Give the search field a real caret and selection

CLAUDE.md

@@ -122,6 +122,7 @@ Works:
 - **Ranking state:** frecency (+100 per launch, 10-day half-life) and learned search terms in `db/frecency.json`. Aliases (exact → top; duplicates rejected), favourites (Ctrl+Shift+F, reorder Ctrl+Alt+↑↓) and disabled commands live in `db/settings.json` `commands`.
 - **Navigation:** pushed Omarchy submenus (search within them), the alias editor, back with Esc / Ctrl+[ / Backspace on an empty query / the header arrow, and Shift+Esc to pop to root.
 - **Keyboard:** Ctrl+K action panel (filterable, per-row shortcuts), ↵ / Ctrl+↵ / Ctrl+Shift+↵ for the first three actions, Ctrl+1–9, Ctrl+↑↓ to jump sections, PageUp/PageDown, ↑ on an empty root for search history, Ctrl+Shift+C copy, Alt+Shift+D disable, Ctrl + / − / 0 zoom.
+  - **Search field:** a real TextInput, so the caret and selection behave like any text field: ←/→, Ctrl+←/→ words, Home/End, Shift and Ctrl+Shift selection, mouse drag or double-click selection, Ctrl+A/C/X/V, Ctrl+Backspace / Ctrl+Delete word deletion (`core/TextCursor.js`), Ctrl+U clear, and IME input. Paste inserts at the caret and replaces the selection.
   - Navigation bindings (`general.navigationBindings`): `emacs` moves down with Ctrl+N; `vim-motions` moves with Ctrl+J/K and puts the action panel on **Alt+K**. Set it with `omacast call settings.updateGeneralSettings '{"navigationBindings":"vim-motions"}'`.
   - **Ctrl+P** opens the root dropdown (All / Applications / Commands); emacs Ctrl+P = up only works inside popups.
   - **Ctrl+T** opens the toast's actions (Copy Error Message on failures, Undo after Disable Command). **Ctrl+Shift+K** opens the About panel for the selected row.

core/TextCursor.js

@@ -0,0 +1,51 @@
+// Word bounds for the launcher's search field. The field itself is a QML
+// TextInput, so Qt owns the caret, the selection and the standard editing
+// keys; this module only supplies the word ranges used by Ctrl+Backspace and
+// Ctrl+Delete [D]. A word is a run of non-whitespace characters; a move in
+// either direction skips whitespace first, then the word.
+
+function clampPosition(text, position) {
+  text = String(text == null ? "" : text)
+  position = Number(position)
+  if (!isFinite(position)) return 0
+  return Math.max(0, Math.min(text.length, Math.round(position)))
+}
+
+function isSpace(ch) {
+  return /\s/.test(ch)
+}
+
+// Start of the word before `position`: "alpha beta " at 11 -> 6, at 6 -> 0.
+function wordStart(text, position) {
+  text = String(text == null ? "" : text)
+  var i = clampPosition(text, position)
+  while (i > 0 && isSpace(text.charAt(i - 1))) i--
+  while (i > 0 && !isSpace(text.charAt(i - 1))) i--
+  return i
+}
+
+// End of the word after `position`: "alpha beta" at 0 -> 5, at 5 -> 10.
+function wordEnd(text, position) {
+  text = String(text == null ? "" : text)
+  var i = clampPosition(text, position)
+  var n = text.length
+  while (i < n && isSpace(text.charAt(i))) i++
+  while (i < n && !isSpace(text.charAt(i))) i++
+  return i
+}
+
+// Range removed by Ctrl+Backspace (forward false) / Ctrl+Delete (forward
+// true): the selection when there is one, otherwise one word next to the
+// caret. start === end means there is nothing to delete.
+function deletionRange(text, anchor, caret, forward) {
+  text = String(text == null ? "" : text)
+  var start = clampPosition(text, Math.min(anchor, caret))
+  var end = clampPosition(text, Math.max(anchor, caret))
+  if (start !== end) return { start: start, end: end }
+  var at = clampPosition(text, caret)
+  return forward
+    ? { start: at, end: wordEnd(text, at) }
+    : { start: wordStart(text, at), end: at }
+}
+
+if (typeof module !== "undefined") module.exports = { clampPosition, wordStart, wordEnd, deletionRange }

tests/launcher-paste.test.js

@@ -3,6 +3,7 @@ const assert = require("node:assert/strict")
 const fs = require("node:fs")
 const path = require("node:path")
 const vm = require("node:vm")
+const TextCursor = require("../core/TextCursor.js")
 
 const source = fs.readFileSync(path.join(__dirname, "../ui/LauncherWindow.qml"), "utf8")
 
