Add a generic, text based front panel generator

This adds a front panel generator that lets you automatically generate
all the cutouts and text placements needed in a box.

Eventually, it might be great it integrate this kind of feature into the
box generators, but that sounds complicated.  At this point, I'm happy]
to have this.

boxes/generators/frontpanel.py

@@ -0,0 +1,217 @@
+#!/usr/bin/env python3
+# Copyright (C) 2013-2017 Florian Festi
+#
+#   This program is free software: you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation, either version 3 of the License, or
+#   (at your option) any later version.
+#
+#   This program is distributed in the hope that it will be useful,
+#   but WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#   GNU General Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License
+#   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from boxes import *
+import io
+import shlex
+
+def str_to_bool(s):
+    if (s.lower() in ['true', '1', 't', 'y', 'yes', 'yeah', 'yup', 'certainly', 'uh-huh']):
+        return True
+    else:
+        return False
+
+class FrontPanel(Boxes):
+    """Mounting Holes and cutouts for all your holy needs."""
+
+    description = f"""
+<script type="module" src="https://md-block.verou.me/md-block.js"></script>
+<md-block>
+
+
+This will help you create font (and side and top) panels for your
+boxes that are pre-configured for all the bits and bobs you'd like to
+install
+
+    The layout can create several types of holes including rectangles,
+    circles and mounting holes.  The default shows an example layout with all
+    currently supported objects.
+
+#### 
+`rect x y w h [cr=0] [cx=True] [cy=True]`
+
+     x: x position
+     y: y position
+     w: width
+     h: height
+    cr: optional, Corner radius, default=0
+    cx: optional, Center x.  the x position denotes the center of the rectangle.
+        accepts t, T, 1, or other true-like values.
+    cy: optional, Center y.  the y position denotes the center of the rectangle.
+
+#### outline
+`rect w h`
+
+    w: width
+    h: height
+
+`outline` has a special meaning: You can create multiple panel outlines with one command.  
+This has the effect of making it easy to manage all the holes on all the sides of
+your boxes.
+
+#### circle
+`circle x y r`
+
+    x: x position
+    y: y position
+    r: radius
+
+#### mountinghole
+mountinghole x y d_shaft [d_head=0] [angle=0]
+
+          x: x position
+          y: y position
+    d_shaft: diameter of the shaft part of the mounting hole
+     d_head: optional. diameter of the head
+      angle: optional. angle of the mounting hole
+
+#### text
+`text x y size "some text" [angle=0] [align=bottom|left]`
+
+        x: x position
+        y: y position
+     size: size, in mm
+     text: text to render.  This *must* be in quotation marks
+    angle: angle (in degrees)
+    align: string with combinations of (top|middle|bottom) and (left|center|right),
+           separated by '|'.  Default is 'bottom|left'
+
+
+
+#### nema
+`nema x y size [screwhole_size=0]`
+
+        x: x position (center of shaft)
+        y: y position (center of shaft)
+     size: nema size.  One of [{', '.join([f'{x}' for x in Boxes.nema_sizes])}]
+    screw: screw size, in mm.  Optional.  Default=0, which means the default size
+</md-block>
+    """
+
+    ui_group = "Holes"
+
+    def __init__(self) -> None:
+        Boxes.__init__(self)
+        self.argparser.add_argument(
+            "--layout", action="store", type=str,
+            default="""
+outline 100 100
+rect 50 60 80 30 3 True False
+text 50 91 7 "Super Front Panel With Buttons!" 0 bottom|center
+circle 10 45 3.5
+circle 30 45 3.5
+circle 50 45 3.5
+circle 70 45 3.5
+circle 90 45 3.5
+text 10 40 3 "BTN_1" 0 top|center
+text 35 45 3 "BTN_2" 90 top|center
+text 50 50 3 "BTN_3" 180 top|center
+text 65 45 3 "BTN_4" 270 top|center
