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"""document layout engine."""
class Layout:
"""the document layout engine
.widgets -- elements are kept in this list. read-only, use add to add items to it.
"""
def __init__(self,rect=None):
"""initialize the object with the size of the box."""
self._widgets = []
self.rect = rect
def add(self,e):
"""add a document element to the layout.
a document element may be
- a tuple (w,h) if it is a whitespace element
- a tuple (0,h) if it is a linebreak element
- an integer -1,0,1 if it is a command to start a new block of elements that are aligned either left,center, or right.
- an object with a .rect (for size) -- such as a word element
- an object with a .rect (for size) and .align -- such as an image element
"""
self._widgets.append(e)
def resize(self):
"""resize the layout
this method recalculates the position of all document elements
after they have been added to the document. .rect.x,y will be updated for all
objects.
"""
self.init()
self.widgets = []
for e in self._widgets:
if type(e) is tuple and e[0] != 0:
self.do_space(e)
elif type(e) is tuple and e[0] == 0:
self.do_br(e[1])
elif type(e) is int:
self.do_block(align=e)
elif hasattr(e,'align'):
self.do_align(e)
else:
self.do_item(e)
self.line()
self.rect.h = max(self.y,self.left_bottom,self.right_bottom)
def init(self):
self.x,self.y = self.rect.x,self.rect.y
self.left = self.rect.left
self.right = self.rect.right
self.left_bottom = 0
self.right_bottom = 0
self.y = self.rect.y
self.x = self.rect.x
self.h = 0
self.items = []
self.align = -1
def getleft(self):
if self.y > self.left_bottom:
self.left = self.rect.left
return self.left
def getright(self):
if self.y > self.right_bottom:
self.right = self.rect.right
return self.right
def do_br(self,h):
self.line()
self.h = h
def do_block(self,align=-1):
self.line()
self.align = align
def do_align(self,e):
align = e.align
ox,oy,oh = self.x,self.y,self.h
w,h = e.rect.w,e.rect.h
if align == 0:
self.line()
self.x = self.rect.left + (self.rect.width-w)/2
self.fit = 0
elif align == -1:
self.line()
self.y = max(self.left_bottom,self.y + self.h)
self.h = 0
self.x = self.rect.left
elif align == 1:
self.line()
self.y = max(self.right_bottom,self.y + self.h)
self.h = 0
self.x = self.rect.left + (self.rect.width-w)
e.rect.x,e.rect.y = self.x,self.y
self.x = self.x + w
self.y = self.y
if align == 0:
self.h = max(self.h,h)
self.y = self.y + self.h
self.x = self.getleft()
self.h = 0
elif align == -1:
self.left = self.x
self.left_bottom = self.y + h
self.x,self.y,self.h = ox + w,oy,oh
elif align == 1:
self.right = self.x - w
self.right_bottom = self.y + h
self.x,self.y,self.h = ox,oy,oh
self.widgets.append(e)
def do_space(self,e):
w,h = e
if self.x+w >= self.getright():
self.line()
else:
self.items.append(e)
self.h = max(self.h,h)
self.x += w
def do_item(self,e):
w,h = e.rect.w,e.rect.h
if self.x+w >= self.getright():
self.line()
self.items.append(e)
self.h = max(self.h,h)
self.x += w
def line(self):
x1 = self.getleft()
x2 = self.getright()
align = self.align
y = self.y
if len(self.items) != 0 and type(self.items[-1]) == tuple:
del self.items[-1]
w = 0
for e in self.items:
if type(e) == tuple: w += e[0]
else: w += e.rect.w
if align == -1: x = x1
elif align == 0:
x = x1 + ((x2-x1)-w)/2
self.fit = 0
elif align == 1: x = x2 - w
for e in self.items:
if type(e) == tuple: x += e[0]
else:
e.rect.x,e.rect.y = x,y
self.widgets.append(e)
x += e.rect.w
self.items = []
self.y = self.y + self.h
self.x = self.getleft()
self.h = 0
# vim: set filetype=python sts=4 sw=4 noet si :
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