Lib/plat-irix6/panel.py

   1 # Module 'panel'
   2 #
   3 # Support for the Panel library.
   4 # Uses built-in module 'pnl'.
   5 # Applications should use 'panel.function' instead of 'pnl.function';
   6 # most 'pnl' functions are transparently exported by 'panel',
   7 # but dopanel() is overridden and you have to use this version
   8 # if you want to use callbacks.
   9
  10
  11 import pnl
  12
  13
  14 debug = 0
  15
  16
  17 # Test if an object is a list.
  18 #
  19 def is_list(x):
  20         return type(x) == type([])
  21
  22
  23 # Reverse a list.
  24 #
  25 def reverse(list):
  26         res = []
  27         for item in list:
  28                 res.insert(0, item)
  29         return res
  30
  31
  32 # Get an attribute of a list, which may itself be another list.
  33 # Don't use 'prop' for name.
  34 #
  35 def getattrlist(list, name):
  36         for item in list:
  37                 if item and is_list(item) and item[0] == name:
  38                         return item[1:]
  39         return []
  40
  41
  42 # Get a property of a list, which may itself be another list.
  43 #
  44 def getproplist(list, name):
  45         for item in list:
  46                 if item and is_list(item) and item[0] == 'prop':
  47                         if len(item) > 1 and item[1] == name:
  48                                 return item[2:]
  49         return []
  50
  51
  52 # Test if an actuator description contains the property 'end-of-group'
  53 #
  54 def is_endgroup(list):
  55         x = getproplist(list, 'end-of-group')
  56         return (x and x[0] == '#t')
  57
  58
  59 # Neatly display an actuator definition given as S-expression
  60 # the prefix string is printed before each line.
  61 #
  62 def show_actuator(prefix, a):
  63         for item in a:
  64                 if not is_list(item):
  65                         print prefix, item
  66                 elif item and item[0] == 'al':
  67                         print prefix, 'Subactuator list:'
  68                         for a in item[1:]:
  69                                 show_actuator(prefix + '    ', a)
  70                 elif len(item) == 2:
  71                         print prefix, item[0], '=>', item[1]
  72                 elif len(item) == 3 and item[0] == 'prop':
  73                         print prefix, 'Prop', item[1], '=>',
  74                         print item[2]
  75                 else:
  76                         print prefix, '?', item
  77
  78
  79 # Neatly display a panel.
  80 #
  81 def show_panel(prefix, p):
  82         for item in p:
  83                 if not is_list(item):
  84                         print prefix, item
  85                 elif item and item[0] == 'al':
  86                         print prefix, 'Actuator list:'
  87                         for a in item[1:]:
  88                                 show_actuator(prefix + '    ', a)
  89                 elif len(item) == 2:
  90                         print prefix, item[0], '=>', item[1]
  91                 elif len(item) == 3 and item[0] == 'prop':
  92                         print prefix, 'Prop', item[1], '=>',
  93                         print item[2]
  94                 else:
  95                         print prefix, '?', item
  96
  97
  98 # Exception raised by build_actuator or build_panel.
  99 #
 100 panel_error = 'panel error'
 101
 102
 103 # Dummy callback used to initialize the callbacks.
 104 #
 105 def dummy_callback(arg):
 106         pass
 107
 108
 109 # Assign attributes to members of the target.
 110 # Attribute names in exclist are ignored.
 111 # The member name is the attribute name prefixed with the prefix.
 112 #
 113 def assign_members(target, attrlist, exclist, prefix):
 114         for item in attrlist:
 115                 if is_list(item) and len(item) == 2 and item[0] not in exclist:
 116                         name, value = item[0], item[1]
 117                         ok = 1
 118                         if value[0] in '-0123456789':
 119                                 value = eval(value)
 120                         elif value[0] == '"':
 121                                 value = value[1:-1]
 122                         elif value == 'move-then-resize':
 123                                 # Strange default set by Panel Editor...
 124                                 ok = 0
 125                         else:
 126                                 print 'unknown value', value, 'for', name
 127                                 ok = 0
 128                         if ok:
 129                                 lhs = 'target.' + prefix + name
 130                                 stmt = lhs + '=' + `value`
 131                                 if debug: print 'exec', stmt
 132                                 try:
 133                                         exec stmt + '\n'
 134                                 except KeyboardInterrupt: # Don't catch this!
 135                                         raise KeyboardInterrupt
 136                                 except:
 137                                         print 'assign failed:', stmt
 138
 139
 140 # Build a real actuator from an actuator description.
 141 # Return a pair (actuator, name).
