Internals: Settings: added ClearWindowSettings(). Extract part of CreateNewWindow() into InitOrLoadWindowSettings().

Designed to that if the window reappear in the session it won't take an additional slot.

imgui.cpp

@@ -3631,7 +3631,7 @@ ImGuiWindow::ImGuiWindow(ImGuiContext* context, const char* name) : DrawListInst
     ScrollTargetCenterRatio = ImVec2(0.5f, 0.5f);
     AutoFitFramesX = AutoFitFramesY = -1;
     AutoPosLastDirection = ImGuiDir_None;
-    SetWindowPosAllowFlags = SetWindowSizeAllowFlags = SetWindowCollapsedAllowFlags = ImGuiCond_Always | ImGuiCond_Once | ImGuiCond_FirstUseEver | ImGuiCond_Appearing;
+    SetWindowPosAllowFlags = SetWindowSizeAllowFlags = SetWindowCollapsedAllowFlags = 0;
     SetWindowPosVal = SetWindowPosPivot = ImVec2(FLT_MAX, FLT_MAX);
     LastFrameActive = -1;
     LastTimeActive = -1.0f;
@@ -5360,32 +5360,22 @@ static void UpdateWindowInFocusOrderList(ImGuiWindow* window, bool just_created,
     window->IsExplicitChild = new_is_explicit_child;
 }
 
-static ImGuiWindow* CreateNewWindow(const char* name, ImGuiWindowFlags flags)
+static void InitOrLoadWindowSettings(ImGuiWindow* window, ImGuiWindowSettings* settings)
 {
-    ImGuiContext& g = *GImGui;
-    //IMGUI_DEBUG_LOG("CreateNewWindow '%s', flags = 0x%08X\n", name, flags);
-
-    // Create window the first time
-    ImGuiWindow* window = IM_NEW(ImGuiWindow)(&g, name);
-    window->Flags = flags;
-    g.WindowsById.SetVoidPtr(window->ID, window);
-
-    // Default/arbitrary window position. Use SetNextWindowPos() with the appropriate condition flag to change the initial position of a window.
+    // Initial window state with e.g. default/arbitrary window position
+    // Use SetNextWindowPos() with the appropriate condition flag to change the initial position of a window.
     const ImGuiViewport* main_viewport = ImGui::GetMainViewport();
     window->Pos = main_viewport->Pos + ImVec2(60, 60);
+    window->SetWindowPosAllowFlags = window->SetWindowSizeAllowFlags = window->SetWindowCollapsedAllowFlags = ImGuiCond_Always | ImGuiCond_Once | ImGuiCond_FirstUseEver | ImGuiCond_Appearing;
 
-    // User can disable loading and saving of settings. Tooltip and child windows also don't store settings.
-    if (!(flags & ImGuiWindowFlags_NoSavedSettings))
-        if (ImGuiWindowSettings* settings = ImGui::FindWindowSettingsByWindow(window))
-        {
-            // Retrieve settings from .ini file
-            window->SettingsOffset = g.SettingsWindows.offset_from_ptr(settings);
-            SetWindowConditionAllowFlags(window, ImGuiCond_FirstUseEver, false);
-            ApplyWindowSettings(window, settings);
-        }
+    if (settings != NULL)
+    {
+        SetWindowConditionAllowFlags(window, ImGuiCond_FirstUseEver, false);
+        ApplyWindowSettings(window, settings);
+    }
     window->DC.CursorStartPos = window->DC.CursorMaxPos = window->DC.IdealMaxPos = window->Pos; // So first call to CalcWindowContentSizes() doesn't return crazy values
 
-    if ((flags & ImGuiWindowFlags_AlwaysAutoResize) != 0)
+    if ((window->Flags & ImGuiWindowFlags_AlwaysAutoResize) != 0)
     {
         window->AutoFitFramesX = window->AutoFitFramesY = 2;
         window->AutoFitOnlyGrows = false;
@@ -5398,6 +5388,23 @@ static ImGuiWindow* CreateNewWindow(const char* name, ImGuiWindowFlags flags)
             window->AutoFitFramesY = 2;
         window->AutoFitOnlyGrows = (window->AutoFitFramesX > 0) || (window->AutoFitFramesY > 0);
     }
+}
+
+static ImGuiWindow* CreateNewWindow(const char* name, ImGuiWindowFlags flags)
+{
+    // Create window the first time
+    //IMGUI_DEBUG_LOG("CreateNewWindow '%s', flags = 0x%08X\n", name, flags);
+    ImGuiContext& g = *GImGui;
+    ImGuiWindow* window = IM_NEW(ImGuiWindow)(&g, name);
+    window->Flags = flags;
+    g.WindowsById.SetVoidPtr(window->ID, window);
+
+    ImGuiWindowSettings* settings = NULL;
+    if (!(flags & ImGuiWindowFlags_NoSavedSettings))
+        if ((settings = ImGui::FindWindowSettingsByWindow(window)) != 0)
+            window->SettingsOffset = g.SettingsWindows.offset_from_ptr(settings);
+
+    InitOrLoadWindowSettings(window, settings);
 
