diff --git a/apps/graph/app.cpp b/apps/graph/app.cpp
index 8c8bd9188..d7b347aeb 100644
--- a/apps/graph/app.cpp
+++ b/apps/graph/app.cpp
@@ -70,7 +70,7 @@ App::App(Container * container, Snapshot * snapshot) :
   m_valuesAlternateEmptyViewController(&m_valuesHeader, &m_valuesController, &m_valuesController),
   m_valuesHeader(&m_valuesStackViewController, &m_valuesAlternateEmptyViewController, &m_valuesController),
   m_valuesStackViewController(&m_tabViewController, &m_valuesHeader),
-  m_tabViewController(&m_inputViewController, &m_listStackViewController, &m_graphStackViewController, &m_valuesStackViewController),
+  m_tabViewController(&m_inputViewController, snapshot, &m_listStackViewController, &m_graphStackViewController, &m_valuesStackViewController),
   m_inputViewController(&m_modalViewController, &m_tabViewController, this)
 {
 }
diff --git a/apps/regression/app.cpp b/apps/regression/app.cpp
index e378caf2f..ae4276bdf 100644
--- a/apps/regression/app.cpp
+++ b/apps/regression/app.cpp
@@ -70,7 +70,7 @@ App::App(Container * container, Snapshot * snapshot) :
   m_storeController(&m_storeHeader, snapshot->store(), &m_storeHeader),
   m_storeHeader(&m_storeStackViewController, &m_storeController, &m_storeController),
   m_storeStackViewController(&m_tabViewController, &m_storeHeader),
-  m_tabViewController(&m_modalViewController, &m_storeStackViewController, &m_graphStackViewController, &m_calculationHeader)
+  m_tabViewController(&m_modalViewController, snapshot, &m_storeStackViewController, &m_graphStackViewController, &m_calculationHeader)
 {
 }
 
diff --git a/apps/regression/app.h b/apps/regression/app.h
index 521a66ae9..78288fae9 100644
--- a/apps/regression/app.h
+++ b/apps/regression/app.h
@@ -18,7 +18,7 @@ public:
     I18n::Message upperName() override;
     const Image * icon() override;
   };
-  class Snapshot : public ::App::Snapshot {
+  class Snapshot : public ::App::Snapshot, public TabViewDataSource {
   public:
     Snapshot();
     App * unpack(Container * container) override;
diff --git a/apps/sequence/app.cpp b/apps/sequence/app.cpp
index 1dfb024b5..eab2e392c 100644
--- a/apps/sequence/app.cpp
+++ b/apps/sequence/app.cpp
@@ -68,7 +68,7 @@ App::App(Container * container, Snapshot * snapshot) :
   m_valuesAlternateEmptyViewController(&m_valuesHeader, &m_valuesController, &m_valuesController),
   m_valuesHeader(nullptr, &m_valuesAlternateEmptyViewController, &m_valuesController),
   m_valuesStackViewController(&m_tabViewController, &m_valuesHeader),
-  m_tabViewController(&m_inputViewController, &m_listStackViewController, &m_graphStackViewController, &m_valuesStackViewController),
+  m_tabViewController(&m_inputViewController, snapshot, &m_listStackViewController, &m_graphStackViewController, &m_valuesStackViewController),
   m_inputViewController(&m_modalViewController, &m_tabViewController, &m_listController)
 {
 }
diff --git a/apps/shared/function_app.h b/apps/shared/function_app.h
index 68a7e6a4a..b4d1a63ca 100644
--- a/apps/shared/function_app.h
+++ b/apps/shared/function_app.h
@@ -12,7 +12,7 @@ namespace Shared {
 
 class FunctionApp : public TextFieldDelegateApp {
 public:
-  class Snapshot : public ::App::Snapshot {
+  class Snapshot : public ::App::Snapshot, public TabViewDataSource {
   public:
     Snapshot();
     CurveViewCursor * cursor();
diff --git a/apps/statistics/app.cpp b/apps/statistics/app.cpp
index 8b487457c..a73742354 100644
--- a/apps/statistics/app.cpp
+++ b/apps/statistics/app.cpp
@@ -85,7 +85,7 @@ App::App(Container * container, Snapshot * snapshot) :
   m_storeController(&m_storeHeader, snapshot->store(), &m_storeHeader),
   m_storeHeader(&m_storeStackViewController, &m_storeController, &m_storeController),
   m_storeStackViewController(&m_tabViewController, &m_storeHeader),
-   m_tabViewController(&m_modalViewController, &m_storeStackViewController, &m_histogramStackViewController, &m_boxHeader, &m_calculationHeader)
+  m_tabViewController(&m_modalViewController, snapshot, &m_storeStackViewController, &m_histogramStackViewController, &m_boxHeader, &m_calculationHeader)
 {
 }
 
