Internal: Tabbing/Focus: Tidying up old code, moved some state to context instead of window. Storing new data will allow us to fix the bug mentioned in #2215 (probably in next commit).

imgui.cpp

@@ -2552,10 +2552,6 @@ ImGuiWindow::ImGuiWindow(ImGuiContext* context, const char* name)
     NavLastIds[0] = NavLastIds[1] = 0;
     NavRectRel[0] = NavRectRel[1] = ImRect();
     NavLastChildNavWindow = NULL;
-
-    FocusIdxAllCounter = FocusIdxTabCounter = -1;
-    FocusIdxAllRequestCurrent = FocusIdxTabRequestCurrent = INT_MAX;
-    FocusIdxAllRequestNext = FocusIdxTabRequestNext = INT_MAX;
 }
 
 ImGuiWindow::~ImGuiWindow()
@@ -2901,22 +2897,28 @@ bool ImGui::FocusableItemRegister(ImGuiWindow* window, ImGuiID id)
 
     // Increment counters
     const bool is_tab_stop = (window->DC.ItemFlags & (ImGuiItemFlags_NoTabStop | ImGuiItemFlags_Disabled)) == 0;
-    window->FocusIdxAllCounter++;
+    window->DC.FocusCounterAll++;
     if (is_tab_stop)
-        window->FocusIdxTabCounter++;
+        window->DC.FocusCounterTab++;
 
     // Process TAB/Shift-TAB to tab *OUT* of the currently focused item.
     // (Note that we can always TAB out of a widget that doesn't allow tabbing in)
-    if (g.ActiveId == id && g.FocusTabPressed && !(g.ActiveIdBlockNavInputFlags & (1 << ImGuiNavInput_KeyTab_)))
+    if (g.ActiveId == id && g.FocusTabPressed && !(g.ActiveIdBlockNavInputFlags & (1 << ImGuiNavInput_KeyTab_)) && g.FocusRequestNextWindow == NULL)
-        if (window->FocusIdxAllRequestNext == INT_MAX && window->FocusIdxTabRequestNext == INT_MAX)
-            window->FocusIdxTabRequestNext = window->FocusIdxTabCounter + (g.IO.KeyShift ? (is_tab_stop ? -1 : 0) : +1); // Modulo on index will be applied at the end of frame once we've got the total counter of items.
-
-    if (window->FocusIdxAllCounter == window->FocusIdxAllRequestCurrent)
-        return true;
-    if (is_tab_stop && window->FocusIdxTabCounter == window->FocusIdxTabRequestCurrent)
     {
-        g.NavJustTabbedId = id;
+        g.FocusRequestNextWindow = window;
-        return true;
+        g.FocusRequestNextCounterTab = window->DC.FocusCounterTab + (g.IO.KeyShift ? (is_tab_stop ? -1 : 0) : +1); // Modulo on index will be applied at the end of frame once we've got the total counter of items.
+    }
+
+    // Handle focus requests
+    if (g.FocusRequestCurrWindow == window)
+    {
+        if (window->DC.FocusCounterAll == g.FocusRequestCurrCounterAll)
+            return true;
+        if (is_tab_stop && window->DC.FocusCounterTab == g.FocusRequestCurrCounterTab)
+        {
+            g.NavJustTabbedId = id;
+            return true;
+        }
     }
 
     return false;
@@ -2924,8 +2926,8 @@ bool ImGui::FocusableItemRegister(ImGuiWindow* window, ImGuiID id)
 
 void ImGui::FocusableItemUnregister(ImGuiWindow* window)
 {
-    window->FocusIdxAllCounter--;
+    window->DC.FocusCounterAll--;
-    window->FocusIdxTabCounter--;
+    window->DC.FocusCounterTab--;
 }
 
 ImVec2 ImGui::CalcItemSize(ImVec2 size, float default_x, float default_y)
@@ -3515,15 +3517,34 @@ void ImGui::NewFrame()
     UpdateMouseWheel();
 
