Repo created

libs/drape_frontend/animation/show_hide_animation.cpp

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+#include "show_hide_animation.hpp"
+
+#include "base_interpolator.hpp"
+
+#include "base/math.hpp"
+
+namespace df
+{
+class ShowHideAnimation::ShowHideInterpolator : public BaseInterpolator
+{
+public:
+  ShowHideInterpolator(ShowHideAnimation::EState & state, double startT, double endT, double duration)
+    : BaseInterpolator(duration)
+    , m_state(state)
+    , m_startT(startT)
+    , m_endT(endT)
+  {
+    m_state = m_endT > m_startT ? ShowHideAnimation::STATE_SHOW_DIRECTION : ShowHideAnimation::STATE_HIDE_DIRECTION;
+  }
+
+  void Advance(double elapsedSeconds) override
+  {
+    BaseInterpolator::Advance(elapsedSeconds);
+    if (IsFinished())
+      m_state = m_endT > m_startT ? ShowHideAnimation::STATE_VISIBLE : ShowHideAnimation::STATE_INVISIBLE;
+  }
+
+  double GetCurrentT() const { return m_startT + (m_endT - m_startT) * GetT(); }
+
+private:
+  ShowHideAnimation::EState & m_state;
+  double m_startT;
+  double m_endT;
+};
+
+ShowHideAnimation::ShowHideAnimation(bool isInitialVisible, double fullDuration)
+  : m_state(isInitialVisible ? STATE_VISIBLE : STATE_INVISIBLE)
+  , m_fullDuration(fullDuration)
+{}
+
+ShowHideAnimation::~ShowHideAnimation()
+{
+  m_interpolator.reset();
+}
+
+void ShowHideAnimation::Show()
+{
+  EState state = GetState();
+  if (state == STATE_INVISIBLE || state == STATE_HIDE_DIRECTION)
+  {
+    m_state = STATE_VISIBLE;
+    m_interpolator.reset();
+  }
+}
+
+void ShowHideAnimation::ShowAnimated()
+{
+  RefreshInterpolator({{STATE_VISIBLE, STATE_SHOW_DIRECTION}}, 1.0);
+}
+
+void ShowHideAnimation::Hide()
+{
+  EState state = GetState();
+  if (state == STATE_VISIBLE || state == STATE_SHOW_DIRECTION)
+  {
+    m_state = STATE_INVISIBLE;
+    m_interpolator.reset();
+  }
+}
+
+void ShowHideAnimation::HideAnimated()
+{
+  RefreshInterpolator({{STATE_INVISIBLE, STATE_HIDE_DIRECTION}}, 0.0);
+}
+
+ShowHideAnimation::EState ShowHideAnimation::GetState() const
+{
+  return m_state;
+}
+
+double ShowHideAnimation::GetT() const
+{
+  if (m_interpolator)
+    return m_interpolator->GetCurrentT();
+
+  ASSERT(m_state != STATE_SHOW_DIRECTION, ());
+  ASSERT(m_state != STATE_HIDE_DIRECTION, ());
+
+  return m_state == STATE_VISIBLE ? 1.0 : 0.0;
+}
+
+bool ShowHideAnimation::IsFinished() const
+{
+  return m_interpolator == nullptr || m_interpolator->IsFinished();
+}
+
+void ShowHideAnimation::RefreshInterpolator(std::array<EState, 2> validStates, double endValue)
+{
+  EState state = GetState();
+  if (state == validStates[0] || state == validStates[1])
+    return;
+
+  double start = GetT();
+  double end = endValue;
+  double duration = fabs(end - start) * m_fullDuration;
+  m_interpolator.reset(new ShowHideInterpolator(m_state, start, end, duration));
+}
+}  // namespace df