src.com.android.common.widget.CompositeCursorAdapter Maven / Gradle / Ivy
/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.common.widget;
import android.content.Context;
import android.database.Cursor;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import java.util.ArrayList;
/**
* A general purpose adapter that is composed of multiple cursors. It just
* appends them in the order they are added.
*/
public abstract class CompositeCursorAdapter extends BaseAdapter {
private static final int INITIAL_CAPACITY = 2;
public static class Partition {
boolean showIfEmpty;
boolean hasHeader;
Cursor cursor;
int idColumnIndex;
int count;
public Partition(boolean showIfEmpty, boolean hasHeader) {
this.showIfEmpty = showIfEmpty;
this.hasHeader = hasHeader;
}
/**
* True if the directory should be shown even if no contacts are found.
*/
public boolean getShowIfEmpty() {
return showIfEmpty;
}
public boolean getHasHeader() {
return hasHeader;
}
public boolean isEmpty() {
return count == 0;
}
}
private final Context mContext;
private ArrayList mPartitions;
private int mCount = 0;
private boolean mCacheValid = true;
private boolean mNotificationsEnabled = true;
private boolean mNotificationNeeded;
public CompositeCursorAdapter(Context context) {
this(context, INITIAL_CAPACITY);
}
public CompositeCursorAdapter(Context context, int initialCapacity) {
mContext = context;
mPartitions = new ArrayList();
}
public Context getContext() {
return mContext;
}
/**
* Registers a partition. The cursor for that partition can be set later.
* Partitions should be added in the order they are supposed to appear in the
* list.
*/
public void addPartition(boolean showIfEmpty, boolean hasHeader) {
addPartition(new Partition(showIfEmpty, hasHeader));
}
public void addPartition(Partition partition) {
mPartitions.add(partition);
invalidate();
notifyDataSetChanged();
}
public void addPartition(int location, Partition partition) {
mPartitions.add(location, partition);
invalidate();
notifyDataSetChanged();
}
public void removePartition(int partitionIndex) {
Cursor cursor = mPartitions.get(partitionIndex).cursor;
if (cursor != null && !cursor.isClosed()) {
cursor.close();
}
mPartitions.remove(partitionIndex);
invalidate();
notifyDataSetChanged();
}
/**
* Removes cursors for all partitions.
*/
// TODO: Is this really what this is supposed to do? Just remove the cursors? Not close them?
// Not remove the partitions themselves? Isn't this leaking?
public void clearPartitions() {
for (Partition partition : mPartitions) {
partition.cursor = null;
}
invalidate();
notifyDataSetChanged();
}
/**
* Closes all cursors and removes all partitions.
*/
public void close() {
for (Partition partition : mPartitions) {
Cursor cursor = partition.cursor;
if (cursor != null && !cursor.isClosed()) {
cursor.close();
}
}
mPartitions.clear();
invalidate();
notifyDataSetChanged();
}
public void setHasHeader(int partitionIndex, boolean flag) {
mPartitions.get(partitionIndex).hasHeader = flag;
invalidate();
}
public void setShowIfEmpty(int partitionIndex, boolean flag) {
mPartitions.get(partitionIndex).showIfEmpty = flag;
invalidate();
}
public Partition getPartition(int partitionIndex) {
return mPartitions.get(partitionIndex);
}
protected void invalidate() {
mCacheValid = false;
}
public int getPartitionCount() {
return mPartitions.size();
}
protected void ensureCacheValid() {
if (mCacheValid) {
return;
}
mCount = 0;
for (Partition partition : mPartitions) {
Cursor cursor = partition.cursor;
int count;
if (cursor == null || cursor.isClosed()) {
count = 0;
} else {
count = cursor.getCount();
}
if (partition.hasHeader) {
if (count != 0 || partition.showIfEmpty) {
count++;
}
}
partition.count = count;
mCount += count;
}
mCacheValid = true;
}
/**
* Returns true if the specified partition was configured to have a header.
*/
public boolean hasHeader(int partition) {
return mPartitions.get(partition).hasHeader;
}
/**
* Returns the total number of list items in all partitions.
