From aaffb434167fd9600b26c65bb339f94738bffa40 Mon Sep 17 00:00:00 2001
From: CMorley <chrisinnanaimo@hotmail.com>
Date: Tue, 28 Feb 2023 21:17:59 -0800
Subject: [PATCH] qtvcp -mdi_line: fix multi axes movement on single axis G0
 MDI call

https://forum.linuxcnc.org/qtvcp/48337-qtdragon-mdi-jogging-strange-diagonals
reloading the display was actually done before the MDI command was run.
This would cause the old axis position to be updated to linucnc's state.

if you call MDI commandsL
G0 X 10
G0 Y 10
G0 x 20

On the third MDI command both X and Y would move.

Nonw will added a callnack to reload the display after the MDI command
---
 lib/python/qtvcp/widgets/mdi_line.py | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/lib/python/qtvcp/widgets/mdi_line.py b/lib/python/qtvcp/widgets/mdi_line.py
index c6aa865b8a1..0c687643de8 100644
--- a/lib/python/qtvcp/widgets/mdi_line.py
+++ b/lib/python/qtvcp/widgets/mdi_line.py
@@ -66,6 +66,8 @@ def __init__(self, parent=None):
         except:
             self.mdiLast = None
             pass
+        # return callback GObject id
+        self._return_id = None
 
     def submit(self):
         self.mdiError = False
@@ -115,8 +117,20 @@ def submit(self):
         elif self.spindleInhibit and self.inhibit_spindle_commands(text):
             return
         else:
+
+            # make sure we didn't miss an display update callback.
+            # shouldn't be an update pending before the coming mdi command call
+            if self._return_id is not None:
+                STATUS.handler_disconnect(self._return_id)
+
             ACTION.CALL_MDI(text+'\n')
-            ACTION.RELOAD_DISPLAY()
+
+            # reloading the display causes a task_plan_synch()
+            # set up a callback so the display is updated only after the command is run.
+            # other wise the next MDI command could have stale linuxcnc state, causing
+            # multiple axes to move when ony issuing one axis to move.
+            self._return_id = STATUS.connect('command-stopped', lambda w: self.update_display())
+
         t = time.time() + 0.1
         while time.time() < t:
             QApplication.processEvents()
@@ -132,6 +146,14 @@ def submit(self):
             self.mdiLast = text.lower()
             STATUS.emit('mdi-history-changed')
 
+    # only reload after the command is run
+    # remove the callback handler so this is only run once
+    # per MDI command 9nect MDI command will issue another callback)
+    def update_display(self):
+        ACTION.RELOAD_DISPLAY()
+        STATUS.handler_disconnect(self._return_id)
+        self._return_id = None
+
     # Gcode widget can emit a signal to this
     def external_line_selected(self, w, text, filename):
         LOG.debug('Ext line selected: {}, {}'.format(text, filename))