TracePlotLineVector> tracePlotLines = std::make_shared<TracePlotLineVector>();
 };
 
diff --git a/DRAMSys/traceAnalyzer/presentation/traceplot.cpp b/DRAMSys/traceAnalyzer/presentation/traceplot.cpp
index c1781592..1e8fe77f 100644
--- a/DRAMSys/traceAnalyzer/presentation/traceplot.cpp
+++ b/DRAMSys/traceAnalyzer/presentation/traceplot.cpp
@@ -63,7 +63,8 @@ using namespace std;
 
 
 TracePlot::TracePlot(QWidget *parent):
-    QwtPlot(parent), isInitialized(false)
+    QwtPlot(parent), isInitialized(false),
+    customLabelScaleDraw(new CustomLabelScaleDraw(drawingProperties.getLabels()))
 {
     canvas()->setCursor(Qt::ArrowCursor);
     setUpActions();
@@ -193,6 +194,9 @@ void TracePlot::init(TraceNavigator *navigator, QScrollBar *scrollBar)
                                          navigator->GeneralTraceInfo().clkPeriod, this->mouseDownData.zoomSpan);
     getAndDrawComments();
     setZoomLevel(1000);
+
+    updateScrollbar();
+
     replot();
 }
 
@@ -209,7 +213,7 @@ void TracePlot::connectNavigatorQ_SIGNALS()
 
 void TracePlot::setUpDrawingProperties()
 {
-    drawingProperties.init(navigator->getTracePlotLines(), navigator->getCollapsedRanks());
+    drawingProperties.init(navigator->getTracePlotLines(), this);
 
     drawingProperties.numberOfRanks = navigator->GeneralTraceInfo().numberOfRanks;
     drawingProperties.numberOfBankgroups = navigator->GeneralTraceInfo().numberOfBankgroups;
@@ -271,6 +275,8 @@ void TracePlot::updateScrollbar()
     }
     else
         scrollBar->hide();
+
+    verticalScrollbarChanged(scrollBar->value());
 }
 
 void TracePlot::verticalScrollbarChanged(int value)
@@ -291,63 +297,9 @@ void TracePlot::verticalScrollbarChanged(int value)
 
 void TracePlot::setUpAxis()
 {
-    CustomLabelScaleDraw *customLabelScaleDraw = new CustomLabelScaleDraw(drawingProperties.getLabels());
-    customLabelScaleDraw->setMinimumExtent(135.0);
-
-    auto positionButton = [&](const TracePlotFirstRankLine &firstRankLine, RankButton &rankButton) {
-        QPointF point = this->axisScaleDraw(yLeft)->labelPosition(firstRankLine.getYVal());
-        rankButton.setGeometry(point.x(), point.y() - 4, 25, 25);
-    };
-
-    QObject::connect(customLabelScaleDraw, &CustomLabelScaleDraw::scaleRedraw, this, [=]() {
-        for (auto rankButton : rankCollapseButtons)
-        {
-            for (auto line : drawingProperties.getFirstRankLines(rankButton->rank))
-            {
-                auto firstRankLine = static_pointer_cast<TracePlotFirstRankLine>(line);
-                positionButton(*firstRankLine, *rankButton);
-            }
-        }
-    });
-
-    updateScrollbar();
-
     // Set up y axis.
-    verticalScrollbarChanged(scrollBar->value());
     setAxisScaleDraw(yLeft, customLabelScaleDraw);
-
-    // Add push buttons
-    for (auto line : drawingProperties.getTracePlotLines())
-    {
-        auto firstRankLine = std::dynamic_pointer_cast<TracePlotFirstRankLine>(line);
-        if (firstRankLine)
-        {
-            auto button = new RankButton(firstRankLine->rank, this);
-            if (drawingProperties.getRankCollapsedState(firstRankLine->rank))
-                button->setText("+");
-            else
-                button->setText("-");
-
-            positionButton(*firstRankLine, *button);
-
-            QObject::connect(button, &QPushButton::pressed, this, [=]() {
-                bool wasCollapsed = drawingProperties.getRankCollapsedState(button->rank);
-                drawingProperties.setRankCollapsedState(button->rank, !wasCollapsed);
-
-                if (wasCollapsed)
-                    button->setText("-");
-                else
-                    button->setText("+");
-
-                updateScrollbar();
-
-                Q_EMIT scrollBar->valueChanged(scrollBar->value());
-                Q_EMIT tracePlotLinesChanged();
-            });
-
-            rankCollapseButtons.push_back(button);
-        }
-    }
+    customLabelScaleDraw->setMinimumExtent(135.0);
 
