apps: calc: Created memory-saving calculator app

Signed-off-by: Johannes Wache <jbwa@posteo.de>

README.rst

@@ -185,6 +185,10 @@ using one of the techniques is the Application Writer's guide.
    :alt: Music Player running in the wasp-os simulator
    :width: 179
 
+.. image:: res/CalcApp.png
+   :alt: Calculator running in the wasp-os simulator
+   :width: 179
+
 .. image:: res/SnakeApp.png
    :alt: Snake Game running in the wasp-os simulator
    :width: 179

wasp/apps/calc.py

@@ -0,0 +1,121 @@
+# 2-bit RLE, generated from res/calc.png, 413 bytes
+calc = (
+    b'\x02'
+    b'`@'
+    b'(@\x03P?\x0eV?\x08[?\x04_?\x01b'
+    b'<f9h7j5l3n1p/r-t'
+    b'+H\xd1D\xd1H*H\xd2B\xd2H)I\xd2B'
+    b"\xd2I'J\xd2B\xd2I'J\xc8\xc2\xc8B\xd2J"
+    b'%K\xc7\xc1\x02\xc1\xc7B\xd2J%K\xc7\xc1\x02\xc2'
+    b'\xc6B\xd2K$K\xc5\xc2\xc1\x02\xc1\xc2\xc5B\xd2K'
+    b'#L\xc4\xc1\x08\xc1\xc4B\xc5\x08\xc5L"L\xc4\xc1'
+    b'\x08\xc2\xc3B\xc5\x08\xc1\xc1\xc3L"L\xc5\xc2\xc1\x02'
+    b'\xc8B\xcf\xc1\xc2L!M\xc6\xc2\x02\xc8B\xd0\xc1\xc1'
+    b'M M\xc7\xc1\x02\xc8B\xd1\xc1M M\xc8\xc2\xc8'
+    b'B\xd2M M\xc9\xc1\xc8B\xd2M M\xd2B\xd2'
+    b'M M\xd2B\xd2M N\xd0D\xd0N \x7f\x01'
+    b' \x7f\x01 N\xd0D\xc1\xcfN M\xd2B\xc1\xd1'
+    b'M M\xd2B\xd2AL M\xd2B\xd2AL '
+    b'M\xd2B\xd2AL M\xc7\xc1\xcaB\xc5\xc8\xc5A'
+    b'L M\xc5\xc1\x02\xc2\x02\xc1\xc5B\xc4\xc1\x08\xc1\xc4'
+    b'AL!L\xc5\xc1\x06\xc1\xc5B\xc4\xc1\x08\xc1\xc1\xc3'
+    b'AK"L\xc6\xc1\x04\xc1\xc6B\xc6\xca\xc2AK"'
+    b'L\xc6\xc1\x04\xc1\xc6B\xc7\xca\xc1L#K\xc5\xc1\x06'
+    b'\xc1\xc5B\xc4\xc1\x08\xc1\xc4JA$K\xc5\xc1\x02\xc2'
+    b'\x02\xc1\xc5B\xc4\xc1\x08\xc1\xc4K%J\xc6\xc2\xc2\xc2'
+    b"\xc6B\xc5\xc8\xc5J&J\xd2B\xc6\xccJ'I\xd2"
+    b'B\xc7\xcbI(I\xd2B\xc8\xcaI)H\xd2B\xc9'
+    b'\xc9H*H\xd1D\xc9\xc8H+t-r/p1'
+    b'n3l5j7h9f<b?\x01^?\x05'
+    b'XAA?\tV?\x0eP(')
+
+
+# SPDX-License-Identifier: LGPL-3.0-or-latesettingsr
+# Copyright (C) 2020 Johannes Wache
+"""Calculator application
+
+This is a simple calculator app that uses the build-in eval() function to compute the solution for an equation.
+"""
+
+import wasp, fonts
+
+class CalculatorApp():
+    NAME = 'Calc'
+    ICON = calc
+
+    def __init__(self):
+        self.output = ""
+        self.fields = [["7","8","9","+","("],
+                        ["4","5","6","-",")"],
+                        ["1","2","3","*","^"],
+                        ["C","0",".",":","="]]
+    
+    def foreground(self):
+        self._draw()
+        self.output = ""
+        wasp.system.request_event(wasp.EventMask.TOUCH)
+
+    def touch(self, event):
+        if (event[2] < 48):
+            if (event[1] > 200): # undo button pressed
+                if (self.output != ""):
+                    self.output = self.output[:-1]
+        else:
+            indices = [(event[2]// 48)-1,event[1]//47]
+            # Error handling for touching at the border
+            if (indices[0]>3):
+                indices[0] = 3
+            if (indices[1]>4):
+                indices[1] = 4
+            button_pressed = self.fields[indices[0]][indices[1]]
+            if (button_pressed == "C"):
+                self.output = ""
+            elif (button_pressed == "="):
+                self.output = self.calculate(self.output)
+            else:
+                self.output +=  button_pressed
+        self.display_output()
+
+    def _draw(self):
+        draw = wasp.watch.drawable
+        draw.fill()
+        # Make grid:
+        for i in range(4):
+            # horizontal lines
+            draw.line(x0=0,y0=(i+1)*47,x1=240,y1=(i+1)*47)
+            # vertical lines
+            draw.line(x0=(i+1)*47,y0=47,x1=(i+1)*47,y1=240)
+        # Draw button label:
+        for y in range(4):
+            for x in range(5):
+                label = self.fields[y][x]
+                if (x == 0):
+                    draw.string(label, x*47+14, y*47+60)
+                else:
+                    draw.string(label, x*47+16, y*47+60)
+        draw.string("<", 215, 10)
+    
+
+
+    def display_output(self):
+        wasp.watch.drawable.fill(x=2,y=2,w=170,h=40) 
+        if (self.output != ""):
+            if len(self.output) >= 10:
+                wasp.watch.drawable.string(self.output[len(self.output)-9:], 6, 14, width=170)
+            else:
+                wasp.watch.drawable.string(self.output, 6, 14, width=170)
+
+    def calculate(self,s):
+        equation = s
+        
+        # Normal calculator stuff    
+        for i in range(len(s)):
+            if (s[i] =="^"):
+                equation = s[:i] + "**"+s[i+1:]
+            elif (s[i] == ":"):
+                equation = s[:i] + "/"+s[i+1:]
+        try:
+            result = eval(equation)
+        except: # Error
+            result = ""
+        return str(result)

wasp/boards/manifest_240x240.py

@@ -10,6 +10,7 @@ manifest = (
     'apps/haiku.py',
     'apps/heart.py',
     'apps/musicplayer.py',
+    'apps/calc.py',
     'apps/launcher.py',
     'apps/pager.py',
     'apps/settings.py',

wasp/boards/simulator/main.py

@@ -15,6 +15,9 @@ wasp.system.register(GameOfLifeApp())
 from apps.snake import SnakeGameApp
 wasp.system.register(SnakeGameApp())
 
+from apps.calc import CalculatorApp
+wasp.system.register(CalculatorApp())
+
 from apps.musicplayer import MusicPlayerApp
 wasp.system.register(MusicPlayerApp())
 wasp.system.set_music_info({