Settings: Added LoadIniSettingsFromDisk(), LoadIniSettingsFromMemory(), SaveIniSettingsToDisk(), SaveIniSettingsToMemory(), io.WantSaveIniSettings. (#923, #993)

CHANGELOG.txt

@@ -53,6 +53,8 @@ Other Changes:
 - Window: Fixed windows using the ImGuiWindowFlags_NoSavedSettings flag from not using the same default position as other windows. (#1760)
 - Window: Relaxed the internal stack size checker to allow Push/Begin/Pop/.../End patterns to be used with PushStyleColor, PushStyleVar, PushFont without causing a false positive assert. (#1767)
 - Columns: Fixed a bug introduced in 1.51 where columns would affect the contents size of their container, often creating feedback loops when ImGuiWindowFlags_AlwaysAutoResize was used. (#1760)
+- Settings: Added LoadIniSettingsFromDisk(), LoadIniSettingsFromMemory(), SaveIniSettingsToDisk(), SaveIniSettingsToMemory() to manually load/save .ini settings. (#923, #993)
+- Settings: Added io.WantSaveIniSettings flag, which is set to notify the application that e.g. SaveIniSettingsToMemory() should be called. (#923, #993)
 - MenuBar: Made BeginMainMenuBar() honor style.DisplaySafeAreaPadding so the text can be made visible on TV settings that don't display all pixels. (#1439) [@dougbinks]
 - InputText: On Mac OS X, filter out characters when the CMD modifier is held. (#1747) [@sivu]
 - InputText: On Mac OS X, support CMD+SHIFT+Z for Redo. CMD+Y is also supported as major apps seems to default to support both. (#1765) [@lfnoise]

TODO.txt

@@ -183,7 +183,6 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - tree node: tweak color scheme to distinguish headers from selected tree node (#581)
  - tree node: leaf/non-leaf highlight mismatch.
 
-!- settings: expose enough to save/load .ini from RAM instead of fopen
  - settings: write more decent code to allow saving/loading new fields: columns, selected tree nodes?
  - settings: api for per-tool simple persistent data (bool,int,float,columns sizes,etc.) in .ini file (#437)
  - stb: add defines to disable stb implementations

imgui.cpp

@@ -733,12 +733,6 @@ static void             AddWindowToSortedBuffer(ImVector<ImGuiWindow*>* out_sort
 
 static ImGuiWindowSettings* AddWindowSettings(const char* name);
 
-static void             LoadIniSettingsFromDisk(const char* ini_filename);
-static void             LoadIniSettingsFromMemory(const char* buf);
-static void             SaveIniSettingsToDisk(const char* ini_filename);
-static void             SaveIniSettingsToMemory(ImVector<char>& out_buf);
-static void             MarkIniSettingsDirty(ImGuiWindow* window);
-
 static ImRect           GetViewportRect();
 
 static void             ClosePopupToLevel(int remaining);
@@ -1455,7 +1449,7 @@ FILE* ImFileOpen(const char* filename, const char* mode)
 
 // Load file content into memory
 // Memory allocated with ImGui::MemAlloc(), must be freed by user using ImGui::MemFree()
-void* ImFileLoadToMemory(const char* filename, const char* file_open_mode, int* out_file_size, int padding_bytes)
+void* ImFileLoadToMemory(const char* filename, const char* file_open_mode, size_t* out_file_size, int padding_bytes)
 {
     IM_ASSERT(filename && file_open_mode);
     if (out_file_size)
@@ -1472,14 +1466,14 @@ void* ImFileLoadToMemory(const char* filename, const char* file_open_mode, int*
         return NULL;
     }
 
-    int file_size = (int)file_size_signed;
-    void* file_data = ImGui::MemAlloc((size_t)(file_size + padding_bytes));
+    size_t file_size = (size_t)file_size_signed;
+    void* file_data = ImGui::MemAlloc(file_size + padding_bytes);
     if (file_data == NULL)
     {
         fclose(f);
         return NULL;
     }
-    if (fread(file_data, 1, (size_t)file_size, f) != (size_t)file_size)
+    if (fread(file_data, 1, file_size, f) != file_size)
     {
         fclose(f);
         ImGui::MemFree(file_data);
@@ -3444,20 +3438,27 @@ void ImGui::NewFrame()
     if (g.IO.ConfigFlags & ImGuiConfigFlags_NavEnableKeyboard)
         IM_ASSERT(g.IO.KeyMap[ImGuiKey_Space] != -1 && "ImGuiKey_Space is not mapped, required for keyboard navigation.");
 