     if (flags & ImGuiWindowFlags_NoBringToFrontOnFocus)
         g.Windows.push_front(window); // Quite slow but rare and only once
@@ -12699,6 +12706,20 @@ ImGuiWindowSettings* ImGui::FindWindowSettingsByWindow(ImGuiWindow* window)
     return FindWindowSettingsByName(window->Name); // Actual search executed once, so at this point we don't mind the redundant hashing.
 }
 
+// This will revert window to its initial state, including enabling the ImGuiCond_FirstUseEver/ImGuiCond_Once conditions once more.
+void ImGui::ClearWindowSettings(const char* name)
+{
+    //IMGUI_DEBUG_LOG("ClearWindowSettings('%s')\n", name);
+    ImGuiWindow* window = FindWindowByName(name);
+    if (window != NULL)
+    {
+        window->Flags |= ImGuiWindowFlags_NoSavedSettings;
+        InitOrLoadWindowSettings(window, NULL);
+    }
+    if (ImGuiWindowSettings* settings = window ? FindWindowSettingsByWindow(window) : FindWindowSettingsByName(name))
+        settings->WantDelete = true;
+}
+
 static void WindowSettingsHandler_ClearAll(ImGuiContext* ctx, ImGuiSettingsHandler*)
 {
     ImGuiContext& g = *ctx;
@@ -12765,12 +12786,15 @@ static void WindowSettingsHandler_WriteAll(ImGuiContext* ctx, ImGuiSettingsHandl
         settings->Size = ImVec2ih(window->SizeFull);
 
         settings->Collapsed = window->Collapsed;
+        settings->WantDelete = false;
     }
 
     // Write to text buffer
     buf->reserve(buf->size() + g.SettingsWindows.size() * 6); // ballpark reserve
     for (ImGuiWindowSettings* settings = g.SettingsWindows.begin(); settings != NULL; settings = g.SettingsWindows.next_chunk(settings))
     {
+        if (settings->WantDelete)
+            continue;
         const char* settings_name = settings->GetName();
         buf->appendf("[%s][%s]\n", handler->TypeName, settings_name);
         buf->appendf("Pos=%d,%d\n", settings->Pos.x, settings->Pos.y);
@@ -14106,8 +14130,12 @@ void ImGui::DebugNodeWindow(ImGuiWindow* window, const char* label)
 
 void ImGui::DebugNodeWindowSettings(ImGuiWindowSettings* settings)
 {
+    if (settings->WantDelete)
+        BeginDisabled();
     Text("0x%08X \"%s\" Pos (%d,%d) Size (%d,%d) Collapsed=%d",
         settings->ID, settings->GetName(), settings->Pos.x, settings->Pos.y, settings->Size.x, settings->Size.y, settings->Collapsed);
+    if (settings->WantDelete)
+        EndDisabled();
 }
 
 void ImGui::DebugNodeWindowsList(ImVector<ImGuiWindow*>* windows, const char* label)

imgui_internal.h

@@ -1607,6 +1607,7 @@ struct ImGuiWindowSettings
     ImVec2ih    Size;
     bool        Collapsed;
     bool        WantApply;      // Set when loaded from .ini data (to enable merging/loading .ini data into an already running context)
+    bool        WantDelete;     // Set to invalidate/delete the settings entry
 
     ImGuiWindowSettings()       { memset(this, 0, sizeof(*this)); }
     char* GetName()             { return (char*)(this + 1); }
@@ -2771,6 +2772,7 @@ namespace ImGui
     IMGUI_API ImGuiWindowSettings*  CreateNewWindowSettings(const char* name);
     IMGUI_API ImGuiWindowSettings*  FindWindowSettingsByName(const char* name);
     IMGUI_API ImGuiWindowSettings*  FindWindowSettingsByWindow(ImGuiWindow* window);
+    IMGUI_API void                  ClearWindowSettings(const char* name);
 
     // Localization
     IMGUI_API void          LocalizeRegisterEntries(const ImGuiLocEntry* entries, int count);