Add floating soft keyboard input

html_orig/jssrc/soft_keyboard.js

@@ -0,0 +1,36 @@
+$.ready(() => {
+  const input = qs('#softkb-input')
+  let keyboardOpen = false
+
+  let updateInputPosition = function () {
+    if (!keyboardOpen) return
+
+    let [x, y] = Screen.gridToScreen(Screen.cursor.x, Screen.cursor.y)
+    input.style.transform = `translate(${x}px, ${y}px)`
+  }
+
+  input.addEventListener('focus', () => {
+    keyboardOpen = true
+    updateInputPosition()
+  })
+  input.addEventListener('blur', () => (keyboardOpen = false))
+  Screen.on('cursor-moved', updateInputPosition)
+
+  window.kbOpen = function openSoftKeyboard (open) {
+    keyboardOpen = open
+    updateInputPosition()
+    if (open) input.focus()
+    else input.blur()
+  }
+
+  input.addEventListener('keydown', e => {
+    if (e.key === 'Backspace') {
+      e.preventDefault()
+      e.stopPropagation()
+      Input.sendString('\b')
+    }
+  })
+  input.addEventListener('keypress', e => {
+    e.stopPropagation()
+  })
+})