CustomWebViewClient.java

/*
 * Tint Browser for Android
 * 
 * Copyright (C) 2012 - to infinity and beyond J. Devauchelle and contributors.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 3 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

package com.seal.ui.components;

import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import android.app.AlertDialog;
import android.content.ActivityNotFoundException;
import android.content.DialogInterface;
import android.content.DialogInterface.OnCancelListener;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.graphics.Bitmap;
import android.net.Uri;
import android.net.http.SslError;
import android.os.Message;
import android.text.Html;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.WindowManager;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.Toast;

import com.mogoweb.chrome.HttpAuthHandler;
import com.mogoweb.chrome.SslErrorHandler;
import com.mogoweb.chrome.WebView;
import com.mogoweb.chrome.WebViewClient;
import com.seal.R;
import com.seal.providers.SslExceptionsWrapper;
import com.seal.ui.managers.UIManager;

public class CustomWebViewClient extends WebViewClient {

	private static final Pattern ACCEPTED_URI_SCHEMA = Pattern.compile("(?i)" + // switch on case insensitive matching
			"(" + // begin group for schema
			"(?:http|https|file):\\/\\/" + "|(?:inline|data|about|javascript):" + ")" + "(.*)");

	private UIManager mUIManager;

	private Message mDontResend;
	private Message mResend;

	public CustomWebViewClient(UIManager uiManager) {
		mUIManager = uiManager;
	}

	@Override
	public void onPageStarted(WebView view, String url, Bitmap favicon) {
		mUIManager.onPageStarted(view, url, favicon);
		((CustomWebView) view).onClientPageStarted(url);
	}

	@Override
	public void onPageFinished(WebView view, String url) {
		mUIManager.onPageFinished(view, url);
		((CustomWebView) view).onClientPageFinished(url);
	}

	@Override
	public boolean shouldOverrideUrlLoading(WebView view, String url) {
		return checkUrlLoading(url);
	}

	@Override
	public void onReceivedSslError(final WebView view, final SslErrorHandler handler, SslError error) {

		boolean hasAuthority = false;
		String authority = view.getResources().getString(R.string.UnknownAutority);
		if (error.getUrl() != null) {
			try {
				URL url = new URL(error.getUrl());
				authority = url.getAuthority();
				hasAuthority = true;
			} catch (MalformedURLException e) {
				hasAuthority = false;
			}
		}

		boolean askUser = true;

		if (hasAuthority) {
			int result = SslExceptionsWrapper.getStatusForAuthority(view.getContext().getContentResolver(), authority);

			switch (result) {
			case SslExceptionsWrapper.AUTHORITY_UNKNOWN:
				askUser = true;
				break;

			case SslExceptionsWrapper.AUTHORITY_ALLOWED:
				askUser = false;
				handler.proceed();
				Toast.makeText(view.getContext(), String.format(view.getResources().getString(R.string.SslExceptionAccessAllowedByUserToast), authority),
						Toast.LENGTH_SHORT).show();
				break;

			case SslExceptionsWrapper.AUTHORITY_DISALLOWED:
				askUser = false;
				handler.cancel();
				Toast.makeText(view.getContext(), String.format(view.getResources().getString(R.string.SslExceptionAccessDisallowedByUserToast), authority),
						Toast.LENGTH_SHORT).show();
				break;

			default:
				askUser = true;
				break;
			}
		}

		if (askUser) {

			final int errorCode = SslExceptionsWrapper.sslErrorToInt(error);

			StringBuilder sb = new StringBuilder();

			sb.append(String.format(view.getResources().getString(R.string.SslWarningsHeader), authority));
			sb.append("\n\n");

			sb.append(Html.fromHtml(SslExceptionsWrapper.sslErrorReasonToString(view.getContext(), errorCode)));

			final String finalAuthority = authority;

			AlertDialog.Builder builder = new AlertDialog.Builder(view.getContext());
			builder.setCancelable(true);
			builder.setIcon(android.R.drawable.ic_dialog_info);
			builder.setTitle(view.getResources().getString(R.string.SslWarning));
			builder.setMessage(sb.toString());

			LayoutInflater adbInflater = LayoutInflater.from(view.getContext());
			View checkBoxLayout = adbInflater.inflate(R.layout.checkbox_layout, null);
			final CheckBox rememberCheckBox = (CheckBox) checkBoxLayout.findViewById(R.id.RemenberChoiceCheckBox);

			builder.setView(checkBoxLayout);

			builder.setInverseBackgroundForced(true);
			builder.setPositiveButton(view.getResources().getString(R.string.Continue), new DialogInterface.OnClickListener() {

				@Override
				public void onClick(DialogInterface dialog, int which) {
					if (rememberCheckBox.isChecked()) {
						SslExceptionsWrapper.setSslException(view.getContext().getContentResolver(), finalAuthority, errorCode, true);
					}

					dialog.dismiss();
					handler.proceed();
				}

			});

			builder.setNegativeButton(view.getResources().getString(R.string.Cancel), new DialogInterface.OnClickListener() {

				@Override
				public void onClick(DialogInterface dialog, int which) {
					if (rememberCheckBox.isChecked()) {
						SslExceptionsWrapper.setSslException(view.getContext().getContentResolver(), finalAuthority, errorCode, false);
					}

					dialog.dismiss();
					handler.cancel();
				}

			});

