wxPython/wx/lib/expando.py

   1 #---------------------------------------------------------------------------
   2 # Name:        expando.py
   3 # Purpose:     A multi-line text control that expands and collapses as more
   4 #              or less lines are needed to display its content.
   5 #
   6 # Author:      Robin Dunn
   7 #
   8 # Created:     18-Sept-2006
   9 # RCS-ID:      $Id$
  10 # Copyright:   (c) 2006 by Total Control Software
  11 # Licence:     wxWindows license
  12 #
  13 #---------------------------------------------------------------------------
  14 """
  15 This module contains the `ExpandoTextCtrl` which is a multi-line
  16 text control that will expand its height on the fly to be able to show
  17 all the lines of the content of the control.
  18 """
  19
  20 import wx
  21 import wx.lib.newevent
  22
  23
  24 # This event class and binder object can be used to catch
  25 # notifications that the ExpandoTextCtrl has resized itself and
  26 # that layout adjustments may need to be made.
  27 wxEVT_ETC_LAYOUT_NEEDED = wx.NewEventType()
  28 EVT_ETC_LAYOUT_NEEDED = wx.PyEventBinder( wxEVT_ETC_LAYOUT_NEEDED, 1 )
  29
  30
  31 #---------------------------------------------------------------------------
  32
  33 class ExpandoTextCtrl(wx.TextCtrl):
  34     """
  35     The ExpandoTextCtrl is a multi-line wx.TextCtrl that will
  36     adjust its height on the fly as needed to accomodate the number of
  37     lines needed to display the current content of the control.  It is
  38     assumed that the width of the control will be a fixed value and
  39     that only the height will be adjusted automatically.  If the
  40     control is used in a sizer then the width should be set as part of
  41     the initial or min size of the control.
  42
  43     When the control resizes itself it will attempt to also make
  44     necessary adjustments in the sizer hierarchy it is a member of (if
  45     any) but if that is not suffiecient then the programmer can catch
  46     the EVT_ETC_LAYOUT_NEEDED event in the container and make any
  47     other layout adjustments that may be needed.
  48     """
  49     _defaultHeight = -1
  50
  51     def __init__(self, parent, id=-1, value="",
  52                  pos=wx.DefaultPosition,  size=wx.DefaultSize,
  53                  style=0, validator=wx.DefaultValidator, name="expando"):
  54         # find the default height of a single line control
  55         self.defaultHeight = self._getDefaultHeight(parent)
  56         # make sure we default to that height if none was given
  57         w, h = size
  58         if h == -1:
  59             h = self.defaultHeight
  60         # always use the multi-line style
  61         style = style | wx.TE_MULTILINE | wx.TE_NO_VSCROLL | wx.TE_RICH2
  62         # init the base class
  63         wx.TextCtrl.__init__(self, parent, id, value, pos, (w, h),
  64                              style, validator, name)
  65         # save some basic metrics
  66         self.extraHeight = self.defaultHeight - self.GetCharHeight()
  67         self.numLines = self.GetNumberOfLines()
  68         self.maxHeight = -1
  69
  70         self.Bind(wx.EVT_TEXT, self.OnTextChanged)
  71
  72
  73     def SetMaxHeight(self, h):
  74         """
  75         Sets the max height that the control will expand to on its
  76         own, and adjusts it down if needed.
