/*
* 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.content.Context;
import android.database.Cursor;
import android.net.Uri;
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. Separate XML files for child and groups are possible.
*
* Binding occurs in two phases. First, if a
* {@link android.widget.SimpleCursorTreeAdapter.ViewBinder} is available,
* {@link ViewBinder#setViewValue(android.view.View, android.database.Cursor, int)}
* is invoked. If the returned value is true, binding has occurred. 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.
*/
public abstract class SimpleCursorTreeAdapter extends ResourceCursorTreeAdapter {
/** The name of the columns that contain the data to display for a group. */
private String[] mGroupFromNames;
/** The indices of columns that contain data to display for a group. */
private int[] mGroupFrom;
/**
* The View IDs that will display a group's data fetched from the
* corresponding column.
*/
private int[] mGroupTo;
/** The name of the columns that contain the data to display for a child. */
private String[] mChildFromNames;
/** The indices of columns that contain data to display for a child. */
private int[] mChildFrom;
/**
* The View IDs that will display a child's data fetched from the
* corresponding column.
*/
private int[] mChildTo;
/**
* View binder, if supplied
*/
private ViewBinder mViewBinder;
/**
* Constructor.
*
* @param context The context where the {@link ExpandableListView}
* associated with this {@link SimpleCursorTreeAdapter} is
* running
* @param cursor The database cursor
* @param collapsedGroupLayout The resource identifier of a layout file that
* defines the views for a collapsed group. The layout file
* should include at least those named views defined in groupTo.
* @param expandedGroupLayout The resource identifier of a layout file that
* defines the views for an expanded group. The layout file
* should include at least those named views defined in groupTo.
* @param groupFrom A list of column names that will be used to display the
* data for a group.
* @param groupTo The group views (from the group layouts) that should
* display column in the "from" parameter. These should all be
* TextViews or ImageViews. The first N views in this list are
* given the values of the first N columns in the from parameter.
* @param childLayout The resource identifier of a layout file that defines
* the views for a child (except the last). The layout file
* should include at least those named views defined in childTo.
* @param lastChildLayout The resource identifier of a layout file that
* defines the views for the last child within a group. The
* layout file should include at least those named views defined
* in childTo.
* @param childFrom A list of column names that will be used to display the
* data for a child.
* @param childTo The child views (from the child layouts) that should
* display column in the "from" parameter. These should all be
* TextViews or ImageViews. The first N views in this list are
* given the values of the first N columns in the from parameter.
*/
public SimpleCursorTreeAdapter(Context context, Cursor cursor, int collapsedGroupLayout,
int expandedGroupLayout, String[] groupFrom, int[] groupTo, int childLayout,
int lastChildLayout, String[] childFrom, int[] childTo) {
super(context, cursor, collapsedGroupLayout, expandedGroupLayout, childLayout,
lastChildLayout);
init(groupFrom, groupTo, childFrom, childTo);
}
/**
* Constructor.
*
* @param context The context where the {@link ExpandableListView}
* associated with this {@link SimpleCursorTreeAdapter} is
* running
* @param cursor The database cursor
* @param collapsedGroupLayout The resource identifier of a layout file that
* defines the views for a collapsed group. The layout file
* should include at least those named views defined in groupTo.
* @param expandedGroupLayout The resource identifier of a layout file that
* defines the views for an expanded group. The layout file
* should include at least those named views defined in groupTo.
* @param groupFrom A list of column names that will be used to display the
* data for a group.
* @param groupTo The group views (from the group layouts) that should
* display column in the "from" parameter. These should all be
* TextViews or ImageViews. The first N views in this list are
* given the values of the first N columns in the from parameter.
* @param childLayout The resource identifier of a layout file that defines
* the views for a child. The layout file
* should include at least those named views defined in childTo.
* @param childFrom A list of column names that will be used to display the
* data for a child.
* @param childTo The child views (from the child layouts) that should
* display column in the "from" parameter. These should all be
* TextViews or ImageViews. The first N views in this list are
* given the values of the first N columns in the from parameter.