-    // Load settings on first frame
+    // Load settings on first frame (if not explicitly loaded manually before)
     if (!g.SettingsLoaded)
     {
         IM_ASSERT(g.SettingsWindows.empty());
-        LoadIniSettingsFromDisk(g.IO.IniFilename);
+        if (g.IO.IniFilename)
+            LoadIniSettingsFromDisk(g.IO.IniFilename);
         g.SettingsLoaded = true;
     }
 
-    // Save settings (with a delay so we don't spam disk too much)
+    // Save settings (with a delay after the last modification, so we don't spam disk too much)
     if (g.SettingsDirtyTimer > 0.0f)
     {
         g.SettingsDirtyTimer -= g.IO.DeltaTime;
         if (g.SettingsDirtyTimer <= 0.0f)
-            SaveIniSettingsToDisk(g.IO.IniFilename);
+        {
+            if (g.IO.IniFilename != NULL)
+                SaveIniSettingsToDisk(g.IO.IniFilename);
+            else
+                g.IO.WantSaveIniSettings = true;  // Let user know they can call SaveIniSettingsToMemory(). user will need to clear io.WantSaveIniSettings themselves.
+            g.SettingsDirtyTimer = 0.0f;
+        }
     }
 
     g.Time += g.IO.DeltaTime;
@@ -3685,19 +3686,18 @@ void ImGui::Initialize(ImGuiContext* context)
 // This function is merely here to free heap allocations.
 void ImGui::Shutdown(ImGuiContext* context)
 {
-    ImGuiContext& g = *context;
-
     // The fonts atlas can be used prior to calling NewFrame(), so we clear it even if g.Initialized is FALSE (which would happen if we never called NewFrame)
+    ImGuiContext& g = *context;
     if (g.IO.Fonts && g.FontAtlasOwnedByContext)
         IM_DELETE(g.IO.Fonts);
     g.IO.Fonts = NULL;
 
-    // Cleanup of other data are conditional on actually having initialize ImGui.
+    // Cleanup of other data are conditional on actually having initialized ImGui.
     if (!g.Initialized)
         return;
 
     // Save settings (unless we haven't attempted to load them: CreateContext/DestroyContext without a call to NewFrame shouldn't save an empty file)
-    if (g.SettingsLoaded)
+    if (g.SettingsLoaded && g.IO.IniFilename != NULL)
         SaveIniSettingsToDisk(g.IO.IniFilename);
 
     // Clear everything else
@@ -3759,14 +3759,13 @@ static ImGuiWindowSettings* AddWindowSettings(const char* name)
     return settings;
 }
 
-static void LoadIniSettingsFromDisk(const char* ini_filename)
+void ImGui::LoadIniSettingsFromDisk(const char* ini_filename)
 {
-    if (!ini_filename)
-        return;
-    char* file_data = (char*)ImFileLoadToMemory(ini_filename, "rb", NULL, +1);
+    size_t file_data_size = 0;
+    char* file_data = (char*)ImFileLoadToMemory(ini_filename, "rb", &file_data_size);
     if (!file_data)
         return;
-    LoadIniSettingsFromMemory(file_data);
+    LoadIniSettingsFromMemory(file_data, (size_t)file_data_size);
     ImGui::MemFree(file_data);
 }
 
@@ -3781,13 +3780,21 @@ ImGuiSettingsHandler* ImGui::FindSettingsHandler(const char* type_name)
 }
 
