Can display older conversation messages

app/src/main/java/org/communiquons/android/comunic/client/data/helpers/ConversationMessagesDbHelper.java

@@ -92,6 +92,38 @@ class ConversationMessagesDbHelper {
         return message;
     }
 
+    /**
+     * Get the oldest message known of a conversation
+     *
+     * @param convID Target conversation ID
+     * @return The ID of the latest known message / -1 in case of failure
+     */
+    int getOldestMessageID(int convID) {
+
+        SQLiteDatabase db = dbHelper.getReadableDatabase();
+
+        //Prepare the query over the database
+        String[] columns = {ConversationsMessagesSchema.COLUMN_NAME_MESSAGE_ID};
+        String selection = ConversationsMessagesSchema.COLUMN_NAME_CONVERSATION_ID + " = ?";
+        String[] selectionArgs = {""+convID};
+        String orderBy = ConversationsMessagesSchema.COLUMN_NAME_MESSAGE_ID;
+
+        //Perform the request
+        Cursor response = db.query(TABLE_NAME, columns, selection, selectionArgs, null,
+                null, orderBy, "1");
+
+        //Process response
+        int messageID = 0;
+        if(response.getCount() != 0){
+            response.moveToFirst();
+            messageID = response.getInt(response.getColumnIndexOrThrow(
+                    ConversationsMessagesSchema.COLUMN_NAME_MESSAGE_ID));
+        }
+        response.close();
+
+        return  messageID;
+    }
+
     /**
      * Insert a list of messages into the database
      *

app/src/main/java/org/communiquons/android/comunic/client/data/helpers/ConversationMessagesHelper.java

@@ -138,6 +138,39 @@ public class ConversationMessagesHelper {
 
     }
 
+    /**
+     * Request the request of older messages from the database / API
+     *
+     * @param convID Target conversationID
+     * @param oldestMessageID The ID of the oldest known message
+     * @return The list of messages / null in case of failure
+     */
+    @Nullable
+    public ArrayList<ConversationMessage> getOlderMessages(int convID, int oldestMessageID){
+
+        //Check what is the oldest message stored in the database
+        int oldestMessageDownloaded = mDbHelper.getOldestMessageID(convID);
+
+        //Check if no message has been already download
+        if(oldestMessageDownloaded == 0)
+            return null;
+
+        //Download older messages from the server
+        ArrayList<ConversationMessage> messages =
+                downloadOlder(convID, oldestMessageDownloaded, 10);
+
+        //Check for errors
+        if(messages == null)
+            return null;
+
+        //Save the new messages
+        if(!mDbHelper.insertMultiple(messages))
+            return null;
+
+        //Get the messages
+        return mDbHelper.getInterval(convID, 0, oldestMessageID - 1);
+    }
+
     /**
      * Get the ID of the last message of the conversation from the database
      *
@@ -200,6 +233,49 @@ public class ConversationMessagesHelper {
         return list;
     }
 
+    /**
+     * Get older messages for a conversation
+     *
+     * @param conversationID The ID of the target conversation
+     * @param oldestMessageID The ID of the oldest known message
+     * @param limit The limit for the download
+     * @return The list of message / null in case of failure
+     */
+    @Nullable
+    private ArrayList<ConversationMessage> downloadOlder(int conversationID, int oldestMessageID,
+                                                         int limit){
+
+        ArrayList<ConversationMessage> list = new ArrayList<>();
+
+        //Prepare a request over the server
+        APIRequest req = new APIRequest(mContext, "conversations/get_older_messages");
+        req.addInt("conversationID", conversationID);
+        req.addInt("oldest_message_id", oldestMessageID);
+        req.addInt("limit", limit);
+
+        //Perform the request
+        try {
+
+            APIResponse response = new APIRequestHelper().exec(req);
+
+            //Check for errors
+            if(response.getResponse_code() != 200)
+                return null;
+
+            //Process the list of messages
+            JSONArray messages = response.getJSONArray();
+
+            for(int i = 0; i < messages.length(); i++)
+                list.add(getMessageObject(conversationID, messages.getJSONObject(i)));
+
+        } catch (Exception e){
+            e.printStackTrace();
+            return null;
+        }
+
+        return list;
+    }
+
     /**
      * Convert a JSON object into a conversation message element
      *

app/src/main/java/org/communiquons/android/comunic/client/data/utils/PreferencesUtils.java

@@ -22,7 +22,8 @@ public class PreferencesUtils {
      * @return The preference value (if found) or the default value
      */
     public static boolean getBoolean(Context context, String key, boolean def){
-        SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(context);
+        SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(
+                context.getApplicationContext());
         return sharedPrefs.getBoolean(key, def);
     }
 

app/src/main/java/org/communiquons/android/comunic/client/ui/fragments/ConversationFragment.java

