Nav: Moving the big chunk of code from ItemAdd() to NavProcessItem()

imgui.cpp

@@ -2200,33 +2200,10 @@ void ImGui::RenderNavHighlight(const ImRect& bb, ImGuiID id, ImGuiNavHighlightFl
     }
 }
 
-// Declare item bounding box for clipping and interaction.
-// Note that the size can be different than the one provided to ItemSize(). Typically, widgets that spread over available surface
-// declare their minimum size requirement to ItemSize() and then use a larger region for drawing/interaction, which is passed to ItemAdd().
-bool ImGui::ItemAdd(const ImRect& bb, const ImGuiID* id, const ImRect* nav_bb_arg)
+static void NavProcessItem(ImGuiWindow* window, const ImRect& nav_bb, const ImGuiID id)
 {
     ImGuiContext& g = *GImGui;
-    ImGuiWindow* window = g.CurrentWindow;
-    const bool is_clipped = IsClippedEx(bb, id, false);
-    window->DC.LastItemId = id ? *id : 0;
-    window->DC.LastItemRect = bb;
-    window->DC.LastItemRectHoveredRect = false;
-    if (id != NULL) 
-        window->DC.NavLayerActiveMaskNext |= (1 << window->DC.NavLayerCurrent);
-
-	// Navigation processing runs prior to clipping early-out
-    //  (a) So that NavInitDefaultRequest can be honored, for newly opened windows to select a default widget
-    //  (b) So that we can scroll up/down past clipped items. This adds a small O(N) cost to regular navigation requests unfortunately, but it is still limited to one window. 
-    //      it may not scale very well for windows with ten of thousands of item, but at least the NavRequest is only performed on user interaction, aka maximum once a frame.
-    //      We could early out with `if (is_clipped && !g.NavInitDefaultRequest) return false;` but when we wouldn't be able to reach unclipped widgets. This would work if user had explicit scrolling control (e.g. mapped on a stick)
-    //      A more pragmatic solution for handling long lists is relying on the fact that they are likely evenly spread items (so that clipper can be used) and we could Nav at higher-level (apply index, etc.)
-    //      So eventually we would like to provide the user will the primitives to be able to implement that customized/efficient navigation handling whenever necessary.
     const ImGuiItemFlags item_flags = window->DC.ItemFlags;
-    if (id != NULL && g.NavWindow == window->RootNavWindow)
-        if (g.NavId == *id || g.NavMoveRequest || g.NavInitDefaultRequest || IMGUI_DEBUG_NAV)
-            if (g.IO.NavUsable && !(item_flags & ImGuiItemFlags_NoNav))
-            {
-                const ImRect& nav_bb = nav_bb_arg ? *nav_bb_arg : bb;
     const ImRect nav_bb_rel(nav_bb.Min - g.NavWindow->Pos, nav_bb.Max - g.NavWindow->Pos);
     if (g.NavInitDefaultRequest && g.NavLayer == window->DC.NavLayerCurrent)
     {
@@ -2235,7 +2212,7 @@ bool ImGui::ItemAdd(const ImRect& bb, const ImGuiID* id, const ImRect* nav_bb_ar
             g.NavInitDefaultRequest = g.NavInitDefaultResultExplicit = false; // Found a match, clear request
         if (g.NavInitDefaultResultId == 0 || !(item_flags & ImGuiItemFlags_NoNavDefaultFocus))
         {
-                        g.NavInitDefaultResultId = *id;
+            g.NavInitDefaultResultId = id;
             g.NavInitDefaultResultRectRel = nav_bb_rel;
         }
     }
@@ -2245,27 +2222,53 @@ bool ImGui::ItemAdd(const ImRect& bb, const ImGuiID* id, const ImRect* nav_bb_ar
     // [DEBUG] Score items at all times
     if (!g.NavMoveRequest) 
         g.NavMoveDir = g.NavMoveDirLast;
-                if (g.NavId != *id)
+    if (g.NavId != id)
         new_best = NavScoreItem(nav_bb) && g.NavMoveRequest;
 #else
-                if (g.NavMoveRequest && g.NavId != *id)
+    if (g.NavMoveRequest && g.NavId != id)
         new_best = NavScoreItem(nav_bb);
 #endif
     if (new_best)
     {
-                    g.NavMoveResultId = *id;
+        g.NavMoveResultId = id;
         g.NavMoveResultParentId = window->IDStack.back();
         g.NavMoveResultRectRel = nav_bb_rel;
     }
 
     // Update window-relative bounding box of navigated item
-                if (g.NavId == *id)
+    if (g.NavId == id)
     {
         window->NavRectRel[window->DC.NavLayerCurrent] = nav_bb_rel;
         g.NavIdIsAlive = true;
         g.NavIdTabCounter = window->FocusIdxTabCounter;
     }
-            }
+}
+
+// Declare item bounding box for clipping and interaction.
+// Note that the size can be different than the one provided to ItemSize(). Typically, widgets that spread over available surface
+// declare their minimum size requirement to ItemSize() and then use a larger region for drawing/interaction, which is passed to ItemAdd().
+bool ImGui::ItemAdd(const ImRect& bb, const ImGuiID* id, const ImRect* nav_bb_arg)
+{
+    ImGuiContext& g = *GImGui;
+    ImGuiWindow* window = g.CurrentWindow;
+    const bool is_clipped = IsClippedEx(bb, id, false);
+    window->DC.LastItemId = id ? *id : 0;
+    window->DC.LastItemRect = bb;
+    window->DC.LastItemRectHoveredRect = false;
+    if (id != NULL) 
+        window->DC.NavLayerActiveMaskNext |= (1 << window->DC.NavLayerCurrent);
+
+	// Navigation processing runs prior to clipping early-out
+    //  (a) So that NavInitDefaultRequest can be honored, for newly opened windows to select a default widget
+    //  (b) So that we can scroll up/down past clipped items. This adds a small O(N) cost to regular navigation requests unfortunately, but it is still limited to one window. 
+    //      it may not scale very well for windows with ten of thousands of item, but at least the NavRequest is only performed on user interaction, aka maximum once a frame.
+    //      We could early out with `if (is_clipped && !g.NavInitDefaultRequest) return false;` but when we wouldn't be able to reach unclipped widgets. This would work if user had explicit scrolling control (e.g. mapped on a stick)
+    //      A more pragmatic solution for handling long lists is relying on the fact that they are likely evenly spread items (so that clipper can be used) and we could Nav at higher-level (apply index, etc.)
+    //      So eventually we would like to provide the user will the primitives to be able to implement that customized/efficient navigation handling whenever necessary.
+    if (id != NULL && g.NavWindow == window->RootNavWindow)
+        if (g.NavId == *id || g.NavMoveRequest || g.NavInitDefaultRequest || IMGUI_DEBUG_NAV)
+            if (g.IO.NavUsable)
+                NavProcessItem(window, nav_bb_arg ? *nav_bb_arg : bb, *id);
 
     if (is_clipped)
         return false;