RangeSelect/MultiSelect: clear selection when leaving a scope with a nav directional request.

May need to clarify how to depends on actions being performed (e.g. click doesn't).
May become optional?

imgui.cpp

@@ -12200,6 +12200,7 @@ static void ImGui::NavUpdate()
 
     // Process navigation init request (select first/default focus)
     g.NavJustMovedToId = 0;
+    g.NavJustMovedToFocusScopeId = g.NavJustMovedFromFocusScopeId = 0;
     if (g.NavInitResult.ID != 0)
         NavInitRequestApplyResult();
     g.NavInitRequest = false;
@@ -12352,6 +12353,7 @@ void ImGui::NavInitRequestApplyResult()
     ImGuiNavItemData* result = &g.NavInitResult;
     if (g.NavId != result->ID)
     {
+        g.NavJustMovedFromFocusScopeId = g.NavFocusScopeId;
         g.NavJustMovedToId = result->ID;
         g.NavJustMovedToFocusScopeId = result->FocusScopeId;
         g.NavJustMovedToKeyMods = 0;
@@ -12609,10 +12611,12 @@ void ImGui::NavMoveRequestApplyResult()
     // PageUp/PageDown however sets always set NavJustMovedTo (vs Home/End which doesn't) mimicking Windows behavior.
     if ((g.NavId != result->ID || (g.NavMoveFlags & ImGuiNavMoveFlags_IsPageMove)) && (g.NavMoveFlags & ImGuiNavMoveFlags_NoSelect) == 0)
     {
+        g.NavJustMovedFromFocusScopeId = g.NavFocusScopeId;
         g.NavJustMovedToId = result->ID;
         g.NavJustMovedToFocusScopeId = result->FocusScopeId;
         g.NavJustMovedToKeyMods = g.NavMoveKeyMods;
         g.NavJustMovedToHasSelectionData = (result->InFlags & ImGuiItemFlags_HasSelectionUserData) != 0;
+        //IMGUI_DEBUG_LOG_NAV("[nav] NavJustMovedFromFocusScopeId = 0x%08X, NavJustMovedToFocusScopeId = 0x%08X\n", g.NavJustMovedFromFocusScopeId, g.NavJustMovedToFocusScopeId);
     }
 
     // Apply new NavID/Focus

imgui_internal.h

@@ -2084,6 +2084,7 @@ struct ImGuiContext
     ImGuiID                 NavHighlightActivatedId;
     float                   NavHighlightActivatedTimer;
     ImGuiID                 NavJustMovedToId;                   // Just navigated to this id (result of a successfully MoveRequest).
+    ImGuiID                 NavJustMovedFromFocusScopeId;       // Just navigated from this focus scope id (result of a successfully MoveRequest).
     ImGuiID                 NavJustMovedToFocusScopeId;         // Just navigated to this focus scope id (result of a successfully MoveRequest).
     ImGuiKeyChord           NavJustMovedToKeyMods;
     bool                    NavJustMovedToHasSelectionData;     // " (FIXME-NAV: We should maybe just store ImGuiNavMoveResult)
@@ -2360,7 +2361,7 @@ struct ImGuiContext
 
         NavWindow = NULL;
         NavId = NavFocusScopeId = NavActivateId = NavActivateDownId = NavActivatePressedId = 0;
-        NavJustMovedToId = NavJustMovedToFocusScopeId = NavNextActivateId = 0;
+        NavJustMovedToId = NavJustMovedToFocusScopeId = NavJustMovedFromFocusScopeId = NavNextActivateId = 0;
         NavActivateFlags = NavNextActivateFlags = ImGuiActivateFlags_None;
         NavHighlightActivatedId = 0;
         NavHighlightActivatedTimer = 0.0f;

imgui_widgets.cpp

@@ -7048,10 +7048,7 @@ ImGuiMultiSelectIO* ImGui::BeginMultiSelect(ImGuiMultiSelectFlags flags)
     ms->BeginIO.NavIdItem = ms->EndIO.NavIdItem = storage->NavIdItem;
     ms->BeginIO.NavIdSelected = ms->EndIO.NavIdSelected = (storage->NavIdSelected == 1) ? true : false;
 
-    if (!ms->IsFocused)
-        return &ms->BeginIO; // This is cleared at this point.
-
-    // Auto clear when using Navigation to move within the selection
+    // Clear when using Navigation to move within the scope
     // (we compare FocusScopeId so it possible to use multiple selections inside a same window)
     if (g.NavJustMovedToId != 0 && g.NavJustMovedToFocusScopeId == ms->FocusScopeId && g.NavJustMovedToHasSelectionData)
     {
@@ -7062,7 +7059,15 @@ ImGuiMultiSelectIO* ImGui::BeginMultiSelect(ImGuiMultiSelectFlags flags)
         if ((ms->KeyMods & (ImGuiMod_Ctrl | ImGuiMod_Shift)) == 0)
             ms->BeginIO.RequestClear = true;
     }
+    else if (g.NavJustMovedFromFocusScopeId == ms->FocusScopeId)
+    {
+        // Also clear on leaving scope (may be optional?)
+        if ((ms->KeyMods & (ImGuiMod_Ctrl | ImGuiMod_Shift)) == 0)
+            ms->BeginIO.RequestClear = true;
+    }
 
+    if (ms->IsFocused)
+    {
         // Shortcut: Select all (CTRL+A)
         if (!(flags & ImGuiMultiSelectFlags_SingleSelect) && !(flags & ImGuiMultiSelectFlags_NoSelectAll))
             if (Shortcut(ImGuiMod_Ctrl | ImGuiKey_A))
@@ -7074,6 +7079,7 @@ ImGuiMultiSelectIO* ImGui::BeginMultiSelect(ImGuiMultiSelectFlags flags)
         if (flags & ImGuiMultiSelectFlags_ClearOnEscape)
             if (Shortcut(ImGuiKey_Escape))
                 ms->BeginIO.RequestClear = true;
+    }
 
     if (g.DebugLogFlags & ImGuiDebugLogFlags_EventSelection)
         DebugLogMultiSelectRequests("BeginMultiSelect", &ms->BeginIO);