 // Zero-tolerance, no error reporting, cheap .ini parsing
-static void LoadIniSettingsFromMemory(const char* buf_readonly)
+void ImGui::LoadIniSettingsFromMemory(const char* ini_data, size_t ini_size)
 {
-    // For convenience and to make the code simpler, we'll write zero terminators inside the buffer. So let's create a writable copy.
-    char* buf = ImStrdup(buf_readonly);
-    char* buf_end = buf + strlen(buf);
-
     ImGuiContext& g = *GImGui;
+    IM_ASSERT(g.Initialized);
+    IM_ASSERT(g.SettingsLoaded == false && g.FrameCount == 0);
+
+    // For user convenience, we allow passing a non zero-terminated string (hence the ini_size parameter).
+    // For our convenience and to make the code simpler, we'll also write zero-terminators within the buffer. So let's create a writable copy..
+    if (ini_size == 0)
+        ini_size = strlen(ini_data);
+    char* buf = (char*)ImGui::MemAlloc(ini_size + 1);
+    char* buf_end = buf + ini_size;
+    memcpy(buf, ini_data, ini_size);
+    buf[ini_size] = 0;
+
     void* entry_data = NULL;
     ImGuiSettingsHandler* entry_handler = NULL;
 
@@ -3820,7 +3827,7 @@ static void LoadIniSettingsFromMemory(const char* buf_readonly)
                 *type_end = 0; // Overwrite first ']' 
                 name_start++;  // Skip second '['
             }
-            entry_handler = ImGui::FindSettingsHandler(type_start);
+            entry_handler = FindSettingsHandler(type_start);
             entry_data = entry_handler ? entry_handler->ReadOpenFn(&g, entry_handler, name_start) : NULL;
         }
         else if (entry_handler != NULL && entry_data != NULL)
@@ -3833,37 +3840,37 @@ static void LoadIniSettingsFromMemory(const char* buf_readonly)
     g.SettingsLoaded = true;
 }
 
-static void SaveIniSettingsToDisk(const char* ini_filename)
+void ImGui::SaveIniSettingsToDisk(const char* ini_filename)
 {
     ImGuiContext& g = *GImGui;
     g.SettingsDirtyTimer = 0.0f;
     if (!ini_filename)
         return;
 
-    ImVector<char> buf;
-    SaveIniSettingsToMemory(buf);
-
+    size_t ini_data_size = 0;
+    const char* ini_data = SaveIniSettingsToMemory(&ini_data_size);
     FILE* f = ImFileOpen(ini_filename, "wt");
     if (!f)
         return;
-    fwrite(buf.Data, sizeof(char), (size_t)buf.Size, f);
+    fwrite(ini_data, sizeof(char), ini_data_size, f);
     fclose(f);
 }
 
-static void SaveIniSettingsToMemory(ImVector<char>& out_buf)
+// Call registered handlers (e.g. SettingsHandlerWindow_WriteAll() + custom handlers) to write their stuff into a text buffer
+const char* ImGui::SaveIniSettingsToMemory(size_t* out_size)
 {
     ImGuiContext& g = *GImGui;
     g.SettingsDirtyTimer = 0.0f;
-
-    ImGuiTextBuffer buf;
+    g.SettingsIniData.Buf.resize(0);
+    g.SettingsIniData.Buf.push_back(0);
     for (int handler_n = 0; handler_n < g.SettingsHandlers.Size; handler_n++)
     {
         ImGuiSettingsHandler* handler = &g.SettingsHandlers[handler_n];
-        handler->WriteAllFn(&g, handler, &buf);
+        handler->WriteAllFn(&g, handler, &g.SettingsIniData);
     }
-
-    buf.Buf.pop_back(); // Remove extra zero-terminator used by ImGuiTextBuffer
-    out_buf.swap(buf.Buf);
+    if (out_size)
+        *out_size = (size_t)g.SettingsIniData.size();
+    return g.SettingsIniData.c_str();
 }
 
 void ImGui::MarkIniSettingsDirty()
@@ -3873,7 +3880,7 @@ void ImGui::MarkIniSettingsDirty()
         g.SettingsDirtyTimer = g.IO.IniSavingRate;
 }
 
-static void MarkIniSettingsDirty(ImGuiWindow* window)
+void ImGui::MarkIniSettingsDirty(ImGuiWindow* window)
 {
     ImGuiContext& g = *GImGui;
     if (!(window->Flags & ImGuiWindowFlags_NoSavedSettings))

imgui.h

@@ -542,6 +542,13 @@ namespace ImGui
     IMGUI_API const char*   GetClipboardText();
     IMGUI_API void          SetClipboardText(const char* text);
 
