FarGroupgh-750: Fixed VMenu set selection behavior around list edges.

Warning! Bugs are expected.

far/changelog

@@ -1,3 +1,9 @@
+--------------------------------------------------------------------------------
+MZK 2023-11-26 18:50:33-08:00 - build 6219
+
+1. gh-750: Fixed VMenu set selection behavior around list edges.
+ Warning! Bugs are expected.
+
 --------------------------------------------------------------------------------
 drkns 2023-11-26 15:22:17+00:00 - build 6218
 

far/headers.hpp

@@ -82,6 +82,7 @@ THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <mutex>
 #include <numeric>
 #include <optional>
+#include <ranges>
 #include <random>
 #include <regex>
 #include <set>

far/vbuild.m4

@@ -1 +1 @@
-6218
+6219

far/vmenu.cpp

@@ -140,15 +140,45 @@ void VMenu::ResetCursor()
  GetCursorType(PrevCursorVisible,PrevCursorSize);
 }
 
+template <typename coll, typename pred>
+int FindNearestSelectableItem(const coll& Coll, const int Pos, pred&& Pred, const bool GoBackward, const bool DoWrap)
+{
+ assert(0 <= Pos && Pos < static_cast<int>(Coll.size()));
+
+ const auto FindPos{
+ [&](const auto First, const auto Second)
+ {
+ const auto FindPos{
+ [&](const auto Part)
+ {
+ const auto Found{ std::ranges::find_if(Part, Pred) };
+ if (Found == std::ranges::end(Part)) return -1;
+ return static_cast<int>(std::ranges::distance(&*std::ranges::begin(Coll), &*Found));
+ } };
+
+ if (const auto Found{ FindPos(Coll | First) }; Found != -1) return Found;
+ if (const auto Found{ FindPos(Coll | Second) }; Found != -1) return Found;
+ return -1;
+ } };
+
+ return GoBackward
+ ? (DoWrap
+ ? FindPos(std::views::take(Pos + 1) | std::views::reverse, std::views::drop(Pos + 1) | std::views::reverse)
+ : FindPos(std::views::take(Pos + 1) | std::views::reverse, std::views::drop(Pos + 1)))
+ : (DoWrap
+ ? FindPos(std::views::drop(Pos), std::views::take(Pos))
+ : FindPos(std::views::drop(Pos), std::views::take(Pos) | std::views::reverse));
+}
+
 //может иметь фокус
-static bool ItemCanHaveFocus(unsigned long long const Flags)
+static bool ItemCanHaveFocusFlags(unsigned long long const Flags)
 {
  return !(Flags & (LIF_DISABLE | LIF_HIDDEN | LIF_FILTERED | LIF_SEPARATOR));
 }
 
 static bool ItemCanHaveFocus(MenuItemEx const& Item)
 {
- return ItemCanHaveFocus(Item.Flags);
+ return ItemCanHaveFocusFlags(Item.Flags);
 }
 
 //может быть выбран
@@ -177,7 +207,7 @@ void VMenu::UpdateItemFlags(int Pos, unsigned long long NewFlags)
  --ItemHiddenCount;
 
 
- if (!ItemCanHaveFocus(NewFlags))
+ if (!ItemCanHaveFocusFlags(NewFlags))
  NewFlags &= ~LIF_SELECTED;
 
  //remove selection
@@ -228,54 +258,20 @@ int VMenu::SetSelectPos(int Pos, int Direct, bool stop_on_edge)
  i.Flags &= ~LIF_SELECTED;
  }
 
- for (int Pass=0, I=0;;I++)
- {
- if (Pos<0)
- {
- if (CheckFlags(VMENU_WRAPMODE))
- {
- Pos = static_cast<int>(Items.size()-1);
- TopPos = Pos;
- }
- else
- {
- Pos = 0;
- TopPos = 0;
- Pass++;
- }
- }
- else if (Pos>=static_cast<int>(Items.size()))
- {
- if (CheckFlags(VMENU_WRAPMODE))
- {
- Pos = 0;
- TopPos = 0;
- }
- else
- {
- Pos = static_cast<int>(Items.size()-1);
- Pass++;
- }
- }
-
- if (ItemCanHaveFocus(Items[Pos]))
- break;
-
- if (Pass)
- {
- Pos = SelectPos;
- break;
- }
-
- Pos += Direct;
+ const auto DoWrap{ CheckFlags(VMENU_WRAPMODE) && Direct != 0 && !stop_on_edge };
+ const auto GoBackward{ Direct < 0 };
+ const auto ItemsSize{ static_cast<int>(Items.size()) };
 
- if (I>=static_cast<int>(Items.size())) // круг пройден - ничего не найдено :-(
- Pass++;
+ if (Pos < 0)
+ {
+ Pos = DoWrap ? ItemsSize - 1 : 0;
+ }
+ else if (Pos >= ItemsSize)
+ {
+ Pos = DoWrap ? 0 : ItemsSize - 1;
  }
 
