Merge pull request #265 from CanonicalLtd/mwhudson/scrollbars

add scrollbars to listboxes

subiquity/palette.py

@@ -87,6 +87,8 @@ STYLES = [
     ('string_input focus',  'bg',      'fg'),
     ('progress_incomplete', 'fg',      'aubergine'),
     ('progress_complete',   'fg',      'orange'),
+    ('scrollbar_fg',        'orange',  'bg'),
+    ('scrollbar_bg',        'fg',      'bg'),
 ]
 
 focus_styles = set([

subiquity/ui/views/filesystem/disk_partition.py

@@ -38,10 +38,10 @@ class DiskPartitionView(BaseView):
             ('pack', Text("")),
             Padding.center_79(ListBox(
                 self._build_model_inputs() + [
-                Text(""),
-                self.show_disk_info_w(),
                 ])),
             ('pack', Pile([
+                Text(""),
+                ('pack', Padding.center_79(self.show_disk_info_w())),
                 ('pack', Text("")),
                 self._build_buttons(),
                 ('pack', Text("")),

subiquity/ui/views/filesystem/filesystem.py

@@ -64,7 +64,7 @@ class FilesystemConfirmationView(WidgetWrap):
             Text(""),
             ])
         lb = LineBox(pile, title=_("Confirm destructive action"))
-        super().__init__(Padding.center_75(lb))
+        super().__init__(lb)
 
     def ok(self, sender):
         self.controller.finish()
@@ -261,4 +261,4 @@ class FilesystemView(BaseView):
         self.controller.reset()
 
     def done(self, button):
-        self.show_overlay(FilesystemConfirmationView(self, self.controller))
+        self.show_overlay(FilesystemConfirmationView(self, self.controller), min_width=0)

subiquity/ui/views/installprogress.py

@@ -40,7 +40,8 @@ class ProgressView(BaseView):
         self.model = model
         self.controller = controller
         self.listwalker = SimpleFocusListWalker([])
-        self.linebox = MyLineBox(ListBox(self.listwalker))
+        self.listbox = ListBox(self.listwalker)
+        self.linebox = MyLineBox(self.listbox)
         body = [
             ('pack', Text("")),
             ('weight', 1, Padding.center_79(self.linebox)),
@@ -50,9 +51,11 @@ class ProgressView(BaseView):
         super().__init__(self.pile)
 
     def add_log_tail(self, text):
+        at_end = len(self.listwalker) == 0 or self.listbox.focus_position == len(self.listwalker) - 1
         for line in text.splitlines():
             self.listwalker.append(Text(line))
-        self.listwalker.set_focus(len(self.listwalker) - 1)
+        if at_end:
+            self.listbox.set_focus(len(self.listwalker) - 1)
 
     def clear_log_tail(self):
         self.listwalker[:] = []

subiquitycore/controllers/network.py

@@ -405,7 +405,7 @@ class NetworkController(BaseController):
             self.cs.cancel()
             self.task_error('canceled')
         self.acw = ApplyingConfigWidget(len(tasks), cancel)
-        self.ui.frame.body.show_overlay(self.acw)
+        self.ui.frame.body.show_overlay(self.acw, min_width=60)
 
         self.cs = TaskSequence(self.run_in_bg, tasks, self)
         self.cs.run()

subiquitycore/ui/container.py

@@ -230,6 +230,78 @@ class FocusTrackingListBox(TabCyclingListBox):
     def gained_focus(self):
         _maybe_call(self.focus, 'gained_focus')
 
