Qu

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Language & UI

GUI controls

a GUI declared by the script itself.

catalog/qu_gui_controls.qu

Qu's GUI model is IMMEDIATE MODE: there is no widget tree to build and no callbacks to register. A script calls `ui_slider(...)` / `ui_select(...)` etc. as it runs, and each call hands back that control's CURRENT value. The host (QuStudio) re-runs the whole script whenever a control changes.

The consequence worth noticing: this file is still an ordinary script. Run it from a plain terminal with no GUI anywhere in sight and every control simply returns its own declared default, so it prints real results rather than erroring. Run it inside a host and the same lines become live controls. One script, both ways, no branching.

What it exercises

Results

printed
Damped oscillation: sine at 3 Hz, amplitude 1, decay 0.4
peak = 0.9674, rms = 0.5865
-0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Damped oscillation Time (s) Amplitude sine @ 3 Hz
Drawn by running the program above.

The whole program

Runnable as it stands: qu run catalog/qu_gui_controls.qu

# qu_gui_controls.qu -- a GUI declared by the script itself.

#

# Qu's GUI model is IMMEDIATE MODE: there is no widget tree to build and

# no callbacks to register. A script calls `ui_slider(...)` / `ui_select(...)`

# etc. as it runs, and each call hands back that control's CURRENT value.

# The host (QuStudio) re-runs the whole script whenever a control changes.

#

# The consequence worth noticing: this file is still an ordinary script.

# Run it from a plain terminal with no GUI anywhere in sight and every

# control simply returns its own declared default, so it prints real

# results rather than erroring. Run it inside a host and the same lines

# become live controls. One script, both ways, no branching.

#

# Constructs exercised:

#   ui_slider(label, min, max, [default], [step=], [fill=], [size=], [id=])

#   ui_number(label, [default])          ui_checkbox(label, [default])

#   ui_select(label, options, [default])  ui_text(label, [default])

#   ui_button(label)                      -- true only on the run it's pressed


# ---- Controls -------------------------------------------------------

# `fill` is true by default (the dock/fill convention: a control adapts to

# the width it's given). Turn it off and `size` gives a RELATIVE weight, so

# two controls at size 1 and 2 keep their 1:2 split at any window size.

title = ui_text("Title", "Damped oscillation")
freq  = ui_slider("Frequency (Hz)", 0.5, 20, 3, step = 0.5)
decay = ui_slider("Decay", 0, 2, 0.4, step = 0.05)
amp   = ui_number("Amplitude", 1.0, fill = false, size = 1)
wave  = ui_select("Waveform", ("sine", "square", "sawtooth"), "sine")
grid_on = ui_checkbox("Grid", true, fill = false, size = 1)

# ---- Signal ---------------------------------------------------------

Fs = 500
N  = 500
t  = (0 to N - 1) / Fs

if wave == "square"
    base = signals.square(freq, Fs, N)
elseif wave == "sawtooth"
    base = signals.sawtooth(freq, Fs, N)
else
    base = sin(2 * pi * freq * t)
end

y = amp * base * exp(-decay * t)

# ---- Report + plot --------------------------------------------------

print("{title}: {wave} at {freq} Hz, amplitude {amp}, decay {decay}")
print("peak = {max(y):.4f}, rms = {rms(y):.4f}")

# `ui_button` is true only on the run where it was actually pressed, so

# this reads naturally instead of latching on for every later re-run.

if ui_button("Print samples")
    print("first 5 samples: {y[0:4]}")
end

plot(t, y, label = "{wave} @ {freq} Hz", color = "blue")
if grid_on
    grid on
end
title("{title}")
xlabel("Time (s)")
ylabel("Amplitude")
legend()