Merge branch 'master' into docking

.github/workflows/build.yml

@@ -527,6 +527,7 @@ jobs:
         emsdk-master/emsdk update
         emsdk-master/emsdk install latest
         emsdk-master/emsdk activate latest
+        sudo apt-get install build-essential
 
     - name: Build example_sdl2_opengl3 with Emscripten
       run: |
@@ -535,13 +536,26 @@ jobs:
         popd
         make -C examples/example_sdl2_opengl3 -f Makefile.emscripten
 
-    - name: Build example_glfw_wgpu
+    # This build compiles example_glfw_wgpu using Makefile.emscripten and Emscripten GLFW built-in implementation (-sUSE_GLFW=3)
+    # This ensures 2 things: the make build works, and the GLFW built-in implementation is tested
+    - name: Build example_glfw_wgpu with Emscripten/Makefile
       run: |
         pushd emsdk-master
         source ./emsdk_env.sh
         popd
         make -C examples/example_glfw_wgpu -f Makefile.emscripten
 
+    # This build compiles example_glfw_wgpu using CMakeLists.txt and Emscripten GLFW contrib port (--use-port=contrib.glfw3)
+    # This ensures 2 things: the CMake build works, and the GLFW contrib port is tested
+    - name: Build example_glfw_wgpu with Emscripten/CMake
+      run: |
+        pushd emsdk-master
+        source ./emsdk_env.sh
+        popd
+        emcc -v
+        emcmake cmake -B build -DCMAKE_BUILD_TYPE=Release examples/example_glfw_wgpu
+        cmake --build build
+
   Android:
     runs-on: ubuntu-24.04
     steps:

backends/imgui_impl_glfw.cpp

@@ -21,6 +21,11 @@
 // - Documentation        https://dearimgui.com/docs (same as your local docs/ folder).
 // - Introduction, links and more at the top of imgui.cpp
 
+// About Emscripten support:
+// - Emscripten provides its own GLFW (3.2.1) implementation (syntax: "-sUSE_GLFW=3"), but Joystick is broken and several features are not supported (multiple windows, clipboard, timer, etc.)
+// - A third-party Emscripten GLFW (3.4.0) implementation (syntax: "--use-port=contrib.glfw3") fixes the Joystick issue and implements all relevant features for the browser.
+// See https://github.com/pongasoft/emscripten-glfw/blob/master/docs/Comparison.md for details.
+
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2024-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
@@ -576,7 +581,7 @@ void ImGui_ImplGlfw_SetCallbacksChainForAllWindows(bool chain_for_all_windows)
 }
 
 #ifdef __EMSCRIPTEN__
-#if EMSCRIPTEN_USE_PORT_CONTRIB_GLFW3 >= 3'4'0'20240817
+#if EMSCRIPTEN_USE_PORT_CONTRIB_GLFW3 >= 34020240817
 void ImGui_ImplGlfw_EmscriptenOpenURL(const char* url) { if (url) emscripten::glfw3::OpenURL(url); }
 #else
 EM_JS(void, ImGui_ImplGlfw_EmscriptenOpenURL, (const char* url), { url = url ? UTF8ToString(url) : null; if (url) window.open(url, '_blank'); });
@@ -668,6 +673,23 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
     ::SetWindowLongPtrW((HWND)main_viewport->PlatformHandleRaw, GWLP_WNDPROC, (LONG_PTR)ImGui_ImplGlfw_WndProc);
 #endif
 
+    // Emscripten: the same application can run on various platforms, so we detect the Apple platform at runtime
+    // to override io.ConfigMacOSXBehaviors from its default (which is always false in Emscripten).
+#ifdef __EMSCRIPTEN__
+#if EMSCRIPTEN_USE_PORT_CONTRIB_GLFW3 >= 34020240817
+    if (emscripten::glfw3::IsRuntimePlatformApple())
+    {
+        ImGui::GetIO().ConfigMacOSXBehaviors = true;
+
+        // Due to how the browser (poorly) handles the Meta Key, this line essentially disables repeats when used.
+        // This means that Meta + V only registers a single key-press, even if the keys are held.
+        // This is a compromise for dealing with this issue in ImGui since ImGui implements key repeat itself.
+        // See https://github.com/pongasoft/emscripten-glfw/blob/v3.4.0.20240817/docs/Usage.md#the-problem-of-the-super-key
+        emscripten::glfw3::SetSuperPlusKeyTimeouts(10, 10);
+    }
+#endif
+#endif
+
     bd->ClientApi = client_api;
     return true;
 }

docs/CHANGELOG.txt

@@ -63,9 +63,18 @@ Other changes:
      #6223, #6364, #6387, #6567, #6692, #6724, #6939, #6984, #7246, #7270, #7375, #7421, #7434,
      #7472, #7581, #7724, #7926, #7937 and probably more..)
 - Nav: pressing any keyboard key while holding Alt disable toggling nav layer on Alt release. (#4439)
+- MultiSelect+Tables: fixed an issue where box-select would skip items while drag-scrolling
+  in a table with outer borders. (#7970, #7821).
+- InputText: internal refactoring to simplify and optimize the code. The ImWchar buffer has been
+  removed. Simplifications allowed to implement new optimizations for handling very large text buffers
+  (e.g. in our testing, handling of a 1 MB text buffer is now 3 times faster in VS2022 Debug build).
+  This is the first step toward more refactorig. (#7925) [@alektron, @ocornut]
 - InputText: added CJK double-width punctuation to list of separators considered for CTRL+Arrow.
+- Fonts: fixed ellipsis "..." rendering width miscalculation bug introduced in 1.91.0. (#7976) [@DDeimos]
 - TextLinkOpenURL(): modified tooltip to display a verb "Open 'xxxx'". (#7885, #7660)
 - Backends: SDL2: use SDL_Vulkan_GetDrawableSize() when available. (#7967, #3190) [@scribam]
+- Backends: GLFW+Emscripten: use OSX behaviors automatically when using contrib glfw port. (#7965, #7915)
+  [@ypujante]
 
 Docking+Viewports Branch:
 

docs/TODO.txt

@@ -65,7 +65,6 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - selectable: generic BeginSelectable()/EndSelectable() mechanism. (work out alongside range-select branch)
  - selectable: a way to visualize partial/mixed selection (e.g. parent tree node has children with mixed selection)
 
- - input text: clean up the mess caused by converting UTF-8 <> wchar. the code is rather inefficient right now and super fragile. (WIP branch)
  - input text: preserve scrolling when unfocused?
  - input text: reorganize event handling, allow CharFilter to modify buffers, allow multiple events? (#541)
  - input text: expose CursorPos in char filter event (#816)

examples/example_glfw_wgpu/CMakeLists.txt

@@ -91,7 +91,6 @@ if(EMSCRIPTEN)
   if("${IMGUI_EMSCRIPTEN_GLFW3}" STREQUAL "--use-port=contrib.glfw3")
     target_compile_options(example_glfw_wgpu PUBLIC
         "${IMGUI_EMSCRIPTEN_GLFW3}"
-        "-DEMSCRIPTEN_USE_PORT_CONTRIB_GLFW3" # unnecessary beyond emscripten 3.1.59
     )
   endif()
   message(STATUS "Using ${IMGUI_EMSCRIPTEN_GLFW3} GLFW implementation")

imgui.cpp

@@ -2035,7 +2035,7 @@ const char* ImStreolRange(const char* str, const char* str_end)
     return p ? p : str_end;
 }
 
-const ImWchar* ImStrbolW(const ImWchar* buf_mid_line, const ImWchar* buf_begin) // find beginning-of-line
+const char* ImStrbol(const char* buf_mid_line, const char* buf_begin) // find beginning-of-line
 {
     while (buf_mid_line > buf_begin && buf_mid_line[-1] != '\n')
         buf_mid_line--;
@@ -4097,7 +4097,7 @@ static void SetCurrentWindow(ImGuiWindow* window)
     if (window)
     {
         g.FontSize = g.DrawListSharedData.FontSize = window->CalcFontSize();
-        g.FontScale = g.FontSize / g.Font->FontSize;
+        g.FontScale = g.DrawListSharedData.FontScale = g.FontSize / g.Font->FontSize;
         ImGui::NavUpdateCurrentWindowIsScrollPushableX();
     }
 }
@@ -9663,7 +9663,7 @@ bool ImGui::IsKeyPressed(ImGuiKey key, bool repeat)
     return IsKeyPressed(key, repeat ? ImGuiInputFlags_Repeat : ImGuiInputFlags_None, ImGuiKeyOwner_Any);
 }
 
