From 5870afd9d1d35518df9152dd3f2a26ca3188c6c6 Mon Sep 17 00:00:00 2001
From: d6 <d_m@plastic-idolatry.com>
Date: Tue, 15 Feb 2022 22:03:31 -0500
Subject: [PATCH] page up/down

---
 femto.tal | 33 +++++++++++++++++++++------------
 1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/femto.tal b/femto.tal
index 436d928..76c0957 100644
--- a/femto.tal
+++ b/femto.tal
@@ -39,7 +39,6 @@
 ( TODO: )
 ( - optimize term drawing )
 ( - get long line truncation/scrolling working )
-( - page up/page down )
 ( - line numbers in left column (toggle mode?) )
 ( - help text )
 ( - save file command -> tmp first )
@@ -233,16 +232,26 @@
     &done BRK
 
 @page-up
-    BRK
+    ;bof-is-visible JSR2 ,&near-eof JCN
+        ;buffer/line-offset LDA2
+        ;term/rows LDA2 SUB2 #0003 ADD2
+        DUP2 ;abs-line JSR2 ;buffer/offset STA2
+                            ;buffer/line-offset STA2
+        ;ensure-visible-cursor JSR2
+        ;draw-all JSR2 BRK
+    &near-eof
+        #00 ;cursor/row STA
+        #00 ;cursor/col STA
+        ;draw-cursor JSR2 BRK
 
 @page-down
     ;eof-is-visible JSR2 ,&near-eof JCN
-    ;buffer/line-offset LDA2 ;term/rows LDA2 ADD2 #0003 SUB2
-            ;buffer/line-count LDA2 ;min2 JSR2
-    DUP2 ;abs-line JSR2 ;buffer/offset STA2
-                   ;buffer/line-offset STA2
-    ;ensure-visible-cursor JSR2
-    ;draw-all JSR2 BRK
+        ;buffer/line-offset LDA2
+        ;term/rows LDA2 ADD2 #0003 SUB2
+        DUP2 ;abs-line JSR2 ;buffer/offset STA2
+                            ;buffer/line-offset STA2
+        ;ensure-visible-cursor JSR2
+        ;draw-all JSR2 BRK
     &near-eof
         ;buffer/line-count LDA2
         ;buffer/line-offset LDA2 INC2
@@ -276,6 +285,9 @@
 @at-line-start ( -> bool^ )
     ;cursor/col LDA #00 EQU JMP2r
 
+@bof-is-visible ( -> bool^ )
+    ;buffer/line-offset LDA2 #0000 EQU2 JMP2r
+
 @eof-is-visible ( -> bool^ )
     ;buffer/line-offset LDA2 ;term/rows LDA2 ADD2 INC2
     ;buffer/line-count LDA2
@@ -367,8 +379,7 @@
     ;rel-line-error ;error! JMP2
 (    #00 #00 DIV BRK )
 
-( TODO: M-v for page up and M-> for goto end )
-(       M-f and M-b for next/previous word )
+( TODO: M-f and M-b for next/previous word )
 (       M-n and M-p for next/previous paragraph )
 (       maybe M-% for search&replace )
 @on-key-escaped
@@ -399,8 +410,6 @@
 
 ( TODO: C-g or C-h for help )
 ( TODO: C-s for search )
-( TODO: C-v for page down )
-( TODO: 8-bit meta/alt? )
 ( TODO: tab input? )
 @on-key
     ;saw-esc LDA ;on-key-escaped JCN2