HAXY

▀ ▄▄▄ ▀ ▀▀ ▄▀ ▀▀▀▀▀▄ ▀▀▀▀▀▀▀▀▀▄ ▀▀▀▀▀▀▀ ▄▀▀▀▀▀▀▀▀▀▀▄▀ ▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▄ ▀▀▀▀▀▀▀▀▀ ▄▀▀▀▀▀▀▀▀▀▀▀▀▀▄ ▀▀▀▀▀▀▀▀▀▀ ▀▀▄▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▄ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▄▀▀▀▀▀▀▀▀▀▀ ▀▀ ▀▀▀▀▀▄▀▀▀▀▀▀▄▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▄▀ ▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀ ▄▄ ▀▀▀ ▀▀▀▀▀▀▀▀▀ ▀ ▀▀▀▀ ▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀ ▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▄▀ ▄▀▀ ▀▀▀▀▀▀▀▀▀▀▄▀▄ ▄▀▀▀▀▀▀▀▀▄▀▀▀▀▀▀▀▀▀▄▄ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▄ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▄▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▄▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▄▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▄▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▄▄ ▀▀▀▀▀▀▀▀▀▀▀▀▀▄▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▄▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀

╭ script.js ────────────────────────────────────────────────────╮ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ │ ╰───────────────────────────────────────────────────────────────╯

╭────╮ ╭ clone ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ╮ │http│ ssh │ │ ╰────╯ ╰ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ╯

.. demon.ans haxy.wasm index.html ╭─────────────────────────────────╮ │script.js │ ╰─────────────────────────────────╯ term.ttf

