def __init__(self, parent = None):
"""
Creates a new layout object. You normally only call this for the root
object of the hierarchy of layout objects, without specifying any parent
object.
"""
# right margin
self.__margin_right = HashPQueue(HashPQueue.GREATER_THAN)
# bottom margin
self.__margin_bottom = HashPQueue(HashPQueue.GREATER_THAN)
# the IDs of the margin entries
self.__margin_ids = (-1, -1)
# whether the element is enabled
self.__enabled = True
# the children of a layout object
self.__children = []
# the parent object
self.__parent = parent
# the object to which this object is placed relative to
self.__relative = None
self.__is_relative = (False, False)
self.__relatives = []
# the position of the positioning anchor given as a percentage of the
# object's size
self.__anchor = (0, 0)
# the layout object's geometry
self.__real_geometry = (Unit.ZERO, Unit.ZERO, Unit.ZERO, Unit.ZERO)
self.__old_real_geometry = (Unit.ZERO, Unit.ZERO, Unit.ZERO, Unit.ZERO)
self.__geometry = (Unit.Unit(), Unit.Unit(), Unit.Unit(), Unit.Unit())
# the widths of the border
self.__border_width = (Unit.ZERO, Unit.ZERO, Unit.ZERO, Unit.ZERO)
# the children bounding box
self.__bbox = (Unit.ZERO, Unit.ZERO, Unit.ZERO, Unit.ZERO)
# the geometry callback handler
self.__geometry_callback = None
# the action callback handler
self.__action_callback = None
class LayoutObject(object):
"""
gDesklets Geometry Engine
(c) 2003 - 2005 Martin Grimme <*****@*****.**>
This engine is licensed under the terms of the GNU LGPL.
This class represents a layout object for handling geometry calculations
for visual elements. It is based on the highly flexible and sophisticated
geometry engine of gDesklets 0.34.3, but is completely decoupled from the
rendering backend now and optimized even further.
"""
__slots__ = ("__margin_right", "__margin_bottom", "__margin_ids",
"__enabled",
"__children", "__parent", "__relative", "__is_relative",
"__relatives", "__anchor",
"__real_geometry", "__old_real_geometry", "__geometry",
"__border_width", "__bbox",
"__geometry_callback", "__action_callback")
def __init__(self, parent = None):
"""
Creates a new layout object. You normally only call this for the root
object of the hierarchy of layout objects, without specifying any parent
object.
"""
# right margin
self.__margin_right = HashPQueue(HashPQueue.GREATER_THAN)
# bottom margin
self.__margin_bottom = HashPQueue(HashPQueue.GREATER_THAN)
# the IDs of the margin entries
self.__margin_ids = (-1, -1)
# whether the element is enabled
self.__enabled = True
# the children of a layout object
self.__children = []
# the parent object
self.__parent = parent
# the object to which this object is placed relative to
self.__relative = None
self.__is_relative = (False, False)
self.__relatives = []
# the position of the positioning anchor given as a percentage of the
# object's size
self.__anchor = (0, 0)
# the layout object's geometry
self.__real_geometry = (Unit.ZERO, Unit.ZERO, Unit.ZERO, Unit.ZERO)
self.__old_real_geometry = (Unit.ZERO, Unit.ZERO, Unit.ZERO, Unit.ZERO)
self.__geometry = (Unit.Unit(), Unit.Unit(), Unit.Unit(), Unit.Unit())
# the widths of the border
self.__border_width = (Unit.ZERO, Unit.ZERO, Unit.ZERO, Unit.ZERO)
# the children bounding box
self.__bbox = (Unit.ZERO, Unit.ZERO, Unit.ZERO, Unit.ZERO)
# the geometry callback handler
self.__geometry_callback = None
# the action callback handler
self.__action_callback = None
def new_child(self):
"""
Creates and returns a new layout object as a child of this layout
object. Use this method to add new objects.
"""
child = LayoutObject(self)
self.__children.append(child)
return child
def remove_child(self, child):
"""
Removes the given child layout object. Raises a ValueError if the object
does not exist.
"""
self.__children.remove(child)
rx, ry, rw, rh = child.get_real_geometry()
self.__margin_right.remove(rx + rw)
self.__margin_bottom.remove(ry + rh)
def set_callback(self, handler):
"""
Sets the callback handler for geometry changes. The callback handler
will be invoked whenever the geometry of the object changes.
The handler has the signature:
handler(src, x, y, width, height)
The callback notifies you about geometry changes of an object.
"""
self.__geometry_callback = handler
def set_action_callback(self, handler):
self.__action_callback = handler
def set_enabled(self, value):
"""
Enables or disables the layout object. Disabled objects don't contribute
to the layout and act as if they did not exist.
