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#
# Reimplementation of gtk.Layout in python
# Example on how to implement a scrollable container in python
#
# Johan Dahlin <johan@gnome.org>, 2006
#
# Requires PyGTK 2.8.0 or later
import gobject
import gtk
from gtk import gdk
class Child:
widget = None
x = 0
y = 0
def set_adjustment_upper(adj, upper, always_emit):
changed = False
value_changed = False
min = max(0.0, upper - adj.page_size)
if upper != adj.upper:
adj.upper = upper
changed = True
if adj.value > min:
adj.value = min
value_changed = True
if changed or always_emit:
adj.changed()
if value_changed:
adj.value_changed()
def new_adj():
return gtk.Adjustment(0.0, 0.0, 0.0,
0.0, 0.0, 0.0)
class Layout(gtk.Container):
__gsignals__ = dict(set_scroll_adjustments=
(gobject.SIGNAL_RUN_LAST, None,
(gtk.Adjustment, gtk.Adjustment)))
def __init__(self):
self._children = []
self._width = 100
self._height = 100
self._hadj = None
self._vadj = None
self._bin_window = None
self._hadj_changed_id = -1
self._vadj_changed_id = -1
gtk.Container.__init__(self)
if not self._hadj or not self._vadj:
self._set_adjustments(self._vadj or new_adj(),
self._hadj or new_adj())
# Public API
def put(self, widget, x=0, y=0):
child = Child()
child.widget = widget
child.x = x
child.y = y
self._children.append(child)
if self.flags() & gtk.REALIZED:
widget.set_parent_window(self._bin_window)
widget.set_parent(self)
def set_size(self, width, height):
if self._width != width:
self._width = width
if self._height != height:
self._height = height
if self._hadj:
set_adjustment_upper(self._hadj, self._width, False)
if self._vadj:
set_adjustment_upper(self._vadj, self._height, False)
if self.flags() & gtk.REALIZED:
self._bin_window.resize(max(width, self.allocation.width),
max(height, self.allocation.height))
# GtkWidget
def do_realize(self):
self.set_flags(self.flags() | gtk.REALIZED)
self.window = gdk.Window(
self.get_parent_window(),
window_type=gdk.WINDOW_CHILD,
x=self.allocation.x,
y=self.allocation.y,
width=self.allocation.width,
height=self.allocation.height,
wclass=gdk.INPUT_OUTPUT,
colormap=self.get_colormap(),
event_mask=gdk.VISIBILITY_NOTIFY_MASK)
self.window.set_user_data(self)
self._bin_window = gdk.Window(
self.window,
window_type=gdk.WINDOW_CHILD,
x=int(-self._hadj.value),
y=int(-self._vadj.value),
width=max(self._width, self.allocation.width),
height=max(self._height, self.allocation.height),
colormap=self.get_colormap(),
wclass=gdk.INPUT_OUTPUT,
event_mask=(self.get_events() | gdk.EXPOSURE_MASK |
gdk.SCROLL_MASK))
self._bin_window.set_user_data(self)
self.set_style(self.style.attach(self.window))
self.style.set_background(self.window, gtk.STATE_NORMAL)
self.style.set_background(self._bin_window, gtk.STATE_NORMAL)
for child in self._children:
child.widget.set_parent_window(self._bin_window)
self.queue_resize()
def do_unrealize(self):
self._bin_window.set_user_data(None)
self._bin_window.destroy()
self._bin_window = None
gtk.Container.do_unrealize(self)
def _do_style_set(self, style):
gtk.Widget.do_style_set(self, style)
if self.flags() & gtk.REALIZED:
self.style.set_background(self._bin_window, gtk.STATE_NORMAL)
def do_expose_event(self, event):
if event.window != self._bin_window:
return False
gtk.Container.do_expose_event(self, event)
return False
def do_map(self):
self.set_flags(self.flags() | gtk.MAPPED)
for child in self._children:
flags = child.widget.flags()
if flags & gtk.VISIBLE:
if not (flags & gtk.MAPPED):
child.widget.map()
self._bin_window.show()
self.window.show()
def do_size_request(self, req):
req.width = 0
req.height = 0
for child in self._children:
child.widget.size_request()
def do_size_allocate(self, allocation):
self.allocation = allocation
for child in self._children:
self._allocate_child(child)
if self.flags() & gtk.REALIZED:
self.window.move_resize(*allocation)
self._bin_window.resize(max(self._width, allocation.width),
max(self._height, allocation.height))
self._hadj.page_size = allocation.width
self._hadj.page_increment = allocation.width * 0.9
self._hadj.lower = 0
set_adjustment_upper(self._hadj,
max(allocation.width, self._width), True)
self._vadj.page_size = allocation.height
self._vadj.page_increment = allocation.height * 0.9
self._vadj.lower = 0
self._vadj.upper = max(allocation.height, self._height)
set_adjustment_upper(self._vadj,
max(allocation.height, self._height), True)
def do_set_scroll_adjustments(self, hadj, vadj):
self._set_adjustments(hadj, vadj)
# GtkContainer
def do_forall(self, include_internals, callback, data):
for child in self._children:
callback(child.widget, data)
def do_add(self, widget):
self.put(widget)
def do_remove(self, widget):
child = self._get_child_from_widget(widget)
self._children.remove(child)
widget.unparent()
# Private
def _set_adjustments(self, hadj, vadj):
if not hadj and self._hadj:
hadj = new_adj()
if not vadj and self._vadj:
vadj = new_adj()
if self._hadj and self._hadj != hadj:
self._hadj.disconnect(self._hadj_changed_id)
if self._vadj and self._vadj != vadj:
self._vadj.disconnect(self._vadj_changed_id)
need_adjust = False
if self._hadj != hadj:
self._hadj = hadj
set_adjustment_upper(hadj, self._width, False)
self._hadj_changed_id = hadj.connect(
"value-changed",
self._adjustment_changed)
need_adjust = True
if self._vadj != vadj:
self._vadj = vadj
set_adjustment_upper(vadj, self._height, False)
self._vadj_changed_id = vadj.connect(
"value-changed",
self._adjustment_changed)
need_adjust = True
if need_adjust and vadj and hadj:
self._adjustment_changed()
def _adjustment_changed(self, adj=None):
if self.flags() & gtk.REALIZED:
self._bin_window.move(int(-self._hadj.value),
int(-self._vadj.value))
self._bin_window.process_updates(True)
def _get_child_from_widget(self, widget):
for child in self._children:
if child.widget == widget:
return child
else:
raise AssertionError
def _allocate_child(self, child):
allocation = gdk.Rectangle()
allocation.x = child.x
allocation.y = child.y
req = child.widget.get_child_requisition()
allocation.width = req[0]
allocation.height = req[1]
child.widget.size_allocate(allocation)
Layout.set_set_scroll_adjustments_signal('set-scroll-adjustments')
def main():
window = gtk.Window()
window.set_size_request(300, 300)
window.connect('delete-event', gtk.main_quit)
sw = gtk.ScrolledWindow()
sw.set_policy(gtk.POLICY_ALWAYS, gtk.POLICY_ALWAYS)
window.add(sw)
layout = Layout()
layout.set_size(1000, 1000)
sw.add(layout)
b = gtk.Button('foobar')
layout.put(b, 100, 100)
window.show_all()
gtk.main()
if __name__ == '__main__':
main()
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