fix building

src/main/java/org/thoughtcrime/securesms/LocalHelpActivity.java

@@ -0,0 +1,102 @@
+package org.thoughtcrime.securesms;
+
+import android.content.res.AssetManager;
+import android.os.Bundle;
+import android.view.Menu;
+import android.view.MenuItem;
+
+import java.io.InputStream;
+import java.util.Locale;
+
+public class LocalHelpActivity extends WebViewActivity
+{
+  public static final String SECTION_EXTRA = "section_extra";
+
+  @Override
+  protected boolean allowInLockedMode() { return true; }
+
+  @Override
+  protected void onCreate(Bundle state, boolean ready) {
+    super.onCreate(state, ready);
+    setForceDark();
+    getSupportActionBar().setTitle(getString(R.string.menu_help));
+
+    String section = getIntent().getStringExtra(SECTION_EXTRA);
+    String helpPath = "help/LANG/help.html";
+    String helpLang = "en";
+    try {
+      Locale locale = dynamicLanguage.getCurrentLocale();
+      String appLang = locale.getLanguage();
+      String appCountry = locale.getCountry();
+      if (assetExists(helpPath.replace("LANG", appLang))) {
+        helpLang = appLang;
+      } else if (assetExists(helpPath.replace("LANG", appLang+"_"+appCountry))) {
+        helpLang = appLang+"_"+appCountry;
+      } else {
+        appLang = appLang.substring(0, 2);
+        if (assetExists(helpPath.replace("LANG", appLang))) {
+          helpLang = appLang;
+        }
+      }
+    } catch(Exception e) {
+      e.printStackTrace();
+    }
+
+    webView.loadUrl("file:///android_asset/" + helpPath.replace("LANG", helpLang) + (section!=null? section : ""));
+  }
+
+  @Override
+  public boolean onPrepareOptionsMenu(Menu menu) {
+    super.onPrepareOptionsMenu(menu);
+    this.getMenuInflater().inflate(R.menu.local_help, menu);
+    return true;
+  }
+
+  @Override
+  public boolean onOptionsItemSelected(MenuItem item) {
+    super.onOptionsItemSelected(item);
+    switch (item.getItemId()) {
+      case R.id.log_scroll_up:
+        webView.scrollTo(0, 0);
+        return true;
+      case R.id.learn_more:
+        openOnlineUrl("https://delta.chat");
+        return true;
+      case R.id.privacy_policy:
+        openOnlineUrl("https://delta.chat/gdpr");
+        return true;
+      case R.id.contribute:
+        openOnlineUrl("https://github.com/deltachat/deltachat-android");
+        return true;
+      case R.id.report_issue:
+        openOnlineUrl("https://github.com/deltachat/deltachat-android/issues");
+        return true;
+    }
+    return false;
+  }
+
+  @Override
+  public void onBackPressed() {
+    if (webView.canGoBack()) {
+      webView.goBack();
+    } else {
+      super.onBackPressed();
+    }
+  }
+
+  private boolean assetExists(String fileName) {
+    // test using AssetManager.open();
+    // AssetManager.list() is unreliable eg. on my Android 7 Moto G
+    // and also reported to be pretty slow.
+    boolean exists = false;
+    try {
+      AssetManager assetManager = getResources().getAssets();
+      InputStream is = assetManager.open(fileName);
+      exists = true;
+      is.close();
+    } catch(Exception e) {
+      ; // a non-existent asset is no error, the function's purpose is to check exactly that.
+    }
+    return exists;
+  }
+}