48e0fac6c2
Applications can use TextWatcher.afterTextChanged() to implement post-edit formatting of text, such as inserting spaces in a credit card number. From the user's perspective, the insertion of the spaces is not a separate action, so that change should be merged with the previous undo operation. * Force merge undo states for edits that are triggered by callbacks after the InputFilter, such as TextWatchers. * Reset the undo state when the whole field is reset with setText(). * Create separate undo operations for direct programmatic changes to the Editable (e.g. directly calling insert). * Remove part of the non-forced replacement edit merging code. An improved version will land in the next CL. Bug: 19332904 Change-Id: Iba5366a5aadbe3534554b668f8d417250deff505