     // Pressing TAB activate widget focus
-    // (This code is old and will be redesigned for Nav. In the meanwhile we use g.NavTabRequest as storage but this doesn't need ImGuiConfigFlags_NavEnableKeyboard to work!)
     g.FocusTabPressed = (g.NavWindow && g.NavWindow->Active && !(g.NavWindow->Flags & ImGuiWindowFlags_NoNavInputs) && !g.IO.KeyCtrl && IsKeyPressedMap(ImGuiKey_Tab));
     if (g.ActiveId == 0 && g.FocusTabPressed)
     {
+        // Note that SetKeyboardFocusHere() sets the Next fields mid-frame. To be consistent we also
+        // manipulate the Next fields even, even though they will be turned into Curr fields by the code below.
+        g.FocusRequestNextWindow = g.NavWindow;
+        g.FocusRequestNextCounterAll = INT_MAX;
         if (g.NavId != 0 && g.NavIdTabCounter != INT_MAX)
-            g.NavWindow->FocusIdxTabRequestNext = g.NavIdTabCounter + 1 + (g.IO.KeyShift ? -1 : 1);
+            g.FocusRequestNextCounterTab = g.NavIdTabCounter + 1 + (g.IO.KeyShift ? -1 : 1);
         else
-            g.NavWindow->FocusIdxTabRequestNext = g.IO.KeyShift ? -1 : 0;
+            g.FocusRequestNextCounterTab = g.IO.KeyShift ? -1 : 0;
     }
+
+    // Turn queued focus request into current one
+    g.FocusRequestCurrWindow = NULL;
+    g.FocusRequestCurrCounterAll = g.FocusRequestCurrCounterTab = INT_MAX;
+    if (g.FocusRequestNextWindow != NULL)
+    {
+        ImGuiWindow* window = g.FocusRequestNextWindow;
+        g.FocusRequestCurrWindow = window;
+        if (g.FocusRequestNextCounterAll != INT_MAX && window->DC.FocusCounterAll != -1)
+            g.FocusRequestCurrCounterAll = ImModPositive(g.FocusRequestNextCounterAll, window->DC.FocusCounterAll + 1);
+        if (g.FocusRequestNextCounterTab != INT_MAX && window->DC.FocusCounterTab != -1)
+            g.FocusRequestCurrCounterTab = ImModPositive(g.FocusRequestNextCounterTab, window->DC.FocusCounterTab + 1);
+        g.FocusRequestNextWindow = NULL;
+        g.FocusRequestNextCounterAll = g.FocusRequestNextCounterTab = INT_MAX;
+    }
+
     g.NavIdTabCounter = INT_MAX;
 
     // Mark all windows as not visible
@@ -5170,12 +5191,6 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         // Lock window rounding for the frame (so that altering them doesn't cause inconsistencies)
         window->WindowRounding = (flags & ImGuiWindowFlags_ChildWindow) ? style.ChildRounding : ((flags & ImGuiWindowFlags_Popup) && !(flags & ImGuiWindowFlags_Modal)) ? style.PopupRounding : style.WindowRounding;
 
