444 

   445 preferredExtent

   446     "return a good extent, one that makes subviews fit.

   447      Note that width is considered as given, and compute height here."

   448 

   449     |subViews xpos totalHeight maxHeightInRow first|

   450 

   451     "/ If I have an explicit preferredExtent..

   452     explicitExtent notNil ifTrue:[

   453         ^ explicitExtent

   454     ].

   455 

   456     "/ If I have a cached preferredExtent value..

   457     preferredExtent notNil ifTrue:[

   458         ^ preferredExtent

   459     ].

   460 

   461     subViews := self subViewsToConsider.

   462     subViews isEmptyOrNil ifTrue:[

   463         ^ super preferredExtent.

   464     ].

   465 

   466     xpos := horizontalSpace.

   467 

   468     totalHeight := 0.

   469     maxHeightInRow := 0.

   470     first := true.

   471 

   472     subViews do:[:eachChild | |childPreferredExtent|

   473         childPreferredExtent := eachChild preferredExtent.

   474         

   475         "go to next row, if this subview won't fit"

   476         first ifFalse: [

   477             (xpos + childPreferredExtent x + horizontalSpace) > width

   478             ifTrue: [

   479                 xpos := horizontalSpace.

   480                 totalHeight := totalHeight + maxHeightInRow + verticalSpace.

   481                 maxHeightInRow := 0.

   482             ]

   483         ].

   484 

   485         xpos := xpos + (childPreferredExtent x) + horizontalSpace.

   486         (maxHeightInRow < (childPreferredExtent y)) ifTrue:[

   487             maxHeightInRow := childPreferredExtent y.

   488         ].

   489         first := false

   490     ].

   491     maxHeightInRow ~= 0 ifTrue:[

   492         totalHeight := totalHeight + maxHeightInRow + verticalSpace.

   493     ].

   494 

   495     ^ width @ totalHeight

   496 !