Nav: Fix not clearing NavWindowingToggleLayer properly (old code left it to true, relied on Alt release only). Removed unnecessary KeyMenu_ from NavInput. (#4439, #787)

imgui.cpp

@@ -4033,6 +4033,7 @@ void ImGui::NewFrame()
 
     // Update keyboard input state
     // Synchronize io.KeyMods with individual modifiers io.KeyXXX bools
+    g.IO.KeyModsPrev = g.IO.KeyMods;
     g.IO.KeyMods = GetMergedKeyModFlags();
     memcpy(g.IO.KeysDownDurationPrev, g.IO.KeysDownDuration, sizeof(g.IO.KeysDownDuration));
     for (int i = 0; i < IM_ARRAYSIZE(g.IO.KeysDown); i++)
@@ -9117,22 +9118,6 @@ static void ImGui::NavUpdate()
             io.NavInputs[ImGuiNavInput_TweakSlow] = 1.0f;
         if (io.KeyShift)
             io.NavInputs[ImGuiNavInput_TweakFast] = 1.0f;
-
-        // AltGR is normally Alt+Ctrl but we can't reliably detect it (not all backends/systems/layout emit it as Alt+Ctrl)
-        // But also even on keyboards without AltGR we don't want Alt+Ctrl to open menu anyway.
-        if (io.KeyAlt && !io.KeyCtrl)
-            io.NavInputs[ImGuiNavInput_KeyMenu_]  = 1.0f;
-
-        // We cancel toggling nav layer when any text has been typed while holding Alt. (See #370)
-        // We cancel toggling nav layer when other modifiers are pressed. (See #4439)
-        if (g.NavWindowingToggleLayer && g.NavInputSource == ImGuiInputSource_Keyboard)
-        {
-            if (io.KeyAlt && !io.KeyCtrl && io.InputQueueCharacters.Size > 0)
-                g.NavWindowingToggleLayer = false;
-            if (io.KeyCtrl || io.KeyShift || io.KeySuper)
-                g.NavWindowingToggleLayer = false;
-        }
-
         #undef NAV_MAP_KEY
     }
     memcpy(io.NavInputsDownDurationPrev, io.NavInputsDownDuration, sizeof(io.NavInputsDownDuration));
@@ -9625,6 +9610,8 @@ static void NavUpdateWindowingHighlightWindow(int focus_change_dir)
 static void ImGui::NavUpdateWindowing()
 {
     ImGuiContext& g = *GImGui;
+    ImGuiIO& io = g.IO;
+
     ImGuiWindow* apply_focus_window = NULL;
     bool apply_toggle_layer = false;
 
@@ -9636,14 +9623,14 @@ static void ImGui::NavUpdateWindowing()
     // Fade out
     if (g.NavWindowingTargetAnim && g.NavWindowingTarget == NULL)
     {
-        g.NavWindowingHighlightAlpha = ImMax(g.NavWindowingHighlightAlpha - g.IO.DeltaTime * 10.0f, 0.0f);
+        g.NavWindowingHighlightAlpha = ImMax(g.NavWindowingHighlightAlpha - io.DeltaTime * 10.0f, 0.0f);
         if (g.DimBgRatio <= 0.0f && g.NavWindowingHighlightAlpha <= 0.0f)
             g.NavWindowingTargetAnim = NULL;
     }
 