     // Set up x axis.
     setAxisTitle(xBottom, "Time in ns");
@@ -380,6 +332,11 @@ void TracePlot::getAndDrawComments()
     }
 }
 
+CustomLabelScaleDraw *TracePlot::getCustomLabelScaleDraw() const
+{
+    return customLabelScaleDraw;
+}
+
 void TracePlot::enterZoomMode()
 {
     mouseDownData.mouseIsDownForZooming = true;
diff --git a/DRAMSys/traceAnalyzer/presentation/traceplot.h b/DRAMSys/traceAnalyzer/presentation/traceplot.h
index e63d3557..de6a70a5 100644
--- a/DRAMSys/traceAnalyzer/presentation/traceplot.h
+++ b/DRAMSys/traceAnalyzer/presentation/traceplot.h
@@ -61,14 +61,7 @@
  */
 
 class TracePlotMouseLabel;
-
-class RankButton : public QPushButton
-{
-    Q_OBJECT
-public:
-    explicit RankButton(unsigned int rank, QWidget *parent = nullptr) : QPushButton(parent), rank(rank) {}
-    const unsigned int rank;
-};
+class CustomLabelScaleDraw;
 
 class TracePlot : public QwtPlot
 {
@@ -87,12 +80,14 @@ public:
     void setUpActions();
 
     void setUpContextMenu();
+
+    CustomLabelScaleDraw *getCustomLabelScaleDraw() const;
 public Q_SLOTS:
     void currentTraceTimeChanged();
     void selectedTransactionsChanged();
     void commentsChanged();
     void verticalScrollbarChanged(int value);
-
+    void updateScrollbar();
 
 Q_SIGNALS:
     void tracePlotZoomChanged();
@@ -127,6 +122,7 @@ private:
     QueryEditor *queryEditor;
     QMenu *contextMenu;
     QScrollBar *scrollBar;
+    CustomLabelScaleDraw *customLabelScaleDraw;
 
     void setUpTracePlotItem();
     void setUpDrawingProperties();
@@ -138,9 +134,6 @@ private:
 
     void getAndDrawComments();
 
-    void updateScrollbar();
-
-
     /* zooming
      *
      */
@@ -206,8 +199,6 @@ private:
 
     MouseDownData mouseDownData;
     KeyPressData keyPressData;
-
-    std::vector<RankButton *> rankCollapseButtons;
 };
 
 
diff --git a/DRAMSys/traceAnalyzer/presentation/traceplotline.cpp b/DRAMSys/traceAnalyzer/presentation/traceplotline.cpp
index 57d7e693..2e561361 100644
--- a/DRAMSys/traceAnalyzer/presentation/traceplotline.cpp
+++ b/DRAMSys/traceAnalyzer/presentation/traceplotline.cpp
@@ -34,16 +34,17 @@
  */
 
 #include "traceplotline.h"
+#include "traceplot.h"
 
+#include <QPushButton>
+#include <qwt_plot.h>
 
-TracePlotLine::TracePlotLine(const QString &label, const std::shared_ptr<QHash<int, bool>> collapsedRanks) :
-    label(label),
-    collapsedRanks(collapsedRanks)
+TracePlotLine::TracePlotLine(const QString &label) :
+    label(label)
 {
 }
 
-TracePlotLine::TracePlotLine(const std::shared_ptr<QHash<int, bool>> collapsedRanks) :
-    collapsedRanks(collapsedRanks)
+TracePlotLine::TracePlotLine()
 {
 }
 
@@ -64,7 +65,6 @@ void TracePlotLine::setYVal (int yVal)
     this->yVal = yVal;
 }
 
-
 int TracePlotLine::getYVal() const
 {
     return yVal;
@@ -72,8 +72,13 @@ int TracePlotLine::getYVal() const
 
