touchy: keep the window within the monitor

Touchy has no scrolling, so its window minimum is the sum of every
child's request with nothing bounding it to the screen: the default
Sans 18 font alone wants ~1280x830 (off a 1024x768 display), and
reloading the tool table has been reported to double the height off
screen with no way back.

Wrap the content in a GtkScrolledWindow and bound the window to the
monitor work area via a max-size geometry hint. The scroller's
min-content is set to the natural size capped to the work area, so the
window opens at its natural size and only scrolls the overflow. On a
display large enough nothing scrolls and behaviour is unchanged.

Author: grandixximo

src/emc/usr_intf/touchy/touchy.py

@@ -107,6 +107,9 @@ def __init__(self, inifile):
                 self.wTree.get_object('MainWindow').set_can_focus(True)
                 self.wTree.get_object('MainWindow').grab_focus()
 
+                # Stop the window growing past the screen (see method).
+                self._constrain_to_monitor()
+
                 self.num_mdi_labels = 11
                 self.num_filechooser_labels = 11
                 self.num_listing_labels = 20
@@ -627,6 +630,67 @@ def change_theme(self, b):
                 settings = Gtk.Settings.get_default()
                 settings.set_string_property("gtk-theme-name", theme, "")
 
+        def _constrain_to_monitor(self):
+            # Wrap the content in a scroller so the window can be bounded to the
+            # monitor (touchy has no scrolling otherwise, so the window grows
+            # past the screen when a panel does). Best-effort.
+            try:
+                win = self.wTree.get_object("MainWindow")
+                child = win.get_child()
+                if child is None or isinstance(child, Gtk.ScrolledWindow):
+                    return
+                scroller = Gtk.ScrolledWindow()
+                scroller.set_policy(Gtk.PolicyType.AUTOMATIC,
+                                    Gtk.PolicyType.AUTOMATIC)
+                win.remove(child)
+                scroller.add(child)
+                viewport = scroller.get_child()
+                if isinstance(viewport, Gtk.Viewport):
+                    viewport.set_shadow_type(Gtk.ShadowType.NONE)
+                win.add(scroller)
+                scroller.show_all()
+                # Size on map, once the monitor and final fonts are known.
+                self._fitted = False
+                win.connect("map-event", self._fit_to_monitor, scroller, child)
+            except Exception:
+                pass
+
+        def _fit_to_monitor(self, win, event, scroller, child):
+            if self._fitted:
+                return False
+            self._fitted = True
+            # Bound the window to the work area now; size the scroller on idle,
+            # once layout has settled and the natural size is final.
+            try:
+                display = win.get_display()
+                gdkwin = win.get_window()
+                if gdkwin is not None:
+                    monitor = display.get_monitor_at_window(gdkwin)
+                else:
+                    monitor = display.get_primary_monitor()
+                if monitor is None:
+                    monitor = display.get_monitor(0)
+                area = monitor.get_workarea()
+                hints = Gdk.Geometry()
+                hints.max_width = area.width
+                hints.max_height = area.height
+                win.set_geometry_hints(None, hints, Gdk.WindowHints.MAX_SIZE)
+                GLib.idle_add(self._size_scroller, scroller, child, area)
+            except Exception:
+                pass
+            return False
+
+        def _size_scroller(self, scroller, child, area):
+            try:
+                natural = child.get_preferred_size()[1]
+                scroller.set_min_content_width(min(natural.width, area.width))
+                scroller.set_max_content_width(area.width)
+                scroller.set_min_content_height(min(natural.height, area.height))
+                scroller.set_max_content_height(area.height)
+            except Exception:
+                pass
+            return False
+
         def setfont(self):
                 # buttons
                 for i in ["1", "2", "3", "4", "5", "6", "7",