*/
public SimpleCursorTreeAdapter(Context context, Cursor cursor, int collapsedGroupLayout,
int expandedGroupLayout, String[] groupFrom, int[] groupTo,
int childLayout, String[] childFrom, int[] childTo) {
super(context, cursor, collapsedGroupLayout, expandedGroupLayout, childLayout);
init(groupFrom, groupTo, childFrom, childTo);
}
/**
* Constructor.
*
* @param context The context where the {@link ExpandableListView}
* associated with this {@link SimpleCursorTreeAdapter} is
* running
* @param cursor The database cursor
* @param groupLayout The resource identifier of a layout file that defines
* the views for a group. The layout file should include at least
* those named views defined in groupTo.
* @param groupFrom A list of column names that will be used to display the
* data for a group.
* @param groupTo The group views (from the group layouts) that should
* display column in the "from" parameter. These should all be
* TextViews or ImageViews. The first N views in this list are
* given the values of the first N columns in the from parameter.
* @param childLayout The resource identifier of a layout file that defines
* the views for a child. The layout file should include at least
* those named views defined in childTo.
* @param childFrom A list of column names that will be used to display the
* data for a child.
* @param childTo The child views (from the child layouts) that should
* display column in the "from" parameter. These should all be
* TextViews or ImageViews. The first N views in this list are
* given the values of the first N columns in the from parameter.
*/
public SimpleCursorTreeAdapter(Context context, Cursor cursor, int groupLayout,
String[] groupFrom, int[] groupTo, int childLayout, String[] childFrom,
int[] childTo) {
super(context, cursor, groupLayout, childLayout);
init(groupFrom, groupTo, childFrom, childTo);
}
private void init(String[] groupFromNames, int[] groupTo, String[] childFromNames,
int[] childTo) {
mGroupFromNames = groupFromNames;
mGroupTo = groupTo;
mChildFromNames = childFromNames;
mChildTo = childTo;
}
/**
* Returns the {@link ViewBinder} used to bind data to views.
*
* @return a ViewBinder or null if the binder does not exist
*
* @see #setViewBinder(android.widget.SimpleCursorTreeAdapter.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 #getViewBinder()
*/
public void setViewBinder(ViewBinder viewBinder) {
mViewBinder = viewBinder;
}
private void bindView(View view, Context context, Cursor cursor, int[] from, int[] to) {
final ViewBinder binder = mViewBinder;
for (int i = 0; i < to.length; i++) {
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("SimpleCursorTreeAdapter can bind values" +
" only to TextView and ImageView!");
}
}
}
}
}
private void initFromColumns(Cursor cursor, String[] fromColumnNames, int[] fromColumns) {
for (int i = fromColumnNames.length - 1; i >= 0; i--) {
fromColumns[i] = cursor.getColumnIndexOrThrow(fromColumnNames[i]);
}
}
@Override
protected void bindChildView(View view, Context context, Cursor cursor, boolean isLastChild) {
if (mChildFrom == null) {
mChildFrom = new int[mChildFromNames.length];
initFromColumns(cursor, mChildFromNames, mChildFrom);
}
bindView(view, context, cursor, mChildFrom, mChildTo);
}
@Override
protected void bindGroupView(View view, Context context, Cursor cursor, boolean isExpanded) {
if (mGroupFrom == null) {
mGroupFrom = new int[mGroupFromNames.length];
initFromColumns(cursor, mGroupFromNames, mGroupFrom);
}
bindView(view, context, cursor, mGroupFrom, mGroupTo);
}
/**
* Called by bindView() to set the image for an ImageView. By default, the
* value will be treated as a 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
*/
protected 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);
}
/**
* This class can be used by external clients of SimpleCursorTreeAdapter
* to bind values from the Cursor to views.
*
* You should use this class to bind values from the Cursor to views
* that are not directly supported by SimpleCursorTreeAdapter or to
* change the way binding occurs for views supported by
* SimpleCursorTreeAdapter.
*
* @see SimpleCursorTreeAdapter#setViewImage(ImageView, String)
* @see SimpleCursorTreeAdapter#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, SimpleCursorTreeAdapter 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);
}
}
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