MediaBrowserActivity.java

/*
 *  Copyright (C) 2012 Simon Robinson
 * 
 *  This file is part of Com-Me.
 * 
 *  Com-Me is free software; you can redistribute it and/or modify it 
 *  under the terms of the GNU Lesser General Public License as 
 *  published by the Free Software Foundation; either version 3 of the 
 *  License, or (at your option) any later version.
 *
 *  Com-Me 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 Lesser General 
 *  Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with Com-Me.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

package ac.robinson.mediatablet.activity;

import group.pals.android.lib.ui.lockpattern.LockPatternActivity;

import java.io.File;
import java.util.ArrayList;

import ac.robinson.mediatablet.MediaTablet;
import ac.robinson.mediatablet.MediaTabletActivity;
import ac.robinson.mediatablet.R;
import ac.robinson.mediatablet.provider.HomesteadManager;
import ac.robinson.mediatablet.provider.MediaAdapter;
import ac.robinson.mediatablet.provider.MediaItem;
import ac.robinson.mediatablet.provider.MediaManager;
import ac.robinson.mediatablet.provider.MediaTabletProvider;
import ac.robinson.mediatablet.provider.PersonItem;
import ac.robinson.mediatablet.provider.PersonManager;
import ac.robinson.mediatablet.view.MediaViewHolder;
import ac.robinson.util.BitmapUtilities;
import ac.robinson.util.ImageCacheUtilities;
import ac.robinson.util.StringUtilities;
import ac.robinson.util.UIUtilities;
import ac.robinson.util.UIUtilities.ReflectionTab;
import ac.robinson.util.UIUtilities.ReflectionTabListener;
import ac.robinson.view.CrossFadeDrawable;
import ac.robinson.view.FastBitmapDrawable;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.ContentResolver;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.res.Resources;
import android.graphics.ColorFilter;
import android.graphics.ColorMatrix;
import android.graphics.ColorMatrixColorFilter;
import android.graphics.drawable.BitmapDrawable;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.ToggleButton;

//TODO: add a search view: http://developer.android.com/guide/topics/ui/actionbar.html#ActionView
//TODO: filter by text - original filename or text content
public class MediaBrowserActivity extends MediaTabletActivity {

	private MediaAdapter mMediaAdapter;
	private FastBitmapDrawable mDefaultIcon;
	private GridView mGrid;

	private final Handler mScrollHandler = new ScrollHandler();
	private int mScrollState = ScrollManager.SCROLL_STATE_IDLE;
	private boolean mPendingIconsUpdate;
	private boolean mFingerUp = true;
	private ColorFilter mToggleButtonFilter;

	// TODO: for showing the grid position hints
	// private PopupWindow mPopup;
	// private View mCurrentGridPositionView;
	// private TextView mCurrentGridPositionText;

	private String mParentId; // the owner of this media, or null if it's the public media view
	private int mMediaVisibility;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);

		// load previous visibility and parent id on screen rotation
		mParentId = null;
		mMediaVisibility = MediaItem.MEDIA_PUBLIC;
		if (savedInstanceState != null) {
			mParentId = savedInstanceState.getString(getString(R.string.extra_parent_id));
			mMediaVisibility = savedInstanceState.getInt(getString(R.string.extra_media_visibility));
		} else {
			final Intent intent = getIntent();
			if (intent != null) {
				mParentId = intent.getStringExtra(getString(R.string.extra_parent_id));
				mMediaVisibility = intent.getIntExtra(getString(R.string.extra_media_visibility),
						MediaItem.MEDIA_PUBLIC);
			}
		}

		if (mParentId != null) {
			addPersonalisedTabs();
		} else {
			UIUtilities.addActionBarTabs(this, new ReflectionTab[] {
					new ReflectionTab(R.id.intent_homestead_browser, R.drawable.ic_menu_homesteads,
							getString(R.string.title_homestead_browser)),
					new ReflectionTab(R.id.intent_media_browser, R.drawable.ic_menu_public_media,
							getString(R.string.title_media_browser_public), true) }, mReflectionTabListener);
		}
		UIUtilities.configureActionBar(this, true, false, R.string.title_media_browser_public, 0);
		setContentView(R.layout.media_browser);

		initialiseMediaGridView();
	}

	@Override
	public void onSaveInstanceState(Bundle savedInstanceState) {
		savedInstanceState.putString(getString(R.string.extra_parent_id), mParentId);
		savedInstanceState.putInt(getString(R.string.extra_media_visibility), mMediaVisibility);
		super.onSaveInstanceState(savedInstanceState);
	}

