It's time to bring in the GUI.

Minimalist (not to say Brutalist) UI based on text windows and mouse
chords.  Experimental.

joy/gui/mousebindings.py

@@ -0,0 +1,206 @@
+# -*- coding: utf-8 -*-
+#
+#    Copyright © 2014, 2015 Simon Forman
+#
+#    This file is part of joy.py
+#
+#    joy.py 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 3 of the License, or
+#    (at your option) any later version.
+#
+#    joy.py 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 joy.py.  If not see <http://www.gnu.org/licenses/>.
+#
+
+
+#Do-nothing event handler.
+nothing = lambda event: None
+
+
+class MouseBindingsMixin:
+  """TextViewerWidget mixin class to provide mouse bindings."""
+
+  def __init__(self):
+
+    #Remember our mouse button state
+    self.B1_DOWN = False
+    self.B2_DOWN = False
+    self.B3_DOWN = False
+
+    #Remember our pending action.
+    self.dothis = nothing
+
+    #We'll need to remember whether or not we've been moving B2.
+    self.beenMovingB2 = False
+
+    #Unbind the events we're interested in.
+    for sequence in (
+      "<Button-1>", "<B1-Motion>", "<ButtonRelease-1>",
+      "<Button-2>", "<B2-Motion>", "<ButtonRelease-2>",
+      "<Button-3>", "<B3-Motion>", "<ButtonRelease-3>",
+      "<B1-Leave>", "<B2-Leave>", "<B3-Leave>", "<Any-Leave>", "<Leave>"
+      ):
+      self.unbind(sequence)
+      self.unbind_all(sequence)
+
+    self.event_delete('<<PasteSelection>>') #I forgot what this was for! :-P  D'oh!
+
+    #Bind our event handlers to their events.
+    self.bind("<Button-1>", self.B1d)
+    self.bind("<B1-Motion>", self.B1m)
+    self.bind("<ButtonRelease-1>", self.B1r)
+
+    self.bind("<Button-2>", self.B2d)
+    self.bind("<B2-Motion>", self.B2m)
+    self.bind("<ButtonRelease-2>", self.B2r)
+
+    self.bind("<Button-3>", self.B3d)
+    self.bind("<B3-Motion>", self.B3m)
+    self.bind("<ButtonRelease-3>", self.B3r)
+
+    self.bind("<Any-Leave>", self.leave)
+
+  def B1d(self, event):
+    '''button one pressed'''
+    self.B1_DOWN = True
+
+    if self.B2_DOWN:
+
+      self.unhighlight_command()
+
+      if self.B3_DOWN :
+        self.dothis = self.cancel
+
+      else:
+        #copy TOS to the mouse (instead of system selection.)
+        self.dothis = self.copyto #middle-left-interclick
+
+    elif self.B3_DOWN :
+      self.unhighlight_command()
+      self.dothis = self.opendoc #right-left-interclick
+
+    else:
+      ##button 1 down, set insertion and begin selection.
+      ##Actually, do nothing. Tk Text widget defaults take care of it.
+      self.dothis = nothing
+      return
+
+    #Prevent further event handling by returning "break".
+    return "break"
+
+  def B2d(self, event):
+    '''button two pressed'''
+    self.B2_DOWN = 1
+
+    if self.B1_DOWN :
+
+      if self.B3_DOWN :
+        self.dothis = self.cancel
+
+      else:
+        #left-middle-interclick - cut selection to stack
+        self.dothis = self.cut
+
+    elif self.B3_DOWN :
+      self.unhighlight_command()
+      self.dothis = self.lookup #right-middle-interclick - lookup
+
+    else:
+      #middle-click - paste X selection to mouse pointer
+      self.set_insertion_point(event)
+      self.dothis = self.paste_X_selection_to_mouse_pointer
+      return
+
+    return "break"
+
+  def B3d(self, event):
+    '''button three pressed'''
+    self.B3_DOWN = 1
+
+    if self.B1_DOWN :
+
+      if self.B2_DOWN :
+        self.dothis = self.cancel
+
+      else:
+        #left-right-interclick - run selection
+        self.dothis = self.run_selection
+
+    elif self.B2_DOWN :
+      #middle-right-interclick - Pop/Cut from TOS to insertion cursor
+      self.unhighlight_command()
+      self.dothis = self.pastecut
+
+    else:
+      #right-click
+      self.CommandFirstDown(event)
+
+    return "break"
+
+  def B1m(self, event):
+    '''button one moved'''
+    if self.B2_DOWN or self.B3_DOWN:
+      return "break"
+
+  def B2m(self, event):
+    '''button two moved'''
+    if self.dothis == self.paste_X_selection_to_mouse_pointer and \
+       not (self.B1_DOWN or self.B3_DOWN):
+
+      self.beenMovingB2 = True
+      return
+
+    return "break"
+
+  def B3m(self, event):
+    '''button three moved'''
+    if self.dothis == self.do_command and \
+       not (self.B1_DOWN or self.B2_DOWN):
+
+      self.update_command_word(event)
+
+    return "break"
+
+  def B1r(self, event):
+    '''button one released'''
+    self.B1_DOWN = False
+
+    if not (self.B2_DOWN or self.B3_DOWN):
+      self.dothis(event)
+
+    return "break"
+
+  def B2r(self, event):
+    '''button two released'''
+    self.B2_DOWN = False
+
+    if not (self.B1_DOWN or self.B3_DOWN or self.beenMovingB2):
+      self.dothis(event)
+
+    self.beenMovingB2 = False
+
+    return "break"
+
+  def B3r(self, event):
+    '''button three released'''
+    self.B3_DOWN = False
+
+    if not (self.B1_DOWN or self.B2_DOWN) :
+      self.dothis(event)
+
+    return "break"
+
+  def InsertFirstDown(self, event):
+    self.focus()
+    self.dothis = nothing
+    self.set_insertion_point(event)
+
+  def CommandFirstDown(self, event):
+    self.dothis = self.do_command
+    self.update_command_word(event)