Store message preview

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

@@ -66,7 +66,6 @@ import android.widget.Toast;
 import com.google.android.material.bottomnavigation.BottomNavigationView;
 import com.google.android.material.snackbar.Snackbar;
 
-import org.jsoup.Jsoup;
 import org.xml.sax.XMLReader;
 
 import java.io.File;
@@ -333,38 +332,8 @@ public class AdapterMessage extends PagedListAdapter<TupleMessageEx, AdapterMess
             ivAttachments.setVisibility(message.attachments > 0 ? View.VISIBLE : View.GONE);
             tvSubject.setText(message.subject);
 
-            tvPreview.setVisibility(View.GONE);
+            tvPreview.setText(message.preview);
-            if (preview && message.content) {
+            tvPreview.setVisibility(preview && !TextUtils.isEmpty(message.preview) ? View.VISIBLE : View.GONE);
-                Bundle args = new Bundle();
-                args.putSerializable("message", message);
-
-                new SimpleTask<String>() {
-                    @Override
-                    protected void onInit(Bundle args) {
-                        tvPreview.setHasTransientState(true);
-                    }
-
-                    @Override
-                    protected String onLoad(Context context, Bundle args) throws Throwable {
-                        TupleMessageEx message = (TupleMessageEx) args.getSerializable("message");
-                        String body = message.read(context);
-                        return Jsoup.parse(body).text();
-                    }
-
-                    @Override
-                    protected void onLoaded(Bundle args, String preview) {
-                        tvPreview.setText(preview);
-                        tvPreview.setVisibility(View.VISIBLE);
-                        tvPreview.setHasTransientState(false);
-                    }
-
-                    @Override
-                    protected void onException(Bundle args, Throwable ex) {
-                        tvPreview.setHasTransientState(false);
-                        Helper.unexpectedError(context, ex);
-                    }
-                }.load(context, owner, args);
-            }
 
             if (viewType == ViewType.UNIFIED)
                 tvFolder.setText(message.accountName);

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

@@ -45,7 +45,7 @@ import androidx.sqlite.db.SupportSQLiteDatabase;
 // https://developer.android.com/topic/libraries/architecture/room.html
 
 @Database(
-        version = 23,
+        version = 24,
         entities = {
                 EntityIdentity.class,
                 EntityAccount.class,
@@ -284,6 +284,13 @@ public abstract class DB extends RoomDatabase {
                         db.execSQL("ALTER TABLE `identity` ADD COLUMN `insecure` INTEGER NOT NULL DEFAULT 0");
                     }
                 })
+                .addMigrations(new Migration(23, 24) {
+                    @Override
+                    public void migrate(SupportSQLiteDatabase db) {
+                        Log.i(Helper.TAG, "DB migration from version " + startVersion + " to " + endVersion);
+                        db.execSQL("ALTER TABLE `message` ADD COLUMN `preview` TEXT");
+                    }
+                })
                 .build();
     }
 

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

@@ -158,6 +158,11 @@ public interface DaoMessage {
             " AND ui_seen")
     List<EntityMessage> getMessageSeen(long folder);
 
+    @Query("SELECT id FROM message" +
+            " WHERE content" +
+            " AND preview IS NULL")
+    List<Long> getMessageWithoutPreview();
+
     @Query("SELECT message.*" +
             ", account.name AS accountName, account.color AS accountColor" +
             ", folder.name AS folderName, folder.display AS folderDisplay, folder.type AS folderType" +
@@ -220,8 +225,8 @@ public interface DaoMessage {
     @Query("UPDATE message SET error = :error WHERE id = :id")
     int setMessageError(long id, String error);
 
-    @Query("UPDATE message SET content = :content WHERE id = :id")
+    @Query("UPDATE message SET content = NOT preview IS NULL, preview = :preview WHERE id = :id")
-    int setMessageContent(long id, boolean content);
+    int setMessageContent(long id, String preview);
 
     @Query("UPDATE message SET headers = :headers WHERE id = :id")
     int setMessageHeaders(long id, String headers);

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

@@ -94,6 +94,7 @@ public class EntityMessage implements Serializable {
     public Integer size;
     @NonNull
     public Boolean content = false;
+    public String preview;
     public Long sent; // compose = null
     @NonNull
     public Long received; // compose = stored
@@ -198,6 +199,7 @@ public class EntityMessage implements Serializable {
                     (this.subject == null ? other.subject == null : this.subject.equals(other.subject)) &&
                     (this.size == null ? other.size == null : this.size.equals(other.size)) &&
                     this.content == other.content &&
+                    (this.preview == null ? other.preview == null : this.preview.equals(other.preview)) &&
                     (this.sent == null ? other.sent == null : this.sent.equals(other.sent)) &&
                     this.received.equals(other.received) &&
                     this.stored.equals(other.stored) &&