	@Override
	protected void onPause() {
		super.onPause();
		mScrollHandler.removeMessages(MediaTablet.MESSAGE_UPDATE_GRID_ICONS);
		// dismissPopup();
	}

	@Override
	protected void onDestroy() {
		ImageCacheUtilities.cleanupCache();
		super.onDestroy();
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		if (mParentId != null) {
			MenuInflater inflater = getMenuInflater();
			inflater.inflate(R.menu.public_media, menu);
			inflater.inflate(R.menu.delete, menu);
		} else {
			getMenuInflater().inflate(R.menu.back, menu);
		}
		return super.onCreateOptionsMenu(menu);
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		switch (item.getItemId()) {
			case android.R.id.home:
				return super.onOptionsItemSelected(item);

			case R.id.menu_back:
				finish();
				return true;

			case R.id.menu_view_public_media:
				viewPublicMedia();
				return true;

			case R.id.menu_delete:
				LayoutInflater inflater = LayoutInflater.from(MediaBrowserActivity.this);
				final View textEntryView = inflater.inflate(R.layout.password_input, null);
				AlertDialog.Builder builder = new AlertDialog.Builder(MediaBrowserActivity.this);
				builder.setMessage(R.string.delete_person_password_prompt).setCancelable(false).setView(textEntryView)
						.setPositiveButton(R.string.button_delete, new DialogInterface.OnClickListener() {
							@Override
							public void onClick(DialogInterface dialog, int id) {
								if (MediaTablet.ADMINISTRATOR_PASSWORD.equals(StringUtilities
										.sha1Hash(((EditText) textEntryView.findViewById(R.id.text_password_entry))
												.getText().toString()))) {
									ContentResolver contentResolver = getContentResolver();
									PersonItem personToDelete = PersonManager.findPersonByInternalId(contentResolver,
											mParentId);
									personToDelete.setDeleted(true);
									PersonManager.updatePerson(contentResolver, personToDelete);

									String parentId = personToDelete.getParentId();
									ArrayList<PersonItem> testPeople = PersonManager.findPeopleByParentId(
											contentResolver, parentId);
									if (testPeople.size() <= 0) {
										HomesteadManager.deleteHomesteadByInternalId(getContentResolver(), parentId);
									} else {
										HomesteadManager.reloadHomesteadIcon(getResources(), contentResolver, parentId);
									}
									UIUtilities.showToast(MediaBrowserActivity.this, R.string.delete_person_deleted);
									viewHomesteads();
								} else {
									UIUtilities.showToast(MediaBrowserActivity.this,
											R.string.delete_person_password_incorrect);
								}
							}
						}).setNegativeButton(R.string.button_cancel, new DialogInterface.OnClickListener() {
							@Override
							public void onClick(DialogInterface dialog, int id) {
								dialog.cancel();
							}
						});
				builder.show();
				return true;

			default:
				return super.onOptionsItemSelected(item);
		}
	}

	@Override
	protected void loadPreferences(SharedPreferences mediaTabletSettings) {
	}

	@Override
	protected String getCurrentPersonId() {
		// only return the current person's id when they are unlocked
		return mMediaVisibility == MediaItem.MEDIA_PRIVATE ? mParentId : PersonItem.UNKNOWN_PERSON_ID;
	}

