Add a bunch of convenience features

Microsoft Windows only:
    - Only allow a single instance
    - Always on top option
    - Touch/click doesn’t steal focus
    - Events triggered without having to activate the window fist

- Automatically try to reconnect with exponential backoff
- Implemented command timeouts per spec
- Fixed volume calculations and display at extremes
- Disable shortcuts for disabled buttons
- Disable volume buttons at extremes
- Improved debugging system
- Update readme and screenshots

Author: rdoursenaud

README.md

@@ -4,9 +4,9 @@ Denon Remote
 Control [Denon Professional DN-500AV surround preamplifier](https://www.denonpro.com/index.php/products/view/dn-500av)
 remotely.
 
-![Screenshot](screenshot-v0.5.0-main.png)
+![Screenshot](screenshot-v0.7.0-main.png)
 
-![Settings Screenshot](screenshot-v0.5.0-settings.png)
+![Settings Screenshot](screenshot-v0.7.0-settings.png)
 
 Author: Raphael Doursenaud <rdoursenaud+denonremote@gmail.com>
 
@@ -19,17 +19,22 @@ Fonts used:
 - [Unicode Power Symbol](https://unicodepowersymbol.com/) Copyright (c) 2013 Joe Loughry licensed under MIT
 - [Free Serif](https://savannah.gnu.org/projects/freefont/) licensed under GPLv3
 
+
 ### Features
 
+
 #### Target hardware
 
 - [x] Denon Professional DN-500AV (Seems based on the same platform as the Denon AVR-1912 and AVR-2112CI.)
 - [ ] More? Contributions welcome!
 
+
 #### Communication
 
 - [x] Ethernet
-    - [x] Using [Twisted](https://twistedmatrix.com):
+    - [x] Using [Twisted](https://twistedmatrix.com)
+    - [x] connection status detection
+    - [x] automatically try to reconnect with exponential backoff
 - [ ] RS-232? also using Twisted
 - [ ] General MIDI input using [Mido](https://mido.readthedocs.io/en/latest/)
     - [ ] Define control scheme.
@@ -87,6 +92,7 @@ Fonts used:
     - [x] Update the GUI
 - [ ] Import EQ settings
     - [ ] From [REW](https://www.roomeqwizard.com/) value file
+        - [ ] Only use negative values! You can’t compensate a destructive room mode by adding energy to it.
 - [ ] Full Profiles/presets?
 
 ##### GUI
@@ -98,7 +104,11 @@ Fonts used:
         - [ ] Left/Right VolPreset +/-
         - [ ] PgUp/PgDwn SrcPreset +/-
 - [x] Systray/Taskbar support using [pystray](https://pypi.org/project/pystray/)
-- [ ] Only one instance should be allowed
+- [x] Only one instance is allowed (Microsoft Windows only)
+- [X] Option to make window stay always on top (Microsoft Windows only)
+- [x] Touch doesn’t activate the window and doesn’t steal focus (Microsoft Windows only)
+- [x] Trigger events without having to activate the window first (Microsoft Windows only)
+- [ ] Draw it on the first touch enabled display if available instead of the main one
 
 ##### Windows executable
 
@@ -161,7 +171,7 @@ PHP
 Python:
 
 - https://github.com/jeroenvds/denonremote (XBMC plugin)
-- https://github.com/Tom360V/DenonAvr (Similar objectives?
+- https://github.com/Tom360V/DenonAvr (Similar objectives?)
 - https://github.com/toebsen/python-denonavr (HTTP RESTful server)
 - https://github.com/MrJavaWolf/DenonPhoneController (Landline phone controller)
 - https://github.com/troykelly/python-denon-avr-serial-over-ip (Library)

denonremote/denon/communication.py

@@ -5,6 +5,7 @@
 from twisted.internet import task, reactor
 from twisted.internet.protocol import ClientFactory
 from twisted.protocols.basic import LineOnlyReceiver
+from twisted.protocols.policies import TimeoutMixin
 
 from denon.dn500av import DN500AVMessage, DN500AVFormat
 
@@ -15,12 +16,20 @@
 # See: https://twistedmatrix.com/documents/15.4.0/api/twisted.internet.serialport.SerialPort.html
 
 
-class DenonProtocol(LineOnlyReceiver):
+class DenonProtocol(LineOnlyReceiver, TimeoutMixin):
     # From DN-500 manual (DN-500AVEM_ENG_CD-ROM_v00.pdf) page 91 (97 in PDF form)
     MAX_LENGTH = 135
-    DELAY = 0.04  # in seconds. The documentation requires 200 ms. 40 ms seems safe.
+    DELAY = 0.04
+    """
+    Delay between messages in seconds.
+    The documentation requires 200 ms. 40 ms seems safe.
+    """
+    TIMEOUT = 0.2
+    """
+    Requests shall time out if no reply is received in under 200 ms.
+    """
     delimiter = b'\r'
-    ongoing_calls = 0  # Delay handling. FIXME: should timeout after 200 ms.
+    ongoing_calls = 0  # Delay handling.
 
