The Android Printing framework includes extensions to the WebView class that make it possible to print HTML based content from within an Android application. This content can be in the form of HTML created dynamically within the application at runtime, or a pre-existing web page loaded into a WebView instance. In the case of dynamically created HTML, it is important to use a WebViewClient instance to ensure that printing does not start until the HTML has been fully loaded into the WebView.
== Designing the User Interface Layout ==
Load the activity_web_print.xml layout resource file into the Graphical Layout editor if it has not already been loaded and select and delete the “Hello World!” TextView object.
Switch to the XML view by clicking on the activity_web_print.xml tab located along the lower edge of the editor panel and remove the padding properties from the file so that the WebView will extend to the edges of the display when added to the layout:
<pre>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".WebPrintActivity" >
</RelativeLayout>
</pre>
Switch back to the graphical layout view and, from the Composite section of the palette, drag and drop a WebView object so that it fills the entire layout canvas as outlined in Figure 50-3:
[[Image:android_printing_webview.png|A WebView object added to the Android web printing example UI]]
Figure 50-3
Right-click on the newly added WebView instance, select the Edit ID… menu option and change the name of the view to myWebView before clicking on OK to commit the change.
Before proceeding to the next step of this tutorial, an additional permission needs to be added to the project to enable the WebView object to access the internet and download a web page for printing. Add this permission by locating the AndroidManifest.xml file in the Project Explorer panel and double clicking on it to load it into the editing panel. Once loaded, directly edit the XML content by clicking on the AndroidManifest.xml tab located along the bottom edge of the manifest editor panel. Within the XML, add the appropriate permission line as shown in the following listing:
<pre>
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.webprint"
android:versionCode="1"
android:versionName="1.0" >
<uses-permission android:name="android.permission.INTERNET" />
<uses-sdk
android:minSdkVersion="19"
android:targetSdkVersion="19" />
.
.
.
</manifest>
</pre>
Save both layout and manifest files before proceeding.
