catch decoder init errors and prepare to send email

app/src/main/java/xdsopl/robot36/Decoder.java

@@ -101,7 +101,7 @@ public class Decoder {
         }
     };
 
-    public Decoder(MainActivity activity, SpectrumView spectrum, SpectrumView spectrogram, ImageView image, VUMeterView meter) {
+    public Decoder(MainActivity activity, SpectrumView spectrum, SpectrumView spectrogram, ImageView image, VUMeterView meter) throws Exception {
         this.image = image;
         this.spectrogram = spectrogram;
         this.spectrum = spectrum;
@@ -112,6 +112,8 @@ public class Decoder {
         spectrogramBuffer = new int[spectrogram.bitmap.getWidth() * spectrogram.bitmap.getHeight()];
 
         int bufferSizeInBytes = AudioRecord.getMinBufferSize(sampleRate, channelConfig, audioFormat);
+        if (bufferSizeInBytes <= 0)
+            throw new Exception("Unable to open audio with " + sampleRate + "Hz samplerate");
         int bufferSizeInSamples = bufferSizeInBytes / 2;
         int framesPerSecond = Math.max(1, sampleRate / bufferSizeInSamples);
         audioBuffer = new short[framesPerSecond * bufferSizeInSamples];

app/src/main/java/xdsopl/robot36/MainActivity.java

@@ -18,11 +18,13 @@ limitations under the License.
 package xdsopl.robot36;
 
 import android.app.Activity;
+import android.app.AlertDialog;
 import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.content.ContentResolver;
 import android.content.ContentValues;
 import android.content.Context;
+import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.res.Configuration;
 import android.graphics.Bitmap;
@@ -143,15 +145,51 @@ public class MainActivity extends Activity {
         menu.setGroupEnabled(R.id.group_decoder, false);
     }
 
+    private Intent createEmailIntent(final String subject, final String text) {
+        Intent intent = new Intent(Intent.ACTION_SEND);
+        intent.setType("text/email");
+        intent.putExtra(Intent.EXTRA_EMAIL, new String[]{ getString(R.string.email_address) });
+        intent.putExtra(Intent.EXTRA_SUBJECT, subject);
+        intent.putExtra(Intent.EXTRA_TEXT, text);
+        return intent;
+    }
+
+    private void showErrorMessage(final String title, final String shortText, final String longText) {
+        AlertDialog.Builder builder = new AlertDialog.Builder(this);
+        builder.setTitle(title);
+        builder.setMessage(shortText);
+        builder.setNeutralButton(getString(R.string.btn_ok), null);
+        builder.setPositiveButton(getString(R.string.btn_send_email), new DialogInterface.OnClickListener() {
+            @Override
+            public void onClick(DialogInterface dialog, int which) {
+                Intent intent = createEmailIntent(getString(R.string.email_subject), longText);
+                startActivity(Intent.createChooser(intent, getString(R.string.chooser_title)));
+            }
+        });
+        builder.show();
+    }
+
+    private String createMessage(Exception ex) {
+        String message = ex.getMessage() + "\n";
+        for (StackTraceElement el : ex.getStackTrace())
+            message += "\n" + el.toString();
+        return message;
+    }
+
     protected void startDecoder() {
         if (decoder != null)
             return;
-        decoder = new Decoder(this,
-                (SpectrumView)findViewById(R.id.spectrum),
-                (SpectrumView)findViewById(R.id.spectrogram),
-                (ImageView)findViewById(R.id.image),
-                (VUMeterView)findViewById(R.id.meter)
-        );
+        try {
+            decoder = new Decoder(this,
+                    (SpectrumView) findViewById(R.id.spectrum),
+                    (SpectrumView) findViewById(R.id.spectrogram),
+                    (ImageView) findViewById(R.id.image),
+                    (VUMeterView) findViewById(R.id.meter)
+            );
+        } catch (Exception e) {
+            showErrorMessage(getString(R.string.decoder_error), e.getMessage(), createMessage(e));
+            return;
+        }
         decoder.enable_analyzer(enableAnalyzer);
         showNotification();
         if (menu != null) {
@@ -191,6 +229,10 @@ public class MainActivity extends Activity {
     public boolean onCreateOptionsMenu(Menu menu) {
         getMenuInflater().inflate(R.menu.menu_main, menu);
         this.menu = menu;
+        if (decoder != null) {
+            menu.findItem(R.id.action_toggle_decoder).setIcon(getResources().getDrawable(android.R.drawable.ic_media_pause));
+            menu.setGroupEnabled(R.id.group_decoder, true);
+        }
         share = (ShareActionProvider)menu.findItem(R.id.menu_item_share).getActionProvider();
         return true;
     }

app/src/main/res/menu/menu_main.xml

@@ -2,25 +2,26 @@
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     tools:context=".MainActivity">
-    <item
-        android:id="@+id/menu_item_share"
-        android:showAsAction="always"
-        android:title="@string/action_share"
-        android:actionProviderClass="android.widget.ShareActionProvider" />
-
-    <item
-        android:id="@+id/action_save_image"
-        android:title="@string/action_save_image"
-        android:icon="@android:drawable/ic_menu_save"
-        android:showAsAction="ifRoom" />
 
     <item
         android:id="@+id/action_toggle_decoder"
         android:title="@string/action_toggle_decoder"
-        android:icon="@android:drawable/ic_media_pause"
+        android:icon="@android:drawable/ic_media_play"
         android:showAsAction="ifRoom" />
 
-    <group android:id="@+id/group_decoder">
+    <group android:id="@+id/group_decoder" android:enabled="false">
+        <item
+            android:id="@+id/menu_item_share"
+            android:showAsAction="always"
+            android:title="@string/action_share"
+            android:actionProviderClass="android.widget.ShareActionProvider" />
+
+        <item
+            android:id="@+id/action_save_image"
+            android:title="@string/action_save_image"
+            android:icon="@android:drawable/ic_menu_save"
+            android:showAsAction="ifRoom" />
+
         <item
             android:id="@+id/action_clear_image"
             android:title="@string/action_clear_image"

app/src/main/res/values-de/strings.xml

@@ -50,4 +50,8 @@
     <string name="martin_modes">Martin Modi</string>
     <string name="scottie_modes">Scottie Modi</string>
     <string name="wraase_modes">Wraase Modi</string>
+    <string name="btn_ok">Ok</string>
+    <string name="btn_send_email">Email senden</string>
+    <string name="chooser_title">Fehlermeldung senden:</string>
+    <string name="decoder_error">Dekodierer Fehler</string>
 </resources>

app/src/main/res/values/strings.xml

@@ -50,4 +50,10 @@
     <string name="martin_modes">Martin Modes</string>
     <string name="scottie_modes">Scottie Modes</string>
     <string name="wraase_modes">Wraase Modes</string>
+    <string name="btn_ok">OK</string>
+    <string name="btn_send_email">Send Email</string>
+    <string name="email_subject">[BUG] Robot36 - SSTV Image Decoder</string>
+    <string name="chooser_title">Send Bug Report:</string>
+    <string name="email_address">xdsopl@googlemail.com</string>
+    <string name="decoder_error">Decoder error</string>
 </resources>