     // Start CTRL-TAB or Square+L/R window selection
     bool start_windowing_with_gamepad = allow_windowing && !g.NavWindowingTarget && IsNavInputTest(ImGuiNavInput_Menu, ImGuiInputReadMode_Pressed);
-    bool start_windowing_with_keyboard = allow_windowing && !g.NavWindowingTarget && g.IO.KeyCtrl && IsKeyPressedMap(ImGuiKey_Tab) && (g.IO.ConfigFlags & ImGuiConfigFlags_NavEnableKeyboard);
+    bool start_windowing_with_keyboard = allow_windowing && !g.NavWindowingTarget && io.KeyCtrl && IsKeyPressedMap(ImGuiKey_Tab) && (io.ConfigFlags & ImGuiConfigFlags_NavEnableKeyboard);
     if (start_windowing_with_gamepad || start_windowing_with_keyboard)
         if (ImGuiWindow* window = g.NavWindow ? g.NavWindow : FindWindowNavFocusable(g.WindowsFocusOrder.Size - 1, -INT_MAX, -1))
         {
@@ -9654,7 +9641,7 @@ static void ImGui::NavUpdateWindowing()
         }
 
     // Gamepad update
-    g.NavWindowingTimer += g.IO.DeltaTime;
+    g.NavWindowingTimer += io.DeltaTime;
     if (g.NavWindowingTarget && g.NavInputSource == ImGuiInputSource_Gamepad)
     {
         // Highlight only appears after a brief time holding the button, so that a fast tap on PadMenu (to toggle NavLayer) doesn't add visual noise
@@ -9686,34 +9673,48 @@ static void ImGui::NavUpdateWindowing()
         // Visuals only appears after a brief time after pressing TAB the first time, so that a fast CTRL+TAB doesn't add visual noise
         g.NavWindowingHighlightAlpha = ImMax(g.NavWindowingHighlightAlpha, ImSaturate((g.NavWindowingTimer - NAV_WINDOWING_HIGHLIGHT_DELAY) / 0.05f)); // 1.0f
         if (IsKeyPressedMap(ImGuiKey_Tab, true))
-            NavUpdateWindowingHighlightWindow(g.IO.KeyShift ? +1 : -1);
-        if (!g.IO.KeyCtrl)
+            NavUpdateWindowingHighlightWindow(io.KeyShift ? +1 : -1);
+        if (!io.KeyCtrl)
             apply_focus_window = g.NavWindowingTarget;
     }
 
     // Keyboard: Press and Release ALT to toggle menu layer
-    // FIXME: We lack an explicit IO variable for "is the imgui window focused", so compare mouse validity to detect the common case of backend clearing releases all keys on ALT-TAB
-    if (IsNavInputTest(ImGuiNavInput_KeyMenu_, ImGuiInputReadMode_Pressed) && g.IO.KeyMods == ImGuiKeyModFlags_Alt)
+    // - Testing that only Alt is tested prevents Alt+Shift or AltGR from toggling menu layer.
+    // - AltGR is normally Alt+Ctrl but we can't reliably detect it (not all backends/systems/layout emit it as Alt+Ctrl). But even on keyboards without AltGR we don't want Alt+Ctrl to open menu anyway.
+    if (io.KeyMods == ImGuiKeyModFlags_Alt && (io.KeyModsPrev & ImGuiKeyModFlags_Alt) == 0)
     {
         g.NavWindowingToggleLayer = true;
         g.NavInputSource = ImGuiInputSource_Keyboard;
     }
-    if ((g.ActiveId == 0 || g.ActiveIdAllowOverlap) && g.NavWindowingToggleLayer && IsNavInputTest(ImGuiNavInput_KeyMenu_, ImGuiInputReadMode_Released))
-        if (IsMousePosValid(&g.IO.MousePos) == IsMousePosValid(&g.IO.MousePosPrev))
-            apply_toggle_layer = true;
+    if (g.NavWindowingToggleLayer && g.NavInputSource == ImGuiInputSource_Keyboard)
+    {
+        // We cancel toggling nav layer when any text has been typed (generally while holding Alt). (See #370)
+        // We cancel toggling nav layer when other modifiers are pressed. (See #4439)
+        if (io.InputQueueCharacters.Size > 0 || io.KeyCtrl || io.KeyShift || io.KeySuper)
+            g.NavWindowingToggleLayer = false;
+
+        // Apply layer toggle on release
+        // FIXME: We lack an explicit IO variable for "is the platform window focused", so compare mouse validity to detect the common case of backend clearing releases all keys on ALT-TAB
+        if (!io.KeyAlt && g.NavWindowingToggleLayer)
+            if (g.ActiveId == 0 || g.ActiveIdAllowOverlap)
+                if (IsMousePosValid(&io.MousePos) == IsMousePosValid(&io.MousePosPrev))
+                    apply_toggle_layer = true;
+        if (!io.KeyAlt)
+            g.NavWindowingToggleLayer = false;
+    }
 
