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A library jar that provides APIs for Applications written for the Google Android Platform.
/*
* Copyright (C) 2006 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 android.widget;
import android.compat.annotation.UnsupportedAppUsage;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.view.View;
/**
* An easy adapter to map columns from a cursor to TextViews or ImageViews
* defined in an XML file. You can specify which columns you want, which
* views you want to display the columns, and the XML file that defines
* the appearance of these views.
*
* Binding occurs in two phases. First, if a
* {@link android.widget.SimpleCursorAdapter.ViewBinder} is available,
* {@link ViewBinder#setViewValue(android.view.View, android.database.Cursor, int)}
* is invoked. If the returned value is true, binding has occured. If the
* returned value is false and the view to bind is a TextView,
* {@link #setViewText(TextView, String)} is invoked. If the returned value
* is false and the view to bind is an ImageView,
* {@link #setViewImage(ImageView, String)} is invoked. If no appropriate
* binding can be found, an {@link IllegalStateException} is thrown.
*
* If this adapter is used with filtering, for instance in an
* {@link android.widget.AutoCompleteTextView}, you can use the
* {@link android.widget.SimpleCursorAdapter.CursorToStringConverter} and the
* {@link android.widget.FilterQueryProvider} interfaces
* to get control over the filtering process. You can refer to
* {@link #convertToString(android.database.Cursor)} and
* {@link #runQueryOnBackgroundThread(CharSequence)} for more information.
*/
public class SimpleCursorAdapter extends ResourceCursorAdapter {
/**
* A list of columns containing the data to bind to the UI.
* This field should be made private, so it is hidden from the SDK.
* {@hide}
*/
@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
protected int[] mFrom;
/**
* A list of View ids representing the views to which the data must be bound.
* This field should be made private, so it is hidden from the SDK.
* {@hide}
*/
@UnsupportedAppUsage
protected int[] mTo;
private int mStringConversionColumn = -1;
private CursorToStringConverter mCursorToStringConverter;
private ViewBinder mViewBinder;
String[] mOriginalFrom;
/**
* Constructor the enables auto-requery.
*
* @deprecated This option is discouraged, as it results in Cursor queries
* being performed on the application's UI thread and thus can cause poor
* responsiveness or even Application Not Responding errors. As an alternative,
* use {@link android.app.LoaderManager} with a {@link android.content.CursorLoader}.
*/
@Deprecated
public SimpleCursorAdapter(Context context, int layout, Cursor c, String[] from, int[] to) {
super(context, layout, c);
mTo = to;
mOriginalFrom = from;
findColumns(c, from);
}
/**
* Standard constructor.
*
* @param context The context where the ListView associated with this
* SimpleListItemFactory is running
* @param layout resource identifier of a layout file that defines the views
* for this list item. The layout file should include at least
* those named views defined in "to"
* @param c The database cursor. Can be null if the cursor is not available yet.
* @param from A list of column names representing the data to bind to the UI. Can be null
* if the cursor is not available yet.
* @param to The views that should display column in the "from" parameter.
* These should all be TextViews. The first N views in this list
* are given the values of the first N columns in the from
* parameter. Can be null if the cursor is not available yet.
* @param flags Flags used to determine the behavior of the adapter,
* as per {@link CursorAdapter#CursorAdapter(Context, Cursor, int)}.
*/
public SimpleCursorAdapter(Context context, int layout, Cursor c, String[] from,
int[] to, int flags) {
super(context, layout, c, flags);
mTo = to;
mOriginalFrom = from;
findColumns(c, from);
}
/**
* Binds all of the field names passed into the "to" parameter of the
* constructor with their corresponding cursor columns as specified in the
* "from" parameter.
*
* Binding occurs in two phases. First, if a
* {@link android.widget.SimpleCursorAdapter.ViewBinder} is available,
* {@link ViewBinder#setViewValue(android.view.View, android.database.Cursor, int)}
* is invoked. If the returned value is true, binding has occured. If the
* returned value is false and the view to bind is a TextView,
* {@link #setViewText(TextView, String)} is invoked. If the returned value is
* false and the view to bind is an ImageView,
* {@link #setViewImage(ImageView, String)} is invoked. If no appropriate
* binding can be found, an {@link IllegalStateException} is thrown.