 142 #
 143 def build_actuator(descr):
 144         namelist = getattrlist(descr, 'name')
 145         if namelist:
 146                 # Assume it is a string
 147                 actuatorname = namelist[0][1:-1]
 148         else:
 149                 actuatorname = ''
 150         type = descr[0]
 151         if type[:4] == 'pnl_': type = type[4:]
 152         act = pnl.mkact(type)
 153         act.downfunc = act.activefunc = act.upfunc = dummy_callback
 154         #
 155         assign_members(act, descr[1:], ['al', 'data', 'name'], '')
 156         #
 157         # Treat actuator-specific data
 158         #
 159         datalist = getattrlist(descr, 'data')
 160         prefix = ''
 161         if type[-4:] == 'puck':
 162                 prefix = 'puck_'
 163         elif type == 'mouse':
 164                 prefix = 'mouse_'
 165         assign_members(act, datalist, [], prefix)
 166         #
 167         return act, actuatorname
 168
 169
 170 # Build all sub-actuators and add them to the super-actuator.
 171 # The super-actuator must already have been added to the panel.
 172 # Sub-actuators with defined names are added as members to the panel
 173 # so they can be referenced as p.name.
 174 #
 175 # Note: I have no idea how panel.endgroup() works when applied
 176 # to a sub-actuator.
 177 #
 178 def build_subactuators(panel, super_act, al):
 179         #
 180         # This is nearly the same loop as below in build_panel(),
 181         # except a call is made to addsubact() instead of addact().
 182         #
 183         for a in al:
 184                 act, name = build_actuator(a)
 185                 act.addsubact(super_act)
 186                 if name:
 187                         stmt = 'panel.' + name + ' = act'
 188                         if debug: print 'exec', stmt
 189                         exec stmt + '\n'
 190                 if is_endgroup(a):
 191                         panel.endgroup()
 192                 sub_al = getattrlist(a, 'al')
 193                 if sub_al:
 194                         build_subactuators(panel, act, sub_al)
 195         #
 196         # Fix the actuator to which whe just added subactuators.
 197         # This can't hurt (I hope) and is needed for the scroll actuator.
 198         #
 199         super_act.fixact()
 200
 201
 202 # Build a real panel from a panel definition.
 203 # Return a panel object p, where for each named actuator a, p.name is a
 204 # reference to a.
 205 #
 206 def build_panel(descr):
 207         #
 208         # Sanity check
 209         #
 210         if (not descr) or descr[0] != 'panel':
 211                 raise panel_error, 'panel description must start with "panel"'
 212         #
 213         if debug: show_panel('', descr)
 214         #
 215         # Create an empty panel
 216         #
 217         panel = pnl.mkpanel()
 218         #
 219         # Assign panel attributes
 220         #
 221         assign_members(panel, descr[1:], ['al'], '')
 222         #
 223         # Look for actuator list
 224         #
 225         al = getattrlist(descr, 'al')
 226         #
 227         # The order in which actuators are created is important
 228         # because of the endgroup() operator.
 229         # Unfortunately the Panel Editor outputs the actuator list
 230         # in reverse order, so we reverse it here.
 231         #
 232         al = reverse(al)
 233         #
 234         for a in al:
 235                 act, name = build_actuator(a)
 236                 act.addact(panel)
 237                 if name:
 238                         stmt = 'panel.' + name + ' = act'
 239                         exec stmt + '\n'
 240                 if is_endgroup(a):
 241                         panel.endgroup()
 242                 sub_al = getattrlist(a, 'al')
 243                 if sub_al:
 244                         build_subactuators(panel, act, sub_al)
 245         #
 246         return panel
 247
 248
 249 # Wrapper around pnl.dopanel() which calls call-back functions.
 250 #
 251 def my_dopanel():
 252         # Extract only the first 4 elements to allow for future expansion
 253         a, down, active, up = pnl.dopanel()[:4]
 254         if down:
 255                 down.downfunc(down)
 256         if active:
 257                 active.activefunc(active)
 258         if up:
 259                 up.upfunc(up)
 260         return a
 261
 262
 263 # Create one or more panels from a description file (S-expressions)
 264 # generated by the Panel Editor.
 265 #
 266 def defpanellist(file):
 267         import panelparser
 268         descrlist = panelparser.parse_file(open(file, 'r'))
 269         panellist = []
 270         for descr in descrlist:
 271                 panellist.append(build_panel(descr))
 272         return panellist
 273
 274
 275 # Import everything from built-in method pnl, so the user can always
 276 # use panel.foo() instead of pnl.foo().
 277 # This gives *no* performance penalty once this module is imported.
 278 #
 279 from pnl import *                       # for export
 280
 281 dopanel = my_dopanel                    # override pnl.dopanel