From 2af8d8fdaec76a8d6c5d9b33cad3f6c9f626605f Mon Sep 17 00:00:00 2001
From: Evan Reichard <evan@reichard.io>
Date: Sun, 26 Jul 2026 21:01:26 -0400
Subject: [PATCH] fix(binarykeyboard): split candidates by on-screen position

---
 apps/BinaryKeyboard/main.lua     | 13 ++++++++++---
 apps/BinaryKeyboard/manifest.txt |  2 +-
 catalog.txt                      |  2 +-
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/apps/BinaryKeyboard/main.lua b/apps/BinaryKeyboard/main.lua
index 224c54c..d0673ef 100644
--- a/apps/BinaryKeyboard/main.lua
+++ b/apps/BinaryKeyboard/main.lua
@@ -6,10 +6,17 @@ local ROWS = {
     { "Z", "X", "C", "V", "B", "N", "M" }
 }
 
+-- Spatial Rank - Halving must split the keyboard left/right on screen, so keys sort by their
+-- centered column position, with the row index only breaking ties.
 local KEYS = {}
-for _, row in ipairs(ROWS) do
-    for _, key in ipairs(row) do KEYS[#KEYS + 1] = key end
+local keyRank = {}
+for rowIndex, row in ipairs(ROWS) do
+    for columnIndex, key in ipairs(row) do
+        KEYS[#KEYS + 1] = key
+        keyRank[key] = (columnIndex - (#row + 1) / 2) * 10 + rowIndex
+    end
 end
+table.sort(KEYS, function(a, b) return keyRank[a] < keyRank[b] end)
 local MAX_TEXT_BYTES = 80
 
 local text = ""
@@ -110,7 +117,7 @@ local function render()
     local visibleText = text == "" and "Type with the side buttons" or text:sub(-38)
     gui.drawText(FONT_UI_12, margin + 12, 96, visibleText, COLOR_BLACK, STYLE_NORMAL)
 
-    gui.drawCenteredText(FONT_UI_10, 170, "UP = plain    DOWN = shaded", COLOR_BLACK, STYLE_NORMAL)
+    gui.drawCenteredText(FONT_UI_10, 170, "UP = plain left    DOWN = shaded right", COLOR_BLACK, STYLE_NORMAL)
     drawKeyboard(width, 195, height - 90)
 
     gui.drawButtonHints(#history == 0 and "Exit" or "Undo", "Space", "Delete", uppercase and "lower" or "UPPER")
diff --git a/apps/BinaryKeyboard/manifest.txt b/apps/BinaryKeyboard/manifest.txt
index bd18ea6..7a74a1a 100644
--- a/apps/BinaryKeyboard/manifest.txt
+++ b/apps/BinaryKeyboard/manifest.txt
@@ -1,2 +1,2 @@
 XTEINK-MANIFEST|1
-main.lua|4726|1a958ed089a1c3b6c8757298a94aed32fb2603732d83d3ed6c3ea98f31bd816a
+main.lua|5085|59fddef1f3259f748e5b84e7c99f8bd2f02d7a0c18c4678872a92a1b0c4e8581
diff --git a/catalog.txt b/catalog.txt
index 9ef08d1..e4619dc 100644
--- a/catalog.txt
+++ b/catalog.txt
@@ -1,5 +1,5 @@
 XTEINK-CATALOG|1
 AppStore|Install apps from public Xteink repositories|apps/AppStore/manifest.txt|192|2eb608b92de6bdeff4fc8ed447b9319f45c0d79d5d73b14db1ab5a92f91e42d4
-BinaryKeyboard|Two-button recursive keyboard experiment|apps/BinaryKeyboard/manifest.txt|97|8d26b7d2057f7ebdca133b936ea5d2074e8771af5235e9bf9722689a6fd8f5fd
+BinaryKeyboard|Two-button recursive keyboard experiment|apps/BinaryKeyboard/manifest.txt|97|893867dba0ae2725caca1eb56375c98c4dd00d351134aa129698c51f97e25690
 HomeAssistant|Home Assistant status cards|apps/HomeAssistant/manifest.txt|177|b38ca49804444fd383a505ce9c51680ad9b7443950d682ca1b9ef3047bff98a5
 Wordle|Guess the five-letter word in six tries|apps/Wordle/manifest.txt|177|199fafdf0d0f6e77916befc011f6e8466c254867800e1d4a9e67e95a06d0366b