Refactorized _GlancesCurses.display_plugin()

Part of nicolargo#2801. The flow is the same. Used as helpers:

    1. `self.set_upper_left_pos`
    2. `self.goto_next_and_ret_first_col`
    3. `self.check_opt_and_add`
    4. `self.x_overbound`
    5. `self.y_overbound`
    6. `self.display_msg`

Signed-off-by: Ariel Otilibili <otilibil@eurecom.fr>

Author: ariel-anieli

glances/outputs/glances_curses.py

@@ -922,6 +922,32 @@ def display_popup(
 
         return None
 
+    def set_upper_left_pos(self, plugin_stats):
+        screen_x = self.term_window.getmaxyx()[1]
+        screen_y = self.term_window.getmaxyx()[0]
+
+        if plugin_stats['align'] == 'right':
+            # Right align (last column)
+            display_x = screen_x - self.get_stats_display_width(plugin_stats)
+        else:
+            display_x = self.column
+        if plugin_stats['align'] == 'bottom':
+            # Bottom (last line)
+            display_y = screen_y - self.get_stats_display_height(plugin_stats)
+        else:
+            display_y = self.line
+
+        return display_y, display_x
+
+    def check_opt_and_add(self, display_optional, display_additional):
+        def neither_optional_nor_additional(m):
+            has_optional = not display_optional and m['optional']
+            has_additional = not display_additional and m['additional']
+
+            return any([has_optional, has_additional])
+
+        return neither_optional_nor_additional
+
     def display_plugin(self, plugin_stats, display_optional=True, display_additional=True, max_y=65535, add_space=0):
         """Display the plugin_stats on the screen.
 
@@ -934,89 +960,97 @@ def display_plugin(self, plugin_stats, display_optional=True, display_additional
         # Exit if:
         # - the plugin_stats message is empty
         # - the display tag = False
-        if plugin_stats is None or not plugin_stats['msgdict'] or not plugin_stats['display']:
+        conditions = [plugin_stats is None, not plugin_stats['msgdict'], not plugin_stats['display']]
+        if any(conditions):
             # Exit
             return 0
 
-        # Get the screen size
-        screen_x = self.term_window.getmaxyx()[1]
+        # Set the upper/left position of the message
+        display_y, display_x = self.set_upper_left_pos(plugin_stats)
+
+        helper = {
+            'goto next and ret first col': self.goto_next_and_ret_first_col(display_x),
+            'neither opt nor add?': self.check_opt_and_add(display_optional, display_additional),
+            'x overbound?': self.x_overbound,
+            'y overbound?': self.y_overbound(max_y),
+        }
+
+        init = {'x': display_x, 'x max': display_x, 'y': display_y}
+        y, x, x_max = self.display_msg(plugin_stats, init, helper)
+
+        # Compute the next Glances column/line position
+        self.next_column = max(self.next_column, x_max + self.space_between_column)
+        self.next_line = max(self.next_line, y + self.space_between_line)
+
+        # Have empty lines after the plugins
+        self.next_line += add_space
+        return None
+
+    def y_overbound(self, max_y):
         screen_y = self.term_window.getmaxyx()[0]
 
-        # Set the upper/left position of the message
-        if plugin_stats['align'] == 'right':
-            # Right align (last column)
-            display_x = screen_x - self.get_stats_display_width(plugin_stats)
-        else:
-            display_x = self.column
-        if plugin_stats['align'] == 'bottom':
-            # Bottom (last line)
-            display_y = screen_y - self.get_stats_display_height(plugin_stats)
-        else:
-            display_y = self.line
+        return lambda y: y < 0 or (y + 1 > screen_y) or (y > max_y)
+
+    def x_overbound(self, m, x):
+        screen_x = self.term_window.getmaxyx()[1]
 
-        # Display
-        x = display_x
-        x_max = x
-        y = display_y
+        return x < 0 or not m['splittable'] and (x + len(m['msg']) > screen_x)
+
+    def goto_next_and_ret_first_col(self, display_x):
+        return lambda y: (y + 1, display_x)
+
+    def display_msg(self, plugin_stats, init, helper):
+        y, x, x_max = init['y'], init['x'], init['x max']
         for m in plugin_stats['msgdict']:
             # New line
             try:
                 if m['msg'].startswith('\n'):
-                    # Go to the next line
-                    y += 1
-                    # Return to the first column
-                    x = display_x
+                    y, x = helper['goto next and ret first col'](y)
                     continue
             except Exception:
                 # Avoid exception (see issue #1692)
                 pass
-            # Do not display outside the screen
-            if x < 0:
-                continue
-            if not m['splittable'] and (x + len(m['msg']) > screen_x):
+            if helper['x overbound?'](m, x) or helper['neither opt nor add?'](m):
                 continue
-            if y < 0 or (y + 1 > screen_y) or (y > max_y):
+            if helper['y overbound?'](y):
                 break
-            # If display_optional = False do not display optional stats
-            if not display_optional and m['optional']:
-                continue
-            # If display_additional = False do not display additional stats
-            if not display_additional and m['additional']:
-                continue
-            # Is it possible to display the stat with the current screen size
-            # !!! Crash if not try/except... Why ???
-            try:
-                self.term_window.addnstr(
-                    y,
-                    x,
-                    m['msg'],
-                    # Do not display outside the screen
-                    screen_x - x,
-                    self.colors_list[m['decoration']],
-                )
-            except Exception:
-                pass
-            else:
-                # New column
-                # Python 2: we need to decode to get real screen size because
-                # UTF-8 special tree chars occupy several bytes.
-                # Python 3: strings are strings and bytes are bytes, all is
-                # good.
-                try:
-                    x += len(u(m['msg']))
-                except UnicodeDecodeError:
-                    # Quick and dirty hack for issue #745
-                    pass
-                if x > x_max:
-                    x_max = x
+            x, x_max = self.display_stats_with_current_size(m, y, x, x_max)
 
-        # Compute the next Glances column/line position
-        self.next_column = max(self.next_column, x_max + self.space_between_column)
-        self.next_line = max(self.next_line, y + self.space_between_line)
+        return y, x, x_max
 
-        # Have empty lines after the plugins
-        self.next_line += add_space
-        return None
+    def display_stats_with_current_size(self, m, y, x, x_max):
+        # Is it possible to display the stat with the current screen size
+        # !!! Crash if not try/except... Why ???
+        screen_x = self.term_window.getmaxyx()[1]
+        try:
+            self.term_window.addnstr(
+                y,
+                x,
+                m['msg'],
+                # Do not display outside the screen
+                screen_x - x,
+                self.colors_list[m['decoration']],
+            )
+        except Exception:
+            pass
+        else:
+            return self.add_new_colum(m, x, x_max)
+
+    def add_new_colum(self, m, x, x_max):
+        # New column
+        # Python 2: we need to decode to get real screen size because
+        # UTF-8 special tree chars occupy several bytes.
+        # Python 3: strings are strings and bytes are bytes, all is
+        # good.
+        try:
+            x += len(u(m['msg']))
+        except UnicodeDecodeError:
+            # Quick and dirty hack for issue #745
+            pass
+        if x > x_max:
+            x_max = x
+
+        return x, x_max
 
     def clear(self):
         """Erase the content of the screen.