1 const grid = document.getElementById("grid"); 2 const overlay = document.getElementById("overlay"); 3 const pageJsonBase64 = document.getElementById("page-data").textContent; 4 5 let wasmInstance; 6 const decoder = new TextDecoder(); 7 const encoder = new TextEncoder(); 8 let currentHtml = ""; 9 // seeded from the server-rendered overlay so the first wasm tick can no-op 10 // when its layout happens to match the server's. otherwise the first tick 11 // always rebuilds and any pre-load focus state is lost. 12 let currentOverlay = overlay.innerHTML; 13 14 const MIN_COLS = 30; 15 16 // measured once after the font is loaded. recomputed lazily if either reads 17 // back as zero (e.g. measured before the font was actually ready). 18 let cellWidth = null; 19 let cellHeight = null; 20 21 function measureCell() { 22 const probe = document.createElement("span"); 23 probe.style.position = "absolute"; 24 probe.style.visibility = "hidden"; 25 probe.style.whiteSpace = "pre"; 26 probe.textContent = "X".repeat(100); 27 grid.appendChild(probe); 28 const rect = probe.getBoundingClientRect(); 29 probe.remove(); 30 cellWidth = rect.width / 100; 31 cellHeight = rect.height; 32 } 33 34 function maxCols() { 35 if (!cellWidth) measureCell(); 36 return Math.max(MIN_COLS, Math.floor(document.body.clientWidth / cellWidth)); 37 } 38 39 // minimum row count for the wasm build — the TUI fills at least the 40 // viewport height, longer content extends past it and the browser scrolls. 41 function minRows() { 42 if (!cellHeight) measureCell(); 43 return Math.max(1, Math.floor(document.documentElement.clientHeight / cellHeight)); 44 } 45 46 function readWasmString(ptr, len) { 47 const memory = wasmInstance.exports.memory; 48 return decoder.decode(new Uint8Array(memory.buffer, ptr, len)); 49 } 50 51 const importObject = { 52 env: { 53 _consoleLog: function (ptr, len) { 54 console.log(readWasmString(ptr, len)); 55 }, 56 _setHtml: function (ptr, len) { 57 const html = readWasmString(ptr, len); 58 if (html === currentHtml) return; 59 currentHtml = html; 60 // the grid only holds non-focusable TUI cell spans now; the 61 // form (inputs + submit button) lives in #overlay and is 62 // never touched by this wipe, so we don't need to save and 63 // restore focus across the swap. 64 grid.innerHTML = html; 65 }, 66 _pushState: function (ptr, len) { 67 const url = readWasmString(ptr, len); 68 // idempotent: wasm tells us its current page every tick after a 69 // change, but we don't want to add history entries for a URL 70 // the browser is already on (e.g., right after the page loaded 71 // from a server-side render of the same route). 72 if (window.location.pathname !== url) { 73 history.pushState({}, "", url); 74 } 75 }, 76 _setOverlay: function (ptr, len) { 77 const html = readWasmString(ptr, len); 78 // diff against the previous overlay HTML; an unchanged overlay 79 // means no layout/structure has shifted (typing alone doesn't 80 // produce a diff because we deliberately omit the `value` 81 // attribute on inputs — the browser tracks that). skipping the 82 // innerHTML assignment keeps the live <form> alive across the 83 // mousedown→focusin→tick→click sequence, which is what lets 84 // the very first click on the submit button actually submit. 85 if (html === currentOverlay) return; 86 currentOverlay = html; 87 overlay.innerHTML = html; 88 }, 89 _focusInput: function (id) { 90 const target = overlay.querySelector(`[data-focus-id="${id}"]`); 91 if (target && document.activeElement !== target) target.focus(); 92 }, 93 }, 94 }; 95 96 function sendTextInputValue(focusId, value) { 97 const bytes = encoder.encode(value); 98 const ptr = wasmInstance.exports._alloc(bytes.length); 99 new Uint8Array(wasmInstance.exports.memory.buffer, ptr, bytes.length).set(bytes); 100 wasmInstance.exports._setTextInputValue(focusId, ptr, bytes.length); 101 wasmInstance.exports._tick(minRows(), maxCols()); 102 } 103 104 function sendEnter(form) { 105 const btn = form.querySelector("button[type=submit][data-focus-id]"); 106 if (!btn) return; 107 wasmInstance.exports._onMouseClick(Number(btn.dataset.focusId)); 108 wasmInstance.exports._onKeyDown(13); 109 wasmInstance.exports._tick(minRows(), maxCols()); 110 } 111 112 WebAssembly.instantiateStreaming(fetch("/haxy.wasm"), importObject).then(async (result) => { 113 wasmInstance = result.instance; 114 115 // wait for the @font-face to load before measuring cell width, otherwise 116 // we get the fallback font's metrics. 117 if (document.fonts && document.fonts.ready) { 118 await document.fonts.ready; 119 } 120 121 // the page is embedded as base64 so it can sit inside the host html 122 // without worrying about characters that would terminate the script tag. 123 // decode here and hand the raw json bytes to the wasm. 124 const jsonBytes = Uint8Array.from(atob(pageJsonBase64), (c) => c.charCodeAt(0)); 125 const ptr = wasmInstance.exports._alloc(jsonBytes.length); 126 new Uint8Array(wasmInstance.exports.memory.buffer, ptr, jsonBytes.length).set(jsonBytes); 127 wasmInstance.exports._init(ptr, jsonBytes.length, minRows(), maxCols()); 128 129 document.addEventListener("keydown", (event) => { 130 // let the browser handle modifier combos. the TUI only uses unmodified keys, 131 // so intercepting these would just break normal browser navigation. 132 if (event.altKey || event.ctrlKey || event.metaKey) return; 133 // when a form element (text input or submit button) owns focus, 134 // the browser handles typing, Enter-to-submit, and Tab natively. 135 // we only forward keys into the TUI when focus is elsewhere. 136 // exception: arrow up/down on an input unfocuses it and forwards 137 // the event so the TUI can move focus between widgets. 138 if (document.activeElement) { 139 const tag = document.activeElement.tagName; 140 const isArrow = event.key === "ArrowUp" || event.key === "ArrowDown" || 141 event.key === "ArrowLeft" || event.key === "ArrowRight"; 142 if (tag === "INPUT" && (event.key === "ArrowUp" || event.key === "ArrowDown")) { 143 // up/down moves between widgets; left/right stay in the input 144 document.activeElement.blur(); 145 } else if (tag === "BUTTON" && isArrow) { 146 // arrows navigate away from a focused submit button 147 document.activeElement.blur(); 148 } else if (tag === "INPUT" || tag === "BUTTON") { 149 // Enter (submit), typing, Tab — handled natively by the browser 150 return; 151 } 152 } 153 if (["ArrowUp", "ArrowDown", "ArrowLeft", "ArrowRight", "PageUp", "PageDown", "Home", "End"].includes(event.key)) { 154 event.preventDefault(); 155 } 156 wasmInstance.exports._onKeyDown(event.keyCode); 157 wasmInstance.exports._tick(minRows(), maxCols()); 158 }); 159 160 // listeners on document (not #grid) since the form lives outside #grid; 161 // input/focus events from form elements still bubble up to document. 162 document.addEventListener("input", (event) => { 163 const t = event.target; 164 if (!t || t.tagName !== "INPUT" || !t.dataset.focusId) return; 165 sendTextInputValue(Number(t.dataset.focusId), t.value); 166 }); 167 168 document.addEventListener("focusin", (event) => { 169 const t = event.target; 170 if (!t || !t.dataset || !t.dataset.focusId) return; 171 wasmInstance.exports._onMouseClick(Number(t.dataset.focusId)); 172 wasmInstance.exports._tick(minRows(), maxCols()); 173 }); 174 175 grid.addEventListener("click", (event) => { 176 const span = event.target.closest(".clickable"); 177 if (!span) return; 178 const focusId = Number(span.dataset.focusId); 179 wasmInstance.exports._onMouseClick(focusId); 180 wasmInstance.exports._tick(minRows(), maxCols()); 181 }); 182 183 let resizeTimer = null; 184 window.addEventListener("resize", () => { 185 clearTimeout(resizeTimer); 186 resizeTimer = setTimeout(() => { 187 wasmInstance.exports._tick(minRows(), maxCols()); 188 }, 100); 189 }); 190 }); 191