"""
self.__enabled = value
self._update_all()
def set_geometry(self, x = None, y = None, width = None, height = None):
"""
Sets the geometry values. The values have to be valid Unit objects.
"""
gx, gy, gw, gh = self.__geometry
if (x): gx = x
if (y): gy = y
if (width): gw = width
if (height): gh = height
self.__geometry = (gx, gy, gw, gh)
self._update_all()
def get_geometry(self):
"""
Returns the user-given geometry in Unit values.
"""
return self.__geometry
def get_real_geometry(self):
"""
Returns the real geometry of the object, with anchors, and relative and
percentual positioning resolved.
"""
return self.__real_geometry
def _update_bbox(self, right_id, bottom_id, x, y, w, h, ignore_x, ignore_y):
"""
Updates the bounding box with the given values.
"""
self.__margin_right.remove(right_id)
self.__margin_bottom.remove(bottom_id)
right_id, bottom_id = -1, -1
if (not ignore_x):
right_id = self.__margin_right.insert(x.copy() + w.copy())
if (not ignore_y):
bottom_id = self.__margin_bottom.insert(y.copy() + h.copy())
return (right_id, bottom_id)
def __get_children_bbox(self):
"""
Returns the bounding box of the child objects.
"""
bx1 = Unit.ZERO
by1 = Unit.ZERO
bx2 = self.__margin_right.top() or Unit.ZERO
by2 = self.__margin_bottom.top() or Unit.ZERO
return (bx1, by1, bx2, by2)
def __get_parent_size(self):
"""
Returns the size of the parent widget.
"""
parent_width, parent_height = \
self.__parent.get_real_geometry()[2:]
# don't allow dangerous values for the parent's size
parent_width = max(Unit.ONE, parent_width)
parent_height = max(Unit.ONE, parent_height)
return (parent_width, parent_height)
def set_anchor(self, x, y):
"""
Sets the positioning anchor to the given place. The coordinates are
given in percentages of the object's size with values between 0.0
and 1.0.
"""
self.__anchor = (x, y)
self._update_all()
def get_anchor(self):
"""
Returns the position of the anchor.
"""
return self.__anchor
def __is_percentual(self):
"""
Returns whether the object has some percentual values.
"""
x, y, w, h = self.__geometry
return Unit.UNIT_PERCENT in (x.get_unit(), y.get_unit(),
w.get_unit(), h.get_unit())
def __resolve_anchor(self, x, y, w, h):
"""
Resolves the anchored position and returns the position of the top-left
corner of the object.
"""
ax, ay = self.get_anchor()
ax = w * ax
ay = h * ay
return (x - ax, y - ay)
def _update_all(self):
"""
Updates the geometry of the layout object and adjusts depending objects
as well.
"""
if (self._update_geometry()):
self._update_relatives()
self._update_children()
self._update_parent()
# objects with percentual geometry sometimes need special treatment
if (self.__is_percentual()):
if (self._update_geometry()):
self._update_relatives()
else:
self._update_children()
def _update_geometry(self):
"""
Updates the geometry of the layout object.
This does not include notifying the parent object or relative objects
about the change.
Returns True if something changed, False otherwise.
