| # Android Stylus Handwriting to HTML text input |
| |
| This directory contains files and classes needed to support the Stylus Handwriting recognition |
| feature provided by the Android Platform, used to commit text to html inputs. |
| |
| Since Android Platform cannot recognize the location of HTML input fields in Chrome Tab or Web view, |
| Stylus writing service expects Chrome to detect stylus writable input field and initiate the stylus |
| handwriting recognition. System settings would be used to determine the status of stylus writing |
| service on the device. There are 2 different ways in which Chromium would interact with the |
| platform's writing services: |
| |
| ## 1. Android Stylus writing |
| Android Platform provides APIs to interact with the stylus writing system so that recognition can be |
| started in HTML input fields. Then the platform uses the InputConnection created for the HTML input |
| field to commit the recognized text. Stylus input gestures like deleting text or adding spaces is |
| also supported with feedback from Chromium about the Input field location and the text around the |
| gesture coordinates. This feature is currently available in Android version T under Developer |
| options only and will be available fully from Android U. |
| |
| ## 2. Direct Writing service available only in Samsung Platform |
| This feature is exposed to webview and Chrome from Samsung Platform via service aidls defined in the |
| //content/public directory. Direct writing service expects Chrome to implement the service callback |
| Interface and forward touch events to the service when writing is detected over and input field. |
| Here, the resposibility of committing the recognized text lies with Chromium and is handled via the |
| ImeAdapter class. The information about Input field bounds, position on screen, caret position are |
| also expected to be provided in the service callback implementation. The Direct Writing service is |
| available on select devices starting Android version R. |
| |
| Stylus Gestures are detected by the service and gesture data like gesture coordinates and gesture |
| type, whether it is to remove or add text near current input text, is sent to Chromium to handle the |
| gesture and take corresponding input action. |
