Add delta sync

app/src/main/java/gallery/memories/MainActivity.kt

@@ -217,15 +217,15 @@ import gallery.memories.databinding.ActivityMainBinding
     fun storeTheme(color: String?, isDark: Boolean) {
         if (color == null) return
         getSharedPreferences(getString(R.string.preferences_key), 0).edit()
-            .putString("themeColor", color)
-            .putBoolean("themeDark", isDark)
+            .putString(getString(R.string.preferences_theme_color), color)
+            .putBoolean(getString(R.string.preferences_theme_dark), isDark)
             .apply()
     }
 
     fun restoreTheme() {
         val preferences = getSharedPreferences(getString(R.string.preferences_key), 0)
-        val color = preferences.getString("themeColor", null)
-        val isDark = preferences.getBoolean("themeDark", false)
+        val color = preferences.getString(getString(R.string.preferences_theme_color), null)
+        val isDark = preferences.getBoolean(getString(R.string.preferences_theme_dark), false)
         applyTheme(color, isDark)
     }
 

app/src/main/java/gallery/memories/NativeX.kt

@@ -37,6 +37,9 @@ import java.net.URLDecoder
 
     init {
         mDlService = DownloadService(mActivity)
+
+        // Synchronize the database
+        mQuery.syncDeltaDb()
     }
 
     companion object {

app/src/main/java/gallery/memories/service/TimelineQuery.kt

@@ -16,12 +16,14 @@ import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.app.AppCompatActivity
 import androidx.collection.ArraySet
 import androidx.exifinterface.media.ExifInterface
+import gallery.memories.R
 import gallery.memories.mapper.Fields
 import gallery.memories.mapper.SystemImage
 import org.json.JSONArray
 import org.json.JSONException
 import org.json.JSONObject
 import java.io.IOException
+import java.time.Instant
 import java.util.concurrent.CountDownLatch
 
 class TimelineQuery(private val mCtx: AppCompatActivity) {
@@ -40,9 +42,6 @@ class TimelineQuery(private val mCtx: AppCompatActivity) {
                 deleteCallback?.let { it(result) }
             }
         }
-
-        // TODO: remove this in favor of a selective sync
-        fullSyncDb()
     }
 
     @Throws(JSONException::class)
@@ -216,16 +215,46 @@ class TimelineQuery(private val mCtx: AppCompatActivity) {
         }
     }
 
-    private fun fullSyncDb() {
-        // Flag all images for removal
-        mDb.execSQL("UPDATE images SET flag = 1")
+    private fun syncDb(startTime: Long) {
+        // Date modified is in seconds, not millis
+        val syncTime = Instant.now().toEpochMilli() / 1000;
+
+        // SystemImage query
+        var selection: String? = null
+        var selectionArgs: Array<String>? = null
+
+        // Query everything modified after startTime
+        if (startTime != 0L) {
+            selection = MediaStore.Images.Media.DATE_MODIFIED + " > ?"
+            selectionArgs = arrayOf(startTime.toString())
+        }
 
         // Iterate all images and videos from system store
         val files =
-            SystemImage.query(mCtx, SystemImage.IMAGE_URI, null, null, null) +
-            SystemImage.query(mCtx, SystemImage.VIDEO_URI, null, null, null)
+            SystemImage.query(mCtx, SystemImage.IMAGE_URI, selection, selectionArgs, null) +
+            SystemImage.query(mCtx, SystemImage.VIDEO_URI, selection, selectionArgs, null)
         files.forEach { insertItemDb(it) }
 
+        // Store last sync time
+        mCtx.getSharedPreferences(mCtx.getString(R.string.preferences_key), 0).edit()
+            .putLong(mCtx.getString(R.string.preferences_last_sync_time), syncTime)
+            .apply()
+    }
+
+    fun syncDeltaDb() {
+        // Get last sync time
+        val syncTime = mCtx.getSharedPreferences(mCtx.getString(R.string.preferences_key), 0)
+            .getLong(mCtx.getString(R.string.preferences_last_sync_time), 0L)
+        syncDb(syncTime)
+    }
+
+    fun syncFullDb() {
+        // Flag all images for removal
+        mDb.execSQL("UPDATE images SET flag = 1")
+
+        // Sync all files, marking them in the process
+        syncDb(0L)
+
         // Clean up stale files
         mDb.execSQL("DELETE FROM images WHERE flag = 1")
     }

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

@@ -3,4 +3,7 @@
     <string name="action_settings">Settings</string>
 
     <string name="preferences_key">memories</string>
+    <string name="preferences_theme_color">themeColor</string>
+    <string name="preferences_theme_dark">themeDark</string>
+    <string name="preferences_last_sync_time">lastDbSyncTime</string>
 </resources>