diff --git a/apps/statistics/app.h b/apps/statistics/app.h
index 9cd2f84cc..ee6e46e02 100644
--- a/apps/statistics/app.h
+++ b/apps/statistics/app.h
@@ -19,7 +19,7 @@ public:
     I18n::Message upperName() override;
     const Image * icon() override;
   };
-  class Snapshot : public ::App::Snapshot {
+  class Snapshot : public ::App::Snapshot, public TabViewDataSource {
   public:
     Snapshot();
     App * unpack(Container * container) override;
diff --git a/escher/Makefile b/escher/Makefile
index 5d4e188d6..0da0c885a 100644
--- a/escher/Makefile
+++ b/escher/Makefile
@@ -55,6 +55,7 @@ objs += $(addprefix escher/src/,\
   tab_view.o\
   tab_view_cell.o\
   tab_view_controller.o\
+  tab_view_data_source.o\
   table_cell.o\
   table_view.o\
   table_view_data_source.o\
diff --git a/escher/include/escher.h b/escher/include/escher.h
index e2d74acb4..35df10e91 100644
--- a/escher/include/escher.h
+++ b/escher/include/escher.h
@@ -58,6 +58,7 @@
 #include <escher/text_field_delegate.h>
 #include <escher/text_view.h>
 #include <escher/tab_view_controller.h>
+#include <escher/tab_view_data_source.h>
 #include <escher/table_cell.h>
 #include <escher/table_view.h>
 #include <escher/table_view_data_source.h>
diff --git a/escher/include/escher/tab_view_controller.h b/escher/include/escher/tab_view_controller.h
index 79131b0b6..d3a581a23 100644
--- a/escher/include/escher/tab_view_controller.h
+++ b/escher/include/escher/tab_view_controller.h
@@ -2,11 +2,12 @@
 #define ESCHER_TAB_VIEW_CONTROLLER_H
 
 #include <escher/view_controller.h>
+#include <escher/tab_view_data_source.h>
 #include <escher/tab_view.h>
 
 class TabViewController : public ViewController {
 public:
-  TabViewController(Responder * parentResponder, ViewController * one, ViewController * two, ViewController * three, ViewController * four = nullptr);
+  TabViewController(Responder * parentResponder, TabViewDataSource * dataSource, ViewController * one, ViewController * two, ViewController * three, ViewController * four = nullptr);
   View * view() override;
   int activeTab() const;
   void setSelectedTab(int8_t index);
@@ -45,8 +46,7 @@ private:
   static constexpr uint8_t k_maxNumberOfChildren = 4;
   ViewController * m_children[k_maxNumberOfChildren];
   uint8_t m_numberOfChildren;
-  int8_t m_activeChildIndex;
-  int8_t m_selectedChildIndex;
+  TabViewDataSource * m_dataSource;
 };
 
 #endif
diff --git a/escher/include/escher/tab_view_data_source.h b/escher/include/escher/tab_view_data_source.h
new file mode 100644
index 000000000..2dde629f4
--- /dev/null
+++ b/escher/include/escher/tab_view_data_source.h
@@ -0,0 +1,20 @@
+#ifndef ESCHER_TAB_VIEW_DATA_SOURCE_H
+#define ESCHER_TAB_VIEW_DATA_SOURCE_H
+
+extern "C" {
+#include <stdint.h>
+}
+
+class TabViewDataSource {
+public:
+  TabViewDataSource();
+  int activeTab() const;
+  int selectedTab() const;
+  void setSelectedTab(int index);
+  void setActiveTab(int index);
+private:
+  int8_t m_activeChildIndex;
+  int8_t m_selectedChildIndex;
+};
+
+#endif
diff --git a/escher/src/tab_view_controller.cpp b/escher/src/tab_view_controller.cpp
index 4df33fb37..0ac87489a 100644
--- a/escher/src/tab_view_controller.cpp
+++ b/escher/src/tab_view_controller.cpp
@@ -52,10 +52,9 @@ const char * TabViewController::ContentView::className() const {
 }
 #endif
 
-TabViewController::TabViewController(Responder * parentResponder, ViewController * one, ViewController * two, ViewController * three, ViewController * four) :
+TabViewController::TabViewController(Responder * parentResponder, TabViewDataSource * dataSource, ViewController * one, ViewController * two, ViewController * three, ViewController * four) :
   ViewController(parentResponder),
-  m_activeChildIndex(-1),
-  m_selectedChildIndex(-1)
+  m_dataSource(dataSource)
 {
   assert(one != nullptr);
   assert(two != nullptr || (three == nullptr && four == nullptr));
@@ -72,7 +71,7 @@ TabViewController::TabViewController(Responder * parentResponder, ViewController
 }
 
 int TabViewController::activeTab() const {
-  return m_activeChildIndex;
+  return m_dataSource->activeTab();
 }
 
