IME = Input Method Editor

• An input method editor (IME) is any user control that enables users to enter text.
• IME is a system abstraction that decouples text input from text processing.

IME = Input Method Editor

• Android input methods include:
  • on-screen keyboards (VKB)
  • hardware keyboards (HKB)
  • hand-writing recognizers
  • speech-to-text input
• Unlike desktop computers, Android uses an IME for all text input, including English.

Composition Strings

• To enter extended characters, a user:
  • composes text in the Input Method Editor
  • then commits the completed text to the application.
• A composition string consists of one or more clauses, where a clause is the smallest combination of characters that have a meaning in the language.
• A fancy English IME might commit the clauses "f" and "i" as one ligature character "fi".

Input Step 1

• Android IME sends text to Java as some sequence of:
  • keydown/keyup events,
  • uncommitted composition clauses,
  • and/or a committed composition strings.

Third-Party IMEs may have bugs

• ArtIME Japanese Input
• A.I.type Keyboard Plus
• COBIME Japanese
• Google Japanese Input
• Google Pinyin (Chinese)
• Google Voice Typing
• GO Keyboard
• Hacker's Keyboard
• ICS Keyboard
• Japanese IME Kaede IME
• KatakanaIME
• nicoWnnG IME
• OpenWnn Plus
• Perfect Keyboard Pro
• Simeji
• SlideIT Keyboard
• Smart Keyboard Pro
• SwiftKey X
• Swype
• Thumb Keyboard
• TouchPal Input
• Ultra Keyboard
• Very Easy Japanese IME (Hiragana, Katakana)
• Very Easy Japanese IME (Kanji)
• ...

Input Step 2

• Fennec's Java code normalizes IME events and device quirks.
• Fennec's JNI code funnels IME input to Gecko's IME Widget events.

Input Step 3

• Gecko dispatches keydown and keyup events to Flash plugin.
• Gecko dispatches events to DOM/JS, such as:
  • keydown
  • keypress
  • keyup
  • input
  • compositionstart
  • compositionupdate
  • compositionend

Input Step 3 (DOM Quirks)

:)