escape-strings.ui: Add proof of concept ui for escape-strings.

basis/escape-strings/ui/authors.txt

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+Doug Coleman

basis/escape-strings/ui/ui.factor

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+! Copyright (C) 2019 Doug Coleman.
+! See http://factorcode.org/license.txt for BSD license.
+USING: accessors documents escape-strings io kernel sequences ui
+ui.gadgets ui.gadgets.editors ui.gadgets.tracks ui.gestures ;
+IN: escape-strings.ui
+
+TUPLE: escape-string-editor < source-editor ;
+
+: <escape-string-editor> ( -- editor )
+    escape-string-editor new-editor ; inline
+
+M: escape-string-editor handle-gesture
+    [ call-next-method ] 2keep
+    nip parent>> children>> first3
+    [ model>> doc-string ] 2dip
+    [ drop [ number-escape-string ] dip model>> set-doc-string ]
+    [ nip [ escape-string ] dip model>> set-doc-string ] 3bi ;
+: run-escape-string-editor ( -- )
+    [
+        vertical <track>
+            ! { 450 500 } >>pref-dim
+            { 450 500 } >>dim
+
+        <escape-string-editor>
+            ! { 450 500 } >>pref-dim
+            { 450 500 } >>dim
+            1/3 track-add
+
+        <escape-string-editor>
+            { 900 1000 } >>pref-dim
+            1/3 track-add
+
+        <escape-string-editor>
+            { 900 1000 } >>pref-dim
+            1/3 track-add
+
+        "escape-string editor" open-window
+    ] with-ui ;
+
+MAIN: run-escape-string-editor