Google云打印源代码

<uses-permission android:name="android.permission.INTERNET" />

Intent printIntent = new Intent(this, PrintDialogActivity.class);
printIntent.setDataAndType(docUri, docMimeType);   //docUri: 文档的Uri路径,docMimeType: 文档的MIME类型，如PDF-> "application/pdf"
printIntent.putExtra("title", docTitle);    //docTitle: 文档标题
startActivity(printIntent);

package google.com.android.cloudprint;
import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.ContentResolver;
import android.content.Intent;
import android.os.Bundle;
import android.util.Base64;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;

import java.io.ByteArrayOutputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;

public class PrintDialogActivity extends Activity {
private static final String PRINT_DIALOG_URL = "https://www.google.com/cloudprint/dialog.html";
private static final String JS_INTERFACE = "AndroidPrintDialog";
private static final String CONTENT_TRANSFER_ENCODING = "base64";

private static final String ZXING_URL = "http://zxing.appspot.com";
private static final int ZXING_SCAN_REQUEST = 65743;

/**
* Post message that is sent by Print Dialog web page when the printing dialog
* needs to be closed.
*/
private static final String CLOSE_POST_MESSAGE_NAME = "cp-dialog-on-close";

/**
* Web view element to show the printing dialog in.
*/
private WebView dialogWebView;

/**
* Intent that started the action.
*/
Intent cloudPrintIntent;

@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);

setContentView(R.layout.print_dialog);
dialogWebView = (WebView) findViewById(R.id.webview);
cloudPrintIntent = this.getIntent();

WebSettings settings = dialogWebView.getSettings();
settings.setJavaScriptEnabled(true);

dialogWebView.setWebViewClient(new PrintDialogWebClient());
dialogWebView.addJavascriptInterface(
new PrintDialogJavaScriptInterface(), JS_INTERFACE);

dialogWebView.loadUrl(PRINT_DIALOG_URL);
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent intent) {
if (requestCode == ZXING_SCAN_REQUEST && resultCode == RESULT_OK) {
dialogWebView.loadUrl(intent.getStringExtra("SCAN_RESULT"));
}
}

final class PrintDialogJavaScriptInterface {
public String getType() {
return cloudPrintIntent.getType();
}

public String getTitle() {
return cloudPrintIntent.getExtras().getString("title");
}

public String getContent() {
try {
ContentResolver contentResolver = getContentResolver();
InputStream is = contentResolver.openInputStream(cloudPrintIntent.getData());
ByteArrayOutputStream baos = new ByteArrayOutputStream();

byte[] buffer = new byte[4096];
int n = is.read(buffer);
while (n >= 0) {
baos.write(buffer, 0, n);
n = is.read(buffer);
}
is.close();
baos.flush();

return Base64.encodeToString(baos.toByteArray(), Base64.DEFAULT);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return "";
}

public String getEncoding() {
return CONTENT_TRANSFER_ENCODING;
}

public void onPostMessage(String message) {
if (message.startsWith(CLOSE_POST_MESSAGE_NAME)) {
finish();
}
}
}

private final class PrintDialogWebClient extends WebViewClient {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if (url.startsWith(ZXING_URL)) {
Intent intentScan = new Intent("com.google.zxing.client.android.SCAN");
intentScan.putExtra("SCAN_MODE", "QR_CODE_MODE");
try {
startActivityForResult(intentScan, ZXING_SCAN_REQUEST);
} catch (ActivityNotFoundException error) {
view.loadUrl(url);
}
} else {
view.loadUrl(url);
}
return false;
}

@Override
public void onPageFinished(WebView view, String url) {
if (PRINT_DIALOG_URL.equals(url)) {
// Submit print document.
view.loadUrl("javascript:printDialog.setPrintDocument(printDialog.createPrintDocument("
+ "window." + JS_INTERFACE + ".getType(),window." + JS_INTERFACE + ".getTitle(),"
+ "window." + JS_INTERFACE + ".getContent(),window." + JS_INTERFACE + ".getEncoding()))");

// Add post messages listener.
view.loadUrl("javascript:window.addEventListener('message',"
+ "function(evt){window." + JS_INTERFACE + ".onPostMessage(evt.data)}, false)");
}
}
}
}

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<WebView android:id="@+id/webview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
</RelativeLayout>