CWAC RichEditText: Letting Users Make Text Pretty

Android's EditText widget supports formatted (a.k.a., "rich text") editing. It just lacks any way for the user to supply formatting, and it does not provide much in the way of convenience methods for a developer to, say, tie in some sort of toolbar to allow users to format selections.

That's where RichEditText comes in.

RichEditText is a drop-in replacement for EditText that:

• Provides an action mode on Android 2.1+ that allows users to format selected pieces of text
• Provides convenience methods to allow developers to trigger formatting for selected text via other means

This widget is packaged as an Android library project, with a demo/ subdirectory containing a regular Android project with a couple of activities demonstrating the use of RichEditText.

Usage

Add the project as a library project to your main project. Then, simply add com.commonsware.cwac.richedit.RichEditText widgets to your layout as needed:

<?xml version="1.0" encoding="utf-8"?>
<com.commonsware.cwac.richedit.RichEditText xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/editor"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:gravity="top|left"
  android:inputType="textMultiLine">

  <requestFocus/>

</com.commonsware.cwac.richedit.RichEditText>

At this time, there are no custom attributes used by RichEditText.

On its own, by default, RichEditText provides one means of users applying formatting: the standard <Ctrl>-<B> for bold, <Ctrl>-<I> for italics, and <Ctrl>-<U> for underline work if there is a selection. You can disable this by calling setKeyboardShortcutsEnabled(false).

If you want an on-screen UI for formatting, you have two choices.

First, you can call enableActionModes() on the RichEditText. This will add a "FORMAT" entry on the action mode that comes up when the user highlights some prose in the editor. Tapping that will allow the user to toggle various effects. This is easy to set up, but there are two significant limitations:

1. If you intend to run on devices prior to API Level 11, you need to be using ActionBarSherlock, and your activity hosting the RichEditText needs to inherit from one of the Sherlock-flavored activiy classes.

2. The action modes work so-so on phones at this time — tablets work better. To get it to work on phones at all, you will need to include android:imeOptions="flagNoExtractUi" as an attribute on the RichEditText.

Alternatively, you can have your own toolbar or gesture interface or whatever to allow users to format text. In that case, here are the two key methods to call on RichEditText:

• applyEffect() changes the current selection, applying or removing an effect (e.g., making the selection bold). The first parameter is the effect to apply (e.g., RichEditText.BOLD). The second parameter is the new value for the effect. Many effects take boolean values, so applyEffect(RichEditText.BOLD, true) would format the current selection as bold.

• setOnSelectionChangedListener() is where you register a RichEditText.OnSelectionChangedListener object, which will be called with onSelectionChanged() whenever the user changes the selection in the widget (i.e., highlights text or taps to un-select the highlight). You are provided the start and end positions of the selection (as were supplied to onSelectionChanged() to RichEditText itself by Android), plus a list of effects that are active on that selection. This will allow you to update your toolbar to indicate what is and is not in use, and so you know what to do when the user taps on one of those toolbar buttons again.

Supported Effects

At the time of this writing, here are the RichEditText static data members for each supported effect:

• BOLD
• ITALIC
• UNDERLINE
• STRIKETHROUGH
• SUPERSCRIPT
• SUBSCRIPT
• TYPEFACE

There are other effects presently implemented, but they will be revised shortly, including name and data type changes, so don't mess with them yet.

Dependencies

This project depends upon ActionBarSherlock. If you check out this project, you will need to update your local configuration to point to your own copy of ActionBarSherlock.

(as the world patiently awaits Android library projects being able to be packaged as JARs...)

This project should work on API Level 7 and higher, except for any portions that may be noted otherwise in this document. Please report bugs if you find features that do not work on API Level 7 and are not noted as requiring a higher version.

Version

This is version v0.2.0 of this module, meaning it is out of its months-long slumber and is proceeding apace.

Demo

In the demo/ sub-project you will find a sample activity that demonstrates the use of RichEditor.

In the tests/ sub-project you will find a small unit test suite for exercising some of the effects.

License

The code in this project is licensed under the Apache Software License 2.0, per the terms of the included LICENSE file.

Questions

If you have questions regarding the use of this code, please post a question on StackOverflow tagged with commonsware and android. Be sure to indicate what CWAC module you are having issues with, and be sure to include source code and stack traces if you are encountering crashes.

If you have encountered what is clearly a bug, or if you have a feature request, please post an issue. Be certain to include complete steps for reproducing the issue.

Do not ask for help via Twitter.

Also, if you plan on hacking on the code with an eye for contributing something back, please open an issue that we can use for discussing implementation details. Just lobbing a pull request over the fence may work, but it may not.

Release Notes

• v0.2.0: added keyboard shortcuts for bold/italic/underline and test suite, bug fixes
• v0.1.1: added disableActionModes() and fixed bug related to conditional action mode usage
• v0.1: added action mode support using ActionBarSherlock for pre-Honeycomb devices
• v0.0.3: removed RichEditor, replaced it with custom action modes
• v0.0.2: added RichEditor and made various fixes
• v0.0.1: initial release