Get context in Java code run from C++

[cristeab]

Hi
I would like to create programmatically an access point in Qt8 on Android. It seems that this is possible in Java with the code below

  public int createAp(String ssid, String pwd) {
      WifiConfiguration netConfig = new WifiConfiguration();

      netConfig.SSID = ssid;
      netConfig.preSharedKey = pwd;
      netConfig.hiddenSSID = false;
      netConfig.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.OPEN);
      netConfig.allowedProtocols.set(WifiConfiguration.Protocol.RSN);
      netConfig.allowedProtocols.set(WifiConfiguration.Protocol.WPA);
      netConfig.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);

      try {
          WifiManager wifiManager = (WifiManager)getBaseContext().getSystemService(Context.WIFI_SERVICE);
          Method setWifiApMethod = wifiManager.getClass().getMethod("setWifiApEnabled",  WifiConfiguration.class, boolean.class);
          boolean apstatus=(Boolean) setWifiApMethod.invoke(wifiManager, netConfig, true);

          Method isWifiApEnabledmethod = wifiManager.getClass().getMethod("isWifiApEnabled");
          while(!(Boolean)isWifiApEnabledmethod.invoke(wifiManager)){};
          Method getWifiApStateMethod = wifiManager.getClass().getMethod("getWifiApState");
          int apstate=(Integer)getWifiApStateMethod.invoke(wifiManager);
          Method getWifiApConfigurationMethod = wifiManager.getClass().getMethod("getWifiApConfiguration");
          netConfig=(WifiConfiguration)getWifiApConfigurationMethod.invoke(wifiManager);
      } catch (Exception e) {
          return -1;
      }
      return 0;

However, the method above requires the Activity context (getBaseContext()). So my question is if there is a way to obtain this from Qt application that runs this Java code ?

thanks
Bogdan

[Ibrahim]

@cristeab Hi;
You must to add a new parameter to createAp method as Context context. Then you must to pass QtAndroid::activityContext() to this parameter. You can write full code like this:
Create Templates -> android/src/com/myjavacode/MyJava.java:

package com.myjavacode;

import android.content.Context;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiManager;

import java.lang.reflect.Method;

public class MyJava extends org.qtproject.qt5.android.bindings.QtActivity
{
  // You use static method:
  public static int createAp(String ssid, String pwd, Context context /* Add context parameter */) {
    WifiConfiguration netConfig = new WifiConfiguration();

    netConfig.SSID = ssid;
    netConfig.preSharedKey = pwd;
    netConfig.hiddenSSID = false;
    netConfig.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.OPEN);
    netConfig.allowedProtocols.set(WifiConfiguration.Protocol.RSN);
    netConfig.allowedProtocols.set(WifiConfiguration.Protocol.WPA);
    netConfig.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);

    try {
      WifiManager wifiManager = (WifiManager) /* change getBaseContext() to context parameter */ context.getSystemService(Context.WIFI_SERVICE);
      Method setWifiApMethod = wifiManager.getClass().getMethod("setWifiApEnabled", WifiConfiguration.class, boolean.class);
      boolean apstatus = (Boolean) setWifiApMethod.invoke(wifiManager, netConfig, true);

      Method isWifiApEnabledmethod = wifiManager.getClass().getMethod("isWifiApEnabled");
      while (!(Boolean) isWifiApEnabledmethod.invoke(wifiManager)) {
      }
      ;
      Method getWifiApStateMethod = wifiManager.getClass().getMethod("getWifiApState");
      int apstate = (Integer) getWifiApStateMethod.invoke(wifiManager);
      Method getWifiApConfigurationMethod = wifiManager.getClass().getMethod("getWifiApConfiguration");
      netConfig = (WifiConfiguration) getWifiApConfigurationMethod.invoke(wifiManager);
    } catch (Exception e) {
      return -1;
    }
    return 0;
  }
}

You can use this Java code like this:

QAndroidJniObject ssid = QAndroidJniObject::fromString("ssid");
  QAndroidJniObject pwd = QAndroidJniObject::fromString("pwd");

  jint res = QAndroidJniObject::callStaticMethod<jint>("com/myjavacode/MyJava",
                                                       "createAp",
                                                       "(Ljava/lang/String;Ljava/lang/String;Landroid/content/Context)I",
                                                       ssid.object<jstring>(), pwd.object<jstring>(), QtAndroid::androidContext().object());

[cristeab]

thank you, it works