Show all barcodes and recover from invalid selection

app/src/main/java/protect/card_locker/BarcodeImageWriterTask.java

@@ -1,6 +1,8 @@
 package protect.card_locker;
 
 import android.graphics.Bitmap;
+import android.graphics.Color;
+import android.graphics.PorterDuff;
 import android.os.AsyncTask;
 import android.util.Log;
 import android.view.View;
@@ -23,6 +25,9 @@ class BarcodeImageWriterTask extends AsyncTask<Void, Void, Bitmap>
 {
     private static final String TAG = "Catima";
 
+    private static final int IS_VALID = 999;
+    private boolean isSuccesful;
+
     // When drawn in a smaller window 1D barcodes for some reason end up
     // squished, whereas 2D barcodes look fine.
     private static final int MAX_WIDTH_1D = 1500;
@@ -30,14 +35,20 @@ class BarcodeImageWriterTask extends AsyncTask<Void, Void, Bitmap>
 
     private final WeakReference<ImageView> imageViewReference;
     private final WeakReference<TextView> textViewReference;
-    private final String cardId;
+    private String cardId;
     private final BarcodeFormat format;
     private final int imageHeight;
     private final int imageWidth;
+    private final boolean showFallback;
+    private final Runnable callback;
 
     BarcodeImageWriterTask(ImageView imageView, String cardIdString,
-                           BarcodeFormat barcodeFormat, TextView textView)
+                           BarcodeFormat barcodeFormat, TextView textView,
+                           boolean showFallback, Runnable callback)
     {
+        isSuccesful = true;
+        this.callback = callback;
+
         // Use a WeakReference to ensure the ImageView can be garbage collected
         imageViewReference = new WeakReference<>(imageView);
         textViewReference = new WeakReference<>(textView);
@@ -59,11 +70,8 @@ class BarcodeImageWriterTask extends AsyncTask<Void, Void, Bitmap>
             double ratio = (double)MAX_WIDTH / (double)imageView.getWidth();
             imageHeight = (int)(imageView.getHeight() * ratio);
         }
-    }
 
-    BarcodeImageWriterTask(ImageView imageView, String cardIdString, BarcodeFormat barcodeFormat)
-    {
-        this(imageView, cardIdString, barcodeFormat, null);
+        this.showFallback = showFallback;
     }
 
     private int getMaxWidth(BarcodeFormat format)
@@ -96,7 +104,41 @@ class BarcodeImageWriterTask extends AsyncTask<Void, Void, Bitmap>
         }
     }
 
-    public Bitmap doInBackground(Void... params)
+    private String getFallbackString(BarcodeFormat format)
+    {
+        switch(format)
+        {
+            // 2D barcodes
+            case AZTEC:
+                return "AZTEC";
+            case DATA_MATRIX:
+                return "DATA_MATRIX";
+            case PDF_417:
+                return "PDF_417";
+            case QR_CODE:
+                return "QR_CODE";
+
+            // 1D barcodes:
+            case CODABAR:
+                return "C0C";
+            case CODE_39:
+                return "CODE_39";
+            case CODE_128:
+                return "CODE_128";
+            case EAN_8:
+                return "32123456";
+            case EAN_13:
+                return "5901234123457";
+            case ITF:
+                return "1003";
+            case UPC_A:
+                return "123456789012";
+            default:
+                throw new IllegalArgumentException("No fallback known for this barcode type");
+        }
+    }
+
+    private Bitmap generate()
     {
         if (cardId.isEmpty())
         {
@@ -165,13 +207,30 @@ class BarcodeImageWriterTask extends AsyncTask<Void, Void, Bitmap>
         catch(OutOfMemoryError e)
         {
             Log.w(TAG, "Insufficient memory to render barcode, "
-                + imageWidth + "x" + imageHeight + ", " + format.name()
-                + ", length=" + cardId.length(), e);
+                    + imageWidth + "x" + imageHeight + ", " + format.name()
+                    + ", length=" + cardId.length(), e);
         }
 
         return null;
     }
 
+    public Bitmap doInBackground(Void... params)
+    {
+        Bitmap bitmap = generate();
+
+        if (bitmap == null) {
+            isSuccesful = false;
+
+            if (showFallback) {
+                Log.i(TAG, "Barcode generation failed, generating fallback...");
+                cardId = getFallbackString(format);
+                bitmap = generate();
+            }
+        }
+
+        return bitmap;
+    }
+
     protected void onPostExecute(Bitmap result)
     {
         Log.i(TAG, "Finished generating barcode image of type " + format + ": " + cardId);
@@ -182,6 +241,8 @@ class BarcodeImageWriterTask extends AsyncTask<Void, Void, Bitmap>
             return;
         }
 
+        imageView.setTag(isSuccesful);
+
         imageView.setImageBitmap(result);
         TextView textView = textViewReference.get();
 
@@ -190,6 +251,12 @@ class BarcodeImageWriterTask extends AsyncTask<Void, Void, Bitmap>
             Log.i(TAG, "Displaying barcode");
             imageView.setVisibility(View.VISIBLE);
 
+            if (isSuccesful) {
+                imageView.setColorFilter(null);
+            } else {
+                imageView.setColorFilter(Color.GRAY, PorterDuff.Mode.LIGHTEN);
+            }
+
             if (textView != null) {
                 textView.setVisibility(View.VISIBLE);
                 textView.setText(format.name());
@@ -203,5 +270,9 @@ class BarcodeImageWriterTask extends AsyncTask<Void, Void, Bitmap>
                 textView.setVisibility(View.GONE);
             }
         }
+
+        if (callback != null) {
+            callback.run();
+        }
     }
 }