/html-textview

TextView to display simple HTML content

Primary LanguageJavaApache License 2.0Apache-2.0

HtmlTextView for Android

HtmlTextView is an extended TextView component for Android, which can load HTML and converts it into Spannable for displaying it. It is a replacement for usage of the WebView component, which behaves strange on some Android versions, flickers while loading, etc.

The library also includes a workaround to prevent TextView from crashing on specific Android versions and the possibility to load images from local drawables folder or from the Internet.

This library is kept tiny without external dependencies. I am using it to provide Help/About Activities in my apps.

How to import

Add this to your build.gradle:

repositories {
    jcenter()
}

dependencies {
    compile 'org.sufficientlysecure:html-textview:3.5'
}

Example

<org.sufficientlysecure.htmltextview.HtmlTextView
            android:id="@+id/html_text"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:textAppearance="@android:style/TextAppearance.Small" />
HtmlTextView htmlTextView = (HtmlTextView) view.findViewById(R.id.html_text);

// loads html from string and displays cat_pic.png from the app's drawable folder
htmlTextView.setHtml("<h2>Hello wold</h2><ul><li>cats</li><li>dogs</li></ul><img src=\"cat_pic\"/>",
    new HtmlResImageGetter(htmlTextView));

or

HtmlTextView htmlTextView = (HtmlTextView) view.findViewById(R.id.html_text);

// loads html from string and displays cat_pic.png from the app's assets folder
htmlTextView.setHtml("<h2>Hello wold</h2><ul><li>cats</li><li>dogs</li></ul><img src=\"cat_pic\"/>",
    new HtmlAssetsImageGetter(htmlTextView));

or

HtmlTextView htmlTextView = (HtmlTextView) view.findViewById(R.id.html_text);

// loads html from string and displays http://www.example.com/cat_pic.png from the Internet
htmlTextView.setHtml("<h2>Hello wold</h2><img src=\"http://www.example.com/cat_pic.png\"/>",
    new HtmlHttpImageGetter(htmlTextView));

or

HtmlTextView htmlTextView = (HtmlTextView) view.findViewById(R.id.html_text);

// loads html from raw resource, i.e., a html file in res/raw/,
// this allows translatable resource (e.g., res/raw-de/ for german)
htmlTextView.setHtml(R.raw.help, new HtmlHttpImageGetter(htmlTextView));

Supported HTML tags

Tags supported by Android (history of Html class)

Extended support by HtmlTextView

  • <ul>
  • <ol>
  • <li>
  • <code>
  • <center>
  • <strike>

Support for HTML tables

HtmlTextView now supports HTML tables (to a limited extent) by condensing the text into a link which developers are able to render in a native WebView. To take advantage of the feature you'll need to:

  1. implement a ClickableTableSpan which provides access to the table HTML (which can be forwarded to a WebView)

  2. provide a DrawTableLinkSpan which defines what the table link should look like (i.e. text, text color, text size)

Take a look at the project's sample app for an example.

We recognize the standard table tags:

  • <table>
  • <tr>
  • <th>
  • <td>

as well as the tags extended by HtmlTextView. However, support doesn’t currently extend to tags natively supported by Android (e.g. <b>, <big>, <h1>) which means tables will not include the extra styling.

Changelog

3.5

  • Allow image compression

3.4

  • Fix textIsSelectable

3.3

  • Fix text cutting bug
  • prevent EmptyStackException when processing malformed li tags

3.2

  • Indenting entries of ordered lists the same way as of unordered lists
  • Fix OutOfMemory

3.1

  • Override handling of <ul> <ol> and <li> tags done by newer versions of Android SDK (removes empty lines between items)

3.0

  • Removed deprecated methods and classes
  • Fix out of bounds issue

2.0

  • Introduce better API

License

Apache License v2

See LICENSE for full license text.

Authors

Contributions

Feel free to fork and do pull requests. I am more than happy to merge them. Please do not introduce external dependencies.