ADHOC/replicant-packages_apps_Email
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Clean up next/prev behavior in MessageView

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To improve functionality of next/prev buttons:
* Stop using managed query for next/prev cursor, so requery won't
    run in UI thread.  Add explicit lifecycle management.
* Requery on every onResume()
* Use a listener to catch external changes.  This applies both to synced
    changes and also local deletes.
* If we ever find ourselves out of the list, finish() immediately
    to avoid any race conditions.

To reduce flicker & other problems during msg-to-msg navigation:
* Clear attachments list so it doesn't accrete as we navigate
* Clear body so we don't show previous body with newer headers

Fixes bug 2076472 and (possibly) 2069241 & 2078933
This commit is contained in:
Andrew Stadler 2009-09-02 16:49:24 -07:00
parent 64814b3928
commit 6d22ccaa2f
1 changed files with 102 additions and 38 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

140
src/com/android/email/activity/MessageView.java
View File

@ -38,6 +38,7 @@ import android.app.ProgressDialog;
import android.content.ActivityNotFoundException;
import android.content.Context;
import android.content.Intent;
import android.database.ContentObserver;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
@ -75,8 +76,7 @@ import java.util.Date;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class MessageView extends Activity
implements OnClickListener {
public class MessageView extends Activity implements OnClickListener {
private static final String EXTRA_MESSAGE_ID = "com.android.email.MessageView_message_id";
private static final String EXTRA_MAILBOX_ID = "com.android.email.MessageView_mailbox_id";
@ -144,6 +144,7 @@ public class MessageView extends Activity
private View mNext;
private LoadPrevNextTask mLoadPrevNextTask;
private Cursor mPrevNextCursor;
private ContentObserver mNextPrevObserver;
// contains the HTML body. Is used by LoadAttachmentTask to display inline images.
private String mHtmlText;
@ -301,37 +302,6 @@ public class MessageView extends Activity
context.startActivity(i);
}
/**
* Re-init everything needed for changing message.
*/
private void messageChanged() {
cancelAllTasks();
setTitle("");
mAttachments.setVisibility(View.GONE);
mAttachmentIcon.setVisibility(View.GONE);
// Start an AsyncTask to make a new cursor and load the message
mLoadMessageTask = new LoadMessageTask(mMessageId, true);
mLoadMessageTask.execute();
updatePrevNextArrows(mPrevNextCursor);
}
private void updatePrevNextArrows(Cursor cursor) {
if (cursor != null) {
boolean hasPrev, hasNext;
if (cursor.isAfterLast() || cursor.isBeforeFirst()) {
// The cursor not being on a message means that the current message was not found.
// While this should not happen, simply disable prev/next arrows in that case.
hasPrev = hasNext = false;
} else {
hasPrev = !cursor.isFirst();
hasNext = !cursor.isLast();
}
mPrevious.setVisibility(hasPrev ? View.VISIBLE : View.GONE);
mNext.setVisibility(hasNext ? View.VISIBLE : View.GONE);
}
}
@Override
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
@ -384,6 +354,7 @@ public class MessageView extends Activity
mController = Controller.getInstance(getApplication());
mNextPrevObserver = new NextPrevObserver(mHandler);
messageChanged();
}
@ -394,6 +365,13 @@ public class MessageView extends Activity
mController.addResultCallback(mControllerCallback);
if (mMessage != null) {
startPresenceCheck();
// get a new next/prev cursor, but only if we already had one
// (otherwise it's "too soon" and other pathways will cause it to be loaded)
if (mLoadPrevNextTask == null && mPrevNextCursor != null) {
mLoadPrevNextTask = new LoadPrevNextTask(mMailboxId);
mLoadPrevNextTask.execute();
}
}
}
@ -401,6 +379,11 @@ public class MessageView extends Activity
public void onPause() {
super.onPause();
mController.removeResultCallback(mControllerCallback);
// Manage the next/prev cursor
if (mPrevNextCursor != null) {
mPrevNextCursor.unregisterContentObserver(mNextPrevObserver);
mPrevNextCursor.deactivate();
}
}
private static void cancelTask(AsyncTask<?, ?, ?> task) {