*
* @throws IllegalStateException if binding cannot occur
*
* @see android.widget.CursorAdapter#bindView(android.view.View,
* android.content.Context, android.database.Cursor)
* @see #getViewBinder()
* @see #setViewBinder(android.widget.SimpleCursorAdapter.ViewBinder)
* @see #setViewImage(ImageView, String)
* @see #setViewText(TextView, String)
*/
@Override
public void bindView(View view, Context context, Cursor cursor) {
final ViewBinder binder = mViewBinder;
final int count = mTo.length;
final int[] from = mFrom;
final int[] to = mTo;
for (int i = 0; i < count; i++) {
final View v = view.findViewById(to[i]);
if (v != null) {
boolean bound = false;
if (binder != null) {
bound = binder.setViewValue(v, cursor, from[i]);
}
if (!bound) {
String text = cursor.getString(from[i]);
if (text == null) {
text = "";
}
if (v instanceof TextView) {
setViewText((TextView) v, text);
} else if (v instanceof ImageView) {
setViewImage((ImageView) v, text);
} else {
throw new IllegalStateException(v.getClass().getName() + " is not a " +
" view that can be bounds by this SimpleCursorAdapter");
}
}
}
}
}
/**
* Returns the {@link ViewBinder} used to bind data to views.
*
* @return a ViewBinder or null if the binder does not exist
*
* @see #bindView(android.view.View, android.content.Context, android.database.Cursor)
* @see #setViewBinder(android.widget.SimpleCursorAdapter.ViewBinder)
*/
public ViewBinder getViewBinder() {
return mViewBinder;
}
/**
* Sets the binder used to bind data to views.
*
* @param viewBinder the binder used to bind data to views, can be null to
* remove the existing binder
*
* @see #bindView(android.view.View, android.content.Context, android.database.Cursor)
* @see #getViewBinder()
*/
public void setViewBinder(ViewBinder viewBinder) {
mViewBinder = viewBinder;
}
/**
* Called by bindView() to set the image for an ImageView but only if
* there is no existing ViewBinder or if the existing ViewBinder cannot
* handle binding to an ImageView.
*
* By default, the value will be treated as an image resource. If the
* value cannot be used as an image resource, the value is used as an
* image Uri.
*
* Intended to be overridden by Adapters that need to filter strings
* retrieved from the database.
*
* @param v ImageView to receive an image
* @param value the value retrieved from the cursor
*/
public void setViewImage(ImageView v, String value) {
try {
v.setImageResource(Integer.parseInt(value));
} catch (NumberFormatException nfe) {
v.setImageURI(Uri.parse(value));
}
}
/**
* Called by bindView() to set the text for a TextView but only if
* there is no existing ViewBinder or if the existing ViewBinder cannot
* handle binding to a TextView.
*
* Intended to be overridden by Adapters that need to filter strings
* retrieved from the database.
*
* @param v TextView to receive text
* @param text the text to be set for the TextView
*/
public void setViewText(TextView v, String text) {
v.setText(text);
}
/**
* Return the index of the column used to get a String representation
* of the Cursor.
*
* @return a valid index in the current Cursor or -1
*
* @see android.widget.CursorAdapter#convertToString(android.database.Cursor)
* @see #setStringConversionColumn(int)
* @see #setCursorToStringConverter(android.widget.SimpleCursorAdapter.CursorToStringConverter)
* @see #getCursorToStringConverter()
*/
public int getStringConversionColumn() {
return mStringConversionColumn;
}
/**
* Defines the index of the column in the Cursor used to get a String
* representation of that Cursor. The column is used to convert the
* Cursor to a String only when the current CursorToStringConverter
* is null.
*
* @param stringConversionColumn a valid index in the current Cursor or -1 to use the default
* conversion mechanism
*
* @see android.widget.CursorAdapter#convertToString(android.database.Cursor)
* @see #getStringConversionColumn()
* @see #setCursorToStringConverter(android.widget.SimpleCursorAdapter.CursorToStringConverter)
* @see #getCursorToStringConverter()
*/
public void setStringConversionColumn(int stringConversionColumn) {
mStringConversionColumn = stringConversionColumn;
}
/**
* Returns the converter used to convert the filtering Cursor
* into a String.
*
* @return null if the converter does not exist or an instance of
* {@link android.widget.SimpleCursorAdapter.CursorToStringConverter}
*
* @see #setCursorToStringConverter(android.widget.SimpleCursorAdapter.CursorToStringConverter)
* @see #getStringConversionColumn()
* @see #setStringConversionColumn(int)
* @see android.widget.CursorAdapter#convertToString(android.database.Cursor)
*/
public CursorToStringConverter getCursorToStringConverter() {
return mCursorToStringConverter;
}
/**
* Sets the converter used to convert the filtering Cursor
* into a String.
