From 7c723133e010d428d1a099b4ecf1db2fdd5e4f02 Mon Sep 17 00:00:00 2001
From: MikeTheWatchGuy <mike_barnett@hotmail.com>
Date: Sat, 7 Sep 2019 09:20:07 -0400
Subject: [PATCH] New demo program that shows how to use Graph Element to draw
 a visualizer for sorts

---
 DemoPrograms/Demo_Sort_Visualizer.py | 59 ++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 DemoPrograms/Demo_Sort_Visualizer.py

diff --git a/DemoPrograms/Demo_Sort_Visualizer.py b/DemoPrograms/Demo_Sort_Visualizer.py
new file mode 100644
index 00000000..1f07a1b9
--- /dev/null
+++ b/DemoPrograms/Demo_Sort_Visualizer.py
@@ -0,0 +1,59 @@
+import PySimpleGUI as sg
+import random
+# ------- Sort visualizer. Displays bar chart representing list items -------
+BAR_SPACING, BAR_WIDTH, EDGE_OFFSET = 11, 10, 3
+DATA_SIZE = GRAPH_SIZE = (700,500)      # width, height of the graph portion
+
+def bubble_sort(arr):
+    def swap(i, j):
+        arr[i], arr[j] = arr[j], arr[i]
+    n = len(arr)
+    swapped = True
+    x = -1
+    while swapped:
+        swapped = False
+        x = x + 1
+        for i in range(1, n - x):
+            if arr[i - 1] > arr[i]:
+                swap(i - 1, i)
+                swapped = True
+                yield arr
+
+def draw_bars(graph, items):            # draws all the bars for all values across screen
+    # type: (sg.Graph, List)->None
+    for i, item in enumerate(items):
+        graph.draw_rectangle(top_left=(i * BAR_SPACING + EDGE_OFFSET, item),
+                            bottom_right=(i * BAR_SPACING + EDGE_OFFSET + BAR_WIDTH, 0), fill_color='#76506d')
+
+def main():
+    sg.change_look_and_feel('LightGreen')
+    # Make list to sort
+    num_bars = DATA_SIZE[0]//(BAR_WIDTH+1)
+    list_to_sort = [DATA_SIZE[1]//num_bars*i  for i in range(1,num_bars)]
+    random.shuffle(list_to_sort)
+
+    # define window layout
+    graph = sg.Graph(GRAPH_SIZE, (0,0), DATA_SIZE)
+    layout = [[graph],
+              [sg.T('Speed    Faster'), sg.Slider((0,20), orientation='h', default_value=10, key='-SPEED-'), sg.T('Slower')]]
+
+    window = sg.Window('Sort Demonstration', layout, finalize=True)
+    draw_bars(graph, list_to_sort)              # draw the initial window's bars
+
+    sg.popup('Click OK to begin Bubblesort')    # Wait for user to start it up
+    bsort = bubble_sort(list_to_sort)           # get an iterator for the sort
+    timeout=10                                  # start with 10ms delays between draws
+    while True:                                 # ----- The event loop -----
+        event, values = window.read(timeout=timeout)
+        if event is None:
+            break
+        try:
+            partially_sorted_list = bsort.__next__()
+        except:
+            sg.popup('Sorting done!')
+            break
+        graph.Erase()
+        draw_bars(graph, partially_sorted_list)
+        timeout = int(values['-SPEED-'])
+    window.close()
+main()
\ No newline at end of file