Specify targetSdkVersion to 26 and request WRITE_EXTERNAL_STORAGE

dynamically at application startup to meet updated Google Play requirements.

Author: gkv311

sview/AndroidManifest.xml

@@ -2,7 +2,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           package="com.sview"
           android:versionCode="16"
-          android:versionName="16.12"
+          android:versionName="19.01"
           android:installLocation="auto">
     <application android:label="@string/app_name"
                  android:hasCode="true"
@@ -227,7 +227,7 @@
         <activity android:name="com.sview.CrashReportActivity" android:label="@string/app_crash_name" android:configChanges="orientation|keyboardHidden"><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.DEFAULT" /></intent-filter></activity>
     </application>
 
-    <uses-sdk android:minSdkVersion="15" />
+    <uses-sdk android:minSdkVersion="15" android:targetSdkVersion="26" />
     <uses-feature android:glEsVersion="0x00020000"/>
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

sview/src/com/sview/StActivity.java

@@ -146,6 +146,8 @@ public void onCreate(Bundle theSavedInstanceState) {
         myContext = new ContextWrapper(this);
         myContext.getExternalFilesDir(null);
 
+        askUserPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE, null);
+
         mySensorMgr = (SensorManager )getSystemService(Context.SENSOR_SERVICE);
         mySensorOri = mySensorMgr.getDefaultSensor(Sensor.TYPE_ROTATION_VECTOR);
         if(mySensorOri == null) {
@@ -172,6 +174,53 @@ public void onCreate(Bundle theSavedInstanceState) {
         updateHideSystemBars(myToHideStatusBar, myToHideNavBar);
     }
 
+    /**
+     * Request user permission.
+     */
+    protected void askUserPermission(String thePermission, String theRationale) {
+        // Dynamically load methods introduced by API level 23.
+        // On older system this permission is granted by user during application installation.
+        java.lang.reflect.Method aMetPtrCheckSelfPermission, aMetPtrRequestPermissions, aMetPtrShouldShowRequestPermissionRationale;
+        try {
+            aMetPtrCheckSelfPermission = myContext.getClass().getMethod("checkSelfPermission", String.class);
+            aMetPtrRequestPermissions = getClass().getMethod("requestPermissions", String[].class, int.class);
+            aMetPtrShouldShowRequestPermissionRationale = getClass().getMethod("shouldShowRequestPermissionRationale", String.class);
+        } catch(SecurityException theError) {
+            //postMessage("Unable to find permission methods:\n" + theError.getMessage());
+            return;
+        } catch(NoSuchMethodException theError) {
+            //postMessage("Unable to find permission methods:\n" + theError.getMessage());
+            return;
+        }
+
+        try {
+            //int isAlreadyGranted = myContext.checkSelfPermission(thePermission);
+            int isAlreadyGranted = (Integer )aMetPtrCheckSelfPermission.invoke(myContext, thePermission);
+            if(isAlreadyGranted == android.content.pm.PackageManager.PERMISSION_GRANTED) {
+                return;
+            }
+
+            //boolean toShowInfo = shouldShowRequestPermissionRationale(thePermission);
+            boolean toShowInfo = theRationale != null && (Boolean )aMetPtrShouldShowRequestPermissionRationale.invoke(this, thePermission);
+            if(toShowInfo) {
+                postMessage(theRationale);
+            }
+
+            // show dialog to user
+            //requestPermissions (new String[]{thePermission}, 0);
+            aMetPtrRequestPermissions.invoke(this, new String[]{thePermission}, 0);
+        } catch(IllegalArgumentException theError) {
+            postMessage("Internal error: Unable to call permission method:\n" + theError.getMessage());
+            return;
+        } catch(IllegalAccessException theError) {
+            postMessage("Internal error: Unable to call permission method:\n" + theError.getMessage());
+            return;
+        } catch(java.lang.reflect.InvocationTargetException theError) {
+            postMessage("Internal error: Unable to call permission method:\n" + theError.getMessage());
+            return;
+        }
+    }
+
     /**
      * Handle new open file event.
      */