form.py

   1 import curses
   2 import sys
   3
   4
   5 class TextEntry:
   6
   7     """A part of a window that handles text entry.
   8     Properties:
   9         value holds the string that was entered
  10
  11     Public Methods:
  12         set_geom(row,column,width)  Sets the geometry in the window
  13         set_value(string)           Set the value and redraw
  14         gain_focus()                Gives it focus, moving cursor and changing the drawing
  15         lose_focus()                Takes focus, moving cursor to start, changing drawing
  16         handle_input(ch)            Pass this the ncurses key, and it manages input
  17         redraw()                    Redraw the text entry (should never need to do this
  18         """
  19
  20     # Public
  21     value = ""  # Use the set_value function to set, but retrieve with value
  22
  23     # Should be Private
  24     cursor = 0
  25     start = 0
  26     focus = False
  27     x = 0
  28     y = 0
  29     width = 10
  30
  31     # Public methods
  32     def __init__(self, parent_window, value=""):
  33         self.w = parent_window
  34         self.value = value
  35
  36     def set_geom(self,y,x,width):
  37         self.x = x
  38         self.y = y
  39         self.width = width
  40
  41     def set_value(self,v):
  42         self.value=v
  43         self.cursor=len(v)
  44         self.redraw()
  45
  46     def gain_focus(self):
  47         #sys.stderr.write('I have focus!\n')
  48         self.focus = True
  49         self._mv_cursor(+len(self.value))
  50         self.start = max(0,self.cursor-self.width)
  51         self.redraw()
  52
  53     def lose_focus(self):
  54         self.focus = False
  55         self.cursor = 0
  56         self.start = 0
  57         self.redraw()
  58
  59     def handle_input(self,ch):
  60         if ch==curses.KEY_LEFT:
  61             self._mv_cursor(-1)
  62         elif ch==curses.KEY_HOME:
  63             self._set_cursor(0)
  64         elif ch==curses.KEY_RIGHT:
  65             self._mv_cursor(+1)
  66         elif ch==curses.KEY_END:
  67             self._set_cursor(len(self.value))
  68         elif ch>=32 and ch<=126:
  69             self._insert(curses.keyname(ch).decode('utf-8'))
  70         elif ch==curses.KEY_BACKSPACE:
  71             self._backspace()
  72         elif ch==curses.KEY_DC:
  73             self._delete()
  74
  75     def redraw(self):
  76         self.w.addnstr(self.y,self.x, self.value[self.start:]+" "*self.width, self.width)
  77         if self.focus:
  78             self.w.chgat(self.y, self.x, self.width, curses.A_UNDERLINE)
  79             curses.curs_set(1)
  80
  81     # Private functions
  82     def _mv_cursor(self,delta):
  83         self._set_cursor(self.cursor + delta)
  84
  85     def _set_cursor(self, new_c):
  86         self.cursor = max(0, min(len(self.value), new_c))
  87         self.start = max(0,self.cursor-self.width+1)
  88         self.redraw()
  89         # Place the drawn cursor in the correct spot
  90         col = self.x + self.cursor - self.start
  91         self.w.move(self.y,col)
  92
  93     def _insert(self,ch):
  94         c = self.cursor
  95         self.value = self.value[:c] +ch+  self.value[c:]
  96         self._mv_cursor(+1)
  97
  98     def _backspace(self):
  99         if self.cursor>0:
 100             c = self.cursor
 101             self.value=self.value[:c-1] + self.value[c:]
 102             self._mv_cursor(-1)
 103
 104     def _delete(self):
 105         c = self.cursor
 106         self.value = self.value[:c] + self.value[c+1:]
 107         self._mv_cursor(0)
 108
 109
 110
 111 class FormWindow:
 112
 113     """General class for a Form Window.
 114
 115     To use, make the window for it, call the constructor, then call event_loop.
 116     """
 117
 118     # Private variables
 119     mx = my = 0
 120     hl = 0
 121     bt = -1
 122     left = 0
 123     top = 2
 124     row = 2
 125     caption = "Form"
 126     blabel = "Done"
 127     labels = ["label1"]
 128
 129     commands = [('pU', 'top'),('pD', 'bottom'),('Es', 'cancel')]
 130
 131
 132     # Public functions
 133     def __init__(self,window,helpbar,book={}, width=50):
 134         self.w = window
 135         self.w.resize(len(self.labels)+6,width)
 136         self.hb = helpbar
 137         self._make_entries()
 138         self._update_geometry()
 139         self._set_entries(book)
 140
 141     def clear(self):
 142         self.w.erase()
 143         self.w.refresh()
 144
 145     def event_loop(self):
 146         self.w.keypad(1)
 147         self.refresh()
 148         self.hl=0;
 149         self.entries[self.hl].gain_focus()
 150
 151         ch = self.w.getch()
 152         while ch != 27:
 153             #sys.stderr.write(curses.keyname(ch).decode('utf-8'))
 154             self.handle_input(ch)
 155             if ch==10 or ch==curses.KEY_ENTER:
 156                 if self.bt==0:
 157                     return {}
 158                 elif self.bt==1:
 159                     return self.return_values()
 160                 else:
 161                     self._mv_focus(+1)
 162             self.w.refresh()
 163             ch = self.w.getch()
 164         curses.curs_set(0)
 165         return {}
 166
 167     def _make_entries(self):
 168         self.entries = []
 169         for e in range(len(self.labels)):
 170             self.entries.append(TextEntry(self.w))
 171
 172     def _update_geometry(self):
 173         (self.my, self.mx) = self.w.getmaxyx()
 174         self.left=0
 175         for l in self.labels:
