Scroll

See the ScrollDemo class.

void DrawSettings()
{
    Gui.Heading("Settings");

    var rects = RectsBuilder.AllocateMainAndToolTipRect();

    Gui.NextRect(rects.Main).LabelInputBool("FixToBottom", ref shouldFixToBottom);
    Gui.NextRect(rects.ToolTip).ToolTip("Keep the scroll fixed at the bottom even when new widgets are added.");
}

void DrawWithDynamic()
{
    Gui.NextWidth(Ctx.GetCurrentRegionWidth() - CharFixedMap.CalcToolTipXAdvance() - Style.SpacingXs.Get())
        .Heading("Dynamic");

    Gui.NextRect(Ctx.GetHorizontalRemainRect())
        .ToolTip(
        "A scroll that allows dynamic addition of widgets.\n" +
        "Suitable when the number of widgets is not large, as it processes all of them.");

    // Controls for modifying scroll properties.
    Gui.LabelSlider("OuterTextCount", ref outerTextCount, 0, 100);
    Gui.LabelSlider("innerTextCount", ref innerTextCount, 0, 100);
    Gui.LabelSlider("OuterHeight", ref outerHeight, 0, 300);
    Gui.LabelSlider("InnerHeight", ref innerHeight, 0, 300);

    using var p = Gui.BeginFramePadding1();
    Gui.NextHeight(Size.Fixed(outerHeight));
    // Outer scrollable area.
    if (Gui.BeginScroll())
    {
        using (Gui.BeginFramePadding1())
        {
            // Inner scrollable area.
            Gui.NextHeight(Size.Fixed(innerHeight));
            if (Gui.BeginScroll())
            {
                for (int i = 0; i < innerTextCount; i++)
                {
                    using (Ctx.PushId(i))
                        Gui.Text($"inner:{i}");
                }
                Gui.EndScroll();
            }
        }

        for (int i = 0; i < outerTextCount; i++)
        {
            Gui.Text($"outer:{i}");
        }

        Gui.EndScroll();
    }
}

void DrawUsingHandler()
{
    Gui.NextWidth(Ctx.GetCurrentRegionWidth() - CharFixedMap.CalcToolTipXAdvance() - Style.SpacingXs.Get())
        .Heading("Fixed");
    Gui.NextRect(Ctx.GetHorizontalRemainRect())
        .ToolTip(
        "A scroll where the number and height of widgets must be determined before processing.\n" +
        "It only processes the displayed widgets, making it fast even when there are many.");

    // Controls for modifying fixed scroll properties.
    Gui.LabelInputNumeric("Height", ref height);
    Gui.LabelSlider("TextCount", ref textCountWithIterator, 0, 100);

    using var p = Gui.BeginFramePadding1();
    // Create a scroll handler with fixed height and item count.
    var handler = Gui.CreateScrollHandler(height, textCountWithIterator, Style.StandardHeight);
    // Render only visible items based on the scroll handler.
    while (handler.Next())
    {
        Gui.Text($"{handler.CurrentIndex}");
    }
}

/// <summary>
/// Demonstrates a scroll handler that automatically extends to the bottom of the window.
/// </summary>
void DrawToBottomOfWindow()
{
    Gui.Heading("To the bottom of the window");
    using var p = Gui.BeginFramePadding1();

    Ctx.AddSpaceIfNeeded();
    // Create a scroll handler that fills the remaining height in the window.
    var handler = Gui.CreateScrollHandler(Ctx.GetRemainRect().height, 100, Style.StandardHeight);
    // Render only visible items based on the scroll handler.
    while (handler.Next())
    {
        Gui.Text(handler.CurrentIndex.ToString());
    }
}