Import LinuxCNC source tree

lib/python/vcpparse.py

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+#    This is a component of AXIS, a front-end for emc
+#    Copyright 2007 Anders Wallin <anders.wallin@helsinki.fi>
+#
+#    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 2 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, write to the Free Software
+#    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+"""
+    Parses a pyVCP XML file and creates widgets by calling pyvcp_widgets.py
+"""
+
+import xml.dom.minidom
+import sys, os
+import linuxcnc
+import pyvcp_widgets
+import hal 
+import time
+import traceback
+import tkinter as Tkinter
+from tkinter import *
+from importlib import reload
+
+# this statement is required so that stuff from Tkinter
+# is not included in the pydoc documentation __All__ should list all 
+# functions in this module
+__all__=["read_file","nodeiterator",
+        "widget_creator","paramiterator","updater","create_vcp"]
+
+
+
+
+def read_file():
+    """
+        Reads the XML file specified by global 'filename'
+        finds the <pyvcp> element and starts the parsing of the 
+        file by calling nodeiterator()
+    """
+    try:
+        doc = xml.dom.minidom.parse(filename) 
+    except xml.parsers.expat.ExpatError as detail:
+        print("Error: could not open",filename,"!")
+        print(detail)
+        sys.exit(1)
+    # find the pydoc element
+    for e in doc.childNodes:
+        if e.nodeType == e.ELEMENT_NODE and e.localName == "pyvcp":
+            break
+
+    if e.localName != "pyvcp":
+        print("Error: no pyvcp element in file!")
+        sys.exit()
+    pyvcproot=e
+    nodeiterator(pyvcproot,pyvcp0) 
+
+
+
+num=0
+def nodeiterator(node,widgetparent):
+    """
+        A recursive function that traverses the dom tree
+        and calls widget_creator() when it finds a valid element
+    """
+    global num
+    num+=1
+    params=[]
+    for e in node.childNodes:
+        if e.nodeType == e.ELEMENT_NODE and (e.nodeName in pyvcp_widgets.elements):  
+            params = paramiterator(e)  # find all the parameters for this node
+            newwidget = widget_creator(widgetparent,e.nodeName,params)
+            nodeiterator(e,newwidget)
+      
+
+
+widgets={}
+def widget_creator(parent,widget_name,params):
+    """
+       creates a pyVCP widget
+           parent = parent widget
+           widget_name = name of widget to be created 
+           params = a list of parameters passed to the widget __init__
+    """
+ 
+    global widgets
+  
+    constructor = getattr(pyvcp_widgets, "pyvcp_" + str(widget_name))
+    if hasattr(parent, "getcontainer"):
+        container = parent.getcontainer()
+    else:
+        container = parent
+    positional_params = (container, pycomp)
+    
+    try:
+        widget = constructor(*positional_params, **params)
+    except Exception as detail:
+        raise SystemExit("Error constructing %s(%s):\n%s" % (widget_name, params, detail))
+
+    # pack the widget according to parent
+    # either hbox or vbox
+    if container==pyvcp0:
+        widget.pack(side='top', fill=BOTH, expand=YES)
+    else:
+        parent.add(container, widget)
+   
+    # add the widget to a global list widgets
+    # to enable calling update() later
+    widgets[pycomp].append(widget)
+
+    return widget
+
+def paramiterator(node):
+    """ returns a list of all parameters for a widget element """
+    outparams = {}
+    for k, v in list(node.attributes.items()):
+        if v and v[0] in "{[(\"'":
+            v = eval(v)
+        else:
+            try:
+                v = int(v)
+            except ValueError:
+                try:
+                    v = float(v)
+                except ValueError:
+                    pass
+        outparams[str(k)] = v
+
+    for e in node.childNodes:
+        if e.nodeType == e.ELEMENT_NODE \
+                and (e.nodeName not in pyvcp_widgets.elements):
+            try:
+                v = eval(e.childNodes[0].nodeValue)
+            except: 
+                exc_type, exc_value, exc_tb = sys.exc_info()
+                raise SystemExit(("Error evaluating xml file:\n"
+                    "Widget %s, Property %s\n%s: %s") % (
+                        node.nodeName, e.nodeName, exc_type.__name__, exc_value))
+            outparams[str(e.nodeName)] = v
+    return outparams
+
+
+
+def updater():
+    """ calls pyvcp_widgets.update() on each widget repeatedly every 100 ms """
+    global widgets, pycomp
+    for w in widgets:
+        for a in widgets[w]:
+            a.update(w)
+    pyvcp0.after(100,updater)
+
+
+
+
+def create_vcp(master, comp = None, compname="pyvcp"):
+    """ 
+        create a pyVCP panel 
+            master = Tkinter root window or other master container
+            comp = HAL component
+            compname = name of HAL component which is created if comp=None
+    """
+    reload(pyvcp_widgets)
+    global pyvcp0, pycomp
+    pyvcp0 = master
+    if comp is None:
+        try: 
+            comp = hal.component(compname)
+        except:
+            print("Error: Multiple components with the same name.")
+            sys.exit(0)
+
+    pycomp = comp
+    widgets[pycomp] = []
+    read_file() 
+    updater()
+    return comp
+    
+if __name__ == '__main__':
+    print("You can't run vcpparse.py by itself...")
+
+    
+    
+
+
+