Trying to create a scrollable uifigure but unsure how to reference positions

I'm having a hard time understanding how MATLAB handles content that is larger than the size of a figure when the figure's scrollable property is true. Here's a toy example. I'll note from this example it seems that it is not possible to buffer space on the top (only on the bottom). I guess my mental model is something like a canvas size and a viewport, where the latter is smaller than the former. I'll note this is not how I normally think about MATLAB figures, but I'm wondering if it is possible to create this effect. Overall the goal is to support something like a scrollable web page.

Here's the code. Is there a better way of thinking of how scrollable interacts with the figure layout?

fig = uifigure('Position', [100 100 500 800]); 
fig.Scrollable = 'on';

canvasWidth  = 450;
canvasHeight = 3500;   % much taller than visible; scrolling required

%   Setting temporarily so that the uiaxes calls make sense.
%
%Does this actually happen? What are the limitations here?
%Should scrolling be enable after rendering/layout?
fig.Position = [1 1 canvasWidth canvasHeight];

% Number of axes
N = 10;
axHeight = 250;
axWidth  = 400;
padding = 20;

ax = gobjects(N,1);

% Create axes stacked vertically
for i = 1:N
    % Compute vertical position from top down
    y = canvasHeight - 400 - i*(axHeight + padding);
    
    ax(i) = uiaxes(fig, ...
        'Position', [20, y, axWidth, axHeight]); 
    plot(ax(i),1:2*i)

    title(ax(i), sprintf('Axes %d', i));
end

linkaxes(ax)

fig.Position = [100 100 500 800];

Answer 1

[Aditya]

Hi Jim,

MATLAB's scrollable figures scroll over the bounding box of their child components. To create extra padding (like a web page), you must add invisible components at the desired edges.

To add space at the top (or left), you must explicitly position a component (even an invisible one) at the desired top-left "corner" of your logical canvas

% Add a dummy (invisible) uilabel for padding at the top
topBuffer = 100; % pixels
dummy = uilabel(fig, 'Position', [1, canvasHeight-topBuffer, 1, 1], ...
                'Text', '', 'Visible', 'off');

This ensures the scrollable region starts topBuffer pixels above your first axes.

You can refer to the following documentation for more details:

Figure - Figure window - MATLAB