  77         """
  78         self.maxHeight = h
  79         if h != -1 and self.GetSize().height > h:
  80             self.SetSize((-1, h))
  81
  82     def GetMaxHeight(self):
  83         """Sets the max height that the control will expand to on its own"""
  84         return self.maxHeight
  85
  86
  87     def SetFont(self, font):
  88         wx.TextCtrl.SetFont(self, font)
  89         self.numLines = -1
  90         self._adjustCtrl()
  91
  92
  93     def OnTextChanged(self, evt):
  94         # check if any adjustments are needed on every text update
  95         self._adjustCtrl()
  96         evt.Skip()
  97
  98
  99     def _adjustCtrl(self):
 100         # if the current number of lines is different than before
 101         # then recalculate the size needed and readjust
 102         numLines = self.GetNumberOfLines()
 103         if numLines != self.numLines:
 104             self.numLines = numLines
 105             charHeight = self.GetCharHeight()
 106             height = numLines * charHeight + self.extraHeight
 107             if not (self.maxHeight != -1 and height > self.maxHeight):
 108                 # The size is changing...  if the control is not in a
 109                 # sizer then we just want to change the size and
 110                 # that's it, the programmer will need to deal with
 111                 # potential layout issues.  If it is being managed by
 112                 # a sizer then we'll change the min size setting and
 113                 # then try to do a layout.  In either case we'll also
 114                 # send an event so the parent can handle any special
 115                 # layout issues that it wants to deal with.
 116                 if self.GetContainingSizer() is not None:
 117                     mw, mh = self.GetMinSize()
 118                     self.SetMinSize((mw, height))
 119                     if self.GetParent().GetSizer() is not None:
 120                         self.GetParent().Layout()
 121                     else:
 122                         self.GetContainingSizer().Layout()
 123                 else:
 124                     self.SetSize((-1, height))
 125                 # send notification that layout is needed
 126                 evt = wx.PyCommandEvent(wxEVT_ETC_LAYOUT_NEEDED, self.GetId())
 127                 evt.SetEventObject(self)
 128                 evt.height = height
 129                 evt.numLines = numLines
 130                 self.GetEventHandler().ProcessEvent(evt)
 131
 132
 133     def _getDefaultHeight(self, parent):
 134         # checked for cached value
 135         if self.__class__._defaultHeight != -1:
 136             return self.__class__._defaultHeight
 137         # otherwise make a single line textctrl and find out its default height
 138         tc = wx.TextCtrl(parent)
 139         sz = tc.GetSize()
 140         tc.Destroy()
 141         self.__class__._defaultHeight = sz.height
 142         return sz.height
 143
 144
 145     if wx.VERSION < (2,7) and 'wxGTK' in wx.PlatformInfo:
 146         # the wxGTK version of GetNumberOfLines in 2.6 doesn't count
 147         # wrapped lines, so we need to implement our own.  This is
 148         # fixed in 2.7.
 149         def GetNumberOfLines(self):
 150             text = self.GetValue()
 151             width = self.GetSize().width
 152             dc = wx.ClientDC(self)
 153             dc.SetFont(self.GetFont())
 154             count = 0
 155             for line in text.split('\n'):
 156                 count += 1
 157                 w, h = dc.GetTextExtent(line)
 158                 if w > width:
 159                     # the width of the text is wider than the control,
 160                     # calc how many lines it will be wrapped to
 161                     count += self._wrapLine(line, dc, width)
 162
 163             if not count:
 164                 count = 1
 165             return count
 166
 167
 168         def _wrapLine(self, line, dc, width):
 169             # Estimate where the control will wrap the lines and
 170             # return the count of extra lines needed.
 171             pte = dc.GetPartialTextExtents(line)
 172             width -= wx.SystemSettings.GetMetric(wx.SYS_VSCROLL_X)
 173             idx = 0
 174             start = 0
 175             count = 0
 176             spc = -1
 177             while idx < len(pte):
 178                 if line[idx] == ' ':
 179                     spc = idx
 180                 if pte[idx] - start > width - _sbw:
 181                     # we've reached the max width, add a new line
 182                     count += 1
 183                     # did we see a space? if so restart the count at that pos
 184                     if spc != -1:
 185                         idx = spc + 1
 186                         spc = -1
 187                     start = pte[idx]
 188                 else:
 189                     idx += 1
 190             return count
 191
 192 #---------------------------------------------------------------------------
 193
 194
 195 if __name__ == '__main__':
 196     print wx.VERSION
 197
 198     class TestFrame(wx.Frame):
 199         def __init__(self):
 200             wx.Frame.__init__(self, None, title="Testing...")
