ui.gadgets.line-support: common code for gadgets that display a vertical list of lines

basis/ui/gadgets/line-support/authors.txt

@@ -0,0 +1 @@
+Slava Pestov

basis/ui/gadgets/line-support/line-support-tests.factor

@@ -0,0 +1,4 @@
+! Copyright (C) 2009 Slava Pestov.
+! See http://factorcode.org/license.txt for BSD license.
+USING: tools.test ui.gadgets.line-support ;
+IN: ui.gadgets.line-support.tests

basis/ui/gadgets/line-support/line-support.factor

@@ -0,0 +1,50 @@
+! Copyright (C) 2009 Slava Pestov.
+! See http://factorcode.org/license.txt for BSD license.
+USING: accessors arrays combinators fry kernel math math.order
+math.ranges math.vectors namespaces opengl sequences ui.gadgets
+ui.render ui.text ;
+IN: ui.gadgets.line-support
+
+! Some code shared by table and editor gadgets
+SLOT: font
+
+: line-height ( gadget -- n )
+    font>> "" text-height ;
+
+: y>line ( y gadget -- n )
+    line-height /i ;
+
+: line>y ( n gadget -- y )
+    line-height * ;
+
+: validate-line ( m gadget -- n )
+    control-value [ drop f ] [ length 1- min 0 max ] if-empty ;
+
+: visible-line ( gadget quot -- n )
+    '[
+        [ clip get @ origin get [ second ] bi@ - ] dip
+        y>line
+    ] keep validate-line ; inline
+
+: first-visible-line ( gadget -- n )
+    [ loc>> ] visible-line ;
+
+: last-visible-line ( gadget -- n )
+    [ [ loc>> ] [ dim>> ] bi v+ ] visible-line 1+ ;
+
+: each-slice-index ( from to seq quot -- )
+    [ [ <slice> ] [ drop [a,b) ] 3bi ] dip 2each ; inline
+
+GENERIC: draw-line ( line index gadget -- )
+
+: draw-lines ( gadget -- )
+    {
+        [ first-visible-line ]
+        [ last-visible-line ]
+        [ control-value ]
+        [ line-height ]
+        [ ]
+    } cleave '[
+        0 over _ * 2array
+        [ _ draw-line ] with-translation
+    ] each-slice-index ;

basis/ui/gadgets/line-support/summary.txt

@@ -0,0 +1 @@
+Code shared between table and editor gadgets