3054 - keep cursor stable on resize in sandbox/

This ports commits 3052 and 3053 from the edit/ app.

7 files changed, 112 insertions, 29 deletions

diff --git a/sandbox/004-programming-environment.mu b/sandbox/004-programming-environment.mu
index 9ed48fb9..a0b529fc 100644
--- a/sandbox/004-programming-environment.mu
+++ b/sandbox/004-programming-environment.mu
@@ -7,7 +7,7 @@ def! main [
   hide-screen 0/screen
   env:address:programming-environment-data <- new-programming-environment 0/screen, initial-sandbox
   env <- restore-sandboxes env
-  render-sandbox-side 0/screen, env
+  render-sandbox-side 0/screen, env, render
   current-sandbox:address:editor-data <- get *env, current-sandbox:offset
   update-cursor 0/screen, current-sandbox, env
   show-screen 0/screen
@@ -95,8 +95,8 @@ def event-loop screen:address:screen, console:address:console, env:address:progr
       }
       {
         break-if more-events?
-        env <- resize screen, env
-        screen <- render-all screen, env
+        env, screen <- resize screen, env
+        screen <- render-all screen, env, render-without-moving-cursor
         render-all-on-no-more-events? <- copy 0/false  # full render done
       }
       loop +next-event:label
@@ -118,14 +118,14 @@ def event-loop screen:address:screen, console:address:console, env:address:progr
         {
           break-unless render-all-on-no-more-events?
           # no more events, and we have to force render
-          screen <- render-all screen, env
+          screen <- render-all screen, env, render
           render-all-on-no-more-events? <- copy 0/false
           jump +finish-event:label
         }
         # no more events, no force render
         {
           break-unless render?
-          screen <- render-sandbox-side screen, env
+          screen <- render-sandbox-side screen, env, render
           jump +finish-event:label
         }
       }
@@ -151,7 +151,90 @@ def resize screen:address:screen, env:address:programming-environment-data -> en
   *current-sandbox <- put *current-sandbox, cursor-column:offset, 0
 ]
 
-def render-all screen:address:screen, env:address:programming-environment-data -> screen:address:screen, env:address:programming-environment-data [
+# Variant of 'render' that updates cursor-row and cursor-column based on
+# before-cursor (rather than the other way around). If before-cursor moves
+# off-screen, it resets cursor-row and cursor-column.
+def render-without-moving-cursor screen:address:screen, editor:address:editor-data -> last-row:number, last-column:number, screen:address:screen, editor:address:editor-data [
+  local-scope
+  load-ingredients
+  return-unless editor, 1/top, 0/left, screen/same-as-ingredient:0, editor/same-as-ingredient:1
+  left:number <- get *editor, left:offset
+  screen-height:number <- screen-height screen
+  right:number <- get *editor, right:offset
+  curr:address:duplex-list:character <- get *editor, top-of-screen:offset
+  prev:address:duplex-list:character <- copy curr  # just in case curr becomes null and we can't compute prev
+  curr <- next curr
+  +render-loop-initialization
+  color:number <- copy 7/white
+  row:number <- copy 1/top
+  column:number <- copy left
+  # save before-cursor
+  old-before-cursor:address:duplex-list:character <- get *editor, before-cursor:offset
+  # initialze cursor-row/cursor-column/before-cursor to the top of the screen
+  # by default
+  *editor <- put *editor, cursor-row:offset, row
+  *editor <- put *editor, cursor-column:offset, column
+  top-of-screen:address:duplex-list:character <- get *editor, top-of-screen:offset
+  *editor <- put *editor, before-cursor:offset, top-of-screen
+  screen <- move-cursor screen, row, column
+  {
+    +next-character
+    break-unless curr
+    off-screen?:boolean <- greater-or-equal row, screen-height
+    break-if off-screen?
+    # if we find old-before-cursor still on the new resized screen, update
+    # editor-data.cursor-row and editor-data.cursor-column based on
+    # old-before-cursor
+    {
+      at-cursor?:boolean <- equal old-before-cursor, prev
+      break-unless at-cursor?
