Function DemoWindowWidgetsTextInput

imgui_tiny_app/imgui/imgui_demo.cpp:3826–4040

//-----------------------------------------------------------------------------

static void DemoWindowWidgetsTextInput()
{
    // To wire InputText() with std::string or any other custom string type,
    // see the "Text Input > Resize Callback" section of this demo, and the misc/cpp/imgui_stdlib.h file.
    if (ImGui::TreeNode("Text Input"))
    {
        IMGUI_DEMO_MARKER("Widgets/Text Input");
        if (ImGui::TreeNode("Multi-line Text Input"))
        {
            IMGUI_DEMO_MARKER("Widgets/Text Input/Multi-line Text Input");
            // WE ARE USING A FIXED-SIZE BUFFER FOR SIMPLICITY HERE.
            // If you want to use InputText() with std::string or any custom dynamic string type:
            // - For std::string: use the wrapper in misc/cpp/imgui_stdlib.h/.cpp
            // - Otherwise, see the 'Dear ImGui Demo->Widgets->Text Input->Resize Callback' for using ImGuiInputTextFlags_CallbackResize.
            static char text[1024 * 16] =
                "/*\n"
                " The Pentium F00F bug, shorthand for F0 0F C7 C8,\n"
                " the hexadecimal encoding of one offending instruction,\n"
                " more formally, the invalid operand with locked CMPXCHG8B\n"
                " instruction bug, is a design flaw in the majority of\n"
                " Intel Pentium, Pentium MMX, and Pentium OverDrive\n"
                " processors (all in the P5 microarchitecture).\n"
                "*/\n\n"
                "label:\n"
                "\tlock cmpxchg8b eax\n";

            static ImGuiInputTextFlags flags = ImGuiInputTextFlags_AllowTabInput;
            HelpMarker("You can use the ImGuiInputTextFlags_CallbackResize facility if you need to wire InputTextMultiline() to a dynamic string type. See misc/cpp/imgui_stdlib.h for an example. (This is not demonstrated in imgui_demo.cpp because we don't want to include <string> in here)");
            ImGui::CheckboxFlags("ImGuiInputTextFlags_ReadOnly", &flags, ImGuiInputTextFlags_ReadOnly);
            ImGui::CheckboxFlags("ImGuiInputTextFlags_WordWrap", &flags, ImGuiInputTextFlags_WordWrap);
            ImGui::SameLine(); HelpMarker("Feature is currently in Beta. Please read comments in imgui.h");
            ImGui::CheckboxFlags("ImGuiInputTextFlags_AllowTabInput", &flags, ImGuiInputTextFlags_AllowTabInput);
            ImGui::SameLine(); HelpMarker("When _AllowTabInput is set, passing through the widget with Tabbing doesn't automatically activate it, in order to also cycling through subsequent widgets.");
            ImGui::CheckboxFlags("ImGuiInputTextFlags_CtrlEnterForNewLine", &flags, ImGuiInputTextFlags_CtrlEnterForNewLine);
            ImGui::InputTextMultiline("##source", text, IM_COUNTOF(text), ImVec2(-FLT_MIN, ImGui::GetTextLineHeight() * 16), flags);
            ImGui::TreePop();
        }

        if (ImGui::TreeNode("Filtered Text Input"))
        {
            IMGUI_DEMO_MARKER("Widgets/Text Input/Filtered Text Input");
            struct TextFilters
            {
                // Modify character input by altering 'data->Eventchar' (ImGuiInputTextFlags_CallbackCharFilter callback)
                static int FilterCasingSwap(ImGuiInputTextCallbackData* data)
                {
                    if (data->EventChar >= 'a' && data->EventChar <= 'z') { data->EventChar -= 'a' - 'A'; } // Lowercase becomes uppercase
                    else if (data->EventChar >= 'A' && data->EventChar <= 'Z') { data->EventChar += 'a' - 'A'; } // Uppercase becomes lowercase
                    return 0;
                }

                // Return 0 (pass) if the character is 'i' or 'm' or 'g' or 'u' or 'i', otherwise return 1 (filter out)
                static int FilterImGuiLetters(ImGuiInputTextCallbackData* data)
                {
                    if (data->EventChar < 256 && strchr("imgui", (char)data->EventChar))
                        return 0;
                    return 1;
                }