+    // Settings/.Ini Utilities
+    // The disk functions are automatically called if io.IniFilename != NULL (default is "imgui.ini"). Set io.IniFilename to NULL to load/save manually.
+    IMGUI_API void          LoadIniSettingsFromDisk(const char* ini_filename);                  // call after CreateContext() and before the first call to NewFrame(). NewFrame() automatically calls LoadIniSettingsFromDisk(io.IniFilename).
+    IMGUI_API void          LoadIniSettingsFromMemory(const char* ini_data, size_t ini_size=0); // call after CreateContext() and before the first call to NewFrame() to provide .ini data from your own data source.
+    IMGUI_API void          SaveIniSettingsToDisk(const char* ini_filename);
+    IMGUI_API const char*   SaveIniSettingsToMemory(size_t* out_ini_size = NULL);               // return a zero-terminated string with the .ini data which you can save by your own mean.
+
     // Memory Utilities
     // All those functions are not reliant on the current context.
     // If you reload the contents of imgui.cpp at runtime, you may need to call SetCurrentContext() + SetAllocatorFunctions() again.
@@ -1001,11 +1008,11 @@ struct ImGuiIO
     //------------------------------------------------------------------
 
     ImGuiConfigFlags   ConfigFlags;         // = 0                  // See ImGuiConfigFlags_ enum. Set by user/application. Gamepad/keyboard navigation options, etc.
-    ImGuiBackendFlags  BackendFlags;        // = 0                  // Set ImGuiBackendFlags_ enum. Set by imgui_impl_xxx files or custom back-end.
+    ImGuiBackendFlags  BackendFlags;        // = 0                  // Set ImGuiBackendFlags_ enum. Set by imgui_impl_xxx files or custom back-end to communicate features supported by the back-end.
     ImVec2        DisplaySize;              // <unset>              // Display size, in pixels. For clamping windows positions.
     float         DeltaTime;                // = 1.0f/60.0f         // Time elapsed since last frame, in seconds.
-    float         IniSavingRate;            // = 5.0f               // Maximum time between saving positions/sizes to .ini file, in seconds.
-    const char*   IniFilename;              // = "imgui.ini"        // Path to .ini file. NULL to disable .ini saving.
+    float         IniSavingRate;            // = 5.0f               // Minimum time between saving positions/sizes to .ini file, in seconds.
+    const char*   IniFilename;              // = "imgui.ini"        // Path to .ini file. Set NULL to disable automatic .ini loading/saving, if e.g. you want to manually load/save from memory.
     const char*   LogFilename;              // = "imgui_log.txt"    // Path to .log file (default parameter to ImGui::LogToFile when no file is specified).
     float         MouseDoubleClickTime;     // = 0.30f              // Time for a double-click, in seconds.
     float         MouseDoubleClickMaxDist;  // = 6.0f               // Distance threshold to stay in to validate a double-click, in pixels.
@@ -1081,6 +1088,7 @@ struct ImGuiIO
     bool        WantCaptureKeyboard;        // When io.WantCaptureKeyboard is true, imgui will use the keyboard inputs, do not dispatch them to your main game/application (in both cases, always pass keyboard inputs to imgui). (e.g. InputText active, or an imgui window is focused and navigation is enabled, etc.).
     bool        WantTextInput;              // Mobile/console: when io.WantTextInput is true, you may display an on-screen keyboard. This is set by ImGui when it wants textual keyboard input to happen (e.g. when a InputText widget is active).
     bool        WantSetMousePos;            // MousePos has been altered, back-end should reposition mouse on next frame. Set only when ImGuiConfigFlags_NavEnableSetMousePos flag is enabled.
+    bool        WantSaveIniSettings;        // If io.IniFilename == NULL, this will be set to notify your application that you can call SaveIniSettingsToMemory() and save yourself. IMPORTANT: You need to clear io.WantSaveIniSettings yourself.
     bool        NavActive;                  // Directional navigation is currently allowed (will handle ImGuiKey_NavXXX events) = a window is focused and it doesn't use the ImGuiWindowFlags_NoNavInputs flag.
     bool        NavVisible;                 // Directional navigation is visible and allowed (will handle ImGuiKey_NavXXX events).
     float       Framerate;                  // Application framerate estimation, in frame per second. Solely for convenience. Rolling average estimation based on IO.DeltaTime over 120 frames

imgui_draw.cpp

@@ -1541,7 +1541,7 @@ ImFont* ImFontAtlas::AddFontDefault(const ImFontConfig* font_cfg_template)
 