+      *editor <- put *editor, cursor-row:offset, row
+      *editor <- put *editor, cursor-column:offset, column
+      *editor <- put *editor, before-cursor:offset, old-before-cursor
+    }
+    c:character <- get *curr, value:offset
+    <character-c-received>
+    {
+      # newline? move to left rather than 0
+      newline?:boolean <- equal c, 10/newline
+      break-unless newline?
+      # clear rest of line in this window
+      clear-line-until screen, right
+      # skip to next line
+      row <- add row, 1
+      column <- copy left
+      screen <- move-cursor screen, row, column
+      curr <- next curr
+      prev <- next prev
+      loop +next-character:label
+    }
+    {
+      # at right? wrap. even if there's only one more letter left; we need
+      # room for clicking on the cursor after it.
+      at-right?:boolean <- equal column, right
+      break-unless at-right?
+      # print wrap icon
+      wrap-icon:character <- copy 8617/loop-back-to-left
+      print screen, wrap-icon, 245/grey
+      column <- copy left
+      row <- add row, 1
+      screen <- move-cursor screen, row, column
+      # don't increment curr
+      loop +next-character:label
+    }
+    print screen, c, color
+    curr <- next curr
+    prev <- next prev
+    column <- add column, 1
+    loop
+  }
+  # save first character off-screen
+  *editor <- put *editor, bottom-of-screen:offset, curr
+  *editor <- put *editor, bottom:offset, row
+  return row, column, screen/same-as-ingredient:0, editor/same-as-ingredient:1
+]
+
+def render-all screen:address:screen, env:address:programming-environment-data, {render-editor: (recipe (address screen) (address editor-data) -> number number (address screen) (address editor-data))} -> screen:address:screen, env:address:programming-environment-data [
   local-scope
   load-ingredients
   trace 10, [app], [render all]
@@ -166,7 +249,7 @@ def render-all screen:address:screen, env:address:programming-environment-data -
   screen <- move-cursor screen, 0/row, button-start
   print screen, [ run (F4) ], 255/white, 161/reddish
   #
-  screen <- render-sandbox-side screen, env
+  screen <- render-sandbox-side screen, env, render-editor
   <render-components-end>
   #
   current-sandbox:address:editor-data <- get *env, current-sandbox:offset
@@ -176,13 +259,13 @@ def render-all screen:address:screen, env:address:programming-environment-data -
 ]
 
 # replaced in a later layer
-def render-sandbox-side screen:address:screen, env:address:programming-environment-data -> screen:address:screen, env:address:programming-environment-data [
+def render-sandbox-side screen:address:screen, env:address:programming-environment-data, {render-editor: (recipe (address screen) (address editor-data) -> number number (address screen) (address editor-data))} -> screen:address:screen, env:address:programming-environment-data [
   local-scope
   load-ingredients
   current-sandbox:address:editor-data <- get *env, current-sandbox:offset
   left:number <- get *current-sandbox, left:offset
   right:number <- get *current-sandbox, right:offset
-  row:number, column:number, screen, current-sandbox <- render screen, current-sandbox
+  row:number, column:number, screen, current-sandbox <- call render-editor, screen, current-sandbox
   clear-line-until screen, right
   row <- add row, 1
   # draw solid line after code (you'll see why in later layers)
@@ -331,7 +414,7 @@ after <global-type> [
   {
     redraw-screen?:boolean <- equal c, 12/ctrl-l
     break-unless redraw-screen?
-    screen <- render-all screen, env:address:programming-environment-data
+    screen <- render-all screen, env:address:programming-environment-data, render
     sync-screen screen
     loop +next-event:label
   }
diff --git a/sandbox/005-sandbox.mu b/sandbox/005-sandbox.mu
index 66f3036d..93c2e83a 100644
--- a/sandbox/005-sandbox.mu
+++ b/sandbox/005-sandbox.mu
@@ -112,7 +112,7 @@ after <global-keypress> [
     error?:boolean, env, screen <- run-sandboxes env, screen, test-recipes
 #?     test-recipes <- copy 0  # abandon
     # F4 might update warnings and results on both sides
-    screen <- render-all screen, env
+    screen <- render-all screen, env, render
     {
       break-if error?
       screen <- update-status screen, [                 ], 245/grey
@@ -218,7 +218,7 @@ def save-sandboxes env:address:programming-environment-data [
   }
 ]
 
-def! render-sandbox-side screen:address:screen, env:address:programming-environment-data -> screen:address:screen, env:address:programming-environment-data [
+def! render-sandbox-side screen:address:screen, env:address:programming-environment-data, {render-editor: (recipe (address screen) (address editor-data) -> number number (address screen) (address editor-data))} -> screen:address:screen, env:address:programming-environment-data [
   local-scope
   load-ingredients
   trace 11, [app], [render sandbox side]
@@ -231,7 +231,7 @@ def! render-sandbox-side screen:address:screen, env:address:programming-environm
   {
     render-current-sandbox?:boolean <- equal render-from, -1
     break-unless render-current-sandbox?