- if (stop_on_edge && CheckFlags(VMENU_WRAPMODE) && ((Direct > 0 && Pos < SelectPos) || (Direct<0 && Pos>SelectPos)))
- Pos = SelectPos;
-
+ Pos = FindNearestSelectableItem(Items, Pos, ItemCanHaveFocus, GoBackward, DoWrap);
 
  if (Pos != SelectPos && CheckFlags(VMENU_COMBOBOX | VMENU_LISTBOX))
  {
@@ -287,11 +283,11 @@ int VMenu::SetSelectPos(int Pos, int Direct, bool stop_on_edge)
  }
 
  if (Pos >= 0)
- UpdateItemFlags(Pos, Items[Pos].Flags|LIF_SELECTED);
+ UpdateItemFlags(Pos, Items[Pos].Flags | LIF_SELECTED);
 
  SetMenuFlags(VMENU_UPDATEREQUIRED);
 
- SelectPosResult=Pos;
+ SelectPosResult = Pos;
  return Pos;
 }
 
@@ -523,7 +519,7 @@ int VMenu::DeleteItem(int ID, int Count)
  ID--;
  }
  SelectPos = -1;
- SetSelectPos(ID,1);
+ SetSelectPos(ID, 0, true);
  }
  else if (SelectPos >= ID+Count)
  {
@@ -1328,26 +1324,14 @@ bool VMenu::ProcessKey(const Manager::Key& Key)
  }
  case KEY_MSWHEEL_UP:
  {
- if(SelectPos)
- {
- FarListPos Pos{ sizeof(Pos), SelectPos - 1, TopPos - 1 };
- SetSelectPos(&Pos);
- ShowMenu(true);
- }
+ SetSelectPos(SelectPos - 1, -1, true);
+ ShowMenu(true);
  break;
  }
  case KEY_MSWHEEL_DOWN:
  {
- if(SelectPos < static_cast<int>(Items.size()-1))
- {
- FarListPos Pos{ sizeof(Pos), SelectPos + 1, TopPos };
- const auto ItemsSize = static_cast<int>(Items.size());
- const auto HeightSize = std::max(0, m_Where.height() - (m_BoxType == NO_BOX? 0 : 2));
- if (!(ItemsSize - TopPos <= HeightSize || ItemsSize <= HeightSize))
- Pos.TopPos++;
- SetSelectPos(&Pos);
- ShowMenu(true);
- }
+ SetSelectPos(SelectPos + 1, 1, true);
+ ShowMenu(true);
  break;
  }
 
@@ -2996,3 +2980,54 @@ size_t VMenu::Text(wchar_t const Char) const
 {
  return ::Text(Char, m_Where.width() - (WhereX() - m_Where.left));
 }
+
+#ifdef ENABLE_TESTS
+
+#include "testing.hpp"
+
+TEST_CASE("find.nearest.selectable.item")
+{
+ std::array<int, 10> arr{};
+
+ const auto Pred{ [](const int b) { return b != 0; } };
+
+ const auto TestAllPositions{
+ [&](const int Found)
+ {
+ for (const auto Pos : std::views::iota(0, static_cast<int>(arr.size())))
+ {
+ REQUIRE(FindNearestSelectableItem(arr, Pos, Pred, false, false) == Found);
+ REQUIRE(FindNearestSelectableItem(arr, Pos, Pred, false, true) == Found);
+ REQUIRE(FindNearestSelectableItem(arr, Pos, Pred, true, false) == Found);
+ REQUIRE(FindNearestSelectableItem(arr, Pos, Pred, true, true) == Found);
+ }
+ } };
+
+ TestAllPositions(-1);
+
+ for (const auto Found : std::views::iota(0, static_cast<int>(arr.size())))
+ {
+ std::ranges::fill(arr, int{});
+ arr[Found] = true;
+ TestAllPositions(Found);
+ }
+
+ std::ranges::fill(arr, int{});
+ arr[3] = arr[7] = true;
+
+ REQUIRE(FindNearestSelectableItem(arr, 1, Pred, false, false) == 3);
+ REQUIRE(FindNearestSelectableItem(arr, 1, Pred, false, true) == 3);
+ REQUIRE(FindNearestSelectableItem(arr, 5, Pred, false, false) == 7);
+ REQUIRE(FindNearestSelectableItem(arr, 5, Pred, false, true) == 7);
+ REQUIRE(FindNearestSelectableItem(arr, 9, Pred, false, false) == 7);
+ REQUIRE(FindNearestSelectableItem(arr, 9, Pred, false, true) == 3);
+
+ REQUIRE(FindNearestSelectableItem(arr, 1, Pred, true, false) == 3);
+ REQUIRE(FindNearestSelectableItem(arr, 1, Pred, true, true) == 7);
+ REQUIRE(FindNearestSelectableItem(arr, 5, Pred, true, false) == 3);
+ REQUIRE(FindNearestSelectableItem(arr, 5, Pred, true, true) == 3);
+ REQUIRE(FindNearestSelectableItem(arr, 9, Pred, true, false) == 7);
+ REQUIRE(FindNearestSelectableItem(arr, 9, Pred, true, true) == 7);
+}
+
+#endif