Internals: Added FocusItem(). Made activation explicit/opt-in via ImGuiNavMoveFlags_Activate. Rename ActivateItem() to ActivateItemByID().

imgui.cpp

@@ -7530,13 +7530,6 @@ void ImGui::SetWindowFontScale(float scale)
     g.FontSize = g.DrawListSharedData.FontSize = window->CalcFontSize();
 }
 
-void ImGui::ActivateItem(ImGuiID id)
-{
-    ImGuiContext& g = *GImGui;
-    g.NavNextActivateId = id;
-    g.NavNextActivateFlags = ImGuiActivateFlags_None;
-}
-
 void ImGui::PushFocusScope(ImGuiID id)
 {
     ImGuiContext& g = *GImGui;
@@ -7552,13 +7545,40 @@ void ImGui::PopFocusScope()
     g.CurrentFocusScopeId = g.FocusScopeStack.Size ? g.FocusScopeStack.back() : 0;
 }
 
+// Focus = move navigation cursor, set scrolling, set focus window.
+void ImGui::FocusItem()
+{
+    ImGuiContext& g = *GImGui;
+    ImGuiWindow* window = g.CurrentWindow;
+    IMGUI_DEBUG_LOG_FOCUS("FocusItem(0x%08x) in window \"%s\"\n", g.LastItemData.ID, window->Name);
+    if (g.DragDropActive || g.MovingWindow != NULL) // FIXME: Opt-in flags for this?
+    {
+        IMGUI_DEBUG_LOG_FOCUS("FocusItem() ignored while DragDropActive!\n");
+        return;
+    }
+
+    ImGuiNavMoveFlags move_flags = ImGuiNavMoveFlags_Tabbing | ImGuiNavMoveFlags_FocusApi; // No activation/selection
+    ImGuiScrollFlags scroll_flags = window->Appearing ? ImGuiScrollFlags_KeepVisibleEdgeX | ImGuiScrollFlags_AlwaysCenterY : ImGuiScrollFlags_KeepVisibleEdgeX | ImGuiScrollFlags_KeepVisibleEdgeY;
+    SetNavWindow(window);
+    NavMoveRequestSubmit(ImGuiDir_None, ImGuiDir_Up, move_flags, scroll_flags);
+    NavMoveRequestResolveWithLastItem(&g.NavMoveResultLocal);
+}
+
+void ImGui::ActivateItemByID(ImGuiID id)
+{
+    ImGuiContext& g = *GImGui;
+    g.NavNextActivateId = id;
+    g.NavNextActivateFlags = ImGuiActivateFlags_None;
+}
+
 // Note: this will likely be called ActivateItem() once we rework our Focus/Activation system!
+// But ActivateItem() should function without altering scroll/focus?
 void ImGui::SetKeyboardFocusHere(int offset)
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
     IM_ASSERT(offset >= -1);    // -1 is allowed but not below
-    IMGUI_DEBUG_LOG_ACTIVEID("SetKeyboardFocusHere(%d) in window \"%s\"\n", offset, window->Name);
+    IMGUI_DEBUG_LOG_FOCUS("SetKeyboardFocusHere(%d) in window \"%s\"\n", offset, window->Name);
 
     // It makes sense in the vast majority of cases to never interrupt a drag and drop.
     // When we refactor this function into ActivateItem() we may want to make this an option.
@@ -7566,14 +7586,15 @@ void ImGui::SetKeyboardFocusHere(int offset)
     // is also automatically dropped in the event g.ActiveId is stolen.
     if (g.DragDropActive || g.MovingWindow != NULL)
     {
-        IMGUI_DEBUG_LOG_ACTIVEID("SetKeyboardFocusHere() ignored while DragDropActive!\n");
+        IMGUI_DEBUG_LOG_FOCUS("SetKeyboardFocusHere() ignored while DragDropActive!\n");
         return;
     }
 
     SetNavWindow(window);
 