-// Important: unless legacy IsKeyPressed(ImGuiKey, bool repeat=true) which DEFAULT to repeat, this requires EXPLICIT repeat.
+// Important: unlike legacy IsKeyPressed(ImGuiKey, bool repeat=true) which DEFAULT to repeat, this requires EXPLICIT repeat.
 bool ImGui::IsKeyPressed(ImGuiKey key, ImGuiInputFlags flags, ImGuiID owner_id)
 {
     const ImGuiKeyData* key_data = GetKeyData(key);

imgui.h

@@ -29,7 +29,7 @@
 // Library Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals, e.g. '#if IMGUI_VERSION_NUM >= 12345')
 #define IMGUI_VERSION       "1.91.2 WIP"
-#define IMGUI_VERSION_NUM   19113
+#define IMGUI_VERSION_NUM   19114
 #define IMGUI_HAS_TABLE
 #define IMGUI_HAS_VIEWPORT          // Viewport WIP branch
 #define IMGUI_HAS_DOCK              // Docking WIP branch

imgui_internal.h

@@ -377,7 +377,7 @@ IMGUI_API const char*   ImStristr(const char* haystack, const char* haystack_end
 IMGUI_API void          ImStrTrimBlanks(char* str);                                         // Remove leading and trailing blanks from a buffer.
 IMGUI_API const char*   ImStrSkipBlank(const char* str);                                    // Find first non-blank character.
 IMGUI_API int           ImStrlenW(const ImWchar* str);                                      // Computer string length (ImWchar string)
-IMGUI_API const ImWchar*ImStrbolW(const ImWchar* buf_mid_line, const ImWchar* buf_begin);   // Find beginning-of-line (ImWchar string)
+IMGUI_API const char*   ImStrbol(const char* buf_mid_line, const char* buf_begin);          // Find beginning-of-line
 IM_MSVC_RUNTIME_CHECKS_OFF
 static inline char      ImToUpper(char c)               { return (c >= 'a' && c <= 'z') ? c &= ~32 : c; }
 static inline bool      ImCharIsBlankA(char c)          { return c == ' ' || c == '\t'; }
@@ -1108,7 +1108,7 @@ struct IMGUI_API ImGuiInputTextDeactivatedState
 #undef IMSTB_TEXTEDIT_STRING
 #undef IMSTB_TEXTEDIT_CHARTYPE
 #define IMSTB_TEXTEDIT_STRING             ImGuiInputTextState
-#define IMSTB_TEXTEDIT_CHARTYPE           ImWchar
+#define IMSTB_TEXTEDIT_CHARTYPE           char
 #define IMSTB_TEXTEDIT_GETWIDTH_NEWLINE   (-1.0f)
 #define IMSTB_TEXTEDIT_UNDOSTATECOUNT     99
 #define IMSTB_TEXTEDIT_UNDOCHARCOUNT      999
@@ -1122,11 +1122,10 @@ struct IMGUI_API ImGuiInputTextState
     ImGuiContext*           Ctx;                    // parent UI context (needs to be set explicitly by parent).
     ImStbTexteditState*     Stb;                    // State for stb_textedit.h
     ImGuiID                 ID;                     // widget id owning the text state
-    int                     CurLenW, CurLenA;       // we need to maintain our buffer length in both UTF-8 and wchar format. UTF-8 length is valid even if TextA is not.
-    ImVector<ImWchar>       TextW;                  // edit buffer, we need to persist but can't guarantee the persistence of the user-provided buffer. so we copy into own buffer.
-    ImVector<char>          TextA;                  // temporary UTF8 buffer for callbacks and other operations. this is not updated in every code-path! size=capacity.
+    int                     CurLenA;                // UTF-8 length of the string in TextA (in bytes)
+    ImVector<char>          TextA;                  // main UTF8 buffer.
     ImVector<char>          InitialTextA;           // value to revert to when pressing Escape = backup of end-user buffer at the time of focus (in UTF-8, unaltered)
-    bool                    TextAIsValid;           // temporary UTF8 buffer is not initially valid before we make the widget active (until then we pull the data from user argument)
+    ImVector<char>          CallbackTextBackup;     // temporary storage for callback to support automatic reconcile of undo-stack
     int                     BufCapacityA;           // end-user buffer capacity
     ImVec2                  Scroll;                 // horizontal offset (managed manually) + vertical scrolling (pulled from child window's own Scroll.y)
     float                   CursorAnim;             // timer for cursor blink, reset on every user action so the cursor reappears immediately
@@ -1140,9 +1139,10 @@ struct IMGUI_API ImGuiInputTextState
 
     ImGuiInputTextState();
     ~ImGuiInputTextState();
-    void        ClearText()                 { CurLenW = CurLenA = 0; TextW[0] = 0; TextA[0] = 0; CursorClamp(); }
-    void        ClearFreeMemory()           { TextW.clear(); TextA.clear(); InitialTextA.clear(); }
+    void        ClearText()                 { CurLenA = 0; TextA[0] = 0; CursorClamp(); }
+    void        ClearFreeMemory()           { TextA.clear(); InitialTextA.clear(); }
     void        OnKeyPressed(int key);      // Cannot be inline because we call in code in stb_textedit.h implementation
+    void        OnCharPressed(unsigned int c);
 
     // Cursor & Selection
     void        CursorAnimReset();

imgui_widgets.cpp

@@ -128,7 +128,7 @@ static const ImU64          IM_U64_MAX = (2ULL * 9223372036854775807LL + 1);
 // For InputTextEx()
 static bool     InputTextFilterCharacter(ImGuiContext* ctx, unsigned int* p_char, ImGuiInputTextFlags flags, ImGuiInputTextCallback callback, void* user_data, bool input_source_is_clipboard = false);
 static int      InputTextCalcTextLenAndLineCount(const char* text_begin, const char** out_text_end);
-static ImVec2   InputTextCalcTextSizeW(ImGuiContext* ctx, const ImWchar* text_begin, const ImWchar* text_end, const ImWchar** remaining = NULL, ImVec2* out_offset = NULL, bool stop_on_new_line = false);
+static ImVec2   InputTextCalcTextSize(ImGuiContext* ctx, const char* text_begin, const char* text_end, const char** remaining = NULL, ImVec2* out_offset = NULL, bool stop_on_new_line = false);
 
 //-------------------------------------------------------------------------
 // [SECTION] Widgets: Text, etc.
@@ -3842,7 +3842,8 @@ static int InputTextCalcTextLenAndLineCount(const char* text_begin, const char**
     return line_count;
 }
 
-static ImVec2 InputTextCalcTextSizeW(ImGuiContext* ctx, const ImWchar* text_begin, const ImWchar* text_end, const ImWchar** remaining, ImVec2* out_offset, bool stop_on_new_line)
+// FIXME: Ideally we'd share code with ImFont::CalcTextSizeA()
+static ImVec2 InputTextCalcTextSize(ImGuiContext* ctx, const char* text_begin, const char* text_end, const char** remaining, ImVec2* out_offset, bool stop_on_new_line)
 {
     ImGuiContext& g = *ctx;
     ImFont* font = g.Font;
@@ -3852,10 +3853,15 @@ static ImVec2 InputTextCalcTextSizeW(ImGuiContext* ctx, const ImWchar* text_begi
     ImVec2 text_size = ImVec2(0, 0);
     float line_width = 0.0f;
 
-    const ImWchar* s = text_begin;
+    const char* s = text_begin;
     while (s < text_end)
     {
-        unsigned int c = (unsigned int)(*s++);
+        unsigned int c = (unsigned int)*s;
+        if (c < 0x80)
+            s += 1;
+        else
+            s += ImTextCharFromUtf8(&c, s, text_end);
+
         if (c == '\n')
         {
             text_size.x = ImMax(text_size.x, line_width);
@@ -3868,7 +3874,7 @@ static ImVec2 InputTextCalcTextSizeW(ImGuiContext* ctx, const ImWchar* text_begi
         if (c == '\r')
             continue;
 
-        const float char_width = font->GetCharAdvance((ImWchar)c) * scale;
+        const float char_width = ((int)c < font->IndexAdvanceX.Size ? font->IndexAdvanceX.Data[c] : font->FallbackAdvanceX) * scale;
         line_width += char_width;
     }
 
@@ -3888,19 +3894,21 @@ static ImVec2 InputTextCalcTextSizeW(ImGuiContext* ctx, const ImWchar* text_begi
 }
 