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

@@ -19,9 +19,12 @@ package eu.faircode.email;
     Copyright 2018 by Marcel Bokhorst (M66B)
 */
 
+import android.content.Context;
 import android.content.SharedPreferences;
+import android.net.ConnectivityManager;
 import android.os.Bundle;
 import android.preference.PreferenceManager;
+import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
@@ -29,6 +32,10 @@ import android.widget.AdapterView;
 import android.widget.CompoundButton;
 import android.widget.Spinner;
 
+import org.jsoup.Jsoup;
+
+import java.io.IOException;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.widget.SwitchCompat;
@@ -113,6 +120,36 @@ public class FragmentOptions extends FragmentEx {
             @Override
             public void onCheckedChanged(CompoundButton compoundButton, boolean checked) {
                 prefs.edit().putBoolean("preview", checked).apply();
+                if (checked)
+                    new SimpleTask<Void>() {
+                        @Override
+                        protected Void onLoad(Context context, Bundle args) {
+                            DB db = DB.getInstance(context);
+
+                            ConnectivityManager cm = context.getSystemService(ConnectivityManager.class);
+                            boolean metered = (cm == null || cm.isActiveNetworkMetered());
+
+                            for (Long id : db.message().getMessageWithoutPreview()) {
+                                EntityMessage message = db.message().getMessage(id);
+                                try {
+                                    Log.i(Helper.TAG, "Building preview id=" + id);
+                                    String html = message.read(context);
+                                    String text = Jsoup.parse(html).text();
+                                    String preview = text.substring(0, Math.min(text.length(), 250));
+                                    db.message().setMessageContent(message.id, preview);
+                                } catch (IOException ex) {
+                                    Log.e(Helper.TAG, ex + "\n" + Log.getStackTraceString(ex));
+                                    db.message().setMessageContent(message.id, null);
+                                    if (!metered)
+                                        EntityOperation.queue(db, message, EntityOperation.BODY);
+                                }
+                            }
+
+                            EntityOperation.process(context);
+
+                            return null;
+                        }
+                    }.load(FragmentOptions.this, null);
             }
         });
 

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

@@ -61,6 +61,7 @@ import com.sun.mail.util.MailConnectException;
 
 import org.json.JSONArray;
 import org.json.JSONException;
+import org.jsoup.Jsoup;
 
 import java.io.IOException;
 import java.net.SocketException;
@@ -134,6 +135,7 @@ public class ServiceSynchronize extends LifecycleService {
     private static final int SYNC_BATCH_SIZE = 20;
     private static final int DOWNLOAD_BATCH_SIZE = 20;
     private static final long RECONNECT_BACKOFF = 90 * 1000L; // milliseconds
+    private static final int PREVIEW_SIZE = 250;
 
     static final int PI_CLEAR = 1;
     static final int PI_SEEN = 2;
@@ -1432,8 +1434,11 @@ public class ServiceSynchronize extends LifecycleService {
             throw new MessageRemovedException();
 
         MessageHelper helper = new MessageHelper((MimeMessage) imessage);
-        message.write(this, helper.getHtml());
+        String html = helper.getHtml();
-        db.message().setMessageContent(message.id, true);
+        String text = Jsoup.parse(html).text();
+        String preview = text.substring(0, Math.min(text.length(), PREVIEW_SIZE));
+        message.write(this, html);
+        db.message().setMessageContent(message.id, preview);
     }
 
     private void doAttachment(EntityFolder folder, EntityOperation op, IMAPFolder ifolder, EntityMessage message, JSONArray jargs, DB db) throws JSONException, MessagingException, IOException {
@@ -1890,8 +1895,11 @@ public class ServiceSynchronize extends LifecycleService {
 
         if (!message.content)
             if (!metered || (message.size != null && message.size < download)) {
-                message.write(context, helper.getHtml());
+                String html = helper.getHtml();
-                db.message().setMessageContent(message.id, true);
+                String text = Jsoup.parse(html).text();
+                String preview = text.substring(0, Math.min(text.length(), PREVIEW_SIZE));
+                message.write(context, html);
+                db.message().setMessageContent(message.id, preview);
                 Log.i(Helper.TAG, folder.name + " downloaded message id=" + message.id + " size=" + message.size);
             }