1942

1 files changed, 90 insertions, 11 deletions

diff --git a/edit.mu b/edit.mu
index c02777ad..a39b007e 100644
--- a/edit.mu
+++ b/edit.mu
@@ -2829,21 +2829,21 @@ after +scroll-down [
   top-of-screen:address:address:duplex-list <- get-address *editor, top-of-screen:offset
   left:number <- get *editor, left:offset
   right:number <- get *editor, right:offset
-  width:number <- subtract right, left
-  *top-of-screen <- start-of-next-line *top-of-screen, width
+  max:number <- subtract right, left
+  *top-of-screen <- start-of-next-line *top-of-screen, max
 ]
 
-# takes a pointer 'curr' into the doubly-linked list, scans ahead at most
-# width positions until just past the next newline
+# takes a pointer into the doubly-linked list, scans ahead at most 'max'
+# positions until just past the next newline
 recipe start-of-next-line [
   local-scope
   original:address:duplex-list <- next-ingredient
-  width:number <- next-ingredient
+  max:number <- next-ingredient
   count:number <- copy 0
   curr:address:duplex-list <- copy original
   {
     reply-unless curr, original
-    done?:boolean <- greater-or-equal count, width
+    done?:boolean <- greater-or-equal count, max
     break-if done?
     c:character <- get *curr, value:offset
     at-newline?:boolean <- equal c, 10/newline
@@ -2856,6 +2856,39 @@ recipe start-of-next-line [
   reply curr
 ]
 
+scenario editor-scrolls-down-past-wrapped-line-using-arrow-keys [
+  # screen has 1 line for menu + 3 lines
+  assume-screen 10/width, 4/height
+  # initialize editor with a long, wrapped line and more than a screen of
+  # other lines
+  1:address:array:character <- new [abcdef
+g
+h
+i]
+  2:address:editor-data <- new-editor 1:address:array:character, screen:address, 0/left, 5/right
+  screen-should-contain [
+    .          .
+    .abcd↩     .
+    .ef        .
+    .g         .
+  ]
+  # position cursor at last line, then try to move further down
+  assume-console [
+    left-click 3, 0
+    press 65516  # down-arrow
+  ]
+  run [
+    editor-event-loop screen:address, console:address, 2:address:editor-data
+  ]
+  # screen shows partial wrapped line
+  screen-should-contain [
+    .          .
+    .ef        .
+    .g         .
+    .h         .
+  ]
+]
+
 # cursor-up can scroll if necessary
 
 scenario editor-can-scroll-up-using-arrow-keys [
@@ -2895,17 +2928,18 @@ after +scroll-up [
   top-of-screen:address:address:duplex-list <- get-address *editor, top-of-screen:offset
   left:number <- get *editor, left:offset
   right:number <- get *editor, right:offset
-  width:number <- subtract right, left
-  *top-of-screen <- start-of-previous-line *top-of-screen, width
+  max:number <- subtract right, left
+  max <- subtract max, 1  # include wrapped line but without newline
+  *top-of-screen <- start-of-previous-line *top-of-screen, max
 ]
 
-# takes a pointer into the doubly-linked list, scans back at most width
+# takes a pointer into the doubly-linked list, scans back at most 'max'
 # positions to previous newline. Returns original pointer if falls off edge of
 # list.
 recipe start-of-previous-line [
   local-scope
   original:address:duplex-list <- next-ingredient
-  width:number <- next-ingredient
+  max:number <- next-ingredient
   count:number <- copy 0
   curr:address:duplex-list <- copy original
   reply-unless curr, original
@@ -2915,7 +2949,7 @@ recipe start-of-previous-line [
   # now skip before until previous newline
   {
     reply-unless curr, original
-    done?:boolean <- greater-or-equal count, width
+    done?:boolean <- greater-or-equal count, max
     break-if done?
     c:character <- get *curr, value:offset
     at-newline?:boolean <- equal c, 10/newline
@@ -2928,6 +2962,51 @@ recipe start-of-previous-line [
   reply curr
 ]
 
+scenario editor-scrolls-up-past-wrapped-line-using-arrow-keys [
+  # screen has 1 line for menu + 3 lines
+  assume-screen 10/width, 4/height
+  # initialize editor with a long, wrapped line and more than a screen of
+  # other lines
+  1:address:array:character <- new [abcdef
+g
+h
+i]
+  2:address:editor-data <- new-editor 1:address:array:character, screen:address, 0/left, 5/right
+  screen-should-contain [
+    .          .
+    .abcd↩     .
+    .ef        .
+    .g         .
+  ]
+  # position cursor at top of second page, just below wrapped line
+  assume-console [
+    press 65518  # page-down
+  ]
+  run [
+    editor-event-loop screen:address, console:address, 2:address:editor-data
+  ]
+  screen-should-contain [
+    .          .
+    .g         .
+    .h         .
+    .i         .
+  ]
+  # now move up one line
+  assume-console [
+    press 65517  # up-arrow
+  ]
+  run [
+    editor-event-loop screen:address, console:address, 2:address:editor-data
+  ]
+  # screen shows partial wrapped line
+  screen-should-contain [
+    .          .
+    .ef        .
+    .g         .
+    .h         .
+  ]
+]
+
 ## putting the environment together out of editors
 
 container programming-environment-data [