@@ -22,19 +23,53 @@ function harness(text) {
   const changes = []
   const window = {
     query: "prefix ", actionPanelOpen: false, view: { kind: "root" }, historyIndex: 0, argFocus: -1, argDefs: [],
+    queryInputSyncing: false,
     rebuild: reset => changes.push(reset), isTyping: () => false,
     isActionPanelKey: () => false, direction: () => 0
   }
+  // The subset of TextInput the launcher touches, with the same caret and
+  // selection rules the widget has (selectionStart === selectionEnd === caret
+  // when nothing is selected).
+  const queryInput = {
+    text: window.query,
+    selectionStart: window.query.length,
+    selectionEnd: window.query.length,
+    cursorPosition: window.query.length,
+    deselect() { this.selectionStart = this.selectionEnd = this.cursorPosition },
+    remove(start, end) {
+      this.text = this.text.slice(0, start) + this.text.slice(end)
+      this.onTextChanged()
+    },
+    insert(position, value) {
+      this.text = this.text.slice(0, position) + value + this.text.slice(position)
+      this.onTextChanged()
+    },
+    onTextChanged() { window.queryEdited(this.text) }
+  }
   const actionPanel = { item: { filter: "" } }
   const clipboardInput = { text: "", clear() { this.text = "" }, paste() { this.text = text } }
-  const context = vm.createContext({ Qt, window, actionPanel, clipboardInput, Util: { editsFilter: () => false } })
+  const context = vm.createContext({ Qt, window, queryInput, actionPanel, clipboardInput, TextCursor, Util: { editsFilter: () => false } })
+  window.queryEdited = value => {
+    context.value = value
+    vm.runInContext(body("function queryEdited(value)"), context)
+  }
+  window.syncQueryInput = () => vm.runInContext(body("function syncQueryInput()"), context)
   window.setQuery = next => {
     context.next = next
     vm.runInContext(body("function setQuery(next)"), context)
+    window.syncQueryInput()
+  }
+  window.deleteQueryWord = forward => {
+    context.forward = forward
+    vm.runInContext(body("function deleteQueryWord(forward)"), context)
+  }
+  window.insertQueryText = text => {
+    context.text = text
+    vm.runInContext(body("function insertQueryText(text)"), context)
   }
   window.pasteClipboard = () => vm.runInContext(body("function pasteClipboard()"), context)
   return {
-    Qt, window, actionPanel, clipboardInput, changes,
+    Qt, window, queryInput, actionPanel, clipboardInput, changes,
     press(key, modifiers) {
       context.event = { key: Qt["Key_" + key], modifiers }
       return vm.runInContext(body("function handleKey(event)"), context)
@@ -89,11 +124,48 @@ test("clipboard paste also works in submenu queries and alias editing", () => {
   h.press("V", h.Qt.ControlModifier)
   assert.equal(h.window.query, "prefix some text with\tspaces")
   h.window.view.kind = "alias"
-  h.window.query = ""
+  h.window.setQuery("")
   h.press("Insert", h.Qt.ShiftModifier)
   assert.equal(h.window.query, "sometextwithspaces")
 })
 