-    row, column, screen, current-sandbox <- render screen, current-sandbox
+    row, column, screen, current-sandbox <- call render-editor, screen, current-sandbox
     clear-screen-from screen, row, column, left, right
     row <- add row, 1
   }
@@ -568,7 +568,7 @@ scenario scrolling-down-past-bottom-of-sandbox-editor [
   # initialize
   1:address:array:character <- new [add 2, 2]
   2:address:programming-environment-data <- new-programming-environment screen:address:screen, 1:address:array:character
-  render-all screen, 2:address:programming-environment-data
+  render-all screen, 2:address:programming-environment-data, render
   assume-console [
     # create a sandbox
     press F4
@@ -644,7 +644,7 @@ after <global-keypress> [
       *env <- put *env, render-from:offset, render-from
     }
     hide-screen screen
-    screen <- render-sandbox-side screen, env
+    screen <- render-sandbox-side screen, env, render
     show-screen screen
     jump +finish-event:label
   }
@@ -673,7 +673,7 @@ after <global-keypress> [
     render-from <- subtract render-from, 1
     *env <- put *env, render-from:offset, render-from
     hide-screen screen
-    screen <- render-sandbox-side screen, env
+    screen <- render-sandbox-side screen, env, render
     show-screen screen
     jump +finish-event:label
   }
@@ -704,7 +704,7 @@ scenario scrolling-through-multiple-sandboxes [
   # initialize environment
   1:address:array:character <- new []
   2:address:programming-environment-data <- new-programming-environment screen:address:screen, 1:address:array:character
-  render-all screen, 2:address:programming-environment-data
+  render-all screen, 2:address:programming-environment-data, render
   # create 2 sandboxes
   assume-console [
     press ctrl-n
@@ -865,7 +865,7 @@ scenario scrolling-manages-sandbox-index-correctly [
   # initialize environment
   1:address:array:character <- new []
   2:address:programming-environment-data <- new-programming-environment screen:address:screen, 1:address:array:character
-  render-all screen, 2:address:programming-environment-data
+  render-all screen, 2:address:programming-environment-data, render
   # create a sandbox
   assume-console [
     press ctrl-n
diff --git a/sandbox/006-sandbox-copy.mu b/sandbox/006-sandbox-copy.mu
index 9953ff15..d1d221d1 100644
--- a/sandbox/006-sandbox-copy.mu
+++ b/sandbox/006-sandbox-copy.mu
@@ -133,7 +133,7 @@ after <global-touch> [
     copy?, env <- try-copy-sandbox click-row, env
     break-unless copy?
     hide-screen screen
-    screen <- render-sandbox-side screen, env
+    screen <- render-sandbox-side screen, env, render
     screen <- update-cursor screen, current-sandbox, env
     show-screen screen
     loop +next-event:label
diff --git a/sandbox/007-sandbox-delete.mu b/sandbox/007-sandbox-delete.mu
index 252b6708..00738646 100644
--- a/sandbox/007-sandbox-delete.mu
+++ b/sandbox/007-sandbox-delete.mu
@@ -68,7 +68,7 @@ after <global-touch> [
     delete?, env <- try-delete-sandbox click-row, env
     break-unless delete?
