/*
* 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.graphics.drawable;
import java.io.IOException;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import android.annotation.NonNull;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.content.res.Resources.Theme;
import android.util.AttributeSet;
/**
* A resource that manages a number of alternate Drawables, each assigned a maximum numerical value.
* Setting the level value of the object with {@link #setLevel(int)} will load the image with the next
* greater or equal value assigned to its max attribute.
* A good example use of
* a LevelListDrawable would be a battery level indicator icon, with different images to indicate the current
* battery level.
* <p>
* It can be defined in an XML file with the <code><level-list></code> element.
* Each Drawable level is defined in a nested <code><item></code>. For example:
* </p>
* <pre>
* <level-list xmlns:android="http://schemas.android.com/apk/res/android">
* <item android:maxLevel="0" android:drawable="@drawable/ic_wifi_signal_1" />
* <item android:maxLevel="1" android:drawable="@drawable/ic_wifi_signal_2" />
* <item android:maxLevel="2" android:drawable="@drawable/ic_wifi_signal_3" />
* <item android:maxLevel="3" android:drawable="@drawable/ic_wifi_signal_4" />
* </level-list>
*</pre>
* <p>With this XML saved into the res/drawable/ folder of the project, it can be referenced as
* the drawable for an {@link android.widget.ImageView}. The default image is the first in the list.
* It can then be changed to one of the other levels with
* {@link android.widget.ImageView#setImageLevel(int)}. For more
* information, see the guide to <a
* href="{@docRoot}guide/topics/resources/drawable-resource.html">Drawable Resources</a>.</p>
*
* @attr ref android.R.styleable#LevelListDrawableItem_minLevel
* @attr ref android.R.styleable#LevelListDrawableItem_maxLevel
* @attr ref android.R.styleable#LevelListDrawableItem_drawable
*/
public class LevelListDrawable extends DrawableContainer {
private LevelListState mLevelListState;
private boolean mMutated;
public LevelListDrawable() {
this(null, null);
}
public void addLevel(int low, int high, Drawable drawable) {
if (drawable != null) {
mLevelListState.addLevel(low, high, drawable);
// in case the new state matches our current state...
onLevelChange(getLevel());
}
}
// overrides from Drawable
@Override
protected boolean onLevelChange(int level) {
int idx = mLevelListState.indexOfLevel(level);
if (selectDrawable(idx)) {
return true;
}
return super.onLevelChange(level);
}
@Override
public void inflate(Resources r, XmlPullParser parser, AttributeSet attrs, Theme theme)
throws XmlPullParserException, IOException {
super.inflate(r, parser, attrs, theme);
int type;
int low = 0;
final int innerDepth = parser.getDepth() + 1;
int depth;
while ((type = parser.next()) != XmlPullParser.END_DOCUMENT
&& ((depth = parser.getDepth()) >= innerDepth
|| type != XmlPullParser.END_TAG)) {
if (type != XmlPullParser.START_TAG) {
continue;
}
if (depth > innerDepth || !parser.getName().equals("item")) {
continue;
}
TypedArray a = obtainAttributes(r, theme, attrs,
com.android.internal.R.styleable.LevelListDrawableItem);
low = a.getInt(
com.android.internal.R.styleable.LevelListDrawableItem_minLevel, 0);
int high = a.getInt(
com.android.internal.R.styleable.LevelListDrawableItem_maxLevel, 0);
int drawableRes = a.getResourceId(
com.android.internal.R.styleable.LevelListDrawableItem_drawable, 0);
a.recycle();
if (high < 0) {
throw new XmlPullParserException(parser.getPositionDescription()
+ ": <item> tag requires a 'maxLevel' attribute");
}
Drawable dr;
if (drawableRes != 0) {
dr = r.getDrawable(drawableRes, theme);
} else {
while ((type = parser.next()) == XmlPullParser.TEXT) {
}
if (type != XmlPullParser.START_TAG) {
throw new XmlPullParserException(
parser.getPositionDescription()
+ ": <item> tag requires a 'drawable' attribute or "
+ "child tag defining a drawable");
}
dr = Drawable.createFromXmlInner(r, parser, attrs, theme);
}
mLevelListState.addLevel(low, high, dr);
}
onLevelChange(getLevel());
}
@Override
public Drawable mutate() {
if (!mMutated && super.mutate() == this) {
mLevelListState.mutate();
mMutated = true;
}
return this;
}
@Override
LevelListState cloneConstantState() {
return new LevelListState(mLevelListState, this, null);
}
/**
* @hide
*/
public void clearMutated() {
super.clearMutated();
mMutated = false;
}
private final static class LevelListState extends DrawableContainerState {
private int[] mLows;
private int[] mHighs;
LevelListState(LevelListState orig, LevelListDrawable owner, Resources res) {
super(orig, owner, res);
if (orig != null) {
// Perform a shallow copy and rely on mutate() to deep-copy.
mLows = orig.mLows;
mHighs = orig.mHighs;
} else {
mLows = new int[getCapacity()];
mHighs = new int[getCapacity()];
}
}
private void mutate() {
mLows = mLows.clone();
mHighs = mHighs.clone();
}
public void addLevel(int low, int high, Drawable drawable) {
int pos = addChild(drawable);
mLows[pos] = low;
mHighs[pos] = high;
}
public int indexOfLevel(int level) {
final int[] lows = mLows;
final int[] highs = mHighs;
final int N = getChildCount();
for (int i = 0; i < N; i++) {
if (level >= lows[i] && level <= highs[i]) {
return i;
}
}
return -1;
}
@Override
public Drawable newDrawable() {
return new LevelListDrawable(this, null);
}
@Override
public Drawable newDrawable(Resources res) {
return new LevelListDrawable(this, res);
}
@Override
public void growArray(int oldSize, int newSize) {
super.growArray(oldSize, newSize);
int[] newInts = new int[newSize];
System.arraycopy(mLows, 0, newInts, 0, oldSize);
mLows = newInts;
newInts = new int[newSize];
System.arraycopy(mHighs, 0, newInts, 0, oldSize);
mHighs = newInts;
}
}
@Override
protected void setConstantState(@NonNull DrawableContainerState state) {
super.setConstantState(state);
if (state instanceof LevelListState) {
mLevelListState = (LevelListState) state;
}
}
private LevelListDrawable(LevelListState state, Resources res) {
final LevelListState as = new LevelListState(state, this, res);
setConstantState(as);
onLevelChange(getLevel());
}
}
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