Added revision properties

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

@@ -56,12 +56,13 @@ import io.requery.android.database.sqlite.RequerySQLiteOpenHelperFactory;
 // https://developer.android.com/topic/libraries/architecture/room.html
 
 @Database(
-        version = 112,
+        version = 113,
         entities = {
                 EntityIdentity.class,
                 EntityAccount.class,
                 EntityFolder.class,
                 EntityMessage.class,
+                EntityRevision.class,
                 EntityAttachment.class,
                 EntityOperation.class,
                 EntityContact.class,
@@ -83,6 +84,8 @@ public abstract class DB extends RoomDatabase {
 
     public abstract DaoMessage message();
 
+    public abstract DaoRevision revision();
+
     public abstract DaoAttachment attachment();
 
     public abstract DaoOperation operation();
@@ -1086,6 +1089,20 @@ public abstract class DB extends RoomDatabase {
                         db.execSQL("ALTER TABLE `account` ADD COLUMN `move_to` INTEGER");
                     }
                 })
+                .addMigrations(new Migration(112, 113) {
+                    @Override
+                    public void migrate(@NonNull SupportSQLiteDatabase db) {
+                        Log.i("DB migration from version " + startVersion + " to " + endVersion);
+                        db.execSQL("CREATE TABLE IF NOT EXISTS `revision`" +
+                                " (`id` INTEGER PRIMARY KEY AUTOINCREMENT" +
+                                ", `message` INTEGER NOT NULL" +
+                                ", `sequence` INTEGER NOT NULL" +
+                                ", `reference` INTEGER NOT NULL" +
+                                ", FOREIGN KEY(`message`) REFERENCES `message`(`id`) ON UPDATE NO ACTION ON DELETE CASCADE )");
+                        db.execSQL("CREATE INDEX IF NOT EXISTS `index_revision_message` ON `revision` (`message`)");
+                        db.execSQL("CREATE UNIQUE INDEX IF NOT EXISTS `index_revision_message_sequence` ON `revision` (`message`, `sequence`)");
+                    }
+                })
                 .build();
     }
 

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

@@ -0,0 +1,35 @@
+package eu.faircode.email;
+
+/*
+    This file is part of FairEmail.
+
+    FairEmail is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    FairEmail is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with FairEmail.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2018-2019 by Marcel Bokhorst (M66B)
+*/
+
+import androidx.room.Dao;
+import androidx.room.Insert;
+import androidx.room.Query;
+
+@Dao
+public interface DaoRevision {
+    @Query("SELECT * FROM revision" +
+            " WHERE message = :message" +
+            " AND sequence = :sequence")
+    EntityRevision getRevision(long message, int sequence);
+
+    @Insert
+    long insertRevision(EntityRevision revision);
+}

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

@@ -0,0 +1,63 @@
+package eu.faircode.email;
+
+/*
+    This file is part of FairEmail.
+
+    FairEmail is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    FairEmail is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with FairEmail.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2018-2019 by Marcel Bokhorst (M66B)
+*/
+
+import androidx.annotation.NonNull;
+import androidx.room.Entity;
+import androidx.room.ForeignKey;
+import androidx.room.Index;
+import androidx.room.PrimaryKey;
+
+import static androidx.room.ForeignKey.CASCADE;
+
+@Entity(
+        tableName = EntityRevision.TABLE_NAME,
+        foreignKeys = {
+                @ForeignKey(childColumns = "message", entity = EntityMessage.class, parentColumns = "id", onDelete = CASCADE),
+        },
+        indices = {
+                @Index(value = {"message"}),
+                @Index(value = {"message", "sequence"}, unique = true)
+        }
+)
+public class EntityRevision {
+    static final String TABLE_NAME = "revision";
+
+    @PrimaryKey(autoGenerate = true)
+    public Long id;
+    @NonNull
+    public Long message;
+    @NonNull
+    public Integer sequence;
+    @NonNull
+    public Boolean reference;
+
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj instanceof EntityRevision) {
+            EntityRevision other = (EntityRevision) obj;
+            return (this.message.equals(other.message) &&
+                    this.sequence.equals(other.sequence) &&
+                    this.reference.equals(other.reference));
+        } else
+            return false;
+    }
+}

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

@@ -784,7 +784,6 @@ public class FragmentCompose extends FragmentBase {
                             html = "<p>" + text.replaceAll("\\r?\\n", "<br>") + "</p>";
                         } else
                             html = HtmlHelper.sanitize(context, ref, true, false);
-                        refFile.delete();
 