	// setBackgroundDrawable is deprecated from API 16+ (Jelly Bean), but we still want to target earlier versions;
	// since this is purely a name change, there's no real reason to do anything platform-independent
	@SuppressWarnings("deprecation")
	private void initialiseMediaGridView() {
		// for API 11 and above, buttons are in the action bar - could use XML-v11 but maintenance is a hassle
		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
			findViewById(R.id.panel_media).setVisibility(View.GONE);
		}

		if (mParentId == null) {
			findViewById(R.id.panel_profile_picture).setVisibility(View.GONE);
			findViewById(R.id.panel_filter_buttons).setBackgroundDrawable(null);
			findViewById(R.id.button_media_view_public_media).setVisibility(View.GONE);
			findViewById(R.id.button_media_view_homesteads).setVisibility(View.GONE);
			((Button) findViewById(R.id.button_media_view_people)).setCompoundDrawablesWithIntrinsicBounds(0,
					android.R.drawable.ic_menu_revert, 0, 0);
		} else {
			((ImageView) findViewById(R.id.profile_picture_overlay_filter))
					.setOnLongClickListener(imageLongPressListener);
		}
		updateOwnerPicture(); // show the locked/unlocked owner picture or the public icon

		mMediaAdapter = new MediaAdapter(this, mParentId, mMediaVisibility);
		mDefaultIcon = mMediaAdapter.getDefaultIcon();
		mGrid = (GridView) findViewById(R.id.grid_media);

		ColorMatrix colourMatrix = new ColorMatrix();
		colourMatrix.setSaturation(0);
		mToggleButtonFilter = new ColorMatrixColorFilter(colourMatrix);
		uncheckOtherFilterButtons(0);

		final GridView grid = mGrid;
		grid.setAdapter(mMediaAdapter);
		grid.setOnScrollListener(new ScrollManager());
		grid.setOnTouchListener(new FingerTracker());
		grid.setOnItemSelectedListener(new SelectionTracker());
		grid.setOnItemClickListener(new MediaViewer());

		// TODO: for the scrolling hints
		// mCurrentGridPositionView = getLayoutInflater().inflate(R.layout.grid_annotation, null);
		// mCurrentGridPositionText = (TextView) mCurrentGridPositionView.findViewById(R.id.text_grid_annotation);
	}

	private void addPersonalisedTabs() {
		UIUtilities.removeActionBarTabs(this);
		PersonItem person = PersonManager.findPersonByInternalId(getContentResolver(), mParentId);
		String personName = person == null ? null : person.getName();
		String mediaTitle = person == null || personName == null ? getString(R.string.title_media_browser) : getString(
				mMediaVisibility == MediaItem.MEDIA_PUBLIC ? R.string.title_media_browser_public_personalised
						: R.string.title_media_browser_private_personalised, personName);
		String peopleTitle = person == null || personName == null ? getString(R.string.title_people_browser) : String
				.format(getString(R.string.title_people_browser_personalised), personName);
		UIUtilities.addActionBarTabs(this, new ReflectionTab[] {
				new ReflectionTab(R.id.intent_homestead_browser, R.drawable.ic_menu_homesteads,
						getString(R.string.title_homestead_browser)),
				new ReflectionTab(R.id.intent_people_browser, R.drawable.ic_menu_people, peopleTitle),
				new ReflectionTab(R.id.intent_media_browser, R.drawable.ic_menu_media, mediaTitle, true) },
				mReflectionTabListener);
	}

	private void updateOwnerPicture() {
		if (mParentId != null && MediaTablet.DIRECTORY_THUMBS != null) {
			Resources resources = getResources();
			int iconWidth = resources.getDimensionPixelSize(R.dimen.media_owner_icon_width);
			int iconHeight = resources.getDimensionPixelSize(R.dimen.media_owner_icon_width);
			ImageView ownerIcon = ((ImageView) findViewById(R.id.profile_picture_image));
			BitmapDrawable cachedIcon = new BitmapDrawable(getResources(), BitmapUtilities.loadAndCreateScaledBitmap(
					new File(MediaTablet.DIRECTORY_THUMBS, PersonItem.getCacheId(mParentId)).getAbsolutePath(),
					iconWidth, iconHeight, BitmapUtilities.ScalingLogic.CROP, true));
			ownerIcon.setImageDrawable(cachedIcon);
		}
		updateLockVisibility();
	}

	private void updateLockVisibility() {
		if (mParentId == null || mMediaVisibility == MediaItem.MEDIA_PRIVATE) {
			findViewById(R.id.profile_picture_overlay).setVisibility(View.GONE);
		} else {
			findViewById(R.id.profile_picture_overlay).setVisibility(View.VISIBLE);
		}
	}