+
 Columns = FocusTrackingColumns
 Pile = FocusTrackingPile
-ListBox = FocusTrackingListBox
+
+
+class ScrollBarListBox(FocusTrackingListBox):
+
+    def __init__(self, walker=None):
+        def f(char, attr):
+            return urwid.AttrMap(urwid.SolidFill(char), attr)
+        self.bar = Pile([
+            ('weight', 1, f("\N{BOX DRAWINGS LIGHT VERTICAL}", 'scrollbar_bg')),
+            ('weight', 1, f("\N{FULL BLOCK}", 'scrollbar_fg')),
+            ('weight', 1, f("\N{BOX DRAWINGS LIGHT VERTICAL}", 'scrollbar_bg')),
+            ])
+        super().__init__(walker)
+
+    def render(self, size, focus=False):
+        visible = self.ends_visible(size, focus)
+        if len(visible) == 2:
+            return super().render(size, focus)
+        else:
+            # This implementation assumes that the number of rows is
+            # not too large (and in particular is finite). That's the
+            # case for all the listboxes we have in subiquity today.
+            maxcol, maxrow = size
+
+            offset, inset = self.get_focus_offset_inset((maxcol - 1, maxrow))
+
+            seen_focus = False
+            height = height_before_focus = 0
+            focus_widget, focus_pos = self.body.get_focus()
+            # Scan through the rows calculating total height and the
+            # height of the rows before the focus widget.
+            for widget in self.body:
+                rows = widget.rows((maxcol - 1,))
+                if widget is focus_widget:
+                    seen_focus = True
+                elif not seen_focus:
+                    height_before_focus += rows
+                height += rows
+
+            # Calculate the number of rows off the top and bottom of
+            # the listbox.
+            if 'top' in visible:
+                top = 0
+            else:
+                top = height_before_focus + inset - offset
+            if 'bottom' in visible:
+                bottom = 0
+            else:
+                bottom = height - top - maxrow
+
+            # Prevent the box from being squished to 0 rows (if it
+            # gets ('weight', maxrow) gets round(maxrow / (top +
+            # maxrow + bottom)) and that being < 1 simplifies to the
+            # below).
+            if maxrow*maxrow < height:
+                boxopt = self.bar.options('given', 1)
+            else:
+                boxopt = self.bar.options('weight', maxrow)
+
+            self.bar.contents[:] = [
+                (self.bar.contents[0][0], self.bar.options('weight', top)),
+                (self.bar.contents[1][0], boxopt),
+                (self.bar.contents[2][0], self.bar.options('weight', bottom)),
+                ]
+            canvases = [
+                (super().render((maxcol - 1, maxrow), focus), self.focus_position, True, maxcol - 1),
+                (self.bar.render((1, maxrow)), None, False, 1)
+                ]
+            return urwid.CanvasJoin(canvases)
+
+
+ListBox = ScrollBarListBox

subiquitycore/ui/views/network.py

@@ -115,11 +115,11 @@ class NetworkView(BaseView):
         self.model_inputs = Pile(self._build_model_inputs())
         self.additional_options = Pile(self._build_additional_options())
         self.body = [
-            Padding.center_90(self.model_inputs),
+            self.model_inputs,
             Padding.center_79(self.additional_options),
             Padding.line_break(""),
         ]
-        self.lb = ListBox(self.body)
+        self.lb = Padding.center_90(ListBox(self.body))
         self.footer = Pile([
                 Text(""),
                 self._build_buttons(),

subiquitycore/ui/views/network_configure_interface.py

@@ -34,7 +34,7 @@ class NetworkConfigureInterfaceView(BaseView):
         self._build_widgets()
         super().__init__(Pile([
             ('pack', Text("")),
-            ListBox(self._build_body()),
+            Padding.center_79(ListBox(self._build_body())),
             ('pack', Pile([
                 ('pack', Text("")),
                 self._build_buttons(),
@@ -57,16 +57,16 @@ class NetworkConfigureInterfaceView(BaseView):
         body = []
         if self.dev.type == 'wlan':
             body.extend([
-                Padding.center_79(self.wifi_info),
-                Padding.center_79(self.wifi_method),
+                self.wifi_info,
+                self.wifi_method,
                 Padding.line_break(""),
                 ])
         body.extend([
-            Padding.center_79(self.ipv4_info),
-            Padding.center_79(self.ipv4_method),
+            self.ipv4_info,
+            self.ipv4_method,
             Padding.line_break(""),
-            Padding.center_79(self.ipv6_info),
-            Padding.center_79(self.ipv6_method),
+            self.ipv6_info,
+            self.ipv6_method,
             Padding.line_break(""),
         ])
         return body