TST: add manual user acceptance test

UAT.py

@@ -0,0 +1,139 @@
+import sys
+
+import matplotlib as mpl
+import mpl_gui as mg
+from matplotlib.figure import Figure
+
+assert sys.modules.get("matplotlib.pyplot", None) is None
+sys.modules["matplotlib.pyplot"] = None
+
+
+_, target = sys.argv
+
+# this is how to force the right Qt binding
+if target.lower().startswith("qt5"):
+    import PyQt5.QtWidgets  # noqa
+elif target.lower().startswith("qt"):
+    import PyQt6.QtWidgets  # noqa
+
+mpl.use(target, force=True)
+
+fig1 = Figure(label="A Label!")
+
+fig2 = Figure()
+
+print(
+    """
+You should see two figures with window titles of
+
+ - "A Label!"
+ - "Figure 0"
+
+both should be empty and the process should block until both
+are closed (the keybinding 'q' should work).
+"""
+)
+mg.show([fig1, fig2])
+
+mg.ion()
+fig = Figure()
+print(f"Interactive mode is on: {mg.is_interactive()}")
+mg.show([fig])  # will not block
+print("A (implicitly) non-blocking show was just called.")
+mg.ioff()
+print(mg.is_interactive())
+print(f"Interactive mode is on: {mg.is_interactive()}")
+print(
+    """
+You should see one open figure with the title
+
+- Figure 2
+
+and the process should again block until it is closed.
+"""
+)
+
+mg.show([fig])  # will block!
+
+fig = Figure(label="control blocking")
+
+mg.show([fig], block=False)  # will never block
+print("A (implicitly) non-blocking show was just called.")
+print(
+    """
+You should see one open figure with the title
+
+- control blocking
+
+and the process should again block until it is closed.
+"""
+)
+mg.show([fig], block=True)  # will always block
+
+
+fig1 = mg.figure()
+fig2, axs = mg.subplots(2, 2)
+fig3, axd = mg.subplot_mosaic("AA\nBC")
+
+print(
+    """
+You should see three open figure with the titles
+
+- Figure 4
+- Figure 5
+- Figure 6
+
+and the process should again block until it is closed.  One will
+be empty, one will have a 2x2 grid, One will have `AA;BC` layout.
+"""
+)
+
+mg.show([fig1, fig2, fig3])
+
+
+fr = mg.FigureRegistry()
+
+fr.figure()
+fr.subplots(2, 2)
+fr.subplot_mosaic("AA\nBC")
+
+print(
+    """
+You should see three open figure with the titles
+
+- Figure 0
+- Figure 1
+- Figure 2
+
+and the process should again block until it is closed.  One will
+be empty, one will have a 2x2 grid, One will have `AA;BC` layout.
+"""
+)
+
+fr.show_all()  # will show all three figures
+# fr.show()  # alias for pyplot compatibility
+
+# fr.close_all()  # will close all three figures
+# fr.close("all")  # alias for pyplot compatibility
+
+
+plt = mg.FigureRegistry()
+
+
+with mg.FigureContext() as fc:
+    fc.subplot_mosaic("AA\nBC")
+    fc.figure()
+    fc.subplots(2, 2)
+
+    print(
+        """
+You should see three open figure with the titles
+
+- Figure 0
+- Figure 1
+- Figure 2
+
+and the process should again block until it is closed.  One will
+be empty, one will have a 2x2 grid, One will have `AA;BC` layout.
+"""
+    )