+text 90 45 3 "5" 0 middle|center
+mountinghole 5 85 3 6 90
+mountinghole 95 85 3 6 90
+
+# Start another panel, 30x50
+outline 30 50
+rect 15 25 15 15 1 True True
+text 15 25 3 "__Fun!"   0 bottom|left
+text 15 25 3 "__Fun!"  45 bottom|left
+text 15 25 3 "__Fun!"  90 bottom|left
+text 15 25 3 "__Fun!" 135 bottom|left
+text 15 25 3 "__Fun!" 180 bottom|left
+text 15 25 3 "__Fun!" 225 bottom|left
+text 15 25 3 "__Fun!" 270 bottom|left
+
+text 3  10 2 "Another panel, for fun" 0 top|left
+
+
+# Let's create another panel with a nema motor on it
+outline 40 40
+nema 20 20 17
+""")
+
+    def applyOffset(self, x, y):
+        return (x+self.offset[0], y+self.offset[1])
+
+    def drawRect(self, x, y, w, h, r=0, center_x="True", center_y="True"):
+        x, y, w, h, r = [float(i) for i in [x, y, w, h, r]]
+        x, y = self.applyOffset(x, y)
+        center_x = str_to_bool(center_x)
+        center_y = str_to_bool(center_y)
+        self.rectangularHole(x, y, w, h, r, center_x, center_y)
+        return
+
+    def drawCircle(self, x, y, r):
+        x, y, r = [float(i) for i in [x, y, r]]
+        x, y = self.applyOffset(x, y)
+        self.hole(x, y, r)
+        return
+
+    def drawMountingHole(self, x, y, d_shaft, d_head=0.0, angle=0):
+        x, y, d_shaft, d_head, angle = [float(i) for i in [x, y, d_shaft, d_head, angle]]
+        x, y = self.applyOffset(x, y)
+        self.mountingHole(x, y, d_shaft, d_head, angle)
+        return
+
+    def drawOutline(self, w, h):
+        w, h = [float(i) for i in [w, h]]
+        if self.outline is not None:
+            self.offset = self.applyOffset(self.outline[0]+10, 0)
+        self.outline = (w, h) # store away for next time
+        x = 0
+        y = 0
+        x, y = self.applyOffset(x, y)
+        border = [(x, y), (x+w, y), (x+w, y+h), (x, y+h), (x, y)]
+        self.showBorderPoly( border )
+        return
+
+    def drawText(self, x, y, size, text, angle=0, align='bottom|left'):
+        x, y, size, angle = [float(i) for i in [x, y, size, angle]]
+        x, y = self.applyOffset(x, y)
+        align = align.replace("|", " ")
+        self.text(text=text, x=x, y=y, fontsize=size, angle=angle, align=align)
+
+    def drawNema(self, x, y, size, screwhole_size=0):
+        x, y, size, screwhole_size = [float(i) for i in [x, y, size, screwhole_size]]
+        if size in self.nema_sizes:
+            x, y = self.applyOffset(x, y)
+            self.NEMA(size, x, y, screwholes=screwhole_size)
+
+    def parse_layout(self, layout):
+        f = io.StringIO(layout)
+        line = 0
+        objects = {
+            'outline': self.drawOutline,
+            'rect': self.drawRect,
+            'circle': self.drawCircle,
+            'mountinghole': self.drawMountingHole,
+            'text': self.drawText,
+            'nema': self.drawNema,
+        }
+
+        for l in f.readlines():
+            line += 1
+            l = re.sub('#.*$', '', l) # remove comments
+            l = l.strip()
+            la = shlex.split(l, comments=True, posix=True)
+            if len(la) > 0 and la[0].lower() in objects:
+                objects[la[0]](*la[1:])
+        return
+
+    def render(self):
+        self.offset = (0.0, 0.0)
+        self.outline = None # No outline yet
+        self.parse_layout(self.layout)

boxes/generators/frontpanel_test.json

@@ -0,0 +1,4 @@
+outline 60 60
+squre 10 20 25 34
+circle 10 20 40
+

static/samples/samples.sha256

@@ -116,3 +116,4 @@ a7ee83b42685295fd02db666841984c55af2f9632540c651f5dea42088a3c170  ../static/samp
 ab47e02fb9736d20b457964aa640f50852ac97bb2857cea753fa4c3067a60d41  ../static/samples/Spool.jpg
 cfc0782f3a952dd0c6ceb0fb7998050f3bdea135d791fa32b731808371514e63  ../static/samples/GearBox.jpg
 75733dfdfd601ace1521bddfea28546ca34d8281acbeb6ec44f15b2b942cb944  ../static/samples/Arcade.jpg
+a21471512fd73c15e1d8a11aa3bd4ef807791895855c2f1d30a00bd207d79919  ../static/samples/FrontPanel.jpg