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#include "win32/base/indicator_visibility_tracker.h"

#include "base/stopwatch.h"

namespace mozc {
namespace win32 {
namespace {

#ifdef MOZC_ENABLE_MODE_INDICATOR
const bool kIndicatorSupported = true;
#else
const bool kIndicatorSupported = false;
#endif  // MOZC_ENABLE_MODE_INDICATOR

const double kIgnoreMoveWindowDuration = 500.0;  // msec

IndicatorVisibilityTracker::Action GetDefaultAction(
    bool previously_visible, bool now_visible) {
  if (!kIndicatorSupported) {
    return IndicatorVisibilityTracker::kNothing;
  }

  if (previously_visible == now_visible) {
    return IndicatorVisibilityTracker::kNothing;
  }
  return IndicatorVisibilityTracker::kUpdateUI;
}

}  // namespace

struct IndicatorVisibilityTracker::InternalState {
 public:
  InternalState()
      : visible(false) {}

  bool visible;
  Stopwatch mode_changed_;

 private:
  DISALLOW_COPY_AND_ASSIGN(InternalState);
};

IndicatorVisibilityTracker::IndicatorVisibilityTracker()
    : state_(new InternalState) {}

IndicatorVisibilityTracker::~IndicatorVisibilityTracker() {}

IndicatorVisibilityTracker::Action
IndicatorVisibilityTracker::OnDissociateContext() {
  const bool original = state_->visible;
  state_->visible = false;
  state_->mode_changed_.Reset();
  return GetDefaultAction(original, state_->visible);
}

IndicatorVisibilityTracker::Action IndicatorVisibilityTracker::OnTestKey(
    const VirtualKey &key, bool is_down, bool eaten) {
  if (!is_down) {
    return kNothing;
  }
  const bool original = state_->visible;
  state_->visible = false;
  state_->mode_changed_.Reset();
  return GetDefaultAction(original, state_->visible);
}

IndicatorVisibilityTracker::Action IndicatorVisibilityTracker::OnKey(
    const VirtualKey &key, bool is_down, bool eaten) {
  if (!is_down) {
    return kNothing;
  }
  const bool original = state_->visible;
  state_->visible = false;
  state_->mode_changed_.Reset();
  return GetDefaultAction(original, state_->visible);
}

IndicatorVisibilityTracker::Action
IndicatorVisibilityTracker::OnMoveFocusedWindow() {
  const bool original = state_->visible;
  if (state_->mode_changed_.IsRunning()) {
    if (state_->mode_changed_.GetElapsedMilliseconds() >=
        kIgnoreMoveWindowDuration) {
      state_->mode_changed_.Reset();
      state_->visible = false;
    }
  } else {
    state_->visible = false;
  }
  return GetDefaultAction(original, state_->visible);
}

IndicatorVisibilityTracker::Action
IndicatorVisibilityTracker::OnChangeInputMode() {
  const bool original = state_->visible;
  state_->visible = true;
  state_->mode_changed_.Stop();
  state_->mode_changed_.Reset();
  state_->mode_changed_.Start();
  return GetDefaultAction(original, state_->visible);
}

bool IndicatorVisibilityTracker::IsVisible() const {
  if (!kIndicatorSupported) {
    return false;
  }

  return state_->visible;
}

}  // namespace win32
}  // namespace mozc