Move keybinder code into its own file

1 files changed, 61 insertions, 0 deletions

diff --git a/src/keybinder.js b/src/keybinder.js
new file mode 100644
index 0000000..1d80348
--- /dev/null
+++ b/src/keybinder.js
@@ -0,0 +1,61 @@
+const splitChars = str => str.split('').map(char => char.charCodeAt(0))
+
+const simpleKeybindings = {
+  space: [0x20],
+  esc: [0x1b], escape: [0x1b],
+  up: [0x1b, ...splitChars('[A')],
+  down: [0x1b, ...splitChars('[B')],
+  right: [0x1b, ...splitChars('[C')],
+  left: [0x1b, ...splitChars('[D')],
+  shiftUp: [0x1b, ...splitChars('[1;2A')],
+  shiftDown: [0x1b, ...splitChars('[1;2B')],
+  shiftRight: [0x1b, ...splitChars('[1;2C')],
+  shiftLeft: [0x1b, ...splitChars('[1;2D')],
+  delete: [0x7f]
+}
+
+module.exports.compileKeybindings = function(bindings, commands) {
+  const handlers = bindings.map(binding => {
+    const [ keys, command, ...args] = binding
+
+    if (!commands.hasOwnProperty(command)) {
+      console.warn('Invalid command', command, 'in keybinding', binding)
+      return
+    }
+
+    let failed = false
+
+    const bufferParts = keys.map(item => {
+      if (typeof item === 'number') {
+        return [item]
+      } else if (Object.keys(simpleKeybindings).includes(item)) {
+        return simpleKeybindings[item]
+      } else if (typeof item === 'string' && item.length === 1) {
+        return [item.charCodeAt(0)]
+      } else {
+        // Error
+        console.warn('Invalid keybinding part', item, 'in keybinding', bindings)
+        failed = true
+        return []
+      }
+    }).reduce((a, b) => a.concat(b), [])
+
+    if (failed) {
+      return
+    }
+
+    const buffer = Buffer.from(bufferParts)
+
+    return function(inputData) {
+      if (buffer.equals(inputData)) {
+        commands[command](...args)
+      }
+    }
+  }).filter(Boolean)
+
+  return function(inputData) {
+    for (let handler of handlers) {
+      handler(inputData)
+    }
+  }
+}