	public void handleFilterClicks(View currentButton) {
		final int buttonId = currentButton.getId();
		final boolean buttonIsChecked = ((ToggleButton) currentButton).isChecked();
		switch (buttonId) {
			case R.id.button_media_filter_images:
				mMediaAdapter.setMediaFilters(buttonIsChecked, MediaTabletProvider.TYPE_IMAGE_BACK,
						MediaTabletProvider.TYPE_IMAGE_FRONT);
				break;

			case R.id.button_media_filter_videos:
				mMediaAdapter.setMediaFilters(buttonIsChecked, MediaTabletProvider.TYPE_VIDEO);
				break;

			case R.id.button_media_filter_audio:
				mMediaAdapter.setMediaFilters(buttonIsChecked, MediaTabletProvider.TYPE_AUDIO);
				break;

			case R.id.button_media_filter_text:
				mMediaAdapter.setMediaFilters(buttonIsChecked, MediaTabletProvider.TYPE_TEXT);
				break;

			case R.id.button_media_filter_narratives:
				mMediaAdapter.setMediaFilters(buttonIsChecked, MediaTabletProvider.TYPE_NARRATIVE);
				break;
		}
		uncheckOtherFilterButtons(buttonId);
	}

	private void uncheckOtherFilterButtons(int currentButtonId) {
		int[] otherButtons = new int[] { R.id.button_media_filter_images, R.id.button_media_filter_videos,
				R.id.button_media_filter_audio, R.id.button_media_filter_text, R.id.button_media_filter_narratives };
		for (int i = 0, n = otherButtons.length; i < n; i++) {
			final ToggleButton currentButton = ((ToggleButton) findViewById(otherButtons[i]));
			if ((currentButtonId == otherButtons[i] && currentButton.isChecked())
					|| (currentButtonId == 0 && currentButton.isChecked())) {
				currentButton.getBackground().setColorFilter(null);
			} else {
				currentButton.setChecked(false);
				currentButton.getBackground().setColorFilter(mToggleButtonFilter);
			}
		}
	}

	public void handlePersonIconClick(View personIcon) {
		if (mMediaVisibility == MediaItem.MEDIA_PUBLIC) {
			PersonItem ownerPerson = PersonManager.findPersonByInternalId(getContentResolver(), mParentId);
			Intent lockPatternIntent = new Intent(MediaBrowserActivity.this, LockPatternActivity.class);
			lockPatternIntent.putExtra(LockPatternActivity._Theme, android.R.style.Theme_Dialog);
			lockPatternIntent.putExtra(LockPatternActivity._Mode, LockPatternActivity.LPMode.ComparePattern);
			lockPatternIntent.putExtra(LockPatternActivity._MaxRetry, 1); // default: 5
			lockPatternIntent.putExtra(LockPatternActivity._PaternSha1, ownerPerson.getPasswordHash());
			startActivityForResult(lockPatternIntent, R.id.intent_lock_pattern);
		} else {
			mMediaVisibility = MediaItem.MEDIA_PUBLIC;
			mMediaAdapter.setVisibilityFilter(mMediaVisibility);
			PersonItem person = PersonManager.findPersonByInternalId(getContentResolver(), mParentId);
			person.setLockStatus(PersonItem.PERSON_LOCKED);
			PersonManager.updatePerson(getContentResolver(), person);
			addPersonalisedTabs(); // must remove and re-add - Android bug means setting text fails
			updateLockVisibility();
			UIUtilities.showToast(MediaBrowserActivity.this, R.string.message_locking_person_success);
		}
	}

	private void viewHomesteads() {
		final Intent resultIntent = new Intent();
		resultIntent.putExtra(getString(R.string.extra_finish_activity), true);
		resultIntent.putExtra(getString(R.string.extra_finish_parent_activities), true); // in case from public media
		setResult(Activity.RESULT_OK, resultIntent); // exit people browser too
		finish();
	}

	public void handleButtonClicks(View currentButton) {
		switch (currentButton.getId()) {
			case R.id.button_media_view_homesteads:
				viewHomesteads();
				break;

			case R.id.button_media_view_people:
				finish();
				break;

			case R.id.button_media_view_public_media:
				viewPublicMedia();
				break;
		}
	}

