wx.lib.layoutf.Layoutf¶

The class Layoutf(wxLayoutConstraints) presents a simplification of the wxLayoutConstraints syntax. The name Layoutf is choosen because of the similarity with C’s printf function.

Quick Example:

lc = Layoutf('t=t#1;l=r10#2;r!100;h%h50#1', (self, self.panel))

is equivalent to:

lc = wx.LayoutContraints()
lc.top.SameAs(self, wx.Top)
lc.left.SameAs(self.panel, wx.Right, 10)
lc.right.Absolute(100)
lc.height.PercentOf(self, wx.Height, 50)

Usage:

You can give a constraint string to the Layoutf constructor, or use the ‘pack’ method. The following are equivalent:

lc = Layoutf('t=t#1;l=r#2;r!100;h%h50#1', (self, self.panel))

and:

lc = Layoutf()
lc.pack('t=t#1;l=r#2;r!100;h%h50#1', (self, self.panel))

Besides ‘pack’ there’s also ‘debug_pack’ which does not set constraints, but prints traditional wxLayoutConstraint calls to stdout.

The calls to the Layoutf constructor and pack methods have the following argument list:

(constraint_string, objects_tuple)

Constraint String syntax:

Constraint directives are separated by semi-colons. You generally (always?) need four directives to completely describe a subwindow’s location.

A single directive has either of the following forms:

<own attribute><compare operation>[numerical argument] for example r!100 -> lc.right.Absolute(100) ) and w* -> lc.width.AsIs()
<own attribute><compare operation>[numerical argument] #<compare object nr.> for example t_10#2 -> lc.top.Below(<second obj>, 10)
<own attribute><compare operation><compare attribute> [numerical argument]#<compare object nr.> for example w%h50#2 -> lc.width.PercentOf(<second obj>, wx.Height, 50) and t=b#1 -> lc.top.SameAs(<first obj>, wx.Bottom)

Which one you need is defined by the <compare operation> type. The following take type 1 (no object to compare with):

‘!’: ‘Absolute’, ‘?’: ‘Unconstrained’, ‘*’: ‘AsIs’

These take type 2 (need to be compared with another object)

‘<’: ‘LeftOf’, ‘>’: ‘RightOf’, ‘^’: ‘Above’, ‘_’: ‘Below’

These take type 3 (need to be compared to another object attribute)

‘=’: ‘SameAs’, ‘%’: ‘PercentOf’

For all types, the <own attribute> letter can be any of

‘t’: ‘top’, ‘l’: ‘left’, ‘b’: ‘bottom’,
‘r’: ‘right’, ‘h’: ‘height’, ‘w’: ‘width’,
‘x’: ‘centreX’, ‘y’: ‘centreY’

If the operation takes an (optional) numerical argument, place it in [numerical argument]. For type 3 directives, the <compare attribute> letter can be any of

‘t’: ‘wxTop’, ‘l’: ‘wxLeft’, ‘b’: ‘wx.Bottom’
‘r’: ‘wxRight’, ‘h’: ‘wxHeight’, ‘w’: ‘wx.Width’,
‘x’: ‘wxCentreX’, ‘y’: ‘wx.CentreY’

Note that these are the same letters as used for <own attribute>, so you’ll only need to remember one set. Finally, the object whose attribute is refered to, is specified by #<compare object nr>, where <compare object nr> is the 1-based (stupid, I know, but I’ve gotten used to it) index of the object in the objects_tuple argument.

Bugs:

Not entirely happy about the logic in the order of arguments after the <compare operation> character.

Not all wxLayoutConstraint methods are included in the syntax. However, the type 3 directives are generally the most used. Further excuse: wxWindows layout constraints are at the time of this writing not documented.

Class Hierarchy¶

Inheritance diagram for class Layoutf:

Known Superclasses¶

wx.LayoutConstraints

Methods Summary¶

`__init__`
`debug_pack`
`pack`

Class API¶

class Layoutf(wx.LayoutConstraints)¶