     def connectionMade(self):
         logger.debug("Connection made")
@@ -38,14 +47,22 @@ def sendLine(self, line):
             # A request is made. We need to delay the next calls
             self.ongoing_calls += 1
             logger.debug("Ongoing calls for delay: %s", self.ongoing_calls)
-        delay = 0
+        delay = 0  # Send now
         if self.ongoing_calls > 0:
-            delay = self.DELAY * (self.ongoing_calls - 1)
+            delay = self.DELAY * (self.ongoing_calls - 1)  # Send after other messages
         logger.debug("Will send line: %s in %f seconds", line, delay)
         return task.deferLater(reactor, delay=delay,
-                               callable=super().sendLine, line=line)
+                               callable=self.sendLineWithTimeout, line=line)
+
+    def sendLineWithTimeout(self, line):
+        timeout = self.TIMEOUT if self.timeOut is None else self.timeOut + self.TIMEOUT
+        self.setTimeout(timeout)
+        del timeout
+        super().sendLine(line)
 
     def lineReceived(self, line):
+        self.resetTimeout()
+        self.setTimeout(None)
         if self.ongoing_calls:
             # We received a reply
             self.ongoing_calls -= 1

denonremote/denon/dn500av.py

@@ -83,42 +83,46 @@ def compute_master_volume_label(value, zerodb_ref=MASTER_VOLUME_ZERODB_REF):
     """Convert Master Volume ASCII value to dB"""
     # TODO: Handle absolute values
     label = '---.-dB'
+    result = None
     if int(value[:2]) < MASTER_VOLUME_MIN or int(value[:2]) > MASTER_VOLUME_MAX:
         logger.error("Master volume value %s out of bounds (%s-%s)", value, MASTER_VOLUME_MIN, MASTER_VOLUME_MAX)
     # Quirks
-    if value == '99':
-        result = "-∞dB"
-    elif value == '995':
-        result = "-80.5dB"
     elif len(value) == 2:
-        # General case
-        result = str(float(value) - zerodb_ref)
+        if value == '99':
+            result = ""  # Minus inf
+        else:
+            # General case
+            result = str(float(value) - zerodb_ref)
     elif len(value) == 3:
         # Handle undocumented special case for half dB
 
-        # Hardcode values around 0 because of computing sign uncertainty
-        # FIXME: test '985' which seems invalid
-        if value == str((zerodb_ref - 1)) + '5':
-            result = "-0.5"
-        elif value == str(zerodb_ref) + '5':
-            result = "0.5"
+        if value == '995':
+            result = "-80.5"
         else:
-            value = int(value[:2])  # Drop the third digit
-            offset = 0
-            if value < zerodb_ref:
-                offset = 1
-            logger.debug("Add offset %i to dB calculation with value %i5", offset, value)
-            result = str(int(value + offset - zerodb_ref)) + ".5"
+
+            # Hardcode values around 0 because of computing sign uncertainty
+            if value == str((zerodb_ref - 1)) + '5':
+                result = "-0.5"
+            elif value == str(zerodb_ref) + '5':
+                result = "0.5"
+            else:
+                value = int(value[:2])  # Drop the third digit
+                offset = 0
+                if value < zerodb_ref:
+                    offset = 1
+                logger.debug("Add offset %i to dB calculation with value %i5", offset, value)
+                result = str(int(value + offset - zerodb_ref)) + ".5"
     else:
         raise ValueError
 
     # Format label with fixed width like the actual display:
     # [ NEG SIGN or EMPTY ] [ DIGIT er EMPTY ] [ DIGIT ] [ DOT ] [ DIGIT ] [ d ] [ B ]
-    label = "%s%s%s.%sdB" % (
-        result[0] if result[0] == '-' else " ",
-        " " if len(result) <= 3 or result[-4] == '-' else result[-4],
-        result[-3],
-        result[-1])
+    if result:
+        label = "%s%s%s.%sdB" % (
+            result[0] if result[0] == '-' else " ",
+            " " if len(result) <= 3 or result[-4] == '-' else result[-4],
+            result[-3],
+            result[-1])
 
     logger.debug(label)
     return label

denonremote/denonremote.kv

@@ -60,12 +60,12 @@ FloatLayout:
                         id: mode_k20
                         text: "SMPTE/K-20"
                         group: 'mode_ref'
+                        state: 'down'  # Default
                         on_press: app.mode_changed(self)
 
                     ForcedToggleButton
                         id: mode_ebu
                         text: "EBU"
-                        state: 'down'  # Default
                         group: 'mode_ref'
                         on_press: app.mode_changed(self)
 
@@ -131,7 +131,7 @@ FloatLayout:
 
                     TextInput:
                         id: volume_display
-                        text: "---.-dB"
+                        text: "---.-dB"  # TODO: decorrelate display from serial commands (SI mandates a space before the unit)
                         font_name: 'RobotoMono-Regular'
                         font_size: 36
                         halign: 'center'