	private ReflectionTabListener mReflectionTabListener = new ReflectionTabListener() {
		@Override
		public void onTabSelected(int tabId) {
			switch (tabId) {
				case R.id.intent_homestead_browser:
					viewHomesteads();
					break;

				case R.id.intent_people_browser:
					finish();
					break;

				default:
					break;
			}
		}

		@Override
		public void onTabReselected(int tabId) {
		}

		@Override
		public void onTabUnselected(int tabId) {
		}
	};

	private View.OnLongClickListener imageLongPressListener = new View.OnLongClickListener() {
		@Override
		public boolean onLongClick(View view) {
			if (mMediaVisibility == MediaItem.MEDIA_PRIVATE) {
				PersonItem person = PersonManager.findPersonByInternalId(getContentResolver(), mParentId);
				if (person != null) {
					editPerson(person.getParentId(), mParentId);
					return true;
				}
				return false;
			}
			return false;
		}
	};

	public int getScrollState() {
		return mScrollState; // for MediaAdapter purposes
	}

	public boolean isPendingIconsUpdate() {
		return mPendingIconsUpdate; // for MediaAdapter purposes
	}

	private void onView(MediaViewHolder currentMediaHolder) {
		Class<?> launchClass = null;
		switch (currentMediaHolder.mediaType) {
			case MediaTabletProvider.TYPE_IMAGE_BACK:
			case MediaTabletProvider.TYPE_IMAGE_FRONT:
			case MediaTabletProvider.TYPE_UNKNOWN:
				launchClass = ImageViewerActivity.class;
				break;
			case MediaTabletProvider.TYPE_AUDIO:
			case MediaTabletProvider.TYPE_VIDEO:
				launchClass = AudioVideoViewerActivity.class;
				break;

			case MediaTabletProvider.TYPE_TEXT:
				launchClass = TextViewerActivity.class;
				break;

			case MediaTabletProvider.TYPE_NARRATIVE:
				launchClass = NarrativeViewerActivity.class;
				break;

			default:
				break;
		}
		if (launchClass != null) {
			Intent storyViewerIntent = new Intent(this, launchClass);
			storyViewerIntent.putExtra(getString(R.string.extra_internal_id), currentMediaHolder.mediaInternalId);
			storyViewerIntent.putExtra(getString(R.string.extra_parent_id), mParentId == null
					|| PersonItem.UNKNOWN_PERSON_ID.equals(currentMediaHolder.mediaOwnerId) ? null
					: currentMediaHolder.mediaOwnerId);
			startActivityForResult(storyViewerIntent, R.id.intent_media_item_viewer);
		}
	}

	// private void dismissPopup() {
	// if (mPopup != null) {
	// mPopup.dismiss();
	// }
	// }

	// private void showPopup() {
	// if (mPopup == null) {
	// PopupWindow p = new PopupWindow(this);
	// p.setFocusable(false);
	// p.setContentView(mCurrentGridPositionView);
	// p.setWidth(ViewGroup.LayoutParams.MATCH_PARENT);
	// p.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
	// p.setBackgroundDrawable(null);
	//
	// p.setAnimationStyle(R.style.PopupAnimation);
	//
	// mPopup = p;
	// }
	//
	// if (mGrid.getWindowVisibility() == View.VISIBLE) {
	// mPopup.showAtLocation(mGrid, Gravity.CENTER, 0, 0);
	// }
	// }

	// setBackgroundDrawable is deprecated from API 16+ (Jelly Bean), but we still want to target earlier versions;
	// since this is purely a name change, there's no real reason to do anything platform-independent
	@SuppressWarnings("deprecation")
	private void updateMediaIcons() {
		mPendingIconsUpdate = false;

		final GridView grid = mGrid;
		final FastBitmapDrawable icon = mDefaultIcon;
		final int count = grid.getChildCount();

