Add support for webapk without runtimeHost

chrome/android/webapk/shell_apk/src/org/chromium/webapk/shell_apk/MainActivity.java

Index: chrome/android/webapk/shell_apk/src/org/chromium/webapk/shell_apk/MainActivity.java
diff --git a/chrome/android/webapk/shell_apk/src/org/chromium/webapk/shell_apk/MainActivity.java b/chrome/android/webapk/shell_apk/src/org/chromium/webapk/shell_apk/MainActivity.java
index 1d6b4c72eb0e389f3c9d88258a67ed9f10f7479a..a665663a8f3c455f3c69967b9cf7e624c4b32e26 100644
--- a/chrome/android/webapk/shell_apk/src/org/chromium/webapk/shell_apk/MainActivity.java
+++ b/chrome/android/webapk/shell_apk/src/org/chromium/webapk/shell_apk/MainActivity.java
@@ -8,18 +8,23 @@ import android.app.Activity;
 import android.content.ActivityNotFoundException;
 import android.content.Intent;
 import android.net.Uri;
+import android.os.AsyncTask;
 import android.os.Bundle;
+import android.text.TextUtils;
 import android.util.Log;
 
 import org.chromium.webapk.lib.common.WebApkConstants;
 import org.chromium.webapk.lib.common.WebApkMetaDataKeys;
 
-import java.net.URISyntaxException;
+import java.io.File;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Set;
 
 /**
  * WebAPK's main Activity.
  */
-public class MainActivity extends Activity {
+public class MainActivity extends Activity implements ChooseHostBrowserDialog.DialogListener {
     private static final String TAG = "cr_MainActivity";
 
     /**
@@ -43,6 +48,15 @@ public class MainActivity extends Activity {
      */
     private static final String KEY_APP_ICON_ID = "app_icon_id";
 
+    /**
+     * The URL to launch the WebAPK. Used in the case of deep-links (intents from other apps) that
+     * fall into the WebAPK scope.
+     */
+    private String mOverrideUrl;
+
+    /** The "start_url" baked in the AndroidManifest.xml. */
+    private String mStartUrl;
+
     /**
      * Creates install Intent.
      * @param packageName Package to install.
@@ -56,45 +70,100 @@ public class MainActivity extends Activity {
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        launch();
-        finish();
-    }
-
-    /**
-     * Launches WebAPK.
-     */
-    private void launch() {
-        String overrideUrl = getOverrideUrl();
-        String startUrl = (overrideUrl != null)
-                ? overrideUrl
+        mOverrideUrl = getOverrideUrl();
+        mStartUrl = (mOverrideUrl != null)
+                ? mOverrideUrl
                 : WebApkUtils.readMetaDataFromManifest(this, WebApkMetaDataKeys.START_URL);
-
-        if (startUrl == null) {
+        if (mStartUrl == null) {
+            finish();
             return;
         }
 
-        if (launchHostBrowserInWebApkMode(startUrl, overrideUrl)) {
+        Log.v(TAG, "Url of the WebAPK: " + mStartUrl);
+        String packageName = getPackageName();
+        Log.v(TAG, "Package name of the WebAPK:" + packageName);
+
+        String runtimeHostInPreferences = WebApkUtils.getHostBrowserFromSharedPreference(this);
+        String runtimeHost = WebApkUtils.getHostBrowserPackageName(this);
+        if (!TextUtils.isEmpty(runtimeHostInPreferences)
+                && !runtimeHostInPreferences.equals(runtimeHost)) {
+            WebApkUtils.deleteSharedPref(this);
+            deleteInternalStorageAsync();
+        }
+
+        if (!TextUtils.isEmpty(runtimeHost)) {
+            launchInHostBrowser(runtimeHost);
+            finish();
             return;
         }
-        if (launchBrowser(startUrl)) {
+
+        String hostUrl = "";
+        try {
+            hostUrl = new URL(mStartUrl).getHost();
+        } catch (MalformedURLException e) {
+            Log.e(TAG, "Invalid URL of the WebApk.");
+            finish();
             return;
         }
-        installBrowser();
+
+        ChooseHostBrowserDialog dialog = new ChooseHostBrowserDialog();
+        dialog.show(this, hostUrl);
     }
 