 176             self.left = max(len(l),self.left)
 177         self.left += 4
 178         width = self.mx-self.left-2
 179         self.top = 2
 180         for r in range(len(self.entries)):
 181             self.entries[r].set_geom(r+self.top, self.left, width)
 182         # next, the buttons
 183         self.brow = self.top+len(self.labels)+1
 184         self.bcol = [self.mx-len(self.blabel)-14, self.mx-len(self.blabel)-4]
 185         self.bwidth = [8,len(self.blabel)+2]
 186
 187     def _set_entries(self,book):
 188         e = 0
 189         for l in self.labels:
 190             #sys.stderr.write('updating label: '+l+'\n')
 191             if l.lower() in book:
 192                 #sys.stderr.write('   '+l+' found\n')
 193                 self.entries[e].value = str(book[l.lower()])
 194             else:
 195                 #sys.stderr.write('   '+l+' notfound\n')
 196                 self.entries[e].value = ""
 197             e += 1
 198
 199     def redraw(self):
 200         self.w.box()
 201         self.w.addstr(0,(self.mx-len(self.caption))//2,self.caption)
 202         r=0
 203         for l in self.labels:
 204             c = self.left-len(l)-2
 205             self.w.addstr(r+self.top,c,l+":")
 206             self.entries[r].redraw()
 207             r+=1
 208         self.w.addstr(self.brow,self.bcol[0], "<cancel>  <"+self.blabel+">")
 209         self.w.refresh()
 210
 211     def refresh(self):
 212         self.hb.commands = self.commands
 213         self.hb.refresh()
 214         self._update_geometry()
 215         self.redraw()
 216
 217     def _highlight_button(self):
 218         self.w.chgat(self.brow, self.bcol[self.bt], self.bwidth[self.bt], curses.A_REVERSE)
 219         curses.curs_set(0)
 220
 221     def _unhighlight_button(self):
 222         self.w.chgat(self.brow,1,self.mx-2,curses.A_NORMAL)
 223
 224     def _mv_focus(self,delta):
 225         if self.bt==-1:
 226             self.entries[self.hl].lose_focus()
 227         else:
 228             self._unhighlight_button()
 229         new = self.hl+delta
 230         new = max(0, min(len(self.labels), new))   # the extra is for the buttons
 231         self.hl = new
 232         if new == len(self.labels):
 233             self.bt = 1
 234             self.bt = min(self.bt,1)
 235             self._highlight_button()
 236         else:
 237             self.bt=-1
 238             self.entries[self.hl].gain_focus()
 239
 240
 241     def _return_values(self):
 242         book = {}
 243         for k,e in zip(self.labels, self.entries):
 244             if v!="" and k.lower()!="publish date":
 245                 book[k.lower()]=e.value
 246         return book
 247
 248
 249     def handle_input(self,ch):
 250         if ch==curses.KEY_UP:
 251             self._mv_focus(-1)
 252         elif ch==curses.KEY_PPAGE:
 253             self._mv_focus(-len(self.labels))
 254         elif ch==curses.KEY_DOWN:
 255             self._mv_focus(+1)
 256         elif ch==curses.KEY_NPAGE:
 257             self._mv_focus(+len(self.labels))
 258         elif ch==curses.KEY_LEFT:
 259             if self.bt==-1:
 260                 self.entries[self.hl].handle_input(ch)
 261             else:
 262                 self._unhighlight_button()
 263                 self.bt=0
 264                 self._highlight_button()
 265         elif ch==curses.KEY_HOME:
 266             if self.bt==-1:
 267                 self._mv_cursor(-len(self.entries[self.hl]))
 268         elif ch==curses.KEY_RIGHT:
 269             if self.bt==-1:
 270                 self.entries[self.hl].handle_input(ch)
 271             else:
 272                 self._unhighlight_button()
 273                 self.bt=1
 274                 self._highlight_button()
 275         else:
 276             if self.bt==-1:
 277                 self.entries[self.hl].handle_input(ch)
 278
 279
 280
 281
 282 class BookForm(FormWindow):
 283     caption = "Add a Book"
 284     blabel = "Add"
 285     labels = ["ISBN", "LCCN", "Title", "Subtitle", "Authors", "Edition",
 286               "Publisher", "Publish Date", "Publish Year", "Publish Month", "Publish location",
 287               "Pages", "Pagination", "Weight"]
 288
 289
 290     # redefineable functions lookup is called when 'enter' is pressed on ISBN
 291     # and returns the looked-up book. Default returns nothing
 292     def lookup_isbn(self,isbn):
 293         return {'isbn':isbn}
 294
 295     def lookup_lccn(self,lccn):
 296         return {'lccn':lccn}
 297
 298     def return_book(self):
 299         return self.return_values()
 300
 301     def handle_input(self,ch):
 302         if ch==10 or ch==curses.KEY_ENTER:
 303             if self.hl==0:          # lookup by isbn
 304                 book = self.lookup_isbn(self.entries[0].value)
 305                 if book != {}:
 306                     #sys.stderr.write('updating entries\n')
 307                     self._set_entries(book)
 308                 self.refresh()
 309                 self._mv_focus(+7)
 310             if self.hl==1:          # lookup by lccn
 311                 book = self.lookup_lccn(self.entries[1].value)
 312                 if book != {}:
 313                     self._set_entries(book)
 314                 self.refresh()
 315                 self._mv_focus(+6)
 316         else:
 317             FormWindow.handle_input(self,ch)
 318
 319 class CategoryForm(FormWindow):
 320     caption = "Add a Category"
 321     blabel = "Add"
 322     labels = ["Category"]
 323
 324     def return_values(self):
 325         return self.entries