		// show a different icon depending on whether we're viewing from the public media or this person's media store
		final int iconVisibility = mParentId == null ? MediaItem.MEDIA_PUBLIC : MediaItem.MEDIA_PRIVATE;
		for (int i = 0; i < count; i++) {
			final View view = grid.getChildAt(i);
			final MediaViewHolder holder = (MediaViewHolder) view.getTag();
			if (holder.queryIcon) {
				// if the icon has gone missing (recently imported or cache deletion), regenerate it
				String mediaCacheId = MediaItem.getCacheId(holder.mediaInternalId, iconVisibility);
				FastBitmapDrawable cachedIcon = ImageCacheUtilities.getCachedIcon(MediaTablet.DIRECTORY_THUMBS,
						mediaCacheId, ImageCacheUtilities.NULL_DRAWABLE);
				if (ImageCacheUtilities.NULL_DRAWABLE.equals(cachedIcon)) {
					MediaManager.reloadMediaIcon(getResources(), getContentResolver(), holder.mediaInternalId,
							iconVisibility);
					cachedIcon = ImageCacheUtilities.getCachedIcon(MediaTablet.DIRECTORY_THUMBS, mediaCacheId, icon);
				}
				CrossFadeDrawable d = holder.transition;
				d.setEnd(cachedIcon.getBitmap());
				holder.display.setImageDrawable(d);
				d.startTransition(MediaTablet.ANIMATION_FADE_TRANSITION_DURATION);
				holder.loader.setVisibility(View.GONE);

				if (mParentId != null && holder.mediaVisibility == MediaItem.MEDIA_PUBLIC) {
					holder.overlay.setBackgroundResource(R.drawable.item_public);
					holder.overlay.setPadding(0, 0, 0, 0);
				} else {
					holder.overlay.setBackgroundDrawable(null);
				}
				holder.queryIcon = false;
			}
		}

		grid.invalidate();
	}

	private void postUpdateMediaIcons() {
		Handler handler = mScrollHandler;
		Message message = handler.obtainMessage(MediaTablet.MESSAGE_UPDATE_GRID_ICONS, MediaBrowserActivity.this);
		handler.removeMessages(MediaTablet.MESSAGE_UPDATE_GRID_ICONS);
		mPendingIconsUpdate = true;
		handler.sendMessage(message);
	}

	private class ScrollManager implements AbsListView.OnScrollListener {
		// private String mPreviousPrefix;
		// private boolean mPopupWillShow;

		// private final Runnable mShowPopup = new Runnable() {
		// public void run() {
		// showPopup();
		// }
		// };

		// private final Runnable mDismissPopup = new Runnable() {
		// public void run() {
		// mScrollHandler.removeCallbacks(mShowPopup);
		// mPopupWillShow = false;
		// dismissPopup();
		// }
		// };

		public void onScrollStateChanged(AbsListView view, int scrollState) {
			if (mScrollState == SCROLL_STATE_FLING && scrollState != SCROLL_STATE_FLING) {
				final Handler handler = mScrollHandler;
				final Message message = handler.obtainMessage(MediaTablet.MESSAGE_UPDATE_GRID_ICONS,
						MediaBrowserActivity.this);
				handler.removeMessages(MediaTablet.MESSAGE_UPDATE_GRID_ICONS);
				handler.sendMessageDelayed(message, mFingerUp ? 0 : MediaTablet.ANIMATION_ICON_SHOW_DELAY);
				mPendingIconsUpdate = true;
			} else if (scrollState == SCROLL_STATE_FLING) {
				mPendingIconsUpdate = false;
				mScrollHandler.removeMessages(MediaTablet.MESSAGE_UPDATE_GRID_ICONS);
			}
			mScrollState = scrollState;
		}

		// TODO: fix this (see MediaPhone)
		public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
			if (mScrollState != SCROLL_STATE_FLING)
				return;