+test("paste replaces the selection at the caret instead of appending", () => {
+  const h = harness("12+34")
+  h.queryInput.text = "alpha beta"
+  h.window.query = "alpha beta"
+  h.queryInput.cursorPosition = 11
+  h.queryInput.deselect()
+  h.queryInput.selectionStart = 6
+  h.queryInput.selectionEnd = 10
+  h.queryInput.cursorPosition = 10
+  h.press("V", h.Qt.ControlModifier)
+  assert.equal(h.window.query, "alpha 12+34")
+  assert.equal(h.queryInput.cursorPosition, 11)
+  assert.equal(h.queryInput.selectionStart, 11)
+  assert.equal(h.queryInput.selectionEnd, 11)
+})
+
+test("Ctrl+Backspace deletes the word before the caret, Ctrl+Delete the next one", () => {
+  const back = harness("x")
+  back.queryInput.text = "alpha beta"
+  back.window.query = "alpha beta"
+  back.queryInput.cursorPosition = 10
+  back.queryInput.deselect()
+  back.press("Backspace", back.Qt.ControlModifier)
+  assert.equal(back.window.query, "alpha ")
+  assert.equal(back.queryInput.text, "alpha ")
+  assert.equal(back.queryInput.cursorPosition, 6)
+
+  const forward = harness("x")
+  forward.queryInput.text = "alpha beta"
+  forward.window.query = "alpha beta"
+  forward.queryInput.cursorPosition = 6
+  forward.queryInput.deselect()
+  forward.press("Delete", forward.Qt.ControlModifier)
+  assert.equal(forward.window.query, "alpha ")
+  assert.equal(forward.queryInput.cursorPosition, 6)
+})
+
 test("action-panel paste edits its filter without changing the query", () => {
   const h = harness("Copy\nResult")
   h.window.actionPanelOpen = true

tests/textcursor.test.js

@@ -0,0 +1,51 @@
+const test = require("node:test")
+const assert = require("node:assert/strict")
+const { clampPosition, wordStart, wordEnd, deletionRange } = require("../core/TextCursor.js")
+
+test("wordStart walks back over whitespace and then the word", () => {
+  const text = "alpha beta  gamma"
+  assert.equal(wordStart(text, text.length), 12)
+  assert.equal(wordStart(text, 12), 6)
+  assert.equal(wordStart(text, 11), 6)
+  assert.equal(wordStart(text, 6), 0)
+  assert.equal(wordStart(text, 5), 0)
+  assert.equal(wordStart(text, 0), 0)
+})
+
+test("wordEnd walks forward over whitespace and then the word", () => {
+  const text = "alpha beta  gamma"
+  assert.equal(wordEnd(text, 0), 5)
+  assert.equal(wordEnd(text, 5), 10)
+  assert.equal(wordEnd(text, 10), 17)
+  assert.equal(wordEnd(text, text.length), text.length)
+})
+
+test("word bounds use characters, not bytes", () => {
+  assert.equal(wordStart("héllo wörld", 11), 6)
+  assert.equal(wordStart("héllo wörld", 6), 0)
+  assert.equal(wordEnd("héllo wörld", 0), 5)
+  assert.equal(wordEnd("你好 世界", 3), 5)
+  assert.equal(wordStart("你好 世界", 5), 3)
+})
+
+test("deletionRange deletes the word next to a collapsed caret", () => {
+  assert.deepEqual(deletionRange("alpha beta", 10, 10, false), { start: 6, end: 10 })
+  assert.deepEqual(deletionRange("alpha beta ", 11, 11, false), { start: 6, end: 11 })
+  assert.deepEqual(deletionRange("alpha beta", 0, 0, true), { start: 0, end: 5 })
+  assert.deepEqual(deletionRange("alpha beta", 3, 3, true), { start: 3, end: 5 })
+  assert.deepEqual(deletionRange("", 0, 0, false), { start: 0, end: 0 })
+  assert.deepEqual(deletionRange("", 0, 0, true), { start: 0, end: 0 })
+})
+
+test("deletionRange deletes the selection whatever the caret side", () => {
+  assert.deepEqual(deletionRange("alpha beta", 8, 2, false), { start: 2, end: 8 })
+  assert.deepEqual(deletionRange("alpha beta", 2, 8, true), { start: 2, end: 8 })
+})
+
+test("clampPosition keeps positions inside the text", () => {
+  assert.equal(clampPosition("abc", -4), 0)
+  assert.equal(clampPosition("abc", 99), 3)
+  assert.equal(clampPosition("abc", 1.6), 2)
+  assert.equal(clampPosition("abc", "x"), 0)
+  assert.equal(clampPosition(null, 2), 0)
+})