                         return body + html;
                     }
@@ -794,6 +793,7 @@ public class FragmentCompose extends FragmentBase {
                         Bundle extras = new Bundle();
                         extras.putString("html", html);
                         extras.putBoolean("show", true);
+                        extras.putBoolean("reference", false);
                         onAction(R.id.action_save, extras);
                     }
 
@@ -2958,50 +2958,53 @@ public class FragmentCompose extends FragmentBase {
                         dirty = true;
 
                         if (draft.revisions == null)
-                            draft.revisions = 1;
-                        else
-                            draft.revisions++;
+                            draft.revisions = 0;
 
-                        if (action != R.id.action_undo && action != R.id.action_redo)
-                            draft.revision = draft.revisions;
+                        boolean reference;
+                        Bundle extras = args.getBundle("extras");
+                        File refFile = EntityMessage.getRefFile(context, draft.id);
+                        if (extras != null && extras.containsKey("reference"))
+                            reference = extras.getBoolean("reference", refFile.exists());
+                        else {
+                            EntityRevision revision = db.revision().getRevision(draft.id, draft.revisions);
+                            reference = (revision == null ? refFile.exists() : revision.reference);
+                        }
 
-                        Helper.writeText(draft.getFile(context), body);
-                        Helper.writeText(draft.getFile(context, draft.revisions), body);
+                        draft.revisions++;
 
-                        db.message().setMessageRevision(draft.id, draft.revision);
-                        db.message().setMessageRevisions(draft.id, draft.revisions);
+                        Log.i("Inserting revision sequence=" + draft.revisions + " reference=" + reference);
+                        EntityRevision revision = new EntityRevision();
+                        revision.message = draft.id;
+                        revision.sequence = draft.revisions;
+                        revision.reference = reference;
+                        db.revision().insertRevision(revision);
 
-                        db.message().setMessageContent(draft.id,
-                                true,
-                                draft.plain_only,
-                                HtmlHelper.getPreview(body),
-                                null);
+                        Helper.writeText(draft.getFile(context), body);
+                        Helper.writeText(draft.getFile(context, draft.revisions), body);
                     }
 
                     if (action == R.id.action_undo || action == R.id.action_redo) {
-                        if (draft.revision != null && draft.revisions != null) {
-                            dirty = true;
-
-                            if (action == R.id.action_undo) {
-                                if (draft.revision > 1)
-                                    draft.revision--;
-                            } else {
-                                if (draft.revision < draft.revisions)
-                                    draft.revision++;
-                            }
+                        if (action == R.id.action_undo) {
+                            if (draft.revision > 1)
+                                draft.revision--;
+                        } else {
+                            if (draft.revision < draft.revisions)
+                                draft.revision++;
+                        }
 
-                            body = Helper.readText(draft.getFile(context, draft.revision));
-                            Helper.writeText(draft.getFile(context), body);
+                        body = Helper.readText(draft.getFile(context, draft.revision));
+                        Helper.writeText(draft.getFile(context), body);
+                    } else
+                        draft.revision = draft.revisions;
 
-                            db.message().setMessageRevision(draft.id, draft.revision);
+                    db.message().setMessageContent(draft.id,
+                            true,
+                            draft.plain_only, // unchanged
+                            HtmlHelper.getPreview(body),
+                            null);
 
-                            db.message().setMessageContent(draft.id,
-                                    true,
-                                    draft.plain_only, // unchanged
-                                    HtmlHelper.getPreview(body),
-                                    null);
-                        }
-                    }
+                    db.message().setMessageRevision(draft.id, draft.revision);
+                    db.message().setMessageRevisions(draft.id, draft.revisions);
 
                     if (dirty) {
                         draft.received = new Date().getTime();
@@ -3308,7 +3311,10 @@ public class FragmentCompose extends FragmentBase {
 
                 Spanned spannedRef = null;
                 File refFile = draft.getRefFile(context);
-                if (refFile.exists()) {
+                EntityRevision revision = db.revision().getRevision(draft.id, draft.revision == null ? 0 : draft.revision);
+                Log.i("Revision sequence=" + (revision == null ? null : revision.sequence) +
+                        " reference=" + (revision == null ? null : revision.reference));
+                if (revision == null ? refFile.exists() : revision.reference) {
                     String quote = HtmlHelper.sanitize(context, Helper.readText(refFile), show_images, false);
                     Spanned spannedQuote = HtmlHelper.fromHtml(quote,
                             new Html.ImageGetter() {