-        // Prepare for item focus requests
-        window->FocusIdxAllRequestCurrent = (window->FocusIdxAllRequestNext == INT_MAX || window->FocusIdxAllCounter == -1) ? INT_MAX : ImModPositive(window->FocusIdxAllRequestNext, window->FocusIdxAllCounter + 1);
-        window->FocusIdxTabRequestCurrent = (window->FocusIdxTabRequestNext == INT_MAX || window->FocusIdxTabCounter == -1) ? INT_MAX : ImModPositive(window->FocusIdxTabRequestNext, window->FocusIdxTabCounter + 1);
-        window->FocusIdxAllCounter = window->FocusIdxTabCounter = -1;
-        window->FocusIdxAllRequestNext = window->FocusIdxTabRequestNext = INT_MAX;
-
         // Apply scrolling
         window->Scroll = CalcNextScrollFromScrollTargetAndClamp(window, true);
         window->ScrollTarget = ImVec2(FLT_MAX, FLT_MAX);
@@ -5350,6 +5365,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         window->DC.ChildWindows.resize(0);
         window->DC.LayoutType = ImGuiLayoutType_Vertical;
         window->DC.ParentLayoutType = parent_window ? parent_window->DC.LayoutType : ImGuiLayoutType_Vertical;
+        window->DC.FocusCounterAll = window->DC.FocusCounterTab = -1;
         window->DC.ItemFlags = parent_window ? parent_window->DC.ItemFlags : ImGuiItemFlags_Default_;
         window->DC.ItemWidth = window->ItemWidthDefault;
         window->DC.TextWrapPos = -1.0f; // disabled
@@ -6462,9 +6478,11 @@ void ImGui::ActivateItem(ImGuiID id)
 void ImGui::SetKeyboardFocusHere(int offset)
 {
     IM_ASSERT(offset >= -1);    // -1 is allowed but not below
-    ImGuiWindow* window = GetCurrentWindow();
+    ImGuiContext& g = *GImGui;
-    window->FocusIdxAllRequestNext = window->FocusIdxAllCounter + 1 + offset;
+    ImGuiWindow* window = g.CurrentWindow;
-    window->FocusIdxTabRequestNext = INT_MAX;
+    g.FocusRequestNextWindow = window;
+    g.FocusRequestNextCounterAll = window->DC.FocusCounterAll + 1 + offset;
+    g.FocusRequestNextCounterTab = INT_MAX;
 }
 
 void ImGui::SetItemDefaultFocus()
@@ -7373,7 +7391,7 @@ static void ImGui::NavProcessItem(ImGuiWindow* window, const ImRect& nav_bb, con
         g.NavWindow = window;                                           // Always refresh g.NavWindow, because some operations such as FocusItem() don't have a window.
         g.NavLayer = window->DC.NavLayerCurrent;
         g.NavIdIsAlive = true;
-        g.NavIdTabCounter = window->FocusIdxTabCounter;
+        g.NavIdTabCounter = window->DC.FocusCounterTab;
         window->NavRectRel[window->DC.NavLayerCurrent] = nav_bb_rel;    // Store item bounding box (relative to window position)
     }
 }

imgui_internal.h

@@ -892,7 +892,13 @@ struct ImGuiContext
     ImGuiNavMoveResult      NavMoveResultLocalVisibleSet;       // Best move request candidate within NavWindow that are mostly visible (when using ImGuiNavMoveFlags_AlsoScoreVisibleSet flag)
     ImGuiNavMoveResult      NavMoveResultOther;                 // Best move request candidate within NavWindow's flattened hierarchy (when using ImGuiWindowFlags_NavFlattened flag)
 
-    // Tabbing system (older than Nav, active when Nav is disabled. Probably needs a redesign)
+    // Tabbing system (older than Nav, active even if Nav is disabled. FIXME-NAV: This needs a redesign!)
+    ImGuiWindow*            FocusRequestCurrWindow;             //
+    ImGuiWindow*            FocusRequestNextWindow;             //
+    int                     FocusRequestCurrCounterAll;         // Any item being requested for focus, stored as an index (we on layout to be stable between the frame pressing TAB and the next frame, semi-ouch)
+    int                     FocusRequestCurrCounterTab;         // Tab item being requested for focus, stored as an index
+    int                     FocusRequestNextCounterAll;         // Stored for next frame
+    int                     FocusRequestNextCounterTab;         // "
     bool                    FocusTabPressed;                    //
 