 bool TabViewController::handleEvent(Ion::Events::Event event) {
@@ -87,23 +86,23 @@ bool TabViewController::handleEvent(Ion::Events::Event event) {
     return false;
   }
   if (event == Ion::Events::Left) {
-    if (m_selectedChildIndex > 0) {
-      setSelectedTab(m_selectedChildIndex-1);
+    if (m_dataSource->selectedTab() > 0) {
+      setSelectedTab(m_dataSource->selectedTab()-1);
     }
     return true;
   }
   if (event == Ion::Events::Right) {
-    if (m_selectedChildIndex < m_numberOfChildren-1) {
-      setSelectedTab(m_selectedChildIndex+1);
+    if (m_dataSource->selectedTab() < m_numberOfChildren-1) {
+      setSelectedTab(m_dataSource->selectedTab()+1);
     }
     return true;
   }
   if (event == Ion::Events::Down) {
-    setActiveTab(m_activeChildIndex, false);
+    setActiveTab(m_dataSource->activeTab(), false);
     return true;
   }
   if (event == Ion::Events::OK || event == Ion::Events::EXE) {
-    setActiveTab(m_selectedChildIndex, true);
+    setActiveTab(m_dataSource->selectedTab(), true);
     return true;
   }
   return false;
@@ -112,28 +111,28 @@ bool TabViewController::handleEvent(Ion::Events::Event event) {
 void TabViewController::setActiveTab(int8_t i, bool forceReactive) {
   assert(i >= 0 && i < m_numberOfChildren);
   ViewController * activeVC = m_children[i];
-  if (i  != m_activeChildIndex || forceReactive) {
-    if (i != m_activeChildIndex) {
+  if (i  != m_dataSource->activeTab() || forceReactive) {
+    if (i != m_dataSource->activeTab()) {
       m_view.setActiveView(activeVC->view());
       m_children[i]->viewWillAppear();
     }
     m_view.m_tabView.setActiveIndex(i);
   }
   app()->setFirstResponder(activeVC);
-  if (i  != m_activeChildIndex || forceReactive) {
-      if (m_activeChildIndex >= 0 && m_activeChildIndex != i) {
-      m_children[m_activeChildIndex]->viewDidDisappear();
+  if (i  != m_dataSource->activeTab() || forceReactive) {
+      if (m_dataSource->activeTab() >= 0 && m_dataSource->activeTab() != i) {
+      m_children[m_dataSource->activeTab()]->viewDidDisappear();
     }
-    m_activeChildIndex = i;
+    m_dataSource->setActiveTab(i);
   }
 }
 
 void TabViewController::setSelectedTab(int8_t i) {
-  if (i == m_selectedChildIndex) {
+  if (i == m_dataSource->selectedTab()) {
     return;
   }
   m_view.m_tabView.setSelectedIndex(i);
-  m_selectedChildIndex = i;
+  m_dataSource->setSelectedTab(i);
 }
 
 void TabViewController::didEnterResponderChain(Responder * previousResponder) {
@@ -141,7 +140,7 @@ void TabViewController::didEnterResponderChain(Responder * previousResponder) {
 }
 
 void TabViewController::didBecomeFirstResponder() {
-  setSelectedTab(m_activeChildIndex);
+  setSelectedTab(m_dataSource->activeTab());
 }
 
 void TabViewController::willResignFirstResponder() {
@@ -167,12 +166,12 @@ void TabViewController::viewWillAppear() {
       m_view.m_tabView.addTab(m_children[i]);
     }
   }
-  if (m_activeChildIndex < 0) {
-    m_activeChildIndex = 0;
+  if (m_dataSource->activeTab() < 0) {
+    m_dataSource->setActiveTab(0);
   }
-  m_view.setActiveView(m_children[m_activeChildIndex]->view());
+  m_view.setActiveView(m_children[m_dataSource->activeTab()]->view());
   activeViewController()->viewWillAppear();
-  m_view.m_tabView.setActiveIndex(m_activeChildIndex);
+  m_view.m_tabView.setActiveIndex(m_dataSource->activeTab());
 }
 
 void TabViewController::viewDidDisappear() {
@@ -180,6 +179,6 @@ void TabViewController::viewDidDisappear() {
 }
 
 ViewController * TabViewController::activeViewController() {
-  assert(m_activeChildIndex >= 0 && m_activeChildIndex < m_numberOfChildren);
-  return m_children[m_activeChildIndex];
+  assert(m_dataSource->activeTab() >= 0 && m_dataSource->activeTab() < m_numberOfChildren);
+  return m_children[m_dataSource->activeTab()];
 }
diff --git a/escher/src/tab_view_data_source.cpp b/escher/src/tab_view_data_source.cpp
new file mode 100644
index 000000000..7aee60d00
--- /dev/null
+++ b/escher/src/tab_view_data_source.cpp
@@ -0,0 +1,23 @@
+#include <escher/tab_view_data_source.h>
+
+TabViewDataSource::TabViewDataSource() :
+  m_activeChildIndex(-1),
+  m_selectedChildIndex(-1)
+{
+}
+
+int TabViewDataSource::activeTab() const {
+  return m_activeChildIndex;
+}
+
+int TabViewDataSource::selectedTab() const {
+  return m_selectedChildIndex;
+}
+void TabViewDataSource::setActiveTab(int i) {
+  m_activeChildIndex = i;
+}
+
+void TabViewDataSource::setSelectedTab(int i) {
+  m_selectedChildIndex = i;
+}
+