 // Wrapper for stb_textedit.h to edit text (our wrapper is for: statically sized buffer, single-line, wchar characters. InputText converts between UTF-8 and wchar)
+// With our UTF-8 use of stb_textedit:
+// - STB_TEXTEDIT_GETCHAR is nothing more than a a "GETBYTE". It's only used to compare to ascii or to copy blocks of text so we are fine.
+// - One exception is the STB_TEXTEDIT_IS_SPACE feature which would expect a full char in order to handle full-width space such as 0x3000 (see ImCharIsBlankW).
+// - ...but we don't use that feature.
 namespace ImStb
 {
-
-static int     STB_TEXTEDIT_STRINGLEN(const ImGuiInputTextState* obj)                             { return obj->CurLenW; }
-static ImWchar STB_TEXTEDIT_GETCHAR(const ImGuiInputTextState* obj, int idx)                      { IM_ASSERT(idx <= obj->CurLenW); return obj->TextW[idx]; }
-static float   STB_TEXTEDIT_GETWIDTH(ImGuiInputTextState* obj, int line_start_idx, int char_idx)  { ImWchar c = obj->TextW[line_start_idx + char_idx]; if (c == '\n') return IMSTB_TEXTEDIT_GETWIDTH_NEWLINE; ImGuiContext& g = *obj->Ctx; return g.Font->GetCharAdvance(c) * g.FontScale; }
-static int     STB_TEXTEDIT_KEYTOTEXT(int key)                                                    { return key >= 0x200000 ? 0 : key; }
-static ImWchar STB_TEXTEDIT_NEWLINE = '\n';
+static int     STB_TEXTEDIT_STRINGLEN(const ImGuiInputTextState* obj)                             { return obj->CurLenA; }
+static char    STB_TEXTEDIT_GETCHAR(const ImGuiInputTextState* obj, int idx)                      { IM_ASSERT(idx <= obj->CurLenA); return obj->TextA[idx]; }
+static float   STB_TEXTEDIT_GETWIDTH(ImGuiInputTextState* obj, int line_start_idx, int char_idx)  { unsigned int c; ImTextCharFromUtf8(&c, obj->TextA.Data + line_start_idx + char_idx, obj->TextA.Data + obj->TextA.Size); if ((ImWchar)c == '\n') return IMSTB_TEXTEDIT_GETWIDTH_NEWLINE; ImGuiContext& g = *obj->Ctx; return g.Font->GetCharAdvance((ImWchar)c) * g.FontScale; }
+static char    STB_TEXTEDIT_NEWLINE = '\n';
 static void    STB_TEXTEDIT_LAYOUTROW(StbTexteditRow* r, ImGuiInputTextState* obj, int line_start_idx)
 {
-    const ImWchar* text = obj->TextW.Data;
-    const ImWchar* text_remaining = NULL;
-    const ImVec2 size = InputTextCalcTextSizeW(obj->Ctx, text + line_start_idx, text + obj->CurLenW, &text_remaining, NULL, true);
+    const char* text = obj->TextA.Data;
+    const char* text_remaining = NULL;
+    const ImVec2 size = InputTextCalcTextSize(obj->Ctx, text + line_start_idx, text + obj->CurLenA, &text_remaining, NULL, true);
     r->x0 = 0.0f;
     r->x1 = size.x;
     r->baseline_y_delta = size.y;
@@ -3909,6 +3917,25 @@ static void    STB_TEXTEDIT_LAYOUTROW(StbTexteditRow* r, ImGuiInputTextState* ob
     r->num_chars = (int)(text_remaining - (text + line_start_idx));
 }
 
+#define IMSTB_TEXTEDIT_GETNEXTCHARINDEX  IMSTB_TEXTEDIT_GETNEXTCHARINDEX_IMPL
+#define IMSTB_TEXTEDIT_GETPREVCHARINDEX  IMSTB_TEXTEDIT_GETPREVCHARINDEX_IMPL
+
+static int IMSTB_TEXTEDIT_GETNEXTCHARINDEX_IMPL(ImGuiInputTextState* obj, int idx)
+{
+    if (idx >= obj->CurLenA)
+        return obj->CurLenA + 1;
+    unsigned int c;
+    return idx + ImTextCharFromUtf8(&c, obj->TextA.Data + idx, obj->TextA.Data + obj->TextA.Size);
+}
+
+static int IMSTB_TEXTEDIT_GETPREVCHARINDEX_IMPL(ImGuiInputTextState* obj, int idx)
+{
+    if (idx <= 0)
+        return -1;
+    const char* p = ImTextFindPreviousUtf8Codepoint(obj->TextA.Data, obj->TextA.Data + idx);
+    return (int)(p - obj->TextA.Data);
+}
+
 static bool ImCharIsSeparatorW(unsigned int c)
 {
     static const unsigned int separator_list[] =
@@ -3929,10 +3956,15 @@ static int is_word_boundary_from_right(ImGuiInputTextState* obj, int idx)
     if ((obj->Flags & ImGuiInputTextFlags_Password) || idx <= 0)
         return 0;
 
-    bool prev_white = ImCharIsBlankW(obj->TextW[idx - 1]);
-    bool prev_separ = ImCharIsSeparatorW(obj->TextW[idx - 1]);
-    bool curr_white = ImCharIsBlankW(obj->TextW[idx]);
-    bool curr_separ = ImCharIsSeparatorW(obj->TextW[idx]);
+    const char* curr_p = obj->TextA.Data + idx;
+    const char* prev_p = ImTextFindPreviousUtf8Codepoint(obj->TextA.Data, curr_p);
+    unsigned int curr_c; ImTextCharFromUtf8(&curr_c, curr_p, obj->TextA.Data + obj->TextA.Size);
+    unsigned int prev_c; ImTextCharFromUtf8(&prev_c, prev_p, obj->TextA.Data + obj->TextA.Size);
+
+    bool prev_white = ImCharIsBlankW(prev_c);
+    bool prev_separ = ImCharIsSeparatorW(prev_c);
+    bool curr_white = ImCharIsBlankW(curr_c);
+    bool curr_separ = ImCharIsSeparatorW(curr_c);
     return ((prev_white || prev_separ) && !(curr_separ || curr_white)) || (curr_separ && !prev_separ);
 }
 static int is_word_boundary_from_left(ImGuiInputTextState* obj, int idx)
@@ -3940,63 +3972,83 @@ static int is_word_boundary_from_left(ImGuiInputTextState* obj, int idx)
     if ((obj->Flags & ImGuiInputTextFlags_Password) || idx <= 0)
         return 0;
 
-    bool prev_white = ImCharIsBlankW(obj->TextW[idx]);
-    bool prev_separ = ImCharIsSeparatorW(obj->TextW[idx]);
-    bool curr_white = ImCharIsBlankW(obj->TextW[idx - 1]);
-    bool curr_separ = ImCharIsSeparatorW(obj->TextW[idx - 1]);
+    const char* curr_p = obj->TextA.Data + idx;
+    const char* prev_p = ImTextFindPreviousUtf8Codepoint(obj->TextA.Data, curr_p);
+    unsigned int prev_c; ImTextCharFromUtf8(&prev_c, curr_p, obj->TextA.Data + obj->TextA.Size);
+    unsigned int curr_c; ImTextCharFromUtf8(&curr_c, prev_p, obj->TextA.Data + obj->TextA.Size);
+
+    bool prev_white = ImCharIsBlankW(prev_c);
+    bool prev_separ = ImCharIsSeparatorW(prev_c);
+    bool curr_white = ImCharIsBlankW(curr_c);
+    bool curr_separ = ImCharIsSeparatorW(curr_c);
     return ((prev_white) && !(curr_separ || curr_white)) || (curr_separ && !prev_separ);
 }
-static int  STB_TEXTEDIT_MOVEWORDLEFT_IMPL(ImGuiInputTextState* obj, int idx)   { idx--; while (idx >= 0 && !is_word_boundary_from_right(obj, idx)) idx--; return idx < 0 ? 0 : idx; }
-static int  STB_TEXTEDIT_MOVEWORDRIGHT_MAC(ImGuiInputTextState* obj, int idx)   { idx++; int len = obj->CurLenW; while (idx < len && !is_word_boundary_from_left(obj, idx)) idx++; return idx > len ? len : idx; }
-static int  STB_TEXTEDIT_MOVEWORDRIGHT_WIN(ImGuiInputTextState* obj, int idx)   { idx++; int len = obj->CurLenW; while (idx < len && !is_word_boundary_from_right(obj, idx)) idx++; return idx > len ? len : idx; }
+static int  STB_TEXTEDIT_MOVEWORDLEFT_IMPL(ImGuiInputTextState* obj, int idx)
+{
+    idx = IMSTB_TEXTEDIT_GETPREVCHARINDEX(obj, idx);
+    while (idx >= 0 && !is_word_boundary_from_right(obj, idx))
+        idx = IMSTB_TEXTEDIT_GETPREVCHARINDEX(obj, idx);
+    return idx < 0 ? 0 : idx;
+}
+static int  STB_TEXTEDIT_MOVEWORDRIGHT_MAC(ImGuiInputTextState* obj, int idx)
+{
+    int len = obj->CurLenA;
+    idx = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(obj, idx);
+    while (idx < len && !is_word_boundary_from_left(obj, idx))
+        idx = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(obj, idx);
+    return idx > len ? len : idx;
+}
+static int  STB_TEXTEDIT_MOVEWORDRIGHT_WIN(ImGuiInputTextState* obj, int idx)
+{
+    idx = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(obj, idx);
+    int len = obj->CurLenA;
+    while (idx < len && !is_word_boundary_from_right(obj, idx))
+        idx = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(obj, idx);
+    return idx > len ? len : idx;
+}
 static int  STB_TEXTEDIT_MOVEWORDRIGHT_IMPL(ImGuiInputTextState* obj, int idx)  { ImGuiContext& g = *obj->Ctx; if (g.IO.ConfigMacOSXBehaviors) return STB_TEXTEDIT_MOVEWORDRIGHT_MAC(obj, idx); else return STB_TEXTEDIT_MOVEWORDRIGHT_WIN(obj, idx); }
-#define STB_TEXTEDIT_MOVEWORDLEFT   STB_TEXTEDIT_MOVEWORDLEFT_IMPL  // They need to be #define for stb_textedit.h
-#define STB_TEXTEDIT_MOVEWORDRIGHT  STB_TEXTEDIT_MOVEWORDRIGHT_IMPL
+#define STB_TEXTEDIT_MOVEWORDLEFT       STB_TEXTEDIT_MOVEWORDLEFT_IMPL  // They need to be #define for stb_textedit.h
+#define STB_TEXTEDIT_MOVEWORDRIGHT      STB_TEXTEDIT_MOVEWORDRIGHT_IMPL
 
 static void STB_TEXTEDIT_DELETECHARS(ImGuiInputTextState* obj, int pos, int n)
 {
-    ImWchar* dst = obj->TextW.Data + pos;
+    char* dst = obj->TextA.Data + pos;
 