+    ImGuiNavMoveFlags move_flags = ImGuiNavMoveFlags_Tabbing | ImGuiNavMoveFlags_Activate | ImGuiNavMoveFlags_FocusApi;
     ImGuiScrollFlags scroll_flags = window->Appearing ? ImGuiScrollFlags_KeepVisibleEdgeX | ImGuiScrollFlags_AlwaysCenterY : ImGuiScrollFlags_KeepVisibleEdgeX | ImGuiScrollFlags_KeepVisibleEdgeY;
-    NavMoveRequestSubmit(ImGuiDir_None, offset < 0 ? ImGuiDir_Up : ImGuiDir_Down, ImGuiNavMoveFlags_Tabbing | ImGuiNavMoveFlags_FocusApi, scroll_flags); // FIXME-NAV: Once we refactor tabbing, add LegacyApi flag to not activate non-inputable.
+    NavMoveRequestSubmit(ImGuiDir_None, offset < 0 ? ImGuiDir_Up : ImGuiDir_Down, move_flags, scroll_flags); // FIXME-NAV: Once we refactor tabbing, add LegacyApi flag to not activate non-inputable.
     if (offset == -1)
     {
         NavMoveRequestResolveWithLastItem(&g.NavMoveResultLocal);
@@ -11555,9 +11576,10 @@ void ImGui::NavUpdateCreateTabbingRequest()
         g.NavTabbingDir = g.IO.KeyShift ? -1 : (g.NavDisableHighlight == true && g.ActiveId == 0) ? 0 : +1;
     else
         g.NavTabbingDir = g.IO.KeyShift ? -1 : (g.ActiveId == 0) ? 0 : +1;
+    ImGuiNavMoveFlags move_flags = ImGuiNavMoveFlags_Tabbing | ImGuiNavMoveFlags_Activate;
     ImGuiScrollFlags scroll_flags = window->Appearing ? ImGuiScrollFlags_KeepVisibleEdgeX | ImGuiScrollFlags_AlwaysCenterY : ImGuiScrollFlags_KeepVisibleEdgeX | ImGuiScrollFlags_KeepVisibleEdgeY;
     ImGuiDir clip_dir = (g.NavTabbingDir < 0) ? ImGuiDir_Up : ImGuiDir_Down;
-    NavMoveRequestSubmit(ImGuiDir_None, clip_dir, ImGuiNavMoveFlags_Tabbing, scroll_flags); // FIXME-NAV: Once we refactor tabbing, add LegacyApi flag to not activate non-inputable.
+    NavMoveRequestSubmit(ImGuiDir_None, clip_dir, move_flags, scroll_flags); // FIXME-NAV: Once we refactor tabbing, add LegacyApi flag to not activate non-inputable.
     g.NavTabbingCounter = -1;
 }
 
@@ -11623,7 +11645,7 @@ void ImGui::NavMoveRequestApplyResult()
     }
     if (g.ActiveId != result->ID)
         ClearActiveID();
-    if (g.NavId != result->ID)
+    if (g.NavId != result->ID && (g.NavMoveFlags & ImGuiNavMoveFlags_Activate) != 0)
     {
         // Don't set NavJustMovedToId if just landed on the same spot (which may happen with ImGuiNavMoveFlags_AllowCurrentNavId)
         g.NavJustMovedToId = result->ID;
@@ -11644,19 +11666,18 @@ void ImGui::NavMoveRequestApplyResult()
         g.NavWindow->RootWindowForNav->NavPreferredScoringPosRel[g.NavLayer] = preferred_scoring_pos_rel;
     }
 
-    // Tabbing: Activates Inputable or Focus non-Inputable
-    if ((g.NavMoveFlags & ImGuiNavMoveFlags_Tabbing) && (result->InFlags & ImGuiItemFlags_Inputable))
-    {
-        g.NavNextActivateId = result->ID;
-        g.NavNextActivateFlags = ImGuiActivateFlags_PreferInput | ImGuiActivateFlags_TryToPreserveState;
-        g.NavMoveFlags |= ImGuiNavMoveFlags_DontSetNavHighlight;
-    }
+    // Tabbing: Activates Inputable, otherwise only Focus
+    if ((g.NavMoveFlags & ImGuiNavMoveFlags_Tabbing) && (result->InFlags & ImGuiItemFlags_Inputable) == 0)
+        g.NavMoveFlags &= ~ImGuiNavMoveFlags_Activate;
 
