Added new user event Move for scrolling the map by buttons.

drape_frontend/drape_engine.cpp

@@ -188,6 +188,11 @@ void DrapeEngine::Scale(double factor, m2::PointD const & pxPoint, bool isAnim)
   AddUserEvent(make_unique_dp<ScaleEvent>(factor, pxPoint, isAnim));
 }
 
+void DrapeEngine::Move(double factorX, double factorY, bool isAnim)
+{
+  AddUserEvent(make_unique_dp<MoveEvent>(factorX, factorY, isAnim));
+}
+
 void DrapeEngine::SetModelViewCenter(m2::PointD const & centerPt, int zoom, bool isAnim,
                                      bool trackVisibleViewport)
 {

drape_frontend/drape_engine.hpp

@@ -126,6 +126,7 @@ public:
 
   void AddTouchEvent(TouchEvent const & event);
   void Scale(double factor, m2::PointD const & pxPoint, bool isAnim);
+  void Move(double factorX, double factorY, bool isAnim);
 
   // If zoom == -1 then current zoom will not be changed.
   void SetModelViewCenter(m2::PointD const & centerPt, int zoom, bool isAnim,

drape_frontend/user_event_stream.cpp

@@ -177,6 +177,13 @@ ScreenBase const & UserEventStream::ProcessEvents(bool & modelViewChanged, bool
         TouchCancel(m_touches);
       }
       break;
+    case UserEvent::EventType::Move:
+      {
+        ref_ptr<MoveEvent> moveEvent = make_ref(e);
+        breakAnim = OnMove(moveEvent);
+        TouchCancel(m_touches);
+      }
+      break;
     case UserEvent::EventType::Resize:
       {
         ref_ptr<ResizeEvent> resizeEvent = make_ref(e);
@@ -360,6 +367,21 @@ bool UserEventStream::OnSetScale(ref_ptr<ScaleEvent> scaleEvent)
   return true;
 }
 
+bool UserEventStream::OnMove(ref_ptr<MoveEvent> moveEvent)
+{
+  double const factorX = moveEvent->GetFactorX();
+  double const factorY = moveEvent->GetFactorY();
+
+  ScreenBase screen;
+  GetTargetScreen(screen);
+  auto const & rect = screen.PixelRectIn3d();
+  screen.Move(factorX * rect.SizeX(), -factorY * rect.SizeY());
+
+  ShrinkAndScaleInto(screen, df::GetWorldRect());
+
+  return SetScreen(screen, moveEvent->IsAnim());
+}
+
 bool UserEventStream::OnSetAnyRect(ref_ptr<SetAnyRectEvent> anyRectEvent)
 {
   return SetRect(anyRectEvent->GetRect(), anyRectEvent->IsAnim(), anyRectEvent->FitInViewport());

drape_frontend/user_event_stream.hpp

@@ -40,7 +40,8 @@ public:
     Rotate,
     FollowAndRotate,
     AutoPerspective,
-    VisibleViewport
+    VisibleViewport,
+    Move
   };
 
   virtual ~UserEvent() = default;
@@ -134,6 +135,27 @@ private:
   bool m_isAnim;
 };
 
+class MoveEvent : public UserEvent
+{
+public:
+  MoveEvent(double factorX, double factorY, bool isAnim)
+    : m_factorX(factorX)
+    , m_factorY(factorY)
+    , m_isAnim(isAnim)
+  {}
+
+  EventType GetType() const override { return UserEvent::EventType::Move; }
+
+  double GetFactorX() const { return m_factorX; }
+  double GetFactorY() const { return m_factorY; }
+  bool IsAnim() const { return m_isAnim; }
+
+private:
+  double m_factorX;
+  double m_factorY;
+  bool m_isAnim;
+};
+
 class SetCenterEvent : public UserEvent
 {
 public:
@@ -402,6 +424,7 @@ public:
 
 private:
   bool OnSetScale(ref_ptr<ScaleEvent> scaleEvent);
+  bool OnMove(ref_ptr<MoveEvent> moveEvent);
   bool OnSetAnyRect(ref_ptr<SetAnyRectEvent> anyRectEvent);
   bool OnSetRect(ref_ptr<SetRectEvent> rectEvent);
   bool OnSetCenter(ref_ptr<SetCenterEvent> centerEvent);

map/framework.cpp

@@ -1274,6 +1274,12 @@ void Framework::Scale(double factor, m2::PointD const & pxPoint, bool isAnim)
     m_drapeEngine->Scale(factor, pxPoint, isAnim);
 }
 
+void Framework::Move(double factorX, double factorY, bool isAnim)
+{
+  if (m_drapeEngine != nullptr)
+    m_drapeEngine->Move(factorX, factorY, isAnim);
+}
+
 void Framework::TouchEvent(df::TouchEvent const & touch)
 {
   if (m_drapeEngine != nullptr)

map/framework.hpp

@@ -655,6 +655,12 @@ public:
   void Scale(double factor, bool isAnim);
   void Scale(double factor, m2::PointD const & pxPoint, bool isAnim);
 
+  /// Moves the viewport a distance of factorX * viewportWidth and factorY * viewportHeight.
+  /// E.g. factorX == 1.0 moves the map one screen size to the right, factorX == -0.5 moves the map
+  /// half screen size to the left, factorY == -2.0 moves the map two sizes down,
+  /// factorY = 1.5 moves the map one and a half size up.
+  void Move(double factorX, double factorY, bool isAnim);
+
   void TouchEvent(df::TouchEvent const & touch);
   //@}