-    // We maintain our buffer length in both UTF-8 and wchar formats
     obj->Edited = true;
-    obj->CurLenA -= ImTextCountUtf8BytesFromStr(dst, dst + n);
-    obj->CurLenW -= n;
+    obj->CurLenA -= n;
 
     // Offset remaining text (FIXME-OPT: Use memmove)
-    const ImWchar* src = obj->TextW.Data + pos + n;
-    while (ImWchar c = *src++)
+    const char* src = obj->TextA.Data + pos + n;
+    while (char c = *src++)
         *dst++ = c;
     *dst = '\0';
 }
 
-static bool STB_TEXTEDIT_INSERTCHARS(ImGuiInputTextState* obj, int pos, const ImWchar* new_text, int new_text_len)
+static bool STB_TEXTEDIT_INSERTCHARS(ImGuiInputTextState* obj, int pos, const char* new_text, int new_text_len)
 {
     const bool is_resizable = (obj->Flags & ImGuiInputTextFlags_CallbackResize) != 0;
-    const int text_len = obj->CurLenW;
+    const int text_len = obj->CurLenA;
     IM_ASSERT(pos <= text_len);
 
-    const int new_text_len_utf8 = ImTextCountUtf8BytesFromStr(new_text, new_text + new_text_len);
-    if (!is_resizable && (new_text_len_utf8 + obj->CurLenA + 1 > obj->BufCapacityA))
+    if (!is_resizable && (new_text_len + obj->CurLenA + 1 > obj->BufCapacityA))
         return false;
 
     // Grow internal buffer if needed
-    if (new_text_len + text_len + 1 > obj->TextW.Size)
+    if (new_text_len + text_len + 1 > obj->TextA.Size)
     {
         if (!is_resizable)
             return false;
-        IM_ASSERT(text_len < obj->TextW.Size);
-        obj->TextW.resize(text_len + ImClamp(new_text_len * 4, 32, ImMax(256, new_text_len)) + 1);
+        obj->TextA.resize(text_len + ImClamp(new_text_len, 32, ImMax(256, new_text_len)) + 1);
     }
 
-    ImWchar* text = obj->TextW.Data;
+    char* text = obj->TextA.Data;
     if (pos != text_len)
-        memmove(text + pos + new_text_len, text + pos, (size_t)(text_len - pos) * sizeof(ImWchar));
-    memcpy(text + pos, new_text, (size_t)new_text_len * sizeof(ImWchar));
+        memmove(text + pos + new_text_len, text + pos, (size_t)(text_len - pos));
+    memcpy(text + pos, new_text, (size_t)new_text_len);
 
     obj->Edited = true;
-    obj->CurLenW += new_text_len;
-    obj->CurLenA += new_text_len_utf8;
-    obj->TextW[obj->CurLenW] = '\0';
+    obj->CurLenA += new_text_len;
+    obj->TextA[obj->CurLenA] = '\0';
 
     return true;
 }
@@ -4028,8 +4080,8 @@ static bool STB_TEXTEDIT_INSERTCHARS(ImGuiInputTextState* obj, int pos, const Im
 // the stb_textedit_paste() function creates two separate records, so we perform it manually. (FIXME: Report to nothings/stb?)
 static void stb_textedit_replace(ImGuiInputTextState* str, STB_TexteditState* state, const IMSTB_TEXTEDIT_CHARTYPE* text, int text_len)
 {
-    stb_text_makeundo_replace(str, state, 0, str->CurLenW, text_len);
-    ImStb::STB_TEXTEDIT_DELETECHARS(str, 0, str->CurLenW);
+    stb_text_makeundo_replace(str, state, 0, str->CurLenA, text_len);
+    ImStb::STB_TEXTEDIT_DELETECHARS(str, 0, str->CurLenA);
     state->cursor = state->select_start = state->select_end = 0;
     if (text_len <= 0)
         return;
@@ -4063,15 +4115,26 @@ void ImGuiInputTextState::OnKeyPressed(int key)
     CursorAnimReset();
 }
 
+void ImGuiInputTextState::OnCharPressed(unsigned int c)
+{
+    // Convert the key to a UTF8 byte sequence.
+    // The changes we had to make to stb_textedit_key made it very much UTF-8 specific which is not too great.
+    char utf8[5];
+    ImTextCharToUtf8(utf8, c);
+    stb_textedit_text(this, Stb, utf8, (int)strlen(utf8));
+    CursorFollow = true;
+    CursorAnimReset();
+}
+
 // Those functions are not inlined in imgui_internal.h, allowing us to hide ImStbTexteditState from that header.
 void ImGuiInputTextState::CursorAnimReset()                 { CursorAnim = -0.30f; } // After a user-input the cursor stays on for a while without blinking
-void ImGuiInputTextState::CursorClamp()                     { Stb->cursor = ImMin(Stb->cursor, CurLenW); Stb->select_start = ImMin(Stb->select_start, CurLenW); Stb->select_end = ImMin(Stb->select_end, CurLenW); }
+void ImGuiInputTextState::CursorClamp()                     { Stb->cursor = ImMin(Stb->cursor, CurLenA); Stb->select_start = ImMin(Stb->select_start, CurLenA); Stb->select_end = ImMin(Stb->select_end, CurLenA); }
 bool ImGuiInputTextState::HasSelection() const              { return Stb->select_start != Stb->select_end; }
 void ImGuiInputTextState::ClearSelection()                  { Stb->select_start = Stb->select_end = Stb->cursor; }
 int  ImGuiInputTextState::GetCursorPos() const              { return Stb->cursor; }
 int  ImGuiInputTextState::GetSelectionStart() const         { return Stb->select_start; }
 int  ImGuiInputTextState::GetSelectionEnd() const           { return Stb->select_end; }
-void ImGuiInputTextState::SelectAll()                       { Stb->select_start = 0; Stb->cursor = Stb->select_end = CurLenW; Stb->has_preferred_x = 0; }
+void ImGuiInputTextState::SelectAll()                       { Stb->select_start = 0; Stb->cursor = Stb->select_end = CurLenA; Stb->has_preferred_x = 0; }
 void ImGuiInputTextState::ReloadUserBufAndSelectAll()       { ReloadUserBuf = true; ReloadSelectionStart = 0; ReloadSelectionEnd = INT_MAX; }
 void ImGuiInputTextState::ReloadUserBufAndKeepSelection()   { ReloadUserBuf = true; ReloadSelectionStart = Stb->select_start; ReloadSelectionEnd = Stb->select_end; }
 void ImGuiInputTextState::ReloadUserBufAndMoveToEnd()       { ReloadUserBuf = true; ReloadSelectionStart = ReloadSelectionEnd = INT_MAX; }
@@ -4244,26 +4307,21 @@ static bool InputTextFilterCharacter(ImGuiContext* ctx, unsigned int* p_char, Im
 // FIXME: Ideally we should transition toward (1) making InsertChars()/DeleteChars() update undo-stack (2) discourage (and keep reconcile) or obsolete (and remove reconcile) accessing buffer directly.
 static void InputTextReconcileUndoStateAfterUserCallback(ImGuiInputTextState* state, const char* new_buf_a, int new_length_a)
 {
-    ImGuiContext& g = *GImGui;
-    const ImWchar* old_buf = state->TextW.Data;
-    const int old_length = state->CurLenW;
-    const int new_length = ImTextCountCharsFromUtf8(new_buf_a, new_buf_a + new_length_a);
-    g.TempBuffer.reserve_discard((new_length + 1) * sizeof(ImWchar));
-    ImWchar* new_buf = (ImWchar*)(void*)g.TempBuffer.Data;
-    ImTextStrFromUtf8(new_buf, new_length + 1, new_buf_a, new_buf_a + new_length_a);
-
-    const int shorter_length = ImMin(old_length, new_length);
+    const char* old_buf = state->CallbackTextBackup.Data;
+    const int old_length = state->CallbackTextBackup.Size - 1;
+
+    const int shorter_length = ImMin(old_length, new_length_a);
     int first_diff;
     for (first_diff = 0; first_diff < shorter_length; first_diff++)
-        if (old_buf[first_diff] != new_buf[first_diff])
+        if (old_buf[first_diff] != new_buf_a[first_diff])
             break;
-    if (first_diff == old_length && first_diff == new_length)
+    if (first_diff == old_length && first_diff == new_length_a)
         return;
 
