HAXY

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

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

.. 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 _setOverlay: function (ptr, len) { 67 const html = readWasmString(ptr, len); 68 // diff against the previous overlay HTML; an unchanged overlay 69 // means no layout/structure has shifted (typing alone doesn't 70 // produce a diff because we deliberately omit the `value` 71 // attribute on inputs — the browser tracks that). skipping the 72 // innerHTML assignment keeps the live <form> alive across the 73 // mousedown→focusin→tick→click sequence, which is what lets 74 // the very first click on the submit button actually submit. 75 if (html === currentOverlay) return; 76 currentOverlay = html; 77 overlay.innerHTML = html; 78 }, 79 }, 80 }; 81 82 function sendTextInputValue(focusId, value) { 83 const bytes = encoder.encode(value); 84 const ptr = wasmInstance.exports._alloc(bytes.length); 85 new Uint8Array(wasmInstance.exports.memory.buffer, ptr, bytes.length).set(bytes); 86 wasmInstance.exports._setTextInputValue(focusId, ptr, bytes.length); 87 wasmInstance.exports._tick(minRows(), maxCols()); 88 } 89 90 WebAssembly.instantiateStreaming(fetch("haxy.wasm"), importObject).then(async (result) => { 91 wasmInstance = result.instance; 92 93 // wait for the @font-face to load before measuring cell width, otherwise 94 // we get the fallback font's metrics. 95 if (document.fonts && document.fonts.ready) { 96 await document.fonts.ready; 97 } 98 99 // the page is embedded as base64 so it can sit inside the host html 100 // without worrying about characters that would terminate the script tag. 101 // decode here and hand the raw json bytes to the wasm. 102 const jsonBytes = Uint8Array.from(atob(pageJsonBase64), (c) => c.charCodeAt(0)); 103 const ptr = wasmInstance.exports._alloc(jsonBytes.length); 104 new Uint8Array(wasmInstance.exports.memory.buffer, ptr, jsonBytes.length).set(jsonBytes); 105 wasmInstance.exports._start(ptr, jsonBytes.length, minRows(), maxCols()); 106 107 document.addEventListener("keydown", (event) => { 108 // when a form element (text input or submit button) owns focus, 109 // the browser handles typing, Enter-to-submit, and Tab natively. 110 // we only forward keys into the TUI when focus is elsewhere. 111 if (document.activeElement) { 112 const tag = document.activeElement.tagName; 113 if (tag === "INPUT" || tag === "BUTTON") return; 114 } 115 if (["ArrowUp", "ArrowDown", "ArrowLeft", "ArrowRight", "PageUp", "PageDown", "Home", "End"].includes(event.key)) { 116 event.preventDefault(); 117 } 118 wasmInstance.exports._onKeyDown(event.keyCode); 119 wasmInstance.exports._tick(minRows(), maxCols()); 120 }); 121 122 // listeners on document (not #grid) since the form lives outside #grid; 123 // input/focus events from form elements still bubble up to document. 124 document.addEventListener("input", (event) => { 125 const t = event.target; 126 if (!t || t.tagName !== "INPUT" || !t.dataset.focusId) return; 127 sendTextInputValue(Number(t.dataset.focusId), t.value); 128 }); 129 130 document.addEventListener("focusin", (event) => { 131 const t = event.target; 132 if (!t || !t.dataset || !t.dataset.focusId) return; 133 wasmInstance.exports._onMouseClick(Number(t.dataset.focusId)); 134 wasmInstance.exports._tick(minRows(), maxCols()); 135 }); 136 137 grid.addEventListener("click", (event) => { 138 const span = event.target.closest(".clickable"); 139 if (!span) return; 140 const focusId = Number(span.dataset.focusId); 141 wasmInstance.exports._onMouseClick(focusId); 142 wasmInstance.exports._tick(minRows(), maxCols()); 143 }); 144 145 let resizeTimer = null; 146 window.addEventListener("resize", () => { 147 clearTimeout(resizeTimer); 148 resizeTimer = setTimeout(() => { 149 wasmInstance.exports._tick(minRows(), maxCols()); 150 }, 100); 151 }); 152 }); 153