     hide-screen screen
-    screen <- render-sandbox-side screen, env
+    screen <- render-sandbox-side screen, env, render
     screen <- update-cursor screen, current-sandbox, env
     show-screen screen
     loop +next-event:label
@@ -149,7 +149,7 @@ scenario deleting-sandbox-after-scroll [
   # initialize environment
   1:address:array:character <- new []
   2:address:programming-environment-data <- new-programming-environment screen:address:screen, 1:address:array:character
-  render-all screen, 2:address:programming-environment-data
+  render-all screen, 2:address:programming-environment-data, render
   # create 2 sandboxes and scroll to second
   assume-console [
     press ctrl-n
@@ -197,7 +197,7 @@ scenario deleting-top-sandbox-after-scroll [
   # initialize environment
   1:address:array:character <- new []
   2:address:programming-environment-data <- new-programming-environment screen:address:screen, 1:address:array:character
-  render-all screen, 2:address:programming-environment-data
+  render-all screen, 2:address:programming-environment-data, render
   # create 2 sandboxes and scroll to second
   assume-console [
     press ctrl-n
@@ -245,7 +245,7 @@ scenario deleting-final-sandbox-after-scroll [
   # initialize environment
   1:address:array:character <- new []
   2:address:programming-environment-data <- new-programming-environment screen:address:screen, 1:address:array:character
-  render-all screen, 2:address:programming-environment-data
+  render-all screen, 2:address:programming-environment-data, render
   # create 2 sandboxes and scroll to second
   assume-console [
     press ctrl-n
@@ -292,7 +292,7 @@ scenario deleting-updates-sandbox-count [
   # initialize environment
   1:address:array:character <- new []
   2:address:programming-environment-data <- new-programming-environment screen:address:screen, 1:address:array:character
-  render-all screen, 2:address:programming-environment-data
+  render-all screen, 2:address:programming-environment-data, render
   # create 2 sandboxes
   assume-console [
     press ctrl-n
diff --git a/sandbox/008-sandbox-edit.mu b/sandbox/008-sandbox-edit.mu
index 192ed391..66aeadc7 100644
--- a/sandbox/008-sandbox-edit.mu
+++ b/sandbox/008-sandbox-edit.mu
@@ -57,7 +57,7 @@ after <global-touch> [
     edit?, env <- try-edit-sandbox click-row, env
     break-unless edit?
     hide-screen screen
-    screen <- render-sandbox-side screen, env
+    screen <- render-sandbox-side screen, env, render
     screen <- update-cursor screen, current-sandbox, env
     show-screen screen
     loop +next-event:label
@@ -148,7 +148,7 @@ scenario editing-sandbox-after-scrolling-resets-scroll [
   # initialize environment
   1:address:array:character <- new []
   2:address:programming-environment-data <- new-programming-environment screen:address:screen, 1:address:array:character
-  render-all screen, 2:address:programming-environment-data
+  render-all screen, 2:address:programming-environment-data, render
   # create 2 sandboxes and scroll to second
   assume-console [
     press ctrl-n
@@ -195,7 +195,7 @@ scenario editing-sandbox-updates-sandbox-count [
   # initialize environment
   1:address:array:character <- new []
   2:address:programming-environment-data <- new-programming-environment screen:address:screen, 1:address:array:character
-  render-all screen, 2:address:programming-environment-data
+  render-all screen, 2:address:programming-environment-data, render
   # create 2 sandboxes and scroll to second
   assume-console [
     press ctrl-n
diff --git a/sandbox/009-sandbox-test.mu b/sandbox/009-sandbox-test.mu
index 2578e1ab..e8e13d74 100644
--- a/sandbox/009-sandbox-test.mu
+++ b/sandbox/009-sandbox-test.mu
@@ -127,7 +127,7 @@ after <global-touch> [
     sandbox <- toggle-expected-response sandbox
     save-sandboxes env
     hide-screen screen
-    screen <- render-sandbox-side screen, env, 1/clear
+    screen <- render-sandbox-side screen, env, render
     screen <- update-cursor screen, current-sandbox, env
     # no change in cursor
     show-screen screen
diff --git a/sandbox/010-sandbox-trace.mu b/sandbox/010-sandbox-trace.mu
index 4ef03239..d6693035 100644
--- a/sandbox/010-sandbox-trace.mu
+++ b/sandbox/010-sandbox-trace.mu
@@ -192,7 +192,7 @@ after <global-touch> [
     x <- not x
     *sandbox <- put *sandbox, display-trace?:offset, x
     hide-screen screen
-    screen <- render-sandbox-side screen, env, 1/clear
+    screen <- render-sandbox-side screen, env, render
     screen <- update-cursor screen, current-sandbox, env
     # no change in cursor
     show-screen screen