From 20f686d026e75d9f1d6f3b725dd5fce9171cb6ea Mon Sep 17 00:00:00 2001
From: d6 <d_m@plastic-idolatry.com>
Date: Tue, 15 Feb 2022 21:58:12 -0500
Subject: [PATCH] get page-down working

---
 femto.tal | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/femto.tal b/femto.tal
index 8a6aed7..436d928 100644
--- a/femto.tal
+++ b/femto.tal
@@ -232,6 +232,24 @@
     ;draw-cursor JSR2 BRK
     &done BRK
 
+@page-up
+    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
+    &near-eof
+        ;buffer/line-count LDA2
+        ;buffer/line-offset LDA2 INC2
+        SUB2 NIP ;cursor/row STA
+        ;cur-len JSR2 ;cursor/col STA
+        ;draw-cursor JSR2 BRK
+
 @quit quit!
 
 @ignore BRK
@@ -258,6 +276,11 @@
 @at-line-start ( -> bool^ )
     ;cursor/col LDA #00 EQU JMP2r
 
+@eof-is-visible ( -> bool^ )
+    ;buffer/line-offset LDA2 ;term/rows LDA2 ADD2 INC2
+    ;buffer/line-count LDA2
+    GTH2 JMP2r
+
 @backspace ( -> )
     ;at-buffer-start JSR2 ,&skip JCN
     ;at-line-start JSR2 ,&prev-line JCN
@@ -353,6 +376,7 @@
     .Console/read DEI LIT '< EQU ( M-< ) ;goto-start JCN2
     .Console/read DEI LIT '> EQU ( M-> ) ;goto-end JCN2
     .Console/read DEI LIT 'g EQU ( M-g ) ;goto-line JCN2
+    .Console/read DEI LIT 'v EQU ( M-v ) ;page-up JCN2
     BRK
 
 @move-to-message-line ( -> )
@@ -390,6 +414,7 @@
     .Console/read DEI #0e EQU ( C-n ) ;down JCN2
     .Console/read DEI #0f EQU ( C-o ) ;save JCN2
     .Console/read DEI #10 EQU ( C-p ) ;up JCN2
+    .Console/read DEI #16 EQU ( C-v ) ;page-down JCN2
     .Console/read DEI #18 EQU ( C-x ) ;quit JCN2
     .Console/read DEI #1a EQU ( C-z ) ;debug JCN2
     .Console/read DEI #1b EQU ( ESC ) ;escape JCN2
@@ -402,6 +427,9 @@
 @min ( x^ y^ -> min^ )
     LTHk JMP SWP POP JMP2r
 
+@min2 ( x* y* -> min* )
+    LTH2k JMP SWP2 POP2 JMP2r
+
 @term-move-cursor ( col^ row^ -> )
     ansi        INC ( row+1 ) ;emit-dec JSR2
     LIT '; emit INC ( col+1 ) ;emit-dec JSR2