			AlertDialog alert = builder.create();
			alert.show();
		}
	}

	@Override
	public void onReceivedHttpAuthRequest(WebView view, final HttpAuthHandler handler, final String host, final String realm) {
		String username = null;
		String password = null;

		boolean reuseHttpAuthUsernamePassword = handler.useHttpAuthUsernamePassword();

		if (reuseHttpAuthUsernamePassword && view != null) {
			String[] credentials = view.getHttpAuthUsernamePassword(host, realm);
			if (credentials != null && credentials.length == 2) {
				username = credentials[0];
				password = credentials[1];
			}
		}

		if (username != null && password != null) {
			handler.proceed(username, password);
		} else {
			LayoutInflater factory = LayoutInflater.from(mUIManager.getMainActivity());
			final View v = factory.inflate(R.layout.http_authentication_dialog, null);

			if (username != null) {
				((EditText) v.findViewById(R.id.username_edit)).setText(username);
			}
			if (password != null) {
				((EditText) v.findViewById(R.id.password_edit)).setText(password);
			}

			AlertDialog dialog = new AlertDialog.Builder(mUIManager.getMainActivity())
					.setTitle(String.format(mUIManager.getMainActivity().getString(R.string.HttpAuthenticationDialogDialogTitle), host, realm))
					.setIcon(android.R.drawable.ic_dialog_alert).setView(v).setPositiveButton(R.string.Proceed, new DialogInterface.OnClickListener() {
						public void onClick(DialogInterface dialog, int whichButton) {
							String nm = ((EditText) v.findViewById(R.id.username_edit)).getText().toString();
							String pw = ((EditText) v.findViewById(R.id.password_edit)).getText().toString();
							mUIManager.setHttpAuthUsernamePassword(host, realm, nm, pw);
							handler.proceed(nm, pw);
						}
					}).setNegativeButton(R.string.Cancel, new DialogInterface.OnClickListener() {
						public void onClick(DialogInterface dialog, int whichButton) {
							handler.cancel();
						}
					}).setOnCancelListener(new DialogInterface.OnCancelListener() {
						public void onCancel(DialogInterface dialog) {
							handler.cancel();
						}
					}).create();

			dialog.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE);
			dialog.show();

			v.findViewById(R.id.username_edit).requestFocus();
		}
	}

	@Override
	public void onFormResubmission(WebView view, Message dontResend, Message resend) {

		mDontResend = dontResend;
		mResend = resend;

		new AlertDialog.Builder(mUIManager.getMainActivity()).setTitle(R.string.FormResubmitTitle).setMessage(R.string.FormResubmitMessage)
				.setPositiveButton(R.string.OK, new DialogInterface.OnClickListener() {
					public void onClick(DialogInterface dialog, int which) {
						if (mResend != null) {
							mResend.sendToTarget();
							mResend = null;
							mDontResend = null;
						}
					}
				}).setNegativeButton(R.string.Cancel, new DialogInterface.OnClickListener() {
					public void onClick(DialogInterface dialog, int which) {
						if (mDontResend != null) {
							mDontResend.sendToTarget();
							mResend = null;
							mDontResend = null;
						}
					}
				}).setOnCancelListener(new OnCancelListener() {
					public void onCancel(DialogInterface dialog) {
						if (mDontResend != null) {
							mDontResend.sendToTarget();
							mResend = null;
							mDontResend = null;
						}
					}
				}).show();
	}

	/**
	 * Search for intent handlers that are specific to this URL aka, specialized apps like google maps or youtube
	 */
	private boolean isSpecializedHandlerAvailable(Intent intent) {
		PackageManager pm = mUIManager.getMainActivity().getPackageManager();
		List<ResolveInfo> handlers = pm.queryIntentActivities(intent, PackageManager.GET_RESOLVED_FILTER);
		if (handlers == null || handlers.size() == 0) {
			return false;
		}

		for (ResolveInfo resolveInfo : handlers) {
			IntentFilter filter = resolveInfo.filter;
			if (filter == null) {
				// No intent filter matches this intent?
				// Error on the side of staying in the browser, ignore
				continue;
			}

			if (filter.countDataAuthorities() == 0 || filter.countDataPaths() == 0) {
				// Generic handler, skip
				continue;
			}

			return true;
		}

		return false;
	}

	private boolean checkUrlLoading(String url) {
		Intent intent;

		try {
			intent = Intent.parseUri(url, Intent.URI_INTENT_SCHEME);
		} catch (URISyntaxException e) {
			Log.w("CustomWebViewClient", "Bad URI " + url + ": " + e.getMessage());
			return false;
		}

		if (mUIManager.getMainActivity().getPackageManager().resolveActivity(intent, 0) == null) {
			String packagename = intent.getPackage();
			if (packagename != null) {
				intent = new Intent(Intent.ACTION_VIEW, Uri.parse("market://search?q=pname:" + packagename));
				intent.addCategory(Intent.CATEGORY_BROWSABLE);
				mUIManager.getMainActivity().startActivity(intent);

				return true;
			} else {
				return false;
			}
		}

		intent.addCategory(Intent.CATEGORY_BROWSABLE);
		intent.setComponent(null);

		Matcher m = ACCEPTED_URI_SCHEMA.matcher(url);
		if (m.matches() && !isSpecializedHandlerAvailable(intent)) {
			return false;
		}

		try {
			if (mUIManager.getMainActivity().startActivityIfNeeded(intent, -1)) {
				return true;
			}
		} catch (ActivityNotFoundException ex) {
			// ignore the error. If no application can handle the URL,
			// eg about:blank, assume the browser can handle it.
		}

		return false;
	}
}