     // Activate
     if (g.NavMoveFlags & ImGuiNavMoveFlags_Activate)
     {
         g.NavNextActivateId = result->ID;
         g.NavNextActivateFlags = ImGuiActivateFlags_None;
+        g.NavMoveFlags |= ImGuiNavMoveFlags_DontSetNavHighlight;
+        if (g.NavMoveFlags & ImGuiNavMoveFlags_Tabbing)
+            g.NavNextActivateFlags |= ImGuiActivateFlags_PreferInput | ImGuiActivateFlags_TryToPreserveState;
     }
 
     // Enable nav highlight

imgui_internal.h

@@ -1479,9 +1479,9 @@ enum ImGuiNavMoveFlags_
     ImGuiNavMoveFlags_ScrollToEdgeY         = 1 << 6,   // Force scrolling to min/max (used by Home/End) // FIXME-NAV: Aim to remove or reword, probably unnecessary
     ImGuiNavMoveFlags_Forwarded             = 1 << 7,
     ImGuiNavMoveFlags_DebugNoResult         = 1 << 8,   // Dummy scoring for debug purpose, don't apply result
-    ImGuiNavMoveFlags_FocusApi              = 1 << 9,
+    ImGuiNavMoveFlags_FocusApi              = 1 << 9,   // Requests from focus API can land/focus/activate items even if they are marked with _NoTabStop (see NavProcessItemForTabbingRequest() for details)
     ImGuiNavMoveFlags_Tabbing               = 1 << 10,  // == Focus + Activate if item is Inputable + DontChangeNavHighlight
-    ImGuiNavMoveFlags_Activate              = 1 << 11,
+    ImGuiNavMoveFlags_Activate              = 1 << 11,  // Activate/select target item.
     ImGuiNavMoveFlags_DontSetNavHighlight   = 1 << 12,  // Do not alter the visible state of keyboard vs mouse nav highlight
 };
 
@@ -2912,10 +2912,15 @@ namespace ImGui
     IMGUI_API void          NavMoveRequestTryWrapping(ImGuiWindow* window, ImGuiNavMoveFlags move_flags);
     IMGUI_API void          NavClearPreferredPosForAxis(ImGuiAxis axis);
     IMGUI_API void          NavUpdateCurrentWindowIsScrollPushableX();
-    IMGUI_API void          ActivateItem(ImGuiID id);   // Remotely activate a button, checkbox, tree node etc. given its unique ID. activation is queued and processed on the next frame when the item is encountered again.
     IMGUI_API void          SetNavWindow(ImGuiWindow* window);
     IMGUI_API void          SetNavID(ImGuiID id, ImGuiNavLayer nav_layer, ImGuiID focus_scope_id, const ImRect& rect_rel);
 
+    // Focus/Activation
+    // This should be part of a larger set of API: FocusItem(offset = -1), FocusItemByID(id), ActivateItem(offset = -1), ActivateItemByID(id) etc. which are
+    // much harder to design and implement than expected. I have a couple of private branches on this matter but it's not simple. For now implementing the easy ones.
+    IMGUI_API void          FocusItem();                    // Focus last item (no selection/activation).
+    IMGUI_API void          ActivateItemByID(ImGuiID id);   // Activate an item by ID (button, checkbox, tree node etc.). Activation is queued and processed on the next frame when the item is encountered again.
+
     // Inputs
     // FIXME: Eventually we should aim to move e.g. IsActiveIdUsingKey() into IsKeyXXX functions.
     inline bool             IsNamedKey(ImGuiKey key)                                    { return key >= ImGuiKey_NamedKey_BEGIN && key < ImGuiKey_NamedKey_END; }