On Sun, Oct 29, 2017 at 8:28 PM, Thierry Goubier <thierry.goubier@gmail.com> wrote:

Hi Hernan,

It's difficult to do an evaluation for the underlying solver, because the paper doesn't evaluate that aspect.

The solver seems the least interesting part of ALM.�� There two orthogonal concerns:��

* Generating the constraints - which is probably what distinguishes AutoLayout, ConstraintLayout, enaml and the key to usability

* Solving the constraints - while doing it right is well known, doing it efficiently is the challenge which Cassowary has covered.�� But ideally the solver would be pluggable so performance could be improved later��substituting an FFI or GPU implemented solver.�� Also, if it is feasible to include a solver in the main Pharo distribution, it would be great if that could be re-used at the business application level.

So the interesting aspect of ALM seems to be:��

* A new algorithm that automatically generates the constraints necessary to keep a layout non-overlapping.

* Many other layout managers rely on a hierarchy of nested layouts to define more complex layouts. Within nested layouts, widgets typically cannot be aligned across different levels of the hierarchy

* ALM constraints are specified as horizontal and vertical tabstops, which are virtual lines that form a grid to which all the elements of the GUI are aligned.

This last point of virtual guidelines echos some ideas that reoccur for me from time to time - something similar to how professional designer software like Adobe Illustrator operate with virtual guidelines - though they use manual placement rather than dynamic constraint based placement.��

There is also the��Auckland Layout Editor that might provide a good template to copy.�� We've been missing a GUI editor for layouts.

cheers -ben

Le 29/10/2017 �� 13:11, Hern��n Morales Durand a ��crit��:

IMO the right move is to take advantage of this technique/library in Smalltalk :

"The Auckland Layout Model (ALM) is a novel technique for specifying
2D layout as it is used for arranging the controls in a GUI. The model
allows the specification of constraints based on linear algebra, and
an optimal layout is calculated using linear programming. Linear
equalities and inequalities can be specified on horizontal and
vertical tabstops, which are virtual lines that form a grid to which
all the elements of the GUI are aligned. The described technique
supports the dynamic adaptation of a layout to changes in the
environment, e.g. window size, and offers more flexibility than other
layout managers. "

http://aucklandlayout.sourceforge.net/

Contains various models of layouts:

Border Layout
Box Layout (BGroupLayout)

Horizontal Layout
Vertical Layout

Gridbag Layout
Flow Layout
Constraint-Based Layout (BALMLayout)

The paper: https://www.cs.auckland.ac.nz/~lutteroth/publications/ZeidlerEtAl2013-AucklandLayoutEditor.pdf

The video: https://www.youtube.com/watch?v=NPPz1OJwICA

The website: https://www.haiku-os.org/blog/czeidler/2012-09-03_ale_auckland_layout_editor

Cheers,

Hern��n

2017-10-27 14:13 GMT-03:00 Stephane Ducasse <stepharo.self@gmail.com>:

Hi

I was wondering if there is a layout that we can use to propose
alternate placing layout
for widgets in spec?

Like

attached to�� the left 10pixels rubber band box or fixed size box
10pixels attached to the right.

Stef