*/
public int getCount() {
ensureCacheValid();
return mCount;
}
/**
* Returns the cursor for the given partition
*/
public Cursor getCursor(int partition) {
return mPartitions.get(partition).cursor;
}
/**
* Changes the cursor for an individual partition.
*/
public void changeCursor(int partition, Cursor cursor) {
Cursor prevCursor = mPartitions.get(partition).cursor;
if (prevCursor != cursor) {
if (prevCursor != null && !prevCursor.isClosed()) {
prevCursor.close();
}
mPartitions.get(partition).cursor = cursor;
if (cursor != null && !cursor.isClosed()) {
mPartitions.get(partition).idColumnIndex = cursor.getColumnIndex("_id");
}
invalidate();
notifyDataSetChanged();
}
}
/**
* Returns true if the specified partition has no cursor or an empty cursor.
*/
public boolean isPartitionEmpty(int partition) {
Cursor cursor = mPartitions.get(partition).cursor;
return cursor == null || cursor.isClosed() || cursor.getCount() == 0;
}
/**
* Given a list position, returns the index of the corresponding partition.
*/
public int getPartitionForPosition(int position) {
ensureCacheValid();
int start = 0;
for (int i = 0, n = mPartitions.size(); i < n; i++) {
int end = start + mPartitions.get(i).count;
if (position >= start && position < end) {
return i;
}
start = end;
}
return -1;
}
/**
* Given a list position, return the offset of the corresponding item in its
* partition. The header, if any, will have offset -1.
*/
public int getOffsetInPartition(int position) {
ensureCacheValid();
int start = 0;
for (Partition partition : mPartitions) {
int end = start + partition.count;
if (position >= start && position < end) {
int offset = position - start;
if (partition.hasHeader) {
offset--;
}
return offset;
}
start = end;
}
return -1;
}
/**
* Returns the first list position for the specified partition.
*/
public int getPositionForPartition(int partition) {
ensureCacheValid();
int position = 0;
for (int i = 0; i < partition; i++) {
position += mPartitions.get(i).count;
}
return position;
}
@Override
public int getViewTypeCount() {
return getItemViewTypeCount() + 1;
}
/**
* Returns the overall number of item view types across all partitions. An
* implementation of this method needs to ensure that the returned count is
* consistent with the values returned by {@link #getItemViewType(int,int)}.
*/
public int getItemViewTypeCount() {
return 1;
}
/**
* Returns the view type for the list item at the specified position in the
* specified partition.
*/
protected int getItemViewType(int partition, int position) {
return 1;
}
@Override
public int getItemViewType(int position) {
ensureCacheValid();
int start = 0;
for (int i = 0, n = mPartitions.size(); i < n; i++) {
int end = start + mPartitions.get(i).count;
if (position >= start && position < end) {
int offset = position - start;
if (mPartitions.get(i).hasHeader) {
offset--;
}
if (offset == -1) {
return IGNORE_ITEM_VIEW_TYPE;
} else {
return getItemViewType(i, offset);
}
}
start = end;
}
throw new ArrayIndexOutOfBoundsException(position);
}
public View getView(int position, View convertView, ViewGroup parent) {
ensureCacheValid();
int start = 0;
for (int i = 0, n = mPartitions.size(); i < n; i++) {
int end = start + mPartitions.get(i).count;
if (position >= start && position < end) {
int offset = position - start;
if (mPartitions.get(i).hasHeader) {
offset--;
}
View view;
if (offset == -1) {
view = getHeaderView(i, mPartitions.get(i).cursor, convertView, parent);
} else {
if (!mPartitions.get(i).cursor.moveToPosition(offset)) {
throw new IllegalStateException("Couldn't move cursor to position "
+ offset);
}
view = getView(i, mPartitions.get(i).cursor, offset, convertView, parent);
}
if (view == null) {
throw new NullPointerException("View should not be null, partition: " + i
+ " position: " + offset);
}
return view;
}
start = end;
}
throw new ArrayIndexOutOfBoundsException(position);
}
/**
* Returns the header view for the specified partition, creating one if needed.