-    int old_last_diff = old_length - 1;
-    int new_last_diff = new_length - 1;
+    int old_last_diff = old_length   - 1;
+    int new_last_diff = new_length_a - 1;
     for (; old_last_diff >= first_diff && new_last_diff >= first_diff; old_last_diff--, new_last_diff--)
-        if (old_buf[old_last_diff] != new_buf[new_last_diff])
+        if (old_buf[old_last_diff] != new_buf_a[new_last_diff])
             break;
 
     const int insert_len = new_last_diff - first_diff + 1;
@@ -4271,7 +4329,7 @@ static void InputTextReconcileUndoStateAfterUserCallback(ImGuiInputTextState* st
     if (insert_len > 0 || delete_len > 0)
         if (IMSTB_TEXTEDIT_CHARTYPE* p = stb_text_createundo(&state->Stb->undostate, first_diff, delete_len, insert_len))
             for (int i = 0; i < delete_len; i++)
-                p[i] = ImStb::STB_TEXTEDIT_GETCHAR(state, first_diff + i);
+                p[i] = old_buf[first_diff + i];
 }
 
 // As InputText() retain textual data and we currently provide a path for user to not retain it (via local variables)
@@ -4436,17 +4494,14 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
         // Preserve cursor position and undo/redo stack if we come back to same widget
         // FIXME: Since we reworked this on 2022/06, may want to differentiate recycle_cursor vs recycle_undostate?
         bool recycle_state = (state->ID == id && !init_changed_specs && !init_reload_from_user_buf);
-        if (recycle_state && (state->CurLenA != buf_len || (state->TextAIsValid && strncmp(state->TextA.Data, buf, buf_len) != 0)))
+        if (recycle_state && (state->CurLenA != buf_len || (strncmp(state->TextA.Data, buf, buf_len) != 0)))
             recycle_state = false;
 
         // Start edition
-        const char* buf_end = NULL;
         state->ID = id;
-        state->TextW.resize(buf_size + 1);          // wchar count <= UTF-8 count. we use +1 to make sure that .Data is always pointing to at least an empty string.
-        state->TextA.resize(0);
-        state->TextAIsValid = false;                // TextA is not valid yet (we will display buf until then)
-        state->CurLenW = ImTextStrFromUtf8(state->TextW.Data, buf_size, buf, NULL, &buf_end);
-        state->CurLenA = (int)(buf_end - buf);      // We can't get the result from ImStrncpy() above because it is not UTF-8 aware. Here we'll cut off malformed UTF-8.
+        state->TextA.resize(buf_size + 1);          // we use +1 to make sure that .Data is always pointing to at least an empty string.
+        state->CurLenA = (int)strlen(buf);
+        memcpy(state->TextA.Data, buf, state->CurLenA + 1);
 
         if (recycle_state)
         {
@@ -4528,20 +4583,8 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
     bool value_changed = false;
     bool validated = false;
 
-    // When read-only we always use the live data passed to the function
-    // FIXME-OPT: Because our selection/cursor code currently needs the wide text we need to convert it when active, which is not ideal :(
-    if (is_readonly && state != NULL && (render_cursor || render_selection))
-    {
-        const char* buf_end = NULL;
-        state->TextW.resize(buf_size + 1);
-        state->CurLenW = ImTextStrFromUtf8(state->TextW.Data, state->TextW.Size, buf, NULL, &buf_end);
-        state->CurLenA = (int)(buf_end - buf);
-        state->CursorClamp();
-        render_selection &= state->HasSelection();
-    }
-
     // Select the buffer to render.
-    const bool buf_display_from_state = (render_cursor || render_selection || g.ActiveId == id) && !is_readonly && state && state->TextAIsValid;
+    const bool buf_display_from_state = (render_cursor || render_selection || g.ActiveId == id) && !is_readonly && state;
     const bool is_displaying_hint = (hint != NULL && (buf_display_from_state ? state->TextA.Data : buf)[0] == 0);
 
     // Password pushes a temporary font with only a fallback glyph
@@ -4561,11 +4604,9 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
     }
 
     // Process mouse inputs and character inputs
-    int backup_current_text_length = 0;
     if (g.ActiveId == id)
     {
         IM_ASSERT(state != NULL);
-        backup_current_text_length = state->CurLenA;
         state->Edited = false;
         state->BufCapacityA = buf_size;
         state->Flags = flags;
@@ -4646,7 +4687,7 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             {
                 unsigned int c = '\t'; // Insert TAB
                 if (InputTextFilterCharacter(&g, &c, flags, callback, callback_user_data))
-                    state->OnKeyPressed((int)c);
+                    state->OnCharPressed(c);
             }
             // FIXME: Implement Shift+Tab
             /*
@@ -4669,7 +4710,7 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
                     if (c == '\t') // Skip Tab, see above.
                         continue;
                     if (InputTextFilterCharacter(&g, &c, flags, callback, callback_user_data))
-                        state->OnKeyPressed((int)c);
+                        state->OnCharPressed(c);
                 }
 
             // Consume characters
@@ -4753,7 +4794,7 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             {
                 unsigned int c = '\n'; // Insert new line
                 if (InputTextFilterCharacter(&g, &c, flags, callback, callback_user_data))
-                    state->OnKeyPressed((int)c);
+                    state->OnCharPressed(c);
             }
         }
         else if (is_cancel)
@@ -4792,12 +4833,12 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             if (g.PlatformIO.Platform_SetClipboardTextFn != NULL)
             {
                 const int ib = state->HasSelection() ? ImMin(state->Stb->select_start, state->Stb->select_end) : 0;
-                const int ie = state->HasSelection() ? ImMax(state->Stb->select_start, state->Stb->select_end) : state->CurLenW;
-                const int clipboard_data_len = ImTextCountUtf8BytesFromStr(state->TextW.Data + ib, state->TextW.Data + ie) + 1;
-                char* clipboard_data = (char*)IM_ALLOC(clipboard_data_len * sizeof(char));
-                ImTextStrToUtf8(clipboard_data, clipboard_data_len, state->TextW.Data + ib, state->TextW.Data + ie);
-                SetClipboardText(clipboard_data);
-                MemFree(clipboard_data);
+                const int ie = state->HasSelection() ? ImMax(state->Stb->select_start, state->Stb->select_end) : state->CurLenA;
+
+                char backup = state->TextA.Data[ie];
+                state->TextA.Data[ie] = 0; // A bit of a hack since SetClipboardText only takes null terminated strings
+                SetClipboardText(state->TextA.Data + ib);
+                state->TextA.Data[ie] = backup;
             }
             if (is_cut)
             {
@@ -4813,15 +4854,17 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             {
                 // Filter pasted buffer
                 const int clipboard_len = (int)strlen(clipboard);
-                ImWchar* clipboard_filtered = (ImWchar*)IM_ALLOC((clipboard_len + 1) * sizeof(ImWchar));
+                char* clipboard_filtered = (char*)IM_ALLOC(clipboard_len + 1);
                 int clipboard_filtered_len = 0;
                 for (const char* s = clipboard; *s != 0; )
                 {
                     unsigned int c;
-                    s += ImTextCharFromUtf8(&c, s, NULL);
+                    int len = ImTextCharFromUtf8(&c, s, NULL);
+                    s += len;
                     if (!InputTextFilterCharacter(&g, &c, flags, callback, callback_user_data, true))
                         continue;
-                    clipboard_filtered[clipboard_filtered_len++] = (ImWchar)c;
+                    memcpy(clipboard_filtered + clipboard_filtered_len, s - len, len);
+                    clipboard_filtered_len += len;
                 }
                 clipboard_filtered[clipboard_filtered_len] = 0;
                 if (clipboard_filtered_len > 0) // If everything was filtered, ignore the pasting operation
@@ -4857,29 +4900,16 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             }
             else if (strcmp(buf, state->InitialTextA.Data) != 0)
             {
-                // Restore initial value. Only return true if restoring to the initial value changes the current buffer contents.
-                // Push records into the undo stack so we can CTRL+Z the revert operation itself
                 apply_new_text = state->InitialTextA.Data;
                 apply_new_text_length = state->InitialTextA.Size - 1;
+
+                // Restore initial value. Only return true if restoring to the initial value changes the current buffer contents.
+                // Push records into the undo stack so we can CTRL+Z the revert operation itself
                 value_changed = true;
-                ImVector<ImWchar> w_text;
-                if (apply_new_text_length > 0)
-                {
-                    w_text.resize(ImTextCountCharsFromUtf8(apply_new_text, apply_new_text + apply_new_text_length) + 1);
-                    ImTextStrFromUtf8(w_text.Data, w_text.Size, apply_new_text, apply_new_text + apply_new_text_length);
-                }
-                stb_textedit_replace(state, state->Stb, w_text.Data, (apply_new_text_length > 0) ? (w_text.Size - 1) : 0);
+                stb_textedit_replace(state, state->Stb, state->InitialTextA.Data, state->InitialTextA.Size - 1);
             }
         }
 
