MultiSelect: Box-Select: uses SetActiveIdUsingAllKeyboardKeys() to av…

…oid nav interference, much like most drag operations.

imgui.cpp

@@ -5539,7 +5539,8 @@ void ImGui::SetItemAllowOverlap()
 }
 #endif
 
-// FIXME: It might be undesirable that this will likely disable KeyOwner-aware shortcuts systems. Consider a more fine-tuned version for the two users of this function.
+// This is a shortcut for not taking ownership of 100+ keys, frequently used by drag operations.
+// FIXME: It might be undesirable that this will likely disable KeyOwner-aware shortcuts systems. Consider a more fine-tuned version if needed?
 void ImGui::SetActiveIdUsingAllKeyboardKeys()
 {
     ImGuiContext& g = *GImGui;

imgui_internal.h

@@ -2081,7 +2081,7 @@ struct ImGuiContext
     ImGuiKeyOwnerData       KeysOwnerData[ImGuiKey_NamedKey_COUNT];
     ImGuiKeyRoutingTable    KeysRoutingTable;
     ImU32                   ActiveIdUsingNavDirMask;            // Active widget will want to read those nav move requests (e.g. can activate a button and move away from it)
-    bool                    ActiveIdUsingAllKeyboardKeys;       // Active widget will want to read all keyboard keys inputs. (FIXME: This is a shortcut for not taking ownership of 100+ keys but perhaps best to not have the inconsistency)
+    bool                    ActiveIdUsingAllKeyboardKeys;       // Active widget will want to read all keyboard keys inputs. (this is a shortcut for not taking ownership of 100+ keys, frequently used by drag operations)
     ImGuiKeyChord           DebugBreakInShortcutRouting;        // Set to break in SetShortcutRouting()/Shortcut() calls.
 #ifndef IMGUI_DISABLE_OBSOLETE_KEYIO
     ImU32                   ActiveIdUsingNavInputMask;          // If you used this. Since (IMGUI_VERSION_NUM >= 18804) : 'g.ActiveIdUsingNavInputMask |= (1 << ImGuiNavInput_Cancel);' becomes 'SetKeyOwner(ImGuiKey_Escape, g.ActiveId) and/or SetKeyOwner(ImGuiKey_NavGamepadCancel, g.ActiveId);'

imgui_widgets.cpp

@@ -7159,6 +7159,7 @@ static void BoxSelectActivateDrag(ImGuiBoxSelectState* bs, ImGuiWindow* window)
     bs->Window = window;
     bs->IsStarting = false;
     ImGui::SetActiveID(bs->ID, window);
+    ImGui::SetActiveIdUsingAllKeyboardKeys();
     if (bs->IsStartedFromVoid && (bs->KeyMods & (ImGuiMod_Ctrl | ImGuiMod_Shift)) == 0)
         bs->RequestClear = true;
 }