*
* @param cursorToStringConverter the Cursor to String converter, or
* null to remove the converter
*
* @see #setCursorToStringConverter(android.widget.SimpleCursorAdapter.CursorToStringConverter)
* @see #getStringConversionColumn()
* @see #setStringConversionColumn(int)
* @see android.widget.CursorAdapter#convertToString(android.database.Cursor)
*/
public void setCursorToStringConverter(CursorToStringConverter cursorToStringConverter) {
mCursorToStringConverter = cursorToStringConverter;
}
/**
* Returns a CharSequence representation of the specified Cursor as defined
* by the current CursorToStringConverter. If no CursorToStringConverter
* has been set, the String conversion column is used instead. If the
* conversion column is -1, the returned String is empty if the cursor
* is null or Cursor.toString().
*
* @param cursor the Cursor to convert to a CharSequence
*
* @return a non-null CharSequence representing the cursor
*/
@Override
public CharSequence convertToString(Cursor cursor) {
if (mCursorToStringConverter != null) {
return mCursorToStringConverter.convertToString(cursor);
} else if (mStringConversionColumn > -1) {
return cursor.getString(mStringConversionColumn);
}
return super.convertToString(cursor);
}
/**
* Create a map from an array of strings to an array of column-id integers in cursor c.
* If c is null, the array will be discarded.
*
* @param c the cursor to find the columns from
* @param from the Strings naming the columns of interest
*/
private void findColumns(Cursor c, String[] from) {
if (c != null) {
int i;
int count = from.length;
if (mFrom == null || mFrom.length != count) {
mFrom = new int[count];
}
for (i = 0; i < count; i++) {
mFrom[i] = c.getColumnIndexOrThrow(from[i]);
}
} else {
mFrom = null;
}
}
@Override
public Cursor swapCursor(Cursor c) {
// super.swapCursor() will notify observers before we have
// a valid mapping, make sure we have a mapping before this
// happens
findColumns(c, mOriginalFrom);
return super.swapCursor(c);
}
/**
* Change the cursor and change the column-to-view mappings at the same time.
*
* @param c The database cursor. Can be null if the cursor is not available yet.
* @param from A list of column names representing the data to bind to the UI. Can be null
* if the cursor is not available yet.
* @param to The views that should display column in the "from" parameter.
* These should all be TextViews. The first N views in this list
* are given the values of the first N columns in the from
* parameter. Can be null if the cursor is not available yet.
*/
public void changeCursorAndColumns(Cursor c, String[] from, int[] to) {
mOriginalFrom = from;
mTo = to;
// super.changeCursor() will notify observers before we have
// a valid mapping, make sure we have a mapping before this
// happens
findColumns(c, mOriginalFrom);
super.changeCursor(c);
}
/**
* This class can be used by external clients of SimpleCursorAdapter
* to bind values fom the Cursor to views.
*
* You should use this class to bind values from the Cursor to views
* that are not directly supported by SimpleCursorAdapter or to
* change the way binding occurs for views supported by
* SimpleCursorAdapter.
*
* @see SimpleCursorAdapter#bindView(android.view.View, android.content.Context, android.database.Cursor)
* @see SimpleCursorAdapter#setViewImage(ImageView, String)
* @see SimpleCursorAdapter#setViewText(TextView, String)
*/
public static interface ViewBinder {
/**
* Binds the Cursor column defined by the specified index to the specified view.
*
* When binding is handled by this ViewBinder, this method must return true.
* If this method returns false, SimpleCursorAdapter will attempts to handle
* the binding on its own.
*
* @param view the view to bind the data to
* @param cursor the cursor to get the data from
* @param columnIndex the column at which the data can be found in the cursor
*
* @return true if the data was bound to the view, false otherwise
*/
boolean setViewValue(View view, Cursor cursor, int columnIndex);
}
/**
* This class can be used by external clients of SimpleCursorAdapter
* to define how the Cursor should be converted to a String.
*
* @see android.widget.CursorAdapter#convertToString(android.database.Cursor)
*/
public static interface CursorToStringConverter {
/**
* Returns a CharSequence representing the specified Cursor.
*
* @param cursor the cursor for which a CharSequence representation
* is requested
*
* @return a non-null CharSequence representing the cursor
*/
CharSequence convertToString(Cursor cursor);
}
}