Implement window.print() on Android

printing/android/java/src/org/chromium/printing/PrintingControllerImpl.java

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.printing;
 
 import android.os.Bundle;
 import android.os.CancellationSignal;
 import android.os.ParcelFileDescriptor;
 import android.print.PageRange;
 import android.print.PrintAttributes;
 import android.print.PrintDocumentInfo;
+import android.util.Log;
 
 import org.chromium.base.ThreadUtils;
 import org.chromium.printing.PrintDocumentAdapterWrapper.PdfGenerator;
 
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Iterator;
 
 /**
  * Controls the interactions with Android framework related to printing.
@@ skipping 17 matching lines @@
     /** Printing dialog has been dismissed and cleanup has been done. */
     private static final int PRINTING_STATE_FINISHED = 3;
 
     /** The singleton instance for this class. */
     private static PrintingController sInstance;
 
     private final String mErrorMessage;
 
     private PrintingContextInterface mPrintingContext;
 
+    /**
+     * The context of a query initiated by window.print(), stored here to allow syncrhonization
+     * with javascript.
+     */
+    private PrintingContextInterface mContextFromScriptInitiation;
+
     /** The file descriptor into which the PDF will be written.  Provided by the framework. */
     private int mFileDescriptor;
 
     /** Dots per inch, as provided by the framework. */
     private int mDpi;
 
     /** Paper dimensions. */
     private PrintAttributes.MediaSize mMediaSize;
 
     /** Numbers of pages to be printed, zero indexed. */
@@ skipping 19 matching lines @@
     private int mPrintingState = PRINTING_STATE_READY;
 
     /** Whether layouting parameters have been changed to require a new PDF generation. */
     private boolean mNeedNewPdf = false;
 
     /** Total number of pages to print with initial print dialog settings. */
     private int mLastKnownMaxPages = PrintDocumentInfo.PAGE_COUNT_UNKNOWN;
 
     private boolean mIsBusy = false;
 
+    private PrintManagerDelegate mPrintManager;
+
     private PrintingControllerImpl(PrintDocumentAdapterWrapper printDocumentAdapterWrapper,
                                    String errorText) {
         mErrorMessage = errorText;
         mPrintDocumentAdapterWrapper = printDocumentAdapterWrapper;
         mPrintDocumentAdapterWrapper.setPdfGenerator(this);
     }
 
     /**
      * Creates a controller for handling printing with the framework.
      *
@@ skipping 62 matching lines @@
     public boolean isBusy() {
         return mIsBusy;
     }
 
     @Override
     public void setPrintingContext(final PrintingContextInterface printingContext) {
         mPrintingContext = printingContext;
     }
 
     @Override
+    public void setPendingPrint(final Printable printable, PrintManagerDelegate printManager) {
+        if (mIsBusy) return;
+        mPrintable = printable;
+        mPrintManager = printManager;
+    }
+
+    @Override
+    public void startPendingPrint(PrintingContextInterface printingContext) {
+        if (mIsBusy || mPrintManager == null) {
+            Log.w(LOG_TAG, "Pending print can't be started. Is might be busy or not initialized.");
+            if (printingContext != null) printingContext.showSystemDialogDone();
+            return;
+        }
+        mContextFromScriptInitiation = printingContext;
+        mIsBusy = true;
+        mPrintDocumentAdapterWrapper.print(mPrintManager, mPrintable.getTitle());
+        mPrintManager = null;
+    }
+
+    @Override
     public void startPrint(final Printable printable, PrintManagerDelegate printManager) {
         if (mIsBusy) return;
-        mIsBusy = true;
-        mPrintable = printable;
-        mPrintDocumentAdapterWrapper.print(printManager, printable.getTitle());
+        setPendingPrint(printable, printManager);
+        startPendingPrint(null);
     }
 
     @Override
     public void pdfWritingDone(boolean success) {
         if (mPrintingState == PRINTING_STATE_FINISHED) return;
         mPrintingState = PRINTING_STATE_READY;
         if (success) {
             PageRange[] pageRanges = convertIntegerArrayToPageRanges(mPages);
             mOnWriteCallback.onWriteFinished(pageRanges);
         } else {
@@ skipping 128 matching lines @@
                 // extra). If we complete the PDF generation successfully from onLayout or onWrite,
                 // we already make the state PRINTING_STATE_READY and call askUserForSettingsReply
                 // inside pdfWritingDone, thus not entering here.  Also, if we get an extra
                 // AskUserForSettings call, it's handled inside {@link
                 // PrintingContext#pageCountEstimationDone}.
                 mPrintingContext.askUserForSettingsReply(false);
             }
             mPrintingContext.updatePrintingContextMap(mFileDescriptor, true);
             mPrintingContext = null;
         }
+
+        if (mContextFromScriptInitiation != null) {
+            mContextFromScriptInitiation.showSystemDialogDone();
+            mContextFromScriptInitiation = null;
+        }
+
         mPrintingState = PRINTING_STATE_FINISHED;
 
         closeFileDescriptor(mFileDescriptor);
         mFileDescriptor = -1;
 
         resetCallbacks();
         // The printmanager contract is that onFinish() is always called as the last
         // callback. We set busy to false here.
         mIsBusy = false;
     }
@@ skipping 44 matching lines @@
 
         // Convert the list into array.
         int[] ret = new int[pages.size()];
         Iterator<Integer> iterator = pages.iterator();
         for (int i = 0; i < ret.length; i++) {
             ret[i] = iterator.next().intValue();
         }
         return ret;
     }
 }