 201             self.pnl = p = wx.Panel(self)
 202             self.eom = ExpandoTextCtrl(p, pos=(25,25), size=(250,-1))
 203             self.Bind(EVT_ETC_LAYOUT_NEEDED, self.OnRefit, self.eom)
 204
 205             # create some buttons and sizers to use in testing some
 206             # features and also the layout
 207             vBtnSizer = wx.BoxSizer(wx.VERTICAL)
 208
 209             btn = wx.Button(p, -1, "Set MaxHeight")
 210             self.Bind(wx.EVT_BUTTON, self.OnSetMaxHeight, btn)
 211             vBtnSizer.Add(btn, 0, wx.ALL|wx.EXPAND, 5)
 212
 213             btn = wx.Button(p, -1, "Set Font")
 214             self.Bind(wx.EVT_BUTTON, self.OnSetFont, btn)
 215             vBtnSizer.Add(btn, 0, wx.ALL|wx.EXPAND, 5)
 216
 217             btn = wx.Button(p, -1, "Set Value")
 218             self.Bind(wx.EVT_BUTTON, self.OnSetValue, btn)
 219             vBtnSizer.Add(btn, 0, wx.ALL|wx.EXPAND, 5)
 220
 221             for x in range(5):
 222                 btn = wx.Button(p, -1, " ")
 223                 vBtnSizer.Add(btn, 0, wx.ALL|wx.EXPAND, 5)
 224
 225             hBtnSizer = wx.BoxSizer(wx.HORIZONTAL)
 226             for x in range(3):
 227                 btn = wx.Button(p, -1, " ")
 228                 hBtnSizer.Add(btn, 0, wx.ALL, 5)
 229
 230             sizer = wx.BoxSizer(wx.HORIZONTAL)
 231             col1 = wx.BoxSizer(wx.VERTICAL)
 232             col1.Add(self.eom, 0, wx.ALL, 10)
 233             col1.Add(hBtnSizer)
 234             sizer.Add(col1)
 235             sizer.Add(vBtnSizer)
 236             p.SetSizer(sizer)
 237
 238             # Put the panel in a sizer for the frame so we can use self.Fit()
 239             frameSizer = wx.BoxSizer()
 240             frameSizer.Add(p, 1, wx.EXPAND)
 241             self.SetSizer(frameSizer)
 242
 243             self.Fit()
 244
 245
 246         def OnRefit(self, evt):
 247             # The Expando control will redo the layout of the
 248             # sizer it belongs to, but sometimes this may not be
 249             # enough, so it will send us this event so we can do any
 250             # other layout adjustments needed.  In this case we'll
 251             # just resize the frame to fit the new needs of the sizer.
 252             self.Fit()
 253
 254         def OnSetMaxHeight(self, evt):
 255             mh = self.eom.GetMaxHeight()
 256             dlg = wx.NumberEntryDialog(self, "", "Enter new max height:",
 257                                        "MaxHeight", mh, -1, 1000)
 258             if dlg.ShowModal() == wx.ID_OK:
 259                 self.eom.SetMaxHeight(dlg.GetValue())
 260             dlg.Destroy()
 261
 262
 263         def OnSetFont(self, evt):
 264             dlg = wx.FontDialog(self, wx.FontData())
 265             dlg.GetFontData().SetInitialFont(self.eom.GetFont())
 266             if dlg.ShowModal() == wx.ID_OK:
 267                 self.eom.SetFont(dlg.GetFontData().GetChosenFont())
 268             dlg.Destroy()
 269
 270
 271         def OnSetValue(self, evt):
 272             self.eom.SetValue("This is a test...  Only a test.  If this had "
 273                               "been a real emergency you would have seen the "
 274                               "quick brown fox jump over the lazy dog.")
 275
 276
 277     app = wx.App(False)
 278     frm = TestFrame()
 279     frm.Show()
 280     #import wx.py
 281     #shell = wx.py.shell.ShellFrame(frm, size=(500,300),
 282     #                               locals={'wx':wx, 'frm':frm})
 283     #shell.Show()
 284     frm.Raise()
 285     app.MainLoop()
 286
 287
 288