-        // Apply ASCII value
-        if (!is_readonly)
-        {
-            state->TextAIsValid = true;
-            state->TextA.resize(state->TextW.Size * 4 + 1);
-            ImTextStrToUtf8(state->TextA.Data, state->TextA.Size, state->TextW.Data, NULL);
-        }
-
         // When using 'ImGuiInputTextFlags_EnterReturnsTrue' as a special case we reapply the live buffer back to the input buffer
         // before clearing ActiveId, even though strictly speaking it wasn't modified on this frame.
         // If we didn't do that, code like InputInt() with ImGuiInputTextFlags_EnterReturnsTrue would fail.
@@ -4934,6 +4964,10 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
                     callback_data.Flags = flags;
                     callback_data.UserData = callback_user_data;
 
+                    // FIXME-OPT: Undo stack reconcile needs a backup of the data until we rework API, see #7925
+                    state->CallbackTextBackup.resize(state->CurLenA + 1);
+                    memcpy(state->CallbackTextBackup.Data, state->TextA.Data, state->CurLenA + 1);
+
                     char* callback_buf = is_readonly ? buf : state->TextA.Data;
                     callback_data.EventKey = event_key;
                     callback_data.Buf = callback_buf;
@@ -4941,11 +4975,9 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
                     callback_data.BufSize = state->BufCapacityA;
                     callback_data.BufDirty = false;
 
-                    // We have to convert from wchar-positions to UTF-8-positions, which can be pretty slow (an incentive to ditch the ImWchar buffer, see https://github.com/nothings/stb/issues/188)
-                    ImWchar* text = state->TextW.Data;
-                    const int utf8_cursor_pos = callback_data.CursorPos = ImTextCountUtf8BytesFromStr(text, text + state->Stb->cursor);
-                    const int utf8_selection_start = callback_data.SelectionStart = ImTextCountUtf8BytesFromStr(text, text + state->Stb->select_start);
-                    const int utf8_selection_end = callback_data.SelectionEnd = ImTextCountUtf8BytesFromStr(text, text + state->Stb->select_end);
+                    const int utf8_cursor_pos = callback_data.CursorPos = state->Stb->cursor;
+                    const int utf8_selection_start = callback_data.SelectionStart = state->Stb->select_start;
+                    const int utf8_selection_end = state->Stb->select_end;
 
                     // Call user code
                     callback(&callback_data);
@@ -4956,18 +4988,16 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
                     IM_ASSERT(callback_data.BufSize == state->BufCapacityA);
                     IM_ASSERT(callback_data.Flags == flags);
                     const bool buf_dirty = callback_data.BufDirty;
-                    if (callback_data.CursorPos != utf8_cursor_pos || buf_dirty)            { state->Stb->cursor = ImTextCountCharsFromUtf8(callback_data.Buf, callback_data.Buf + callback_data.CursorPos); state->CursorFollow = true; }
-                    if (callback_data.SelectionStart != utf8_selection_start || buf_dirty)  { state->Stb->select_start = (callback_data.SelectionStart == callback_data.CursorPos) ? state->Stb->cursor : ImTextCountCharsFromUtf8(callback_data.Buf, callback_data.Buf + callback_data.SelectionStart); }
-                    if (callback_data.SelectionEnd != utf8_selection_end || buf_dirty)      { state->Stb->select_end = (callback_data.SelectionEnd == callback_data.SelectionStart) ? state->Stb->select_start : ImTextCountCharsFromUtf8(callback_data.Buf, callback_data.Buf + callback_data.SelectionEnd); }
+                    if (callback_data.CursorPos != utf8_cursor_pos || buf_dirty)            { state->Stb->cursor = callback_data.CursorPos; state->CursorFollow = true; }
+                    if (callback_data.SelectionStart != utf8_selection_start || buf_dirty)  { state->Stb->select_start = (callback_data.SelectionStart == callback_data.CursorPos) ? state->Stb->cursor : callback_data.SelectionStart; }
+                    if (callback_data.SelectionEnd != utf8_selection_end || buf_dirty)      { state->Stb->select_end = (callback_data.SelectionEnd == callback_data.SelectionStart) ? state->Stb->select_start : callback_data.SelectionEnd; }
                     if (buf_dirty)
                     {
                         // Callback may update buffer and thus set buf_dirty even in read-only mode.
                         IM_ASSERT(callback_data.BufTextLen == (int)strlen(callback_data.Buf)); // You need to maintain BufTextLen if you change the text!
                         InputTextReconcileUndoStateAfterUserCallback(state, callback_data.Buf, callback_data.BufTextLen); // FIXME: Move the rest of this block inside function and rename to InputTextReconcileStateAfterUserCallback() ?
-                        if (callback_data.BufTextLen > backup_current_text_length && is_resizable)
-                            state->TextW.resize(state->TextW.Size + (callback_data.BufTextLen - backup_current_text_length)); // Worse case scenario resize
-                        state->CurLenW = ImTextStrFromUtf8(state->TextW.Data, state->TextW.Size, callback_data.Buf, NULL);
                         state->CurLenA = callback_data.BufTextLen;  // Assume correct length and valid UTF-8 from user, saves us an extra strlen()
+                        state->TextA.Size = state->CurLenA + 1;
                         state->CursorAnimReset();
                     }
                 }
@@ -4999,9 +5029,9 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
     // Copy result to user buffer. This can currently only happen when (g.ActiveId == id)
     if (apply_new_text != NULL)
     {
-        // We cannot test for 'backup_current_text_length != apply_new_text_length' here because we have no guarantee that the size
-        // of our owned buffer matches the size of the string object held by the user, and by design we allow InputText() to be used
-        // without any storage on user's side.
+        //// We cannot test for 'backup_current_text_length != apply_new_text_length' here because we have no guarantee that the size
+        //// of our owned buffer matches the size of the string object held by the user, and by design we allow InputText() to be used
+        //// without any storage on user's side.
         IM_ASSERT(apply_new_text_length >= 0);
         if (is_resizable)
         {
@@ -5070,12 +5100,12 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
         // - Measure text height (for scrollbar)
         // We are attempting to do most of that in **one main pass** to minimize the computation cost (non-negligible for large amount of text) + 2nd pass for selection rendering (we could merge them by an extra refactoring effort)
         // FIXME: This should occur on buf_display but we'd need to maintain cursor/select_start/select_end for UTF-8.
-        const ImWchar* text_begin = state->TextW.Data;
+        const char* text_begin = state->TextA.Data;
         ImVec2 cursor_offset, select_start_offset;
 
         {
             // Find lines numbers straddling 'cursor' (slot 0) and 'select_start' (slot 1) positions.
-            const ImWchar* searches_input_ptr[2] = { NULL, NULL };
+            const char* searches_input_ptr[2] = { NULL, NULL };
             int searches_result_line_no[2] = { -1000, -1000 };
             int searches_remaining = 0;
             if (render_cursor)
@@ -5095,14 +5125,12 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
             // In multi-line mode, we never exit the loop until all lines are counted, so add one extra to the searches_remaining counter.
             searches_remaining += is_multiline ? 1 : 0;
             int line_count = 0;
-            //for (const ImWchar* s = text_begin; (s = (const ImWchar*)wcschr((const wchar_t*)s, (wchar_t)'\n')) != NULL; s++)  // FIXME-OPT: Could use this when wchar_t are 16-bit
-            for (const ImWchar* s = text_begin; *s != 0; s++)
-                if (*s == '\n')
-                {
-                    line_count++;
-                    if (searches_result_line_no[0] == -1 && s >= searches_input_ptr[0]) { searches_result_line_no[0] = line_count; if (--searches_remaining <= 0) break; }
-                    if (searches_result_line_no[1] == -1 && s >= searches_input_ptr[1]) { searches_result_line_no[1] = line_count; if (--searches_remaining <= 0) break; }
-                }
+            for (const char* s = text_begin; (s = strchr(s, '\n')) != NULL; s++) // FIXME-OPT: memchr() would be faster?
+            {
+                line_count++;
+                if (searches_result_line_no[0] == -1 && s >= searches_input_ptr[0]) { searches_result_line_no[0] = line_count; if (--searches_remaining <= 0) break; }
+                if (searches_result_line_no[1] == -1 && s >= searches_input_ptr[1]) { searches_result_line_no[1] = line_count; if (--searches_remaining <= 0) break; }
+            }
             line_count++;
             if (searches_result_line_no[0] == -1)
                 searches_result_line_no[0] = line_count;
@@ -5110,11 +5138,11 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
                 searches_result_line_no[1] = line_count;
 
             // Calculate 2d position by finding the beginning of the line and measuring distance
-            cursor_offset.x = InputTextCalcTextSizeW(&g, ImStrbolW(searches_input_ptr[0], text_begin), searches_input_ptr[0]).x;
+            cursor_offset.x = InputTextCalcTextSize(&g, ImStrbol(searches_input_ptr[0], text_begin), searches_input_ptr[0]).x;
             cursor_offset.y = searches_result_line_no[0] * g.FontSize;
             if (searches_result_line_no[1] >= 0)
             {
-                select_start_offset.x = InputTextCalcTextSizeW(&g, ImStrbolW(searches_input_ptr[1], text_begin), searches_input_ptr[1]).x;
+                select_start_offset.x = InputTextCalcTextSize(&g, ImStrbol(searches_input_ptr[1], text_begin), searches_input_ptr[1]).x;
                 select_start_offset.y = searches_result_line_no[1] * g.FontSize;
             }
 