*/
protected View getHeaderView(int partition, Cursor cursor, View convertView,
ViewGroup parent) {
View view = convertView != null
? convertView
: newHeaderView(mContext, partition, cursor, parent);
bindHeaderView(view, partition, cursor);
return view;
}
/**
* Creates the header view for the specified partition.
*/
protected View newHeaderView(Context context, int partition, Cursor cursor,
ViewGroup parent) {
return null;
}
/**
* Binds the header view for the specified partition.
*/
protected void bindHeaderView(View view, int partition, Cursor cursor) {
}
/**
* Returns an item view for the specified partition, creating one if needed.
*/
protected View getView(int partition, Cursor cursor, int position, View convertView,
ViewGroup parent) {
View view;
if (convertView != null) {
view = convertView;
} else {
view = newView(mContext, partition, cursor, position, parent);
}
bindView(view, partition, cursor, position);
return view;
}
/**
* Creates an item view for the specified partition and position. Position
* corresponds directly to the current cursor position.
*/
protected abstract View newView(Context context, int partition, Cursor cursor, int position,
ViewGroup parent);
/**
* Binds an item view for the specified partition and position. Position
* corresponds directly to the current cursor position.
*/
protected abstract void bindView(View v, int partition, Cursor cursor, int position);
/**
* Returns a pre-positioned cursor for the specified list position.
*/
public Object getItem(int position) {
ensureCacheValid();
int start = 0;
for (Partition mPartition : mPartitions) {
int end = start + mPartition.count;
if (position >= start && position < end) {
int offset = position - start;
if (mPartition.hasHeader) {
offset--;
}
if (offset == -1) {
return null;
}
Cursor cursor = mPartition.cursor;
if (cursor == null || cursor.isClosed() || !cursor.moveToPosition(offset)) {
return null;
}
return cursor;
}
start = end;
}
return null;
}
/**
* Returns the item ID for the specified list position.
*/
public long getItemId(int position) {
ensureCacheValid();
int start = 0;
for (Partition mPartition : mPartitions) {
int end = start + mPartition.count;
if (position >= start && position < end) {
int offset = position - start;
if (mPartition.hasHeader) {
offset--;
}
if (offset == -1) {
return 0;
}
if (mPartition.idColumnIndex == -1) {
return 0;
}
Cursor cursor = mPartition.cursor;
if (cursor == null || cursor.isClosed() || !cursor.moveToPosition(offset)) {
return 0;
}
return cursor.getLong(mPartition.idColumnIndex);
}
start = end;
}
return 0;
}
/**
* Returns false if any partition has a header.
*/
@Override
public boolean areAllItemsEnabled() {
for (Partition mPartition : mPartitions) {
if (mPartition.hasHeader) {
return false;
}
}
return true;
}
/**
* Returns true for all items except headers.
*/
@Override
public boolean isEnabled(int position) {
ensureCacheValid();
int start = 0;
for (int i = 0, n = mPartitions.size(); i < n; i++) {
int end = start + mPartitions.get(i).count;
if (position >= start && position < end) {
int offset = position - start;
if (mPartitions.get(i).hasHeader && offset == 0) {
return false;
} else {
return isEnabled(i, offset);
}
}
start = end;
}
return false;
}
/**
* Returns true if the item at the specified offset of the specified
* partition is selectable and clickable.
*/
protected boolean isEnabled(int partition, int position) {
return true;
}
/**
* Enable or disable data change notifications. It may be a good idea to
* disable notifications before making changes to several partitions at once.
*/
public void setNotificationsEnabled(boolean flag) {
mNotificationsEnabled = flag;
if (flag && mNotificationNeeded) {
notifyDataSetChanged();
}
}
@Override
public void notifyDataSetChanged() {
if (mNotificationsEnabled) {
mNotificationNeeded = false;
super.notifyDataSetChanged();
} else {
mNotificationNeeded = true;
}
}
}
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