ImGui::InputText with caret at end

imgui.cpp

bool ImGui::InputTextEx(const char* label, char* buf, int buf_size, const ImVec2& size_arg, ImGuiInputTextFlags flags, ImGuiTextEditCallback callback, void* user_data)
{
    ImGuiWindow* window = GetCurrentWindow();
    if (window->SkipItems)
        return false;

    IM_ASSERT(!((flags & ImGuiInputTextFlags_CallbackHistory) && (flags & ImGuiInputTextFlags_Multiline))); // Can't use both together (they both use up/down keys)
    IM_ASSERT(!((flags & ImGuiInputTextFlags_CallbackCompletion) && (flags & ImGuiInputTextFlags_AllowTabInput))); // Can't use both together (they both use tab key)

    ImGuiContext& g = *GImGui;
    const ImGuiIO& io = g.IO;
    const ImGuiStyle& style = g.Style;

    const bool is_multiline = (flags & ImGuiInputTextFlags_Multiline) != 0;
    const bool is_editable = (flags & ImGuiInputTextFlags_ReadOnly) == 0;
    const bool is_password = (flags & ImGuiInputTextFlags_Password) != 0;
    const bool is_undoable = (flags & ImGuiInputTextFlags_NoUndoRedo) == 0;

    if (is_multiline) // Open group before calling GetID() because groups tracks id created during their spawn
        BeginGroup();
    const ImGuiID id = window->GetID(label);
    const ImVec2 label_size = CalcTextSize(label, NULL, true);
    ImVec2 size = CalcItemSize(size_arg, CalcItemWidth(), (is_multiline ? GetTextLineHeight() * 8.0f : label_size.y) + style.FramePadding.y*2.0f); // Arbitrary default of 8 lines high for multi-line
    const ImRect frame_bb(window->DC.CursorPos, window->DC.CursorPos + size);
    const ImRect total_bb(frame_bb.Min, frame_bb.Max + ImVec2(label_size.x > 0.0f ? (style.ItemInnerSpacing.x + label_size.x) : 0.0f, 0.0f));

    ImGuiWindow* draw_window = window;
    if (is_multiline)
    {
        if (!BeginChildFrame(id, frame_bb.GetSize()))
        {
            EndChildFrame();
            EndGroup();
            return false;
        }
        draw_window = GetCurrentWindow();
        size.x -= draw_window->ScrollbarSizes.x;
    }
    else
    {
        ItemSize(total_bb, style.FramePadding.y);
        if (!ItemAdd(total_bb, id))
            return false;
    }
    const bool hovered = ItemHoverable(frame_bb, id);
    if (hovered)
        g.MouseCursor = ImGuiMouseCursor_TextInput;

    // Password pushes a temporary font with only a fallback glyph
    if (is_password)
    {
        const ImFontGlyph* glyph = g.Font->FindGlyph('*');
        ImFont* password_font = &g.InputTextPasswordFont;
        password_font->FontSize = g.Font->FontSize;
        password_font->Scale = g.Font->Scale;
        password_font->DisplayOffset = g.Font->DisplayOffset;
        password_font->Ascent = g.Font->Ascent;
        password_font->Descent = g.Font->Descent;
        password_font->ContainerAtlas = g.Font->ContainerAtlas;
        password_font->FallbackGlyph = glyph;
        password_font->FallbackAdvanceX = glyph->AdvanceX;
        IM_ASSERT(password_font->Glyphs.empty() && password_font->IndexAdvanceX.empty() && password_font->IndexLookup.empty());
        PushFont(password_font);
    }

    // NB: we are only allowed to access 'edit_state' if we are the active widget.
    ImGuiTextEditState& edit_state = g.InputTextState;

    const bool focus_requested = FocusableItemRegister(window, id, (flags & (ImGuiInputTextFlags_CallbackCompletion|ImGuiInputTextFlags_AllowTabInput)) == 0);    // Using completion callback disable keyboard tabbing
    const bool focus_requested_by_code = focus_requested && (window->FocusIdxAllCounter == window->FocusIdxAllRequestCurrent);
    const bool focus_requested_by_tab = focus_requested && !focus_requested_by_code;

    const bool user_clicked = hovered && io.MouseClicked[0];
    const bool user_scrolled = is_multiline && g.ActiveId == 0 && edit_state.Id == id && g.ActiveIdPreviousFrame == draw_window->GetIDNoKeepAlive("#SCROLLY");

    bool clear_active_id = false;