			// final int count = view.getChildCount();
			// if (count == 0)
			// return;
			//
			// final StringBuilder buffer = new StringBuilder(7);
			//
			// String title = Long.toString(((MediaViewHolder) view.getChildAt(0).getTag()).mediaDateCreated);
			// title = title.substring(0, Math.min(title.length(), 2));
			// if (title.length() == 2) {
			// buffer.append(Character.toUpperCase(title.charAt(0)));
			// buffer.append(title.charAt(1));
			// } else {
			// buffer.append(title.toUpperCase());
			// }
			//
			// if (count > 1) {
			// buffer.append(" - ");
			//
			// final int lastChild = count - 1;
			// title = Long.toString(((MediaViewHolder) view.getChildAt(lastChild).getTag()).mediaDateCreated);
			// title = title.substring(0, Math.min(title.length(), 2));
			//
			// if (title.length() == 2) {
			// buffer.append(Character.toUpperCase(title.charAt(0)));
			// buffer.append(title.charAt(1));
			// } else {
			// buffer.append(title.toUpperCase());
			// }
			// }
			//
			// final String prefix = buffer.toString();
			// final Handler scrollHandler = mScrollHandler;
			//
			// if (!mPopupWillShow && (mPopup == null || !mPopup.isShowing()) && !prefix.equals(mPreviousPrefix)) {
			//
			// mPopupWillShow = true;
			// final Runnable showPopup = mShowPopup;
			// scrollHandler.removeCallbacks(showPopup);
			// scrollHandler.postDelayed(showPopup, MediaTablet.ANIMATION_GRIDHINT_SHOW_DELAY);
			// }
			//
			// mCurrentGridPositionText.setText(prefix);
			// mPreviousPrefix = prefix;
			//
			// final Runnable dismissPopup = mDismissPopup;
			// scrollHandler.removeCallbacks(dismissPopup);
			// scrollHandler.postDelayed(dismissPopup, MediaTablet.ANIMATION_GRIDHINT_HIDE_DELAY);
		}
	}

	private static class ScrollHandler extends Handler {
		@Override
		public void handleMessage(Message msg) {
			switch (msg.what) {
				case MediaTablet.MESSAGE_UPDATE_GRID_ICONS:
					((MediaBrowserActivity) msg.obj).updateMediaIcons();
					break;
			}
		}
	}

	private class FingerTracker implements View.OnTouchListener {
		public boolean onTouch(View view, MotionEvent event) {
			final int action = event.getAction();
			mFingerUp = action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL;
			if (mFingerUp && mScrollState != ScrollManager.SCROLL_STATE_FLING) {
				postUpdateMediaIcons();
			}
			return false;
		}
	}

	private class SelectionTracker implements AdapterView.OnItemSelectedListener {
		public void onItemSelected(AdapterView<?> adapterView, View view, int position, long id) {
			if (mScrollState != ScrollManager.SCROLL_STATE_IDLE) {
				mScrollState = ScrollManager.SCROLL_STATE_IDLE;
				postUpdateMediaIcons();
			}
		}

		public void onNothingSelected(AdapterView<?> adapterView) {
		}
	}

	private class MediaViewer implements AdapterView.OnItemClickListener {
		public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
			MediaViewHolder currentMediaHolder = ((MediaViewHolder) view.getTag());
			onView(currentMediaHolder);
		}
	}

	@Override
	public void onActivityResult(int requestCode, int resultCode, Intent resultIntent) {
		switch (requestCode) {
			case R.id.intent_media_browser:
			case R.id.intent_media_item_viewer:
				if (resultCode == Activity.RESULT_OK && resultIntent != null) {
					if (resultIntent.getBooleanExtra(getString(R.string.extra_finish_activity), false)) {
						if (resultIntent.getBooleanExtra(getString(R.string.extra_finish_parent_activities), false)) {
							viewHomesteads();
						} else {
							finish();
						}
					}
				}
				break;

			case R.id.intent_lock_pattern:
				if (resultCode == Activity.RESULT_OK) {
					mMediaVisibility = MediaItem.MEDIA_PRIVATE;
					mMediaAdapter.setVisibilityFilter(mMediaVisibility);
					PersonItem person = PersonManager.findPersonByInternalId(getContentResolver(), mParentId);
					person.setLockStatus(PersonItem.PERSON_UNLOCKED);
					PersonManager.updatePerson(getContentResolver(), person);
					addPersonalisedTabs(); // must remove and re-add - Android bug means setting text fails
					updateLockVisibility();
					UIUtilities.showToast(MediaBrowserActivity.this, R.string.message_unlocking_person_success);
				} else {
					UIUtilities.showToast(MediaBrowserActivity.this, R.string.message_unlocking_person_failed);
				}
				break;

			case R.id.intent_add_user:
				updateOwnerPicture();
				break;

			default:
				super.onActivityResult(requestCode, resultCode, resultIntent);
		}
	}
}