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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.htmlviewer;
import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.ContentResolver;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.Manifest;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.webkit.WebChromeClient;
import android.webkit.WebResourceRequest;
import android.webkit.WebResourceResponse;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
import java.io.IOException;
import java.io.InputStream;
import java.net.URISyntaxException;
import java.util.zip.GZIPInputStream;
/**
* Simple activity that shows the requested HTML page. This utility is
* purposefully very limited in what it supports, including no network or
* JavaScript.
*/
public class HTMLViewerActivity extends Activity {
private static final String TAG = "HTMLViewer";
private WebView mWebView;
private View mLoading;
private Uri mOnPermissionDestination;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mWebView = (WebView) findViewById(R.id.webview);
mLoading = findViewById(R.id.loading);
mWebView.setWebChromeClient(new ChromeClient());
mWebView.setWebViewClient(new ViewClient());
WebSettings s = mWebView.getSettings();
s.setUseWideViewPort(true);
s.setSupportZoom(true);
s.setBuiltInZoomControls(true);
s.setDisplayZoomControls(false);
s.setSavePassword(false);
s.setSaveFormData(false);
s.setBlockNetworkLoads(true);
// Javascript is purposely disabled, so that nothing can be
// automatically run.
s.setJavaScriptEnabled(false);
s.setDefaultTextEncodingName("utf-8");
final Intent intent = getIntent();
if (intent.hasExtra(Intent.EXTRA_TITLE)) {
setTitle(intent.getStringExtra(Intent.EXTRA_TITLE));
}
Uri destination = intent.getData();
if (destination != null) {
// Is this a local file?
if ("file".equals(destination.getScheme())) {
if (PackageManager.PERMISSION_DENIED ==
checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE)) {
// If we don't have local file permissions, save the destination so we can try
// again once they're granted.
mOnPermissionDestination = destination;
requestPermissions(new String[] {Manifest.permission.READ_EXTERNAL_STORAGE}, 0);
}
}
mWebView.loadUrl(destination.toString());
}
}
@Override
public void onRequestPermissionsResult(int requestCode,
String permissions[], int[] grantResults) {
// We only ever request 1 permission, so these arguments should always have the same form.
assert permissions.length == 1;
assert Manifest.permission.READ_EXTERNAL_STORAGE.equals(permissions[0]);
assert grantResults.length == 1;
if (PackageManager.PERMISSION_GRANTED == grantResults[0]) {
// Try again now that we have the permission.
mWebView.loadUrl(mOnPermissionDestination.toString());
}
}
@Override
protected void onDestroy() {
super.onDestroy();
mWebView.destroy();
}
private class ChromeClient extends WebChromeClient {
@Override
public void onReceivedTitle(WebView view, String title) {
if (!getIntent().hasExtra(Intent.EXTRA_TITLE)) {
HTMLViewerActivity.this.setTitle(title);
}
}
}
private class ViewClient extends WebViewClient {
@Override
public void onPageFinished(WebView view, String url) {
mLoading.setVisibility(View.GONE);
}
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
Intent intent;
// Perform generic parsing of the URI to turn it into an Intent.
try {
intent = Intent.parseUri(url, Intent.URI_INTENT_SCHEME);
} catch (URISyntaxException ex) {
Log.w(TAG, "Bad URI " + url + ": " + ex.getMessage());
Toast.makeText(HTMLViewerActivity.this,
R.string.cannot_open_link, Toast.LENGTH_SHORT).show();
return true;
}
// Sanitize the Intent, ensuring web pages can not bypass browser
// security (only access to BROWSABLE activities).
intent.addCategory(Intent.CATEGORY_BROWSABLE);
intent.setComponent(null);
Intent selector = intent.getSelector();
if (selector != null) {
selector.addCategory(Intent.CATEGORY_BROWSABLE);
selector.setComponent(null);
}
try {
view.getContext().startActivity(intent);
} catch (ActivityNotFoundException ex) {
Log.w(TAG, "No application can handle " + url);
Toast.makeText(HTMLViewerActivity.this,
R.string.cannot_open_link, Toast.LENGTH_SHORT).show();
}
return true;
}
@Override
public WebResourceResponse shouldInterceptRequest(WebView view,
WebResourceRequest request) {
final Uri uri = request.getUrl();
if (ContentResolver.SCHEME_FILE.equals(uri.getScheme())
&& uri.getPath().endsWith(".gz")) {
Log.d(TAG, "Trying to decompress " + uri + " on the fly");
try {
final InputStream in = new GZIPInputStream(
getContentResolver().openInputStream(uri));
final WebResourceResponse resp = new WebResourceResponse(
getIntent().getType(), "utf-8", in);
resp.setStatusCodeAndReasonPhrase(200, "OK");
return resp;
} catch (IOException e) {
Log.w(TAG, "Failed to decompress; falling back", e);
}
}
return null;
}
}
}
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