     // Render
@@ -1040,6 +1046,10 @@ struct ImGuiContext
         NavMoveRequestFlags = 0;
         NavMoveRequestForward = ImGuiNavForward_None;
         NavMoveDir = NavMoveDirLast = NavMoveClipDir = ImGuiDir_None;
+
+        FocusRequestCurrWindow = FocusRequestNextWindow = NULL;
+        FocusRequestCurrCounterAll = FocusRequestCurrCounterTab = INT_MAX;
+        FocusRequestNextCounterAll = FocusRequestNextCounterTab = INT_MAX;
         FocusTabPressed = false;
 
         DimBgRatio = 0.0f;
@@ -1127,6 +1137,8 @@ struct IMGUI_API ImGuiWindowTempData
     ImGuiStorage*           StateStorage;
     ImGuiLayoutType         LayoutType;
     ImGuiLayoutType         ParentLayoutType;       // Layout type of parent window at the time of Begin()
+    int                     FocusCounterAll;        // Counter for focus/tabbing system. Start at -1 and increase as assigned via FocusableItemRegister() (FIXME-NAV: Needs redesign)
+    int                     FocusCounterTab;        // (same, but only count widgets which you can Tab through)
 
     // We store the current settings outside of the vectors to increase memory locality (reduce cache misses). The vectors are rarely modified. Also it allows us to not heap allocate for short-lived windows which are not using those settings.
     ImGuiItemFlags          ItemFlags;              // == ItemFlagsStack.back() [empty == ImGuiItemFlags_Default]
@@ -1162,8 +1174,10 @@ struct IMGUI_API ImGuiWindowTempData
         MenuBarOffset = ImVec2(0.0f, 0.0f);
         StateStorage = NULL;
         LayoutType = ParentLayoutType = ImGuiLayoutType_Vertical;
-        ItemWidth = 0.0f;
+        FocusCounterAll = FocusCounterTab = -1;
+
         ItemFlags = ImGuiItemFlags_Default_;
+        ItemWidth = 0.0f;
         TextWrapPos = -1.0f;
         memset(StackSizesBackup, 0, sizeof(StackSizesBackup));
 
@@ -1248,15 +1262,6 @@ struct IMGUI_API ImGuiWindow
     ImGuiID                 NavLastIds[ImGuiNavLayer_COUNT];    // Last known NavId for this window, per layer (0/1)
     ImRect                  NavRectRel[ImGuiNavLayer_COUNT];    // Reference rectangle, in window relative space
 
-    // Navigation / Focus
-    // FIXME-NAV: Merge all this with the new Nav system, at least the request variables should be moved to ImGuiContext
-    int                     FocusIdxAllCounter;                 // Start at -1 and increase as assigned via FocusItemRegister()
-    int                     FocusIdxTabCounter;                 // (same, but only count widgets which you can Tab through)
-    int                     FocusIdxAllRequestCurrent;          // Item being requested for focus
-    int                     FocusIdxTabRequestCurrent;          // Tab-able item being requested for focus
-    int                     FocusIdxAllRequestNext;             // Item being requested for focus, for next update (relies on layout to be stable between the frame pressing TAB and the next frame)
-    int                     FocusIdxTabRequestNext;             // "
-
 public:
     ImGuiWindow(ImGuiContext* context, const char* name);
     ~ImGuiWindow();

imgui_widgets.cpp

@@ -3275,7 +3275,7 @@ bool ImGui::InputTextEx(const char* label, char* buf, int buf_size, const ImVec2
         state = &g.InputTextState;
 
     const bool focus_requested = FocusableItemRegister(window, id);
-    const bool focus_requested_by_code = focus_requested && (window->FocusIdxAllCounter == window->FocusIdxAllRequestCurrent);
+    const bool focus_requested_by_code = focus_requested && (g.FocusRequestCurrWindow == window && g.FocusRequestCurrCounterAll == window->DC.FocusCounterAll);
     const bool focus_requested_by_tab = focus_requested && !focus_requested_by_code;
 
     const bool user_clicked = hovered && io.MouseClicked[0];