@@ -5,7 +5,6 @@ import android.app.Fragment;
 import android.content.DialogInterface;
 import android.content.Intent;
 import android.graphics.Bitmap;
-import android.graphics.BitmapFactory;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.Bundle;
@@ -17,10 +16,8 @@ import android.view.KeyEvent;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
-import android.view.inputmethod.EditorInfo;
 import android.widget.EditText;
 import android.widget.ImageButton;
-import android.widget.ListView;
 import android.widget.ProgressBar;
 import android.widget.TextView;
 import android.widget.Toast;
@@ -38,7 +35,9 @@ import org.communiquons.android.comunic.client.data.utils.AccountUtils;
 import org.communiquons.android.comunic.client.data.utils.FilesUtils;
 import org.communiquons.android.comunic.client.ui.activities.MainActivity;
 import org.communiquons.android.comunic.client.ui.adapters.ConversationMessageAdapter;
+import org.communiquons.android.comunic.client.ui.listeners.OnScrollChangeDetectListener;
 import org.communiquons.android.comunic.client.ui.utils.BitmapUtils;
+import org.communiquons.android.comunic.client.ui.views.ScrollListView;
 
 import java.io.File;
 import java.io.FileNotFoundException;
@@ -57,7 +56,8 @@ import static android.app.Activity.RESULT_OK;
  */
 
 public class ConversationFragment extends Fragment
-        implements ConversationRefreshRunnable.onMessagesChangeListener {
+        implements ConversationRefreshRunnable.onMessagesChangeListener,
+        OnScrollChangeDetectListener {
 
     /**
      * Pick image request number
@@ -115,9 +115,9 @@ public class ConversationFragment extends Fragment
     private TextView no_msg_notice;
 
     /**
-     * Converstion message listView
+     * Conversation message listView
      */
-    private ListView convMessListView;
+    private ScrollListView convMessListView;
 
     /**
      * Conversation messages helper
@@ -164,6 +164,11 @@ public class ConversationFragment extends Fragment
      */
     private GetUsersHelper getUsersHelper;
 
+    /**
+     * Async task used to fetch older messages
+     */
+    private AsyncTask mGetOlderMessagesTask;
+
     @Override
     public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -280,6 +285,10 @@ public class ConversationFragment extends Fragment
 
         //Hide new message sending wheel
         new_message_progress_bar.setVisibility(View.GONE);
+
+
+        //Set a listener to detect when the user reaches the top of the conversation
+        convMessListView.setOnScrollChangeDetectListener(this);
     }
 
     @Override
@@ -607,4 +616,65 @@ public class ConversationFragment extends Fragment
     private void display_not_msg_notice(boolean visible){
         no_msg_notice.setVisibility(visible ? View.VISIBLE : View.GONE);
     }
+
+    /**
+     * This method is called when the user reach the top of the conversation
+     */
+    @Override
+    public void onReachTop() {
+
+        //Check if we have got other messages to get
+        if(messagesList == null)
+            return;
+        if(messagesList.size() == 0)
+            return;
+        final int firstMessageID = messagesList.get(0).getId();
+
+        //Check if another task is running
+        if(mGetOlderMessagesTask != null)
+            return;
+
+        //Create and execute the task
+        mGetOlderMessagesTask = new AsyncTask<Void, Void, ArrayList<ConversationMessage>>(){
+
+            @Override
+            protected ArrayList<ConversationMessage> doInBackground(Void... params) {
+                return convMessHelper.getOlderMessages(conversation_id, firstMessageID);
+            }
+
+            @Override
+            protected void onPostExecute(ArrayList<ConversationMessage> conversationMessages) {
+                if(getActivity() == null)
+                    return;
+
+                onGotOlderMessages(conversationMessages);
+
+            }
+        }.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+
+    }
+
+    /**
+     * Actions to do once we downloaded older messages from the server
+     *
+     * @param list The list of messages that was downloaded
+     */
+    private void onGotOlderMessages(@Nullable ArrayList<ConversationMessage> list){
+
+        //Remove link over task
+        mGetOlderMessagesTask = null;
+
+        //Check if the list is null (in case of error)
+        if(list == null)
+            return;
+
+        if(list.size() == 0)
+            return;
+
+        //Add the messages to the list
+        messagesList.addAll(0, list);
+
+        //Notify adapter
+        convMessAdapter.notifyDataSetChanged();
+    }
 }