zeroinstall/gtkui/treetips.py

   1 """Add tooltips to a TreeView."""
   2 # Copyright (C) 2009, Thomas Leonard
   3 # See the README file for details, or visit http://0install.net.
   4
   5 import time, gobject, gtk
   6
   7 class TreeTips:
   8         """This object allows you to set location-dependent tooltips on a TreeView.
   9         Connect your TreeView's leave-notify-event to the L{hide} method.
  10         In your motion-notify-event handler, call L{prime} when the pointer moves
  11         to an area with a new message. The message will be shown after a delay.
  12         If calculation of the message is expensive, override L{get_tooltip_text}
  13         instead.
  14         """
  15         timeout = None
  16         widget = None
  17         item = None
  18         time = 0
  19
  20         def show(self, parent):
  21                 if self.timeout:
  22                         gobject.source_remove(self.timeout)
  23                         self.timeout = None
  24
  25                 if self.widget:
  26                         self.widget.destroy()
  27                         self.widget = None
  28
  29                 if self.item is None:
  30                         return
  31
  32                 text = self.get_tooltip_text()
  33                 if not text:
  34                         return
  35
  36                 self.widget = gtk.Window(gtk.WINDOW_POPUP)
  37                 self.widget.set_app_paintable(True)
  38                 self.widget.set_name('gtk-tooltips')
  39
  40                 self.widget.connect('expose-event', self.tooltip_draw)
  41
  42                 label = gtk.Label(text)
  43                 label.set_line_wrap(True)
  44                 label.set_padding(4, 2)
  45                 self.widget.add(label)
  46                 label.show()
  47
  48                 w, h = self.widget.size_request()
  49                 if hasattr(parent, 'get_screen'):
  50                         screen = parent.get_screen()
  51                         root = screen.get_root_window()
  52                 else:
  53                         root = gtk.gdk.get_default_root_window()
  54                 px, py, mask = gtk.gdk.Window.get_pointer(root)
  55
  56                 #m = gtk.gdk.screen_get_default().get_monitor_at_point(px, py)
  57
  58                 x = px - w / 2
  59                 y = py + 12
  60
  61                 # Test if pointer is over the tooltip window
  62                 if py >= y and py <= y + h:
  63                         y = py - h - 2
  64                 self.widget.move(x, y)
  65                 self.widget.show()
  66
  67                 self.widget.connect('destroy', self.tooltip_destroyed)
  68                 self.time = time.time()
  69
  70         def prime(self, parent, item):
  71                 """Call this whenever the pointer moves to an area with a different
  72                 tooltip.
  73                 @param parent: the TreeView widget
  74                 @param item: the text to display
  75                 @see L{get_tooltip_text}"""
  76                 self.hide()
  77                 assert self.timeout is None
  78                 self.item = item
  79
  80                 now = time.time()
  81                 if now - self.time > 2:
  82                         delay = 1000
  83                 else:
  84                         delay = 100
  85
  86                 self.timeout = gobject.timeout_add(delay, lambda: self.show(parent))
  87
  88         def tooltip_draw(self, widget, ev):
  89                 widget.window.draw_rectangle(widget.style.fg_gc[widget.state],
  90                                         False, 0, 0,
  91                                         widget.allocation.width - 1,
  92                                         widget.allocation.height - 1)
  93
  94         def tooltip_destroyed(self, widget):
  95                 pass
  96
  97         def hide(self):
  98                 """Hide the tooltip, if any.
  99                 Sets L{item} to None."""
 100                 self.item = None
 101                 self.show(None)
 102
 103         def get_tooltip_text(self):
 104                 """"Converts the object passed to L{prime} to a string for display.
 105                 The default implementation just calls C{str}, but subclasses can override it.
 106                 @return: the tooltip message"""
 107                 return str(self.item)