@ -433,6 +416,8 @@ public class MessageView extends Activity
mMessageContentView.destroy();
mMessageContentView = null;
}
// Destroy the next/prev cursor if we're holding one
// Note, the observer was already unregistered in onPause()
if (mPrevNextCursor != null) {
mPrevNextCursor.close();
mPrevNextCursor = null;
@ -692,6 +677,78 @@ public class MessageView extends Activity
return true;
}
/**
* Re-init everything needed for changing message.
*/
private void messageChanged() {
cancelAllTasks();
setTitle("");
mMessageContentView.loadUrl("file:///android_asset/empty.html");
mAttachments.removeAllViews();
mAttachments.setVisibility(View.GONE);
mAttachmentIcon.setVisibility(View.GONE);
// Start an AsyncTask to make a new cursor and load the message
mLoadMessageTask = new LoadMessageTask(mMessageId, true);
mLoadMessageTask.execute();
updatePrevNextArrows(mPrevNextCursor);
}
/**
* Reposition the next/prev cursor. Finish() the activity if we are no longer
* in the list. Update the UI arrows as appropriate.
*/
private void repositionPrevNextCursor() {
// position the cursor on the current message
mPrevNextCursor.moveToPosition(-1);
while (mPrevNextCursor.moveToNext() && mPrevNextCursor.getLong(0) != mMessageId) {
}
if (mPrevNextCursor.isAfterLast()) {
// overshoot - get out now, the list is no longer valid
finish();
}
updatePrevNextArrows(mPrevNextCursor);
}
/**
* Based on the current position of the prev/next cursor, update the prev / next arrows.
*/
private void updatePrevNextArrows(Cursor cursor) {
if (cursor != null) {
boolean hasPrev, hasNext;
if (cursor.isAfterLast() || cursor.isBeforeFirst()) {
// The cursor not being on a message means that the current message was not found.
// While this should not happen, simply disable prev/next arrows in that case.
hasPrev = hasNext = false;
} else {
hasPrev = !cursor.isFirst();
hasNext = !cursor.isLast();
}
mPrevious.setVisibility(hasPrev ? View.VISIBLE : View.GONE);
mNext.setVisibility(hasNext ? View.VISIBLE : View.GONE);
}
}
/**
* This observer is used to watch for external changes to the next/prev list
*/
private class NextPrevObserver extends ContentObserver {
public NextPrevObserver(Handler handler) {
super(handler);
}
@Override
public void onChange(boolean selfChange) {
// get a new next/prev cursor, but only if we already had one
// (otherwise it's "too soon" and other pathways will cause it to be loaded)
if (mLoadPrevNextTask == null && mPrevNextCursor != null) {
mLoadPrevNextTask = new LoadPrevNextTask(mMailboxId);
mLoadPrevNextTask.execute();
}
}
}
private Bitmap getPreviewIcon(AttachmentInfo attachment) {
try {
return BitmapFactory.decodeStream(
@ -897,7 +954,7 @@ public class MessageView extends Activity
protected Cursor doInBackground(Void... params) {
String selection =
Utility.buildMailboxIdSelection(getContentResolver(), mLocalMailboxId);
Cursor c = MessageView.this.managedQuery(EmailContent.Message.CONTENT_URI,
Cursor c = getContentResolver().query(EmailContent.Message.CONTENT_URI,
EmailContent.ID_PROJECTION,
selection, null,
EmailContent.MessageColumns.TIMESTAMP + " DESC");
@ -906,13 +963,20 @@ public class MessageView extends Activity
@Override
protected void onPostExecute(Cursor cursor) {
// remove the reference to ourselves so another one can be launched
MessageView.this.mLoadPrevNextTask = null;
if (cursor.isClosed()) {
return;
}
// position the cursor on the current message
while (cursor.moveToNext() && cursor.getLong(0) != mMessageId);
// replace the older cursor if there is one
if (mPrevNextCursor != null) {
mPrevNextCursor.unregisterContentObserver(MessageView.this.mNextPrevObserver);
mPrevNextCursor.close();
}
mPrevNextCursor = cursor;
updatePrevNextArrows(mPrevNextCursor);
mPrevNextCursor.registerContentObserver(MessageView.this.mNextPrevObserver);
repositionPrevNextCursor();
}
}
@ -1060,7 +1124,7 @@ public class MessageView extends Activity
if (mMailboxId == -1) {
mMailboxId = message.mMailboxKey;
}
// only start LoadPrevNextTask once
// only start LoadPrevNextTask here if it's the first time
if (mPrevNextCursor == null) {
mLoadPrevNextTask = new LoadPrevNextTask(mMailboxId);
mLoadPrevNextTask.execute();