/*
* Copyright 2014 Google Inc. All rights reserved.
*
* 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.example.leanback.data;
import android.database.sqlite.SQLiteDatabase;
/*
* Modifications:
* -Imported from AOSP frameworks/base/core/java/com/android/internal/content
* -Changed package name
*/
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.text.TextUtils;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
/**
* Helper for building selection clauses for {@link SQLiteDatabase}. Each
* appended clause is combined using {@code AND}. This class is <em>not</em>
* thread safe.
*/
public class SelectionBuilder {
private String mTable = null;
private HashMap<String, String> mProjectionMap;
private StringBuilder mSelection;
private ArrayList<String> mSelectionArgs;
/**
* Reset any internal state, allowing this builder to be recycled.
*/
public SelectionBuilder reset() {
mTable = null;
if (mProjectionMap != null) {
mProjectionMap.clear();
}
if (mSelection != null) {
mSelection.setLength(0);
}
if (mSelectionArgs != null) {
mSelectionArgs.clear();
}
return this;
}
/**
* Append the given selection clause to the internal state. Each clause is
* surrounded with parenthesis and combined using {@code AND}.
*/
public SelectionBuilder where(String selection, String... selectionArgs) {
if (TextUtils.isEmpty(selection)) {
if (selectionArgs != null && selectionArgs.length > 0) {
throw new IllegalArgumentException(
"Valid selection required when including arguments=");
}
// Shortcut when clause is empty
return this;
}
ensureSelection(selection.length());
if (mSelection.length() > 0) {
mSelection.append(" AND ");
}
mSelection.append("(").append(selection).append(")");
if (selectionArgs != null) {
ensureSelectionArgs();
for (String arg : selectionArgs) {
mSelectionArgs.add(arg);
}
}
return this;
}
public SelectionBuilder table(String table) {
mTable = table;
return this;
}
private void assertTable() {
if (mTable == null) {
throw new IllegalStateException("Table not specified");
}
}
private void ensureProjectionMap() {
if (mProjectionMap == null) {
mProjectionMap = new HashMap<String, String>();
}
}
private void ensureSelection(int lengthHint) {
if (mSelection == null) {
mSelection = new StringBuilder(lengthHint + 8);
}
}
private void ensureSelectionArgs() {
if (mSelectionArgs == null) {
mSelectionArgs = new ArrayList<String>();
}
}
public SelectionBuilder mapToTable(String column, String table) {
ensureProjectionMap();
mProjectionMap.put(column, table + "." + column);
return this;
}
public SelectionBuilder map(String fromColumn, String toClause) {
ensureProjectionMap();
mProjectionMap.put(fromColumn, toClause + " AS " + fromColumn);
return this;
}
/**
* Return selection string for current internal state.
*
* @see #getSelectionArgs()
*/
public String getSelection() {
if (mSelection != null) {
return mSelection.toString();
} else {
return null;
}
}
/**
* Return selection arguments for current internal state.
*
* @see #getSelection()
*/
public String[] getSelectionArgs() {
if (mSelectionArgs != null) {
return mSelectionArgs.toArray(new String[mSelectionArgs.size()]);
} else {
return null;
}
}
private void mapColumns(String[] columns) {
if (mProjectionMap == null) return;
for (int i = 0; i < columns.length; i++) {
final String target = mProjectionMap.get(columns[i]);
if (target != null) {
columns[i] = target;
}
}
}
@Override
public String toString() {
return "SelectionBuilder[table=" + mTable + ", selection=" + getSelection()
+ ", selectionArgs=" + Arrays.toString(getSelectionArgs()) + "]";
}
/**
* Execute query using the current internal state as {@code WHERE} clause.
*/
public Cursor query(SQLiteDatabase db, String[] columns, String orderBy) {
return query(db, columns, null, null, orderBy, null);
}
/**
* Execute query using the current internal state as {@code WHERE} clause.
*/
public Cursor query(SQLiteDatabase db, String[] columns, String groupBy,
String having, String orderBy, String limit) {
assertTable();
if (columns != null) mapColumns(columns);
return db.query(mTable, columns, getSelection(), getSelectionArgs(), groupBy, having,
orderBy, limit);
}
/**
* Execute update using the current internal state as {@code WHERE} clause.
*/
public int update(SQLiteDatabase db, ContentValues values) {
assertTable();
return db.update(mTable, values, getSelection(), getSelectionArgs());
}
/**
* Execute delete using the current internal state as {@code WHERE} clause.
*/
public int delete(SQLiteDatabase db) {
assertTable();
return db.delete(mTable, getSelection(), getSelectionArgs());
}
}