From 463a7ee3e227a52a8c5d0bd6bacbf5240f93b42e Mon Sep 17 00:00:00 2001
From: Andreas Baumann <mail@andreasbaumann.cc>
Date: Sun, 1 Dec 2024 13:16:16 +0100
Subject: [PATCH] scrntest: added "B" command to toggle blocking and
 non-blocking screen_getchar

---
 apps/scrntest.asm | 77 +++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 75 insertions(+), 2 deletions(-)

diff --git a/apps/scrntest.asm b/apps/scrntest.asm
index deb795e2..43da3379 100644
--- a/apps/scrntest.asm
+++ b/apps/scrntest.asm
@@ -15,8 +15,11 @@
 .zp style, 1
 .zp ptr1, 2
 .zp ptr2, 2
+.zp kbd_blocking, 1
+.zp spinner_pos, 1
 .label string_init
 .label string_a
+.label chars_spinner
 .label BIOS
 .label SCREEN
 .label update_cursor
@@ -59,6 +62,10 @@
 
     lda #0
     sta style
+    sta spinner_pos
+    
+    lda #1
+    sta kbd_blocking
 
 help:
     \ Clear screen and print help
@@ -95,9 +102,55 @@ mainloop:
     stx cur_y
 
 timeout:
+    \ Show spinnig bar to test non-blocking keyboard read
+    lda #39
+    ldx #0
+    ldy #SCREEN_SETCURSOR
+    jsr SCREEN
+    ldy spinner_pos
+    iny
+    tya
+    cmp #4
+    .zif eq
+        ldy #0
+    .zendif
+    sty spinner_pos
+    ldx kbd_blocking
+    .zif ne
+        lda #'*'
+    .zendif
+    ldx kbd_blocking
+    .zif eq
+        lda chars_spinner, y
+    .zendif
+    ldy #SCREEN_PUTCHAR
+    jsr SCREEN 
+
+    lda #39
+    ldx #1
+    ldy #SCREEN_SETCURSOR
+    jsr SCREEN
+    lda #32
+    ldy #SCREEN_PUTCHAR
+    jsr SCREEN 
+       
+    lda cur_x
+    ldx cur_y
+    ldy #SCREEN_SETCURSOR
+    jsr SCREEN
+
     \ Get and parse command
-    lda #10
-    ldx #00
+    
+    ldy kbd_blocking
+    .zif ne
+        lda #0xff
+        ldx #0x7f
+    .zendif
+    ldy kbd_blocking
+    .zif eq
+        lda #0x10
+        ldx #0x0
+    .zendif
     ldy #SCREEN_GETCHAR
     jsr SCREEN
     bcs timeout \ make sure we don't have consecutive key presses because of short timeouts
@@ -252,6 +305,21 @@ case_done:
         jsr SCREEN
         jmp mainloop
     .zendif
+    
+    \ Toggle keyboard read mode
+    cmp #'B'
+    .zif eq
+        lda kbd_blocking
+        .zif eq
+            lda #1
+            sta kbd_blocking
+            jmp mainloop
+        .zendif
+        lda #0
+        sta kbd_blocking
+        jmp mainloop
+        
+    .zendif
   
     \ Clear screen and print help 
     cmp #'H'
@@ -402,6 +470,7 @@ string_init:
     .byte "J - Scroll down\r\n"
     .byte "L - Clear to End of Line\r\n"
     .byte "I - Toggle style\r\n"
+    .byte "B - Toggle blocking/non-blocking read\r\n"
     .byte "H - Clear screen and print this help\r\n"
     .byte "Q - Quit\r\n"
     .byte 0
@@ -410,3 +479,7 @@ string_a:
     .byte "String"
     .byte 0
 
+chars_spinner:
+    .byte "-\\|/"
+    .byte 0
+