Added PDF previews

app/src/main/java/eu/faircode/email/AdapterImage.java

@@ -23,11 +23,15 @@ import android.content.Context;
 import android.content.SharedPreferences;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
+import android.graphics.Canvas;
+import android.graphics.Color;
 import android.graphics.drawable.AnimatedImageDrawable;
 import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
+import android.graphics.pdf.PdfRenderer;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.ParcelFileDescriptor;
 import android.text.TextUtils;
 import android.view.LayoutInflater;
 import android.view.View;
@@ -60,6 +64,8 @@ public class AdapterImage extends RecyclerView.Adapter<AdapterImage.ViewHolder>
 
     private List<EntityAttachment> items = new ArrayList<>();
 
+    private static final int PDF_WIDTH = 120;
+
     public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener, View.OnLongClickListener {
         private View view;
         private ImageView ivImage;
@@ -108,6 +114,22 @@ public class AdapterImage extends RecyclerView.Adapter<AdapterImage.ViewHolder>
                         String type = args.getString("type");
                         int max = args.getInt("max");
 
+                        if ("application/pdf".equals(type)) {
+                            // https://medium.com/@aditya09tyagi/android-pdf-reader-using-pdfrenderer-6daa2dacec1a
+                            try (ParcelFileDescriptor pfd = ParcelFileDescriptor.open(file, ParcelFileDescriptor.MODE_READ_ONLY)) {
+                                try (PdfRenderer pdf = new PdfRenderer(pfd)) {
+                                    try (PdfRenderer.Page page = pdf.openPage(0)) {
+                                        int width = Helper.dp2pixels(context, PDF_WIDTH);
+                                        int height = (int) ((float) width / page.getWidth() * page.getHeight());
+                                        Bitmap bm = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
+                                        Canvas canvas = new Canvas(bm);
+                                        canvas.drawColor(Color.WHITE);
+                                        page.render(bm, null, null, PdfRenderer.Page.RENDER_MODE_FOR_DISPLAY);
+                                        return new BitmapDrawable(context.getResources(), bm);
+                                    }
+                                }
+                            }
+                        } else {
                             SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
                             boolean webp = prefs.getBoolean("webp", true);
 
@@ -148,6 +170,7 @@ public class AdapterImage extends RecyclerView.Adapter<AdapterImage.ViewHolder>
                                 return null;
                             return new BitmapDrawable(context.getResources(), bm);
                         }
+                    }
 
                     @Override
                     protected void onExecuted(Bundle args, Drawable image) {

app/src/main/java/eu/faircode/email/AdapterMessage.java

@@ -3650,9 +3650,10 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
             List<EntityAttachment> images = new ArrayList<>();
             if (thumbnails && bind_extras) {
                 for (EntityAttachment attachment : attachments)
-                    if (attachment.isAttachment() && attachment.isImage()) {
+                    if (attachment.isPDF() ||
+                            (attachment.isAttachment() && attachment.isImage())) {
                         images.add(attachment);
-                        if (attachment.available)
+                        if (attachment.available && !attachment.isPDF())
                             iavailable++;
                     }
             }

app/src/main/java/eu/faircode/email/EntityAttachment.java

@@ -117,6 +117,10 @@ public class EntityAttachment {
         return ImageHelper.isImage(getMimeType());
     }
 
+    boolean isPDF() {
+        return "application/pdf".equals(getMimeType());
+    }
+
     boolean isCompressed() {
         if ("application/zip".equals(type))
             return true;