@@ -5162,40 +5190,38 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
         const ImVec2 draw_scroll = ImVec2(state->Scroll.x, 0.0f);
         if (render_selection)
         {
-            const ImWchar* text_selected_begin = text_begin + ImMin(state->Stb->select_start, state->Stb->select_end);
-            const ImWchar* text_selected_end = text_begin + ImMax(state->Stb->select_start, state->Stb->select_end);
+            const char* text_selected_begin = text_begin + ImMin(state->Stb->select_start, state->Stb->select_end);
+            const char* text_selected_end = text_begin + ImMax(state->Stb->select_start, state->Stb->select_end);
 
             ImU32 bg_color = GetColorU32(ImGuiCol_TextSelectedBg, render_cursor ? 1.0f : 0.6f); // FIXME: current code flow mandate that render_cursor is always true here, we are leaving the transparent one for tests.
             float bg_offy_up = is_multiline ? 0.0f : -1.0f;    // FIXME: those offsets should be part of the style? they don't play so well with multi-line selection.
             float bg_offy_dn = is_multiline ? 0.0f : 2.0f;
             ImVec2 rect_pos = draw_pos + select_start_offset - draw_scroll;
-            for (const ImWchar* p = text_selected_begin; p < text_selected_end; )
+            for (const char* p = text_selected_begin; p < text_selected_end; )
             {
                 if (rect_pos.y > clip_rect.w + g.FontSize)
                     break;
                 if (rect_pos.y < clip_rect.y)
                 {
-                    //p = (const ImWchar*)wmemchr((const wchar_t*)p, '\n', text_selected_end - p);  // FIXME-OPT: Could use this when wchar_t are 16-bit
-                    //p = p ? p + 1 : text_selected_end;
-                    while (p < text_selected_end)
-                        if (*p++ == '\n')
-                            break;
+                    p = (const char*)memchr((void*)p, '\n', text_selected_end - p);
+                    p = p ? p + 1 : text_selected_end;
                 }
                 else
                 {
-                    ImVec2 rect_size = InputTextCalcTextSizeW(&g, p, text_selected_end, &p, NULL, true);
+                    ImVec2 rect_size = InputTextCalcTextSize(&g, p, text_selected_end, &p, NULL, true);
                     if (rect_size.x <= 0.0f) rect_size.x = IM_TRUNC(g.Font->GetCharAdvance((ImWchar)' ') * 0.50f); // So we can see selected empty lines
                     ImRect rect(rect_pos + ImVec2(0.0f, bg_offy_up - g.FontSize), rect_pos + ImVec2(rect_size.x, bg_offy_dn));
                     rect.ClipWith(clip_rect);
                     if (rect.Overlaps(clip_rect))
                         draw_window->DrawList->AddRectFilled(rect.Min, rect.Max, bg_color);
+                    rect_pos.x = draw_pos.x - draw_scroll.x;
                 }
-                rect_pos.x = draw_pos.x - draw_scroll.x;
                 rect_pos.y += g.FontSize;
             }
         }
 
         // We test for 'buf_display_max_length' as a way to avoid some pathological cases (e.g. single-line 1 MB string) which would make ImDrawList crash.
+        // FIXME-OPT: Multiline could submit a smaller amount of contents to AddText() since we already iterated through it.
         if (is_multiline || (buf_display_end - buf_display) < buf_display_max_length)
         {
             ImU32 col = GetColorU32(is_displaying_hint ? ImGuiCol_TextDisabled : ImGuiCol_Text);
@@ -5289,7 +5315,7 @@ void ImGui::DebugNodeInputTextState(ImGuiInputTextState* state)
     ImStb::StbUndoState* undo_state = &stb_state->undostate;
     Text("ID: 0x%08X, ActiveID: 0x%08X", state->ID, g.ActiveId);
     DebugLocateItemOnHover(state->ID);
-    Text("CurLenW: %d, CurLenA: %d, Cursor: %d, Selection: %d..%d", state->CurLenW, state->CurLenA, stb_state->cursor, stb_state->select_start, stb_state->select_end);
+    Text("CurLenA: %d, Cursor: %d, Selection: %d..%d", state->CurLenA, stb_state->cursor, stb_state->select_start, stb_state->select_end);
     Text("has_preferred_x: %d (%.2f)", stb_state->has_preferred_x, stb_state->preferred_x);
     Text("undo_point: %d, redo_point: %d, undo_char_point: %d, redo_char_point: %d", undo_state->undo_point, undo_state->redo_point, undo_state->undo_char_point, undo_state->redo_char_point);
     if (BeginChild("undopoints", ImVec2(0.0f, GetTextLineHeight() * 10), ImGuiChildFlags_Borders | ImGuiChildFlags_ResizeY)) // Visualize undo state
@@ -5301,11 +5327,10 @@ void ImGui::DebugNodeInputTextState(ImGuiInputTextState* state)
             const char undo_rec_type = (n < undo_state->undo_point) ? 'u' : (n >= undo_state->redo_point) ? 'r' : ' ';
             if (undo_rec_type == ' ')
                 BeginDisabled();
-            char buf[64] = "";
-            if (undo_rec_type != ' ' && undo_rec->char_storage != -1)
-                ImTextStrToUtf8(buf, IM_ARRAYSIZE(buf), undo_state->undo_char + undo_rec->char_storage, undo_state->undo_char + undo_rec->char_storage + undo_rec->insert_length);
-            Text("%c [%02d] where %03d, insert %03d, delete %03d, char_storage %03d \"%s\"",
-                undo_rec_type, n, undo_rec->where, undo_rec->insert_length, undo_rec->delete_length, undo_rec->char_storage, buf);
+            const int buf_preview_len = (undo_rec_type != ' ' && undo_rec->char_storage != -1) ? undo_rec->insert_length : 0;
+            const char* buf_preview_str = undo_state->undo_char + undo_rec->char_storage;
+            Text("%c [%02d] where %03d, insert %03d, delete %03d, char_storage %03d \"%.*s\"",
+                undo_rec_type, n, undo_rec->where, undo_rec->insert_length, undo_rec->delete_length, undo_rec->char_storage, buf_preview_len, buf_preview_str);
             if (undo_rec_type == ' ')
                 EndDisabled();
         }
@@ -7385,6 +7410,7 @@ static void DebugLogMultiSelectRequests(const char* function, const ImGuiMultiSe
 
 static ImRect CalcScopeRect(ImGuiMultiSelectTempData* ms, ImGuiWindow* window)
 {
+    ImGuiContext& g = *GImGui;
     if (ms->Flags & ImGuiMultiSelectFlags_ScopeRect)
     {
         // Warning: this depends on CursorMaxPos so it means to be called by EndMultiSelect() only
@@ -7392,8 +7418,12 @@ static ImRect CalcScopeRect(ImGuiMultiSelectTempData* ms, ImGuiWindow* window)
     }
     else
     {
-        // Add inner table decoration (#7821) // FIXME: Why not baking in InnerClipRect?
+        // When a table, pull HostClipRect, which allows us to predict ClipRect before first row/layout is performed. (#7970)
         ImRect scope_rect = window->InnerClipRect;
+        if (g.CurrentTable != NULL)
+            scope_rect = g.CurrentTable->HostClipRect;
+
+        // Add inner table decoration (#7821) // FIXME: Why not baking in InnerClipRect?
         scope_rect.Min = ImMin(scope_rect.Min + ImVec2(window->DecoInnerSizeX1, window->DecoInnerSizeY1), scope_rect.Max);
         return scope_rect;
     }

imstb_textedit.h

@@ -4,6 +4,7 @@
 // - Fix in stb_textedit_discard_redo (see https://github.com/nothings/stb/issues/321)
 // - Fix in stb_textedit_find_charpos to handle last line (see https://github.com/ocornut/imgui/issues/6000 + #6783)
 // - Added name to struct or it may be forward declared in our code.
+// - Added UTF-8 support (see https://github.com/nothings/stb/issues/188 + https://github.com/ocornut/imgui/pull/7925)
 // Grep for [DEAR IMGUI] to find the changes.
 // - Also renamed macros used or defined outside of IMSTB_TEXTEDIT_IMPLEMENTATION block from STB_TEXTEDIT_* to IMSTB_TEXTEDIT_*
 
