Struct TextPanel

Struct Documentation

struct TextPanel

A multi-line text panel.

Read-only mode:

  • nanogui : a non-editable nanogui::TextBox with vertical scroll, or a sequence of nanogui::Label lines inside a scroll panel. Content is refreshed from live_text each spinOnce tick.

  • ImGui : ImGui::InputTextMultiline with ImGuiInputTextFlags_ReadOnly. live_text->pollIntoDisplay() is called each frame; the widget reads display directly. No copy into a separate buffer needed because ReadOnly mode does not write back.

Editable mode:

  • nanogui : nanogui::TextBox (multiline variant) with setEditable(true). on_change fires when the user commits (focus lost / Enter).

  • ImGui : ImGui::InputTextMultiline with a caller-owned std::string buffer (ImGui 1.89+ supports std::string via InputTextCallback or the imgui_stdlib.h helper - use InputTextMultiline overload that takes std::string*). on_change fires every frame the content differs from the last committed snapshot.

size_pixels sets the widget’s (width, height) in pixels. {0, 0} means “fill available width, auto height” for ImGui (ImVec2(0,0) default) and a reasonable fixed size for nanogui.

When editable is false, on_change is ignored and may be left empty. When editable is true, live_text is still used for the initial content (set it before calling create_subwindow_from_description); after that the ImGui backend owns the buffer and live_text is not polled. The nanogui backend follows the same convention.

Public Members

std::string label

optional heading above the panel

LiveString::Ptr live_text

content; never null

bool editable = false
std::array<int, 2> size_pixels = {0, 0}

{width, height}, 0 = auto

std::function<void(const std::string&)> on_change

editable only