 
 TracePlotBankLine::TracePlotBankLine(unsigned int rank, unsigned int group, unsigned int bank,
-                                     const std::shared_ptr<QHash<int, bool>> collapsedRanks) :
-    TracePlotLine(collapsedRanks),
+                                     std::shared_ptr<TracePlotFirstRankLine> firstRankLine) :
+    TracePlotBankLine(rank, group, bank)
+{
+    this->firstRankLine = firstRankLine;
+}
+
+TracePlotBankLine::TracePlotBankLine(unsigned int rank, unsigned int group, unsigned int bank) :
     rank(rank), group(group), bank(bank)
 {
     QString rankLabel = QString("RA") + QString::number(rank);
@@ -85,25 +90,41 @@ TracePlotBankLine::TracePlotBankLine(unsigned int rank, unsigned int group, unsi
 
 bool TracePlotBankLine::isCollapsed() const
 {
-    return (*collapsedRanks)[rank];
+    return firstRankLine.lock()->isCollapsed();
 }
 
 
 TracePlotFirstRankLine::TracePlotFirstRankLine(unsigned int rank, unsigned int group, unsigned int bank,
-                                               const std::shared_ptr<QHash<int, bool>> collapsedRanks) :
-    TracePlotBankLine(rank, group, bank, collapsedRanks)
+                                               TracePlot *tracePlot) :
+    TracePlotBankLine(rank, group, bank),
+    collapseButton(new QPushButton(tracePlot)), tracePlot(tracePlot)
 {
     collapsedLabel = QString("RA") + QString::number(rank);
+
+    collapseButton->setText(collapsed ? "+" : "-");
+
+    QObject::connect(collapseButton, &QPushButton::pressed, this, [=](){
+        collapsed = !collapsed;
+        collapseButton->setText(collapsed ? "+" : "-");
+        Q_EMIT collapsedStateChanged();
+    });
+    updateButtonPosition();
+}
+
+void TracePlotFirstRankLine::updateButtonPosition()
+{
+    QPointF point = tracePlot->axisScaleDraw(QwtPlot::yLeft)->labelPosition(getYVal());
+    collapseButton->setGeometry(point.x(), point.y() - 4, 25, 25);
 }
 
 bool TracePlotFirstRankLine::isCollapsed() const
 {
-    return false;
+    return collapsed;
 }
 
 const QString & TracePlotFirstRankLine::getLabel() const
 {
-    if (TracePlotBankLine::isCollapsed())
+    if (collapsed)
         return collapsedLabel;
     else
         return TracePlotLine::getLabel();
diff --git a/DRAMSys/traceAnalyzer/presentation/traceplotline.h b/DRAMSys/traceAnalyzer/presentation/traceplotline.h
index 7493d7bc..0a3e9f36 100644
--- a/DRAMSys/traceAnalyzer/presentation/traceplotline.h
+++ b/DRAMSys/traceAnalyzer/presentation/traceplotline.h
@@ -36,14 +36,22 @@
 #ifndef TRACELOTLINE_H
 #define TRACELOTLINE_H
 
+#include <QObject>
 #include <QString>
 #include <QHash>
 #include <memory>
 
-class TracePlotLine
+class QPushButton;
+class TracePlot;
+
+class TracePlotFirstRankLine;
+
+class TracePlotLine : public QObject
 {
+    Q_OBJECT
+
 public:
-    TracePlotLine(const QString &label, const std::shared_ptr<QHash<int, bool>> collapsedRanks);
+    TracePlotLine(const QString &label);
     virtual ~TracePlotLine() = 0;
 
     virtual const QString & getLabel() const;
@@ -53,48 +61,65 @@ public:
     int getYVal() const;
 
 protected:
-    TracePlotLine(const std::shared_ptr<QHash<int, bool>> collapsedRanks);
+    TracePlotLine();
 
     QString label;
     int yVal;
-    const std::shared_ptr<QHash<int, bool>> collapsedRanks;
 };
 