@@ -210,6 +211,7 @@
 //    int  stb_textedit_cut(STB_TEXTEDIT_STRING *str, STB_TexteditState *state)
 //    int  stb_textedit_paste(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, STB_TEXTEDIT_CHARTYPE *text, int len)
 //    void stb_textedit_key(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, STB_TEXEDIT_KEYTYPE key)
+//    void stb_textedit_text(STB_TEXTEDIT_STRING *str, STB_TexteditState *state, STB_TEXTEDIT_CHARTYPE *text, int text_len)
 //
 //    Each of these functions potentially updates the string and updates the
 //    state.
@@ -244,7 +246,12 @@
 //          various definitions like STB_TEXTEDIT_K_LEFT have the is-key-event bit
 //          set, and make STB_TEXTEDIT_KEYTOCHAR check that the is-key-event bit is
 //          clear. STB_TEXTEDIT_KEYTYPE defaults to int, but you can #define it to
-//          anything other type you wante before including.
+//          anything other type you want before including.
+//          if the STB_TEXTEDIT_KEYTOTEXT function is defined, selected keys are
+//          transformed into text and stb_textedit_text() is automatically called.
+//
+//      text: [DEAR IMGUI] added 2024-09
+//          call this to text inputs sent to the textfield.
 //
 //
 //   When rendering, you can read the cursor position and selection state from
@@ -439,13 +446,13 @@ static int stb_text_locate_coord(IMSTB_TEXTEDIT_STRING *str, float x, float y)
    if (x < r.x1) {
       // search characters in row for one that straddles 'x'
       prev_x = r.x0;
-      for (k=0; k < r.num_chars; ++k) {
+      for (k=0; k < r.num_chars; k = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, i + k) - i) {
          float w = STB_TEXTEDIT_GETWIDTH(str, i, k);
          if (x < prev_x+w) {
             if (x < prev_x+w/2)
                return k+i;
             else
-               return k+i+1;
+               return IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, i + k);
          }
          prev_x += w;
       }
@@ -564,7 +571,7 @@ static void stb_textedit_find_charpos(StbFindState *find, IMSTB_TEXTEDIT_STRING
 
    // now scan to find xpos
    find->x = r.x0;
-   for (i=0; first+i < n; ++i)
+   for (i=0; first+i < n; i = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, first + i) - first)
       find->x += STB_TEXTEDIT_GETWIDTH(str, first, i);
 }
 
@@ -641,6 +648,17 @@ static void stb_textedit_move_to_last(IMSTB_TEXTEDIT_STRING *str, STB_TexteditSt
    }
 }
 
+// [DEAR IMGUI]
+// Functions must be implemented for UTF8 support
+// Code in this file that uses those functions is modified for [DEAR IMGUI] and deviates from the original stb_textedit.
+// There is not necessarily a '[DEAR IMGUI]' at the usage sites.
+#ifndef IMSTB_TEXTEDIT_GETPREVCHARINDEX
+#define IMSTB_TEXTEDIT_GETPREVCHARINDEX(obj, idx) (idx - 1)
+#endif
+#ifndef IMSTB_TEXTEDIT_GETNEXTCHARINDEX
+#define IMSTB_TEXTEDIT_GETNEXTCHARINDEX(obj, idx) (idx + 1)
+#endif
+
 #ifdef STB_TEXTEDIT_IS_SPACE
 static int is_word_boundary( IMSTB_TEXTEDIT_STRING *str, int idx )
 {
@@ -721,36 +739,44 @@ static int stb_textedit_paste_internal(IMSTB_TEXTEDIT_STRING *str, STB_TexteditS
 #define STB_TEXTEDIT_KEYTYPE int
 #endif
 
+// [DEAR IMGUI] Added stb_textedit_text(), extracted out and called by stb_textedit_key() for backward compatibility.
+static void stb_textedit_text(IMSTB_TEXTEDIT_STRING* str, STB_TexteditState* state, const IMSTB_TEXTEDIT_CHARTYPE* text, int text_len)
+{
+   // can't add newline in single-line mode
+   if (text[0] == '\n' && state->single_line)
+      return;
+
+   if (state->insert_mode && !STB_TEXT_HAS_SELECTION(state) && state->cursor < STB_TEXTEDIT_STRINGLEN(str)) {
+      stb_text_makeundo_replace(str, state, state->cursor, 1, 1);
+      STB_TEXTEDIT_DELETECHARS(str, state->cursor, 1);
+      if (STB_TEXTEDIT_INSERTCHARS(str, state->cursor, text, text_len)) {
+         state->cursor += text_len;
+         state->has_preferred_x = 0;
+      }
+   }
+   else {
+      stb_textedit_delete_selection(str, state); // implicitly clamps
+      if (STB_TEXTEDIT_INSERTCHARS(str, state->cursor, text, text_len)) {
+         stb_text_makeundo_insert(state, state->cursor, text_len);
+         state->cursor += text_len;
+         state->has_preferred_x = 0;
+      }
+   }
+}
+
 // API key: process a keyboard input
 static void stb_textedit_key(IMSTB_TEXTEDIT_STRING *str, STB_TexteditState *state, STB_TEXTEDIT_KEYTYPE key)
 {
 retry:
    switch (key) {
       default: {
+#ifdef STB_TEXTEDIT_KEYTOTEXT
          int c = STB_TEXTEDIT_KEYTOTEXT(key);
          if (c > 0) {
-            IMSTB_TEXTEDIT_CHARTYPE ch = (IMSTB_TEXTEDIT_CHARTYPE) c;
-
-            // can't add newline in single-line mode
-            if (c == '\n' && state->single_line)
-               break;
-
-            if (state->insert_mode && !STB_TEXT_HAS_SELECTION(state) && state->cursor < STB_TEXTEDIT_STRINGLEN(str)) {
-               stb_text_makeundo_replace(str, state, state->cursor, 1, 1);
-               STB_TEXTEDIT_DELETECHARS(str, state->cursor, 1);
-               if (STB_TEXTEDIT_INSERTCHARS(str, state->cursor, &ch, 1)) {
-                  ++state->cursor;
-                  state->has_preferred_x = 0;
-               }
-            } else {
-               stb_textedit_delete_selection(str,state); // implicitly clamps
-               if (STB_TEXTEDIT_INSERTCHARS(str, state->cursor, &ch, 1)) {
-                  stb_text_makeundo_insert(state, state->cursor, 1);
-                  ++state->cursor;
-                  state->has_preferred_x = 0;
-               }
-            }
+            IMSTB_TEXTEDIT_CHARTYPE ch = (IMSTB_TEXTEDIT_CHARTYPE)c;
+            stb_textedit_text(str, state, &ch, 1);
          }
+#endif
          break;
       }
 
@@ -776,7 +802,7 @@ retry:
             stb_textedit_move_to_first(state);
          else
             if (state->cursor > 0)
-               --state->cursor;
+               state->cursor = IMSTB_TEXTEDIT_GETPREVCHARINDEX(str, state->cursor);
          state->has_preferred_x = 0;
          break;
 
@@ -785,7 +811,7 @@ retry:
          if (STB_TEXT_HAS_SELECTION(state))
             stb_textedit_move_to_last(str, state);
          else
-            ++state->cursor;
+            state->cursor = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, state->cursor);
          stb_textedit_clamp(str, state);
          state->has_preferred_x = 0;
          break;
@@ -795,7 +821,7 @@ retry:
          stb_textedit_prep_selection_at_cursor(state);
          // move selection left
          if (state->select_end > 0)
-            --state->select_end;
+            state->select_end = IMSTB_TEXTEDIT_GETPREVCHARINDEX(str, state->select_end);
          state->cursor = state->select_end;
          state->has_preferred_x = 0;
          break;
@@ -845,7 +871,7 @@ retry:
       case STB_TEXTEDIT_K_RIGHT | STB_TEXTEDIT_K_SHIFT:
          stb_textedit_prep_selection_at_cursor(state);
          // move selection right
-         ++state->select_end;
+         state->select_end = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, state->select_end);
          stb_textedit_clamp(str, state);
          state->cursor = state->select_end;
          state->has_preferred_x = 0;
@@ -901,7 +927,7 @@ retry:
                x += dx;
                if (x > goal_x)
                   break;
-               ++state->cursor;
+               state->cursor = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, state->cursor);
             }
             stb_textedit_clamp(str, state);
 
@@ -963,7 +989,7 @@ retry:
                x += dx;
                if (x > goal_x)
                   break;
-               ++state->cursor;
+               state->cursor = IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, state->cursor);
             }
             stb_textedit_clamp(str, state);
 
@@ -991,7 +1017,7 @@ retry:
          else {
             int n = STB_TEXTEDIT_STRINGLEN(str);
             if (state->cursor < n)
-               stb_textedit_delete(str, state, state->cursor, 1);
+               stb_textedit_delete(str, state, state->cursor, IMSTB_TEXTEDIT_GETNEXTCHARINDEX(str, state->cursor) - state->cursor);
          }
          state->has_preferred_x = 0;
          break;
@@ -1003,8 +1029,9 @@ retry:
          else {
             stb_textedit_clamp(str, state);
             if (state->cursor > 0) {
-               stb_textedit_delete(str, state, state->cursor-1, 1);
-               --state->cursor;
+               int prev = IMSTB_TEXTEDIT_GETPREVCHARINDEX(str, state->cursor);
+               stb_textedit_delete(str, state, prev, state->cursor - prev);
+               state->cursor = prev;
             }
          }
          state->has_preferred_x = 0;