 ImFont* ImFontAtlas::AddFontFromFileTTF(const char* filename, float size_pixels, const ImFontConfig* font_cfg_template, const ImWchar* glyph_ranges)
 {
-    int data_size = 0;
+    size_t data_size = 0;
     void* data = ImFileLoadToMemory(filename, "rb", &data_size, 0);
     if (!data)
     {
@@ -1556,7 +1556,7 @@ ImFont* ImFontAtlas::AddFontFromFileTTF(const char* filename, float size_pixels,
         for (p = filename + strlen(filename); p > filename && p[-1] != '/' && p[-1] != '\\'; p--) {}
         ImFormatString(font_cfg.Name, IM_ARRAYSIZE(font_cfg.Name), "%s, %.0fpx", p, size_pixels);
     }
-    return AddFontFromMemoryTTF(data, data_size, size_pixels, &font_cfg, glyph_ranges);
+    return AddFontFromMemoryTTF(data, (int)data_size, size_pixels, &font_cfg, glyph_ranges);
 }
 
 // NB: Transfer ownership of 'ttf_data' to ImFontAtlas, unless font_cfg_template->FontDataOwnedByAtlas == false. Owned TTF buffer will be deleted after Build().

imgui_internal.h

@@ -96,7 +96,7 @@ IMGUI_API int           ImTextCountUtf8BytesFromStr(const ImWchar* in_text, cons
 
 // Helpers: Misc
 IMGUI_API ImU32         ImHash(const void* data, int data_size, ImU32 seed = 0);    // Pass data_size==0 for zero-terminated strings
-IMGUI_API void*         ImFileLoadToMemory(const char* filename, const char* file_open_mode, int* out_file_size = NULL, int padding_bytes = 0);
+IMGUI_API void*         ImFileLoadToMemory(const char* filename, const char* file_open_mode, size_t* out_file_size = NULL, int padding_bytes = 0);
 IMGUI_API FILE*         ImFileOpen(const char* filename, const char* file_open_mode);
 static inline bool      ImCharIsSpace(unsigned int c)   { return c == ' ' || c == '\t' || c == 0x3000; }
 static inline bool      ImIsPowerOfTwo(int v)           { return v != 0 && (v & (v - 1)) == 0; }
@@ -676,9 +676,10 @@ struct ImGuiContext
 
     // Settings
     bool                           SettingsLoaded;
-    float                          SettingsDirtyTimer;          // Save .ini Settings on disk when time reaches zero
-    ImVector<ImGuiWindowSettings>  SettingsWindows;             // .ini settings for ImGuiWindow
+    float                          SettingsDirtyTimer;          // Save .ini Settings to memory when time reaches zero
+    ImGuiTextBuffer                SettingsIniData;             // In memory .ini settings
     ImVector<ImGuiSettingsHandler> SettingsHandlers;            // List of .ini settings handlers
+    ImVector<ImGuiWindowSettings>  SettingsWindows;             // ImGuiWindow .ini settings entries (parsed from the last loaded .ini file and maintained on saving)
 
     // Logging
     bool                    LogEnabled;
@@ -1022,6 +1023,7 @@ namespace ImGui
     IMGUI_API void          NewFrameUpdateHoveredWindowAndCaptureFlags();
 
     IMGUI_API void                  MarkIniSettingsDirty();
+    IMGUI_API void                  MarkIniSettingsDirty(ImGuiWindow* window);
     IMGUI_API ImGuiSettingsHandler* FindSettingsHandler(const char* type_name);
     IMGUI_API ImGuiWindowSettings*  FindWindowSettings(ImGuiID id);