-
 class TracePlotBankLine : public TracePlotLine
 {
+    Q_OBJECT
+
 public:
     TracePlotBankLine(unsigned int rank, unsigned int group, unsigned int bank,
-                      const std::shared_ptr<QHash<int, bool>> collapsedRanks);
+                      std::shared_ptr<TracePlotFirstRankLine> firstRankLine);
     ~TracePlotBankLine() = default;
-    void setCollapsed(bool value);
     virtual bool isCollapsed() const override;
 
     const unsigned int rank;
     const unsigned int group;
     const unsigned int bank;
+
+protected:
+    TracePlotBankLine(unsigned int rank, unsigned int group, unsigned int bank);
+
+private:
+    std::weak_ptr<TracePlotFirstRankLine> firstRankLine;
 };
 
 
 class TracePlotFirstRankLine final : public TracePlotBankLine
 {
+    Q_OBJECT
+
 public:
     TracePlotFirstRankLine(unsigned int rank, unsigned int group, unsigned int bank,
-                           const std::shared_ptr<QHash<int, bool>> collapsedRanks);
+                           TracePlot *tracePlot);
 
     ~TracePlotFirstRankLine() = default;
 
     bool isCollapsed() const override;
-
     const QString & getLabel() const override;
 
+public Q_SLOTS:
+    void updateButtonPosition();
+
+Q_SIGNALS:
+    void collapsedStateChanged();
+
 private:
     QString collapsedLabel;
+    QPushButton *collapseButton;
+    bool collapsed = true;
+    TracePlot *tracePlot;
 };
 
 
 class TracePlotRequestLine final : public TracePlotLine
 {
+    Q_OBJECT
+
 public:
     using TracePlotLine::TracePlotLine;
     ~TracePlotRequestLine() = default;
@@ -102,6 +127,8 @@ public:
 
 class TracePlotResponseLine final : public TracePlotLine
 {
+    Q_OBJECT
+
 public:
     using TracePlotLine::TracePlotLine;
     ~TracePlotResponseLine() = default;
@@ -109,6 +136,8 @@ public:
 
 class TracePlotDataBusLine final : public TracePlotLine
 {
+    Q_OBJECT
+
 public:
     using TracePlotLine::TracePlotLine;
     ~TracePlotDataBusLine() = default;
@@ -116,6 +145,8 @@ public:
 
 class TracePlotCommandBusLine final : public TracePlotLine
 {
+    Q_OBJECT
+
 public:
     using TracePlotLine::TracePlotLine;
     ~TracePlotCommandBusLine() = default;
diff --git a/DRAMSys/traceAnalyzer/presentation/tracescroller.cpp b/DRAMSys/traceAnalyzer/presentation/tracescroller.cpp
index 629f5c33..4faca38a 100644
--- a/DRAMSys/traceAnalyzer/presentation/tracescroller.cpp
+++ b/DRAMSys/traceAnalyzer/presentation/tracescroller.cpp
@@ -62,9 +62,11 @@ void TraceScroller::init(TraceNavigator *navigator, TracePlot *tracePlot)
     connectNavigatorQ_SIGNALS();
 
     setUpDrawingProperties();
-    // setUpDrawingProperties() must be called before setUpAxis().
     setUpAxis();
     setUpTracePlotItem();
+
+    updateAxis();
+
     getAndDrawComments();
 
     this->tracePlot = tracePlot;
@@ -89,7 +91,7 @@ void TraceScroller::setUpTracePlotItem()
 
 void TraceScroller::setUpDrawingProperties()
 {
-    drawingProperties.init(navigator->getTracePlotLines(), navigator->getCollapsedRanks());
+    drawingProperties.init(navigator->getTracePlotLines());
 
     drawingProperties.numberOfRanks = navigator->GeneralTraceInfo().numberOfRanks;
     drawingProperties.numberOfBankgroups = navigator->GeneralTraceInfo().numberOfBankgroups;
@@ -102,7 +104,6 @@ void TraceScroller::setUpDrawingProperties()
 
 void TraceScroller::setUpAxis()
 {
-    updateAxis();
     axisScaleDraw(yLeft)->enableComponent(QwtAbstractScaleDraw::Labels, false );
     axisScaleDraw(yLeft)->enableComponent(QwtAbstractScaleDraw::Ticks, false );
 }