Add 'Passing android Intents extras to Qt'

Passing-android-Intents-extras-to-Qt.md

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+## Passing android Intents to Qt (Pass parameters between intents) ## 
+
+Working on QField I had the necessity of passing values from the QtActivity.java to the Qt cpp world, here how I did it using an Intent that is sent to the QtActivity (the one you should not edit that comes with Qt). 
+For much more information see [this post series](https://www.kdab.com/qt-android-episode-7/).
+
+hopefully this will be helpful to someone.
+
+#### Start QtActivity
+
+```
+private void startQtActivity() {
+	String dotqgis2_dir = "Test dotqgis2_dir";
+	String share_dir = "Test share_dir";
+	// forward to startQtActivity and finish QFieldActivity
+	Intent intent = new Intent();
+	intent.setClass(QFieldActivity.this, QtActivity.class);
+	intent.putExtra("DOTQGIS2_DIR", dotqgis2_dir);
+        intent.putExtra("SHARE_DIR", share_dir);
+	startActivity(intent);
+	finish();
+}
+```
+
+```
+#include <QAndroidJniObject>
+#include <QtAndroid>
+#include <QDebug>
+#ifdef Q_OS_ANDROID
+QString getExtra(QAndroidJniObject extras, QString extra){
+    if(extras.isValid()){
+        QAndroidJniObject extra_jni = QAndroidJniObject::fromString(extra);
+        extra_jni = extras.callObjectMethod("getString", "(Ljava/lang/String;)Ljava/lang/String;", extra_jni.object<jstring>());
+        if (extra_jni.isValid()){
+            extra = extra_jni.toString();
+            qDebug() << extra;
+            return extra;
+        }
+    }
+    return "";
+}
+void getIntentExtras(QStringList intentExtras)
+{
+    QAndroidJniObject activity = QtAndroid::androidActivity();
+    if (activity.isValid()) {
+        qDebug() << "activity";
+        QAndroidJniObject intent = activity.callObjectMethod("getIntent", "()Landroid/content/Intent;");
+        if (intent.isValid()) {
+            qDebug() << "intent: " << intent.toString();
+            QAndroidJniObject extras = intent.callObjectMethod("getExtras", "()Landroid/os/Bundle;");
+            qDebug() << "extras: " << extras.toString();
+            QString extra;
+            for (int i = 0; i < intentExtras.size(); ++i){
+                extra = intentExtras.at(i).toLocal8Bit().constData();
+                getExtra(extras, extra);
+            }
+          }
+        }
+}
+QStringList intentExtras;
+intentExtras << "DOTQGIS2_DIR" << "SHARE_DIR";
+getIntentExtras(intentExtras);
+#endif
+```
+
+This is the first version of the cpp code that I wrote, just for reference. The below code is much cleaner.
+
+```
+#include <QAndroidJniObject>
+#include <QtAndroid>
+#include <QDebug>
+void getIntent()
+{
+#ifdef Q_OS_ANDROID
+    QAndroidJniObject activity = QtAndroid::androidActivity();
+    if (activity.isValid()) {
+        qDebug() << "activity";
+        QAndroidJniObject intent = activity.callObjectMethod("getIntent", "()Landroid/content/Intent;");
+        if (intent.isValid()) {
+            qDebug() << "intent: " << intent.toString();
+            QAndroidJniObject extras = intent.callObjectMethod("getExtras", "()Landroid/os/Bundle;");
+            if(extras.isValid()){
+                qDebug() << "extras: " << extras.toString();
+                QAndroidJniObject dotqgis2_dir = QAndroidJniObject::fromString("DOTQGIS2_DIR");
+                QAndroidJniObject share_dir = QAndroidJniObject::fromString("SHARE_DIR");
+                dotqgis2_dir = extras.callObjectMethod("getString", "(Ljava/lang/String;)Ljava/lang/String;", dotqgis2_dir.object<jstring>());
+                share_dir = extras.callObjectMethod("getString", "(Ljava/lang/String;)Ljava/lang/String;", share_dir.object<jstring>());
+                if (dotqgis2_dir.isValid()){
+                    qDebug() << dotqgis2_dir.toString();
+                }
+                if (share_dir.isValid()){
+                    qDebug() << share_dir.toString();
+                }
+            }
+          }
+        }
+#endif
+}
+```
+
+[source](https://www.opengis.ch/2015/12/03/passing-android-intents-to-qt/)