Publish Print Api for Webview

Bug:10652036

Change-Id: Ibcc7e48f4e4ce1bc437c0d3fb89d3d66a90dca64

4 files changed, 18 insertions, 44 deletions

diff --git a/api/current.txt b/api/current.txt
index b5930ec..1c2f715 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -30148,6 +30148,7 @@ package android.webkit {
     method public void clearSslPreferences();
     method public deprecated void clearView();
     method public android.webkit.WebBackForwardList copyBackForwardList();
+    method public android.print.PrintDocumentAdapter createPrintDocumentAdapter();
     method public void destroy();
     method public void documentHasImages(android.os.Message);
     method public void evaluateJavascript(java.lang.String, android.webkit.ValueCallback<java.lang.String>);
diff --git a/core/java/android/webkit/WebView.java b/core/java/android/webkit/WebView.java
index 8fc3ce3..15331dc 100644
--- a/core/java/android/webkit/WebView.java
+++ b/core/java/android/webkit/WebView.java
@@ -31,9 +31,8 @@ import android.os.Bundle;
 import android.os.CancellationSignal;
 import android.os.Looper;
 import android.os.Message;
-import android.os.ParcelFileDescriptor;
 import android.os.StrictMode;
-import android.print.PrintAttributes;
+import android.print.PrintDocumentAdapter;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.view.KeyEvent;
@@ -1069,41 +1068,21 @@ public class WebView extends AbsoluteLayout
     }
 
     /**
-     * Exports the contents of this Webview as PDF. Only supported for API levels
+     * Creates a PrintDocumentAdapter that provides the content of this Webview for printing.
+     * Only supported for API levels
      * {@link android.os.Build.VERSION_CODES#KITKAT} and above.
      *
-     * TODO(sgurun) the parameter list is stale. Fix it before unhiding.
-     *
-     * @param fd             The FileDescriptor to export the PDF contents to. Cannot be null.
-     * @param width          The page width. Should be larger than 0.
-     * @param height         The page height. Should be larger than 0.
-     * @param resultCallback A callback to be invoked when the PDF content is exported.
-     *                       A true indicates success, and a false failure. Cannot be null.
-     * @param cancellationSignal Signal for cancelling the PDF conversion request. Must not
-     *                       be null.
-     *
-     * The PDF conversion is done asynchronously and the PDF output is written to the provided
-     * file descriptor. The caller should not close the file descriptor until the resultCallback
-     * is called, indicating PDF conversion is complete. Webview will never close the file
-     * descriptor.
-     * Limitations: Webview cannot be drawn during the PDF export so the  application is
-     * recommended to take it offscreen, or putting in a layer with an overlaid progress
-     * UI / spinner.
-     *
-     * If the caller cancels the task using the cancellationSignal, the cancellation will be
-     * acked using the resultCallback signal.
-     *
-     * Throws an exception if an IO error occurs accessing the file descriptor.
-     *
-     * TODO(sgurun) margins, explain the units, make it public.
-     * @hide
+     * The adapter works by converting the Webview contents to a PDF stream. The Webview cannot
+     * be drawn during the conversion process - any such draws are undefined. It is recommended
+     * to use a dedicated off screen Webview for the printing. If necessary, an application may
+     * temporarily hide a visible WebView by using a custom PrintDocumentAdapter instance
+     * wrapped around the object returned and observing the onStart and onFinish methods. See
+     * {@link android.print.PrintDocumentAdapter} for more information.
      */
-    public void exportToPdf(ParcelFileDescriptor fd, PrintAttributes attributes,
-            ValueCallback<Boolean> resultCallback, CancellationSignal cancellationSignal)
-            throws java.io.IOException {
+    public PrintDocumentAdapter createPrintDocumentAdapter() {
         checkThread();
-        if (DebugFlags.TRACE_API) Log.d(LOGTAG, "exportToPdf");
-        mProvider.exportToPdf(fd, attributes, resultCallback, cancellationSignal);
+        if (DebugFlags.TRACE_API) Log.d(LOGTAG, "createPrintDocumentAdapter");
+        return mProvider.createPrintDocumentAdapter();
     }
 
     /**
diff --git a/core/java/android/webkit/WebViewClassic.java b/core/java/android/webkit/WebViewClassic.java
index 3f22d53..e82ce30 100644
--- a/core/java/android/webkit/WebViewClassic.java
+++ b/core/java/android/webkit/WebViewClassic.java
@@ -62,7 +62,7 @@ import android.os.Handler;
 import android.os.Looper;
 import android.os.Message;
 import android.os.SystemClock;
-import android.print.PrintAttributes;
+import android.print.PrintDocumentAdapter;
 import android.security.KeyChain;
 import android.text.Editable;
 import android.text.InputType;
@@ -2894,12 +2894,10 @@ public final class WebViewClassic implements WebViewProvider, WebViewProvider.Sc
     }
 
     /**
-     * See {@link WebView#exportToPdf()}
+     * See {@link WebView#createPrintDocumentAdapter()}
      */
     @Override
-    public void exportToPdf(android.os.ParcelFileDescriptor fd, PrintAttributes attributes,
-            ValueCallback<Boolean> resultCallback, CancellationSignal cancellationSignal)
-            throws java.io.IOException {
+    public PrintDocumentAdapter createPrintDocumentAdapter() {
         // K-only API not implemented in WebViewClassic.
         throw new IllegalStateException("This API not supported on Android 4.3 and earlier");
     }
diff --git a/core/java/android/webkit/WebViewProvider.java b/core/java/android/webkit/WebViewProvider.java
index d625d8a..696aad4 100644
--- a/core/java/android/webkit/WebViewProvider.java
+++ b/core/java/android/webkit/WebViewProvider.java
@@ -25,10 +25,8 @@ import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
 import android.net.http.SslCertificate;
 import android.os.Bundle;
-import android.os.CancellationSignal;
 import android.os.Message;
-import android.os.ParcelFileDescriptor;
-import android.print.PrintAttributes;
+import android.print.PrintDocumentAdapter;
 import android.view.KeyEvent;
 import android.view.MotionEvent;
 import android.view.View;
@@ -149,9 +147,7 @@ public interface WebViewProvider {
 
     public Picture capturePicture();
 
-    public void exportToPdf(ParcelFileDescriptor fd, PrintAttributes attributes,
-            ValueCallback<Boolean> resultCallback, CancellationSignal cancellationSignal)
-            throws java.io.IOException;
+    public PrintDocumentAdapter createPrintDocumentAdapter();
 
     public float getScale();