     // Move window
     if (g.NavWindowingTarget && !(g.NavWindowingTarget->Flags & ImGuiWindowFlags_NoMove))
     {
         ImVec2 move_delta;
-        if (g.NavInputSource == ImGuiInputSource_Keyboard && !g.IO.KeyShift)
+        if (g.NavInputSource == ImGuiInputSource_Keyboard && !io.KeyShift)
             move_delta = GetNavInputAmount2d(ImGuiNavDirSourceFlags_Keyboard, ImGuiInputReadMode_Down);
         if (g.NavInputSource == ImGuiInputSource_Gamepad)
             move_delta = GetNavInputAmount2d(ImGuiNavDirSourceFlags_PadLStick, ImGuiInputReadMode_Down);
         if (move_delta.x != 0.0f || move_delta.y != 0.0f)
         {
             const float NAV_MOVE_SPEED = 800.0f;
-            const float move_speed = ImFloor(NAV_MOVE_SPEED * g.IO.DeltaTime * ImMin(g.IO.DisplayFramebufferScale.x, g.IO.DisplayFramebufferScale.y)); // FIXME: Doesn't handle variable framerate very well
+            const float move_speed = ImFloor(NAV_MOVE_SPEED * io.DeltaTime * ImMin(io.DisplayFramebufferScale.x, io.DisplayFramebufferScale.y)); // FIXME: Doesn't handle variable framerate very well
             ImGuiWindow* moving_window = g.NavWindowingTarget->RootWindow;
             SetWindowPos(moving_window, moving_window->Pos + move_delta * move_speed, ImGuiCond_Always);
             MarkIniSettingsDirty(moving_window);

imgui.h

@@ -1388,13 +1388,12 @@ enum ImGuiNavInput_
 
     // [Internal] Don't use directly! This is used internally to differentiate keyboard from gamepad inputs for behaviors that require to differentiate them.
     // Keyboard behavior that have no corresponding gamepad mapping (e.g. CTRL+TAB) will be directly reading from io.KeysDown[] instead of io.NavInputs[].
-    ImGuiNavInput_KeyMenu_,      // toggle menu                                  // = io.KeyAlt
     ImGuiNavInput_KeyLeft_,      // move left                                    // = Arrow keys
     ImGuiNavInput_KeyRight_,     // move right
     ImGuiNavInput_KeyUp_,        // move up
     ImGuiNavInput_KeyDown_,      // move down
     ImGuiNavInput_COUNT,
-    ImGuiNavInput_InternalStart_ = ImGuiNavInput_KeyMenu_
+    ImGuiNavInput_InternalStart_ = ImGuiNavInput_KeyLeft_
 };
 
 // Configuration flags stored in io.ConfigFlags. Set by user/application.
@@ -1896,6 +1895,7 @@ struct ImGuiIO
     //------------------------------------------------------------------
 
     ImGuiKeyModFlags KeyMods;                   // Key mods flags (same as io.KeyCtrl/KeyShift/KeyAlt/KeySuper but merged into flags), updated by NewFrame()
+    ImGuiKeyModFlags KeyModsPrev;               // Previous key mods
     ImVec2      MousePosPrev;                   // Previous mouse position (note that MouseDelta is not necessary == MousePos-MousePosPrev, in case either position is invalid)
     ImVec2      MouseClickedPos[5];             // Position at time of clicking
     double      MouseClickedTime[5];            // Time of last click (used to figure out double-click)