-    /**
-     * Launches host browser in WebAPK mode.
-     * @return True if successful.
-     */
-    private boolean launchHostBrowserInWebApkMode(String startUrl, String overrideUrl) {
-        Log.v(TAG, "Url of the WebAPK: " + startUrl);
-        String packageName = getPackageName();
-        Log.v(TAG, "Package name of the WebAPK:" + packageName);
+    @Override
+    public void onHostBrowserSelected(String selectedHostBrowser) {
+        Set<String> installedBrowsers = WebApkUtils.getInstalledBrowsers(getPackageManager());
+        if (installedBrowsers.contains(selectedHostBrowser)) {
+            launchInHostBrowser(selectedHostBrowser);
+        } else {
+            installBrowser(selectedHostBrowser);
+        }
+        // It is safe to cache the selected host browser to the share pref if user didn't install
+        // the browser in {@link installBrowser}. On the next launch,
+        // {@link WebApkUtils#getHostBrowserPackageName()} will catch it, and the dialog to choose
+        // host browser will show again. If user did install the browser chosen, saving the
+        // selected host browser to the shared pref can avoid showing the dialog.
+        WebApkUtils.writeHostBrowserToSharedPref(this, selectedHostBrowser);
+        finish();
+    }
 
-        String runtimeHost = WebApkUtils.getHostBrowserPackageName(this);
+    @Override
+    public void onQuit() {
+        finish();
+    }
+
+    private void deleteInternalStorageAsync() {
+        new AsyncTask<Void, Void, Void>() {
+            @Override
+            protected Void doInBackground(Void... params) {
+                deletePath(getCacheDir());
+                deletePath(getFilesDir());
+                return null;
+            }
+        }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+    }
+
+    private void deletePath(File file) {
+        if (file == null) return;
+
+        if (file.isDirectory()) {
+            File[] children = file.listFiles();
+            if (children != null) {
+                for (File child : children) {
+                    deletePath(child);
+                }
+            }
+        }
+
+        if (!file.delete()) {
+            Log.e(TAG, "Failed to delete : " + file.getAbsolutePath());
+        }
+    }
+
+    private void launchInHostBrowser(String runtimeHost) {
         boolean forceNavigation = false;
         int source = getIntent().getIntExtra(WebApkConstants.EXTRA_SOURCE, 0);
-        if (overrideUrl != null) {
+        if (mOverrideUrl != null) {
             if (source == WebApkConstants.SHORTCUT_SOURCE_UNKNOWN) {
                 source = WebApkConstants.SHORTCUT_SOURCE_EXTERNAL_INTENT;
             }
@@ -107,62 +176,23 @@ public class MainActivity extends Activity {
         Intent intent = new Intent();
         intent.setAction(ACTION_START_WEBAPK);
         intent.setPackage(runtimeHost);
-        intent.putExtra(WebApkConstants.EXTRA_URL, startUrl)
+        intent.putExtra(WebApkConstants.EXTRA_URL, mStartUrl)
                 .putExtra(WebApkConstants.EXTRA_SOURCE, source)
-                .putExtra(WebApkConstants.EXTRA_WEBAPK_PACKAGE_NAME, packageName)
+                .putExtra(WebApkConstants.EXTRA_WEBAPK_PACKAGE_NAME, getPackageName())
                 .putExtra(WebApkConstants.EXTRA_WEBAPK_FORCE_NAVIGATION, forceNavigation);
 
         try {
             startActivity(intent);
-            return true;
         } catch (ActivityNotFoundException e) {
             Log.w(TAG, "Unable to launch browser in WebAPK mode.");
             e.printStackTrace();
-            return false;
         }
     }
 
-    /**
-     * Launches browser (not necessarily the host browser).
-     * @param startUrl URL to navigate browser to.
-     * @return True if successful.
-     */
-    private boolean launchBrowser(String startUrl) {
-        Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(startUrl));
-        intent.addCategory(Intent.CATEGORY_BROWSABLE);
-
-        // The WebAPK can handle {@link startUrl}. Set a selector to prevent the WebAPK from
-        // launching itself.
-        try {
-            Intent selectorIntent = Intent.parseUri("https://", Intent.URI_INTENT_SCHEME);
-            intent.setSelector(selectorIntent);
-        } catch (URISyntaxException e) {
-            return false;
-        }
-
-        // Add extras in case that the URL is launched in Chrome.
-        int source =
-                getIntent().getIntExtra(WebApkConstants.EXTRA_SOURCE, Intent.URI_INTENT_SCHEME);
-        intent.putExtra(REUSE_URL_MATCHING_TAB_ELSE_NEW_TAB, true)
-              .putExtra(WebApkConstants.EXTRA_SOURCE, source);
-
-        try {
-            startActivity(intent);
-        } catch (ActivityNotFoundException e) {
-            return false;
-        }
-        return true;
-    }
-
     /**
      * Launches the Play Store with the host browser's page.
      */
-    private void installBrowser() {
-        String hostBrowserPackageName = WebApkUtils.getHostBrowserPackageName(this);
-        if (hostBrowserPackageName == null) {
-            return;
-        }
-
+    private void installBrowser(String hostBrowserPackageName) {
         try {
             startActivity(createInstallIntent(hostBrowserPackageName));
         } catch (ActivityNotFoundException e) {