    bool select_all = (g.ActiveId != id) && (flags & ImGuiInputTextFlags_AutoSelectAll) != 0;
    // JS: EDIT
    bool bypassClick = false;
    // END JS EDIT
    if (focus_requested || user_clicked || user_scrolled)
    {
        if (g.ActiveId != id)
        {
            // Start edition
            // Take a copy of the initial buffer value (both in original UTF-8 format and converted to wchar)
            // From the moment we focused we are ignoring the content of 'buf' (unless we are in read-only mode)
            const int prev_len_w = edit_state.CurLenW;
            edit_state.Text.resize(buf_size+1);        // wchar count <= UTF-8 count. we use +1 to make sure that .Data isn't NULL so it doesn't crash.
            edit_state.InitialText.resize(buf_size+1); // UTF-8. we use +1 to make sure that .Data isn't NULL so it doesn't crash.
            ImStrncpy(edit_state.InitialText.Data, buf, edit_state.InitialText.Size);
            const char* buf_end = NULL;
            edit_state.CurLenW = ImTextStrFromUtf8(edit_state.Text.Data, edit_state.Text.Size, buf, NULL, &buf_end);
            edit_state.CurLenA = (int)(buf_end - buf); // We can't get the result from ImFormatString() above because it is not UTF-8 aware. Here we'll cut off malformed UTF-8.
            edit_state.CursorAnimReset();

            // Preserve cursor position and undo/redo stack if we come back to same widget
            // FIXME: We should probably compare the whole buffer to be on the safety side. Comparing buf (utf8) and edit_state.Text (wchar).
            const bool recycle_state = (edit_state.Id == id) && (prev_len_w == edit_state.CurLenW);
            if (recycle_state)
            {
                // Recycle existing cursor/selection/undo stack but clamp position
                // Note a single mouse click will override the cursor/position immediately by calling stb_textedit_click handler.
                edit_state.CursorClamp();
            }
            else
            {
                edit_state.Id = id;
                edit_state.ScrollX = 0.0f;
                stb_textedit_initialize_state(&edit_state.StbState, !is_multiline);
                if (!is_multiline && focus_requested_by_code)
                    select_all = true;
            }

            // JS: EDIT
            if (flags & ImGuiInputTextFlags_AutoCaretEnd)
            {
                edit_state.StbState.cursor = edit_state.CurLenW;
                bypassClick = true;
            }
            // END JS EDIT

            if (flags & ImGuiInputTextFlags_AlwaysInsertMode)
                edit_state.StbState.insert_mode = true;
            if (!is_multiline && (focus_requested_by_tab || (user_clicked && io.KeyCtrl)))
                select_all = true;
        }
        SetActiveID(id, window);
        FocusWindow(window);
    }
    else if (io.MouseClicked[0])
    {
        // Release focus when we click outside
        clear_active_id = true;
    }

    bool value_changed = false;
    bool enter_pressed = false;

    if (g.ActiveId == id)
    {
        if (!is_editable && !g.ActiveIdIsJustActivated)
        {
            // When read-only we always use the live data passed to the function
            edit_state.Text.resize(buf_size+1);
            const char* buf_end = NULL;
            edit_state.CurLenW = ImTextStrFromUtf8(edit_state.Text.Data, edit_state.Text.Size, buf, NULL, &buf_end);
            edit_state.CurLenA = (int)(buf_end - buf);
            edit_state.CursorClamp();
        }

        edit_state.BufSizeA = buf_size;

        // Although we are active we don't prevent mouse from hovering other elements unless we are interacting right now with the widget.
        // Down the line we should have a cleaner library-wide concept of Selected vs Active.
        g.ActiveIdAllowOverlap = !io.MouseDown[0];
        g.WantTextInputNextFrame = 1;

        // Edit in progress
        const float mouse_x = (io.MousePos.x - frame_bb.Min.x - style.FramePadding.x) + edit_state.ScrollX;
        const float mouse_y = (is_multiline ? (io.MousePos.y - draw_window->DC.CursorPos.y - style.FramePadding.y) : (g.FontSize*0.5f));

        const bool osx_double_click_selects_words = io.OptMacOSXBehaviors;      // OS X style: Double click selects by word instead of selecting whole text
        if (select_all || (hovered && !osx_double_click_selects_words && io.MouseDoubleClicked[0]))
        {
            edit_state.SelectAll();
            edit_state.SelectedAllMouseLock = true;
        }
        else if (hovered && osx_double_click_selects_words && io.MouseDoubleClicked[0])
        {
            // Select a word only, OS X style (by simulating keystrokes)
            edit_state.OnKeyPressed(STB_TEXTEDIT_K_WORDLEFT);
            edit_state.OnKeyPressed(STB_TEXTEDIT_K_WORDRIGHT | STB_TEXTEDIT_K_SHIFT);
        }
        // JS: EDIT
        else if (io.MouseClicked[0] && !edit_state.SelectedAllMouseLock && !bypassClick)
        // END JS EDIT
        {
            stb_textedit_click(&edit_state, &edit_state.StbState, mouse_x, mouse_y);
            edit_state.CursorAnimReset();
        }
      
      
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