"""
x, y, w, h = self.__real_geometry
ux, uy, uw, uh = self.__geometry
# adjust percentage stuff
if (self.__parent):
parent_width, parent_height = self.__get_parent_size()
w1, h1, w2, h2 = self.__parent.get_border_width()
pw = parent_width - w1 - w2
ph = parent_height - h1 - h2
parent_width = (pw >= Unit.ZERO) and pw or Unit.ZERO
parent_height = (ph >= Unit.ZERO) and ph or Unit.ZERO
if (parent_width.is_unset()): parent_width = w
if (parent_height.is_unset()): parent_height = h
ux.set_100_percent(parent_width.as_px())
uw.set_100_percent(parent_width.as_px())
uy.set_100_percent(parent_height.as_px())
uh.set_100_percent(parent_height.as_px())
# compute geometry
if (ux.is_unset()): new_x = x
else: new_x = ux
if (uy.is_unset()): new_y = y
else: new_y = uy
if (self.__enabled):
if (uw.is_unset()): new_w = self.__get_value_for_unset(width = w)
else: new_w = uw
if (uh.is_unset()): new_h = self.__get_value_for_unset(height = h)
else: new_h = uh
else:
new_w = Unit.ZERO
new_h = Unit.ZERO
# handle relative positioning
if (self.__relative):
is_rel_x, is_rel_y = self.__is_relative
# get the coords of the anchor of the relative
rx, ry, rw, rh = self.__relative.get_real_geometry()
anchor_x, anchor_y = self.__relative.get_anchor()
anchor_x = rw * anchor_x
anchor_y = rh * anchor_y
# get the remaining amount of pixels from the anchor to the
# bottom/right edge of the relative
tw = rw - anchor_x
th = rh - anchor_y
if (not ux.is_unset()): new_x += rx + anchor_x
else: new_x = rx + anchor_x
if (not uy.is_unset()): new_y += ry + anchor_y
else: new_y = ry + anchor_y
if (is_rel_x): new_x += tw
if (is_rel_y): new_y += th
#end if
# get coords of the top left corner, i.e. resolve the anchor
new_x, new_y = self.__resolve_anchor(new_x, new_y, new_w, new_h)
old_x, old_y, old_w, old_h = self.__old_real_geometry
if ((new_x, new_y, new_w, new_h) != self.__old_real_geometry):
self.__real_geometry = (new_x.copy(), new_y.copy(),
new_w.copy(), new_h.copy())
self.__old_real_geometry = (new_x.copy(), new_y.copy(),
new_w.copy(), new_h.copy())
# update the parent's children bounding box
if (self.__parent):
right_id, bottom_id = self.__margin_ids
ignore_x = (Unit.UNIT_PERCENT in
(ux.get_unit(), uw.get_unit()))
ignore_y = (Unit.UNIT_PERCENT in
(uy.get_unit(), uh.get_unit()))
self.__margin_ids = \
self.__parent._update_bbox(right_id, bottom_id,
new_x, new_y, new_w, new_h,
ignore_x, ignore_y)
# call the geometry callback
if (self.__geometry_callback):
self.__geometry_callback(self, new_x, new_y, new_w, new_h)
return True
else:
return False
def _update_relatives(self):
"""
Updates the geometry of the objects placed relative to this object.
"""
for r in self.__relatives:
r._update_geometry()
r._update_relatives()
def _update_children(self):
"""
Updates the geometry of the child objects of this object. This only
affects children with percentual geometry values.
"""
if (not self.__enabled): return
x, y, w, h = self.get_geometry()
for c in self.__children:
ux, uy, uw, uh = c.get_geometry()
if (Unit.UNIT_PERCENT in (ux.get_unit(), uy.get_unit(),
uw.get_unit(), uh.get_unit())):
c._update_geometry()
c._update_relatives()
c._update_children()
#end for
def _update_parent(self):
"""
Updates the geometry of the parent object. This only affects the parent
if it does not have a fixed size.
"""
if (self.__parent):
x, y, w, h = self.__parent.get_geometry()
if (Unit.Unit() in (w, h)):
self.__parent._update_all()
def set_relative_to(self, other, is_rel_x, is_rel_y):
"""
Places the object relative to another one.
"""
self.__relative = other
self.__is_relative = (is_rel_x, is_rel_y)
other._add_relative(self)
self._update_all()
def _add_relative(self, r):
"""
Adds a new relative object.
"""
self.__relatives.append(r)
def _remove_relative(self, r):
"""
Removes a relative object.
"""
try:
self.__relatives.remove(r)
except:
pass
def set_border_width(self, left, top, right, bottom):
"""
Sets the widths of the four borders of the layout object.
A border-width > 0 results in inner padding.
"""
self.__border_width = (left, top, right, bottom)
self._update_all()
def get_border_width(self):
"""
Returns the widths of the four borders as a 4-tuple.
"""
return self.__border_width
def __get_value_for_unset(self, x = None, y = None,
width = None, height = None):
"""
Returns the geometry value that should be used for unset values.
"""
bx1, by1, bx2, by2 = self.__get_children_bbox()
bw1, bh1, bw2, bh2 = self.__border_width
if (x): return x
elif (y): return y
elif (width): return bx2 + bw1 + bw2
elif (height): return by2 + bh1 + bh2
def send_action(self, x, y, *args):
if (self.__action_callback):
self.__action_callback(self, x, y, *args)
bw, bh, nil, nil = self.__border_width
x -= bw
y -= bh
for c in self.__children:
cx, cy, cw, ch = c.get_real_geometry()
if (cx <= x < cx + cw and cy <= y < cy + ch):
c.send_action(x - cx, y - cy, *args)
#end for
def dump(self, indent = 0):
"""
For debugging:
Dumps the geometry values of the layout object together with all
child-objects to stdout.
"""
print " " * indent,
print self.get_geometry(), "---", \
map(lambda f: f.as_px(), self.get_real_geometry())
for c in self.__children:
c.dump(indent + 2)
