y axis labels implemented; test added

Author: salt-die

examples/chart_test.py

@@ -0,0 +1,15 @@
+from random import random
+
+from nurses import ScreenManager, colors
+
+
+with ScreenManager() as sm:
+    blue_to_purple = colors.gradient(20, (0, 255, 255), (103, 15, 215), "blue_to_purple")
+    chart = sm.root.new_widget(create_with="Chart", maxlen=200, gradient=blue_to_purple, size_hint=(.5, .5), y_label=5)
+
+    def update():
+        chart.update(random() * 50)
+        sm.root.refresh()
+
+    sm.schedule(update)
+    sm.run()

nurses/widgets/__init__.py

@@ -14,6 +14,8 @@
 from .textbox import Textbox
 from .text_pad import TextPad
 
+from .chart import Chart
+
 # Layouts
 from .grid import Grid
 from .splits import HSplit, VSplit

nurses/widgets/chart.py

@@ -1,26 +1,77 @@
 from collections import deque
 
-from . import Widget
+from . import ArrayWin
 
-HEIGHTS = "⠀", "⣀", "⣤", "⣶", "⣿"
+FULL = "⣿"
+FRACTION = "⠀", "⣀", "⣤", "⣶", "⣿"
 
 
-class Chart(Widget):
-    """A Widget that provides a real-time view of some value over time.
+class Chart(ArrayWin):
     """
-    def __init__(*args, values=None, maxlen=None, **kwargs):
-        super().__init__(*args, **kwargs)
+    A Widget that provides a real-time view of some value over time.
 
-        if values is None:
-            values = self.width * [0]
-        elif len(values) < self.width:
-            values = [0] * (self.width - len(values)) + values
+    Notes
+    -----
+    If `y_label` or `x_label` are set as any positive integer `n`, labels will be
+    turned on and `n` labels will be printed.
+    """
+    values = None
+    maxlen = None
+    gradient = None
+
+    y_label = False
+    y_label_width = 5
+
+    def update_geometry(self):
+        if self.root is None:
+            return
+
+        super().update_geometry()
 
-        if max_len is not None:
-            values = deque(values, maxlen=maxlen)
+        if self.values is None:
+            self.values = self.width * [0]
+        elif len(self.values) < self.width:
+            self.values = [0] * (self.width - len(self.values)) + self.values
+
+        if self.maxlen is not None:
+            self.values = deque(self.values, maxlen=self.maxlen)
 
     def update(self, value):
         self.values.append(value)
 
     def refresh(self):
-        ...
+        n_labels = self.y_label
+        y_label_width = self.y_label_width * bool(n_labels) + 2
+        h, w = self.buffer[1:, 1:].shape
+
+        it = reversed(self.values)
+        values = tuple(next(it) for _ in range(w - y_label_width))
+        max_v = max(values)
+
+        gradient = self.gradient
+
+        self[:] = " "
+        self.colors[:] = self.color
+
+        if y_label_width:
+            self[:, y_label_width] = "|"
+
+            # Print y labels
+            for i in range(n_labels):
+                percent_of_height = i / (n_labels - 1)
+                value = f"{percent_of_height * max_v:.1f}"  # TODO: attribute to specify places after decimal
+                self[round((1 - percent_of_height) * h), :y_label_width - 2] = f"{value:>{y_label_width - 2}}"
+
+        # Print vertical bars
+        for i, value in enumerate(reversed(values)):
+            percent_of_height = value / max_v
+            whole, fraction = divmod(percent_of_height * h * 4, 4)
+
+            row = round((1 - percent_of_height) * h)
+            self[row + 1:, i + y_label_width + 1] = FULL
+            self[row, i + y_label_width + 1] = FRACTION[round(fraction)]
+
+            if gradient is not None:
+                self.colors[row: , i + y_label_width + 1] = gradient[round(percent_of_height * (len(gradient) - 1))]
+
+        super().refresh()