Cassowary.d

[ketmar via Digitalmars-d-announce]

a small update for parser: it is now possible to parse so-called 
"scripts" (only from 'string' type for now). sample script can 
look like this one, which centers two buttons inside the panel, 
keepeng equal button sizes:

===[cutline]===
var(stay)
   panel.left = 0,
   panel.top = 0,
   panel.width = 80,
   panel.height = 20;


// this is just a simple constants,
// use 'define' to avoid introducing new vars
define
   button.hpadding = 4,
   button.defheight = 10+6; // simple math


var
   bt0.left, // default is 0
   bt0.top,
   <stay> bt0.width = 30,
   <stay> bt0.height = button.defheight;
     // oh, yeah, this will be calculated in-place


var
   bt1.left,
   bt1.top,
   bt1.width,
   bt1.height;


// some useful macros
define
   panel.right = (panel.left+panel.width),
   panel.bottom = (panel.top+panel.height),

   bt0.right = (bt0.left+bt0.width),
   bt0.bottom = (bt0.top+bt0.height),

   bt1.right = (bt1.left+bt1.width),
   bt1.bottom = (bt1.top+bt1.height);


// button-button placement and sizes
// default strength is <required>
bt1.left >= bt0.right+button.hpadding; // buttons padding
bt1.height == bt0.height; // same height
bt1.width == bt0.width; // same width
bt1.top == bt0.top; // same vertical position


// button-panel placement (this should center buttons)
// horizontal
bt0.left-panel.left == panel.right-bt1.right;
// vertical
bt0.top-panel.top == panel.bottom-bt0.bottom;


// print values (for debug mode)
print panel.left;
print panel.top;
print panel.width;
print panel.height;

print bt0.left;
print bt0.top;
print bt0.width;
print bt0.height;

print bt1.left;
print bt1.top;
print bt1.width;
print bt1.height;
===[cutline]===

there is no support for any kind of 'autobinding' variables to 
class/struct properties yet, and parser code is awful. but the 
whole thing is slowly growing…

anyway, it's really fun to play with various layout scripts. try 
it yourself!