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