/*
* Copyright (C) 2007 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.content.res.TypedArray;
import android.graphics.drawable.shapes.RectShape;
import android.graphics.drawable.shapes.Shape;
import android.util.AttributeSet;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import com.android.internal.R;
/**
* A RatingBar is an extension of SeekBar and ProgressBar that shows a rating in
* stars. The user can touch/drag or use arrow keys to set the rating when using
* the default size RatingBar. The smaller RatingBar style (
* {@link android.R.attr#ratingBarStyleSmall}) and the larger indicator-only
* style ({@link android.R.attr#ratingBarStyleIndicator}) do not support user
* interaction and should only be used as indicators.
* <p>
* When using a RatingBar that supports user interaction, placing widgets to the
* left or right of the RatingBar is discouraged.
* <p>
* The number of stars set (via {@link #setNumStars(int)} or in an XML layout)
* will be shown when the layout width is set to wrap content (if another layout
* width is set, the results may be unpredictable).
* <p>
* The secondary progress should not be modified by the client as it is used
* internally as the background for a fractionally filled star.
*
* @attr ref android.R.styleable#RatingBar_numStars
* @attr ref android.R.styleable#RatingBar_rating
* @attr ref android.R.styleable#RatingBar_stepSize
* @attr ref android.R.styleable#RatingBar_isIndicator
*/
public class RatingBar extends AbsSeekBar {
/**
* A callback that notifies clients when the rating has been changed. This
* includes changes that were initiated by the user through a touch gesture
* or arrow key/trackball as well as changes that were initiated
* programmatically.
*/
public interface OnRatingBarChangeListener {
/**
* Notification that the rating has changed. Clients can use the
* fromUser parameter to distinguish user-initiated changes from those
* that occurred programmatically. This will not be called continuously
* while the user is dragging, only when the user finalizes a rating by
* lifting the touch.
*
* @param ratingBar The RatingBar whose rating has changed.
* @param rating The current rating. This will be in the range
* 0..numStars.
* @param fromUser True if the rating change was initiated by a user's
* touch gesture or arrow key/horizontal trackbell movement.
*/
void onRatingChanged(RatingBar ratingBar, float rating, boolean fromUser);
}
private int mNumStars = 5;
private int mProgressOnStartTracking;
private OnRatingBarChangeListener mOnRatingBarChangeListener;
public RatingBar(Context context, AttributeSet attrs, int defStyleAttr) {
this(context, attrs, defStyleAttr, 0);
}
public RatingBar(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
final TypedArray a = context.obtainStyledAttributes(
attrs, R.styleable.RatingBar, defStyleAttr, defStyleRes);
final int numStars = a.getInt(R.styleable.RatingBar_numStars, mNumStars);
setIsIndicator(a.getBoolean(R.styleable.RatingBar_isIndicator, !mIsUserSeekable));
final float rating = a.getFloat(R.styleable.RatingBar_rating, -1);
final float stepSize = a.getFloat(R.styleable.RatingBar_stepSize, -1);
a.recycle();
if (numStars > 0 && numStars != mNumStars) {
setNumStars(numStars);
}
if (stepSize >= 0) {
setStepSize(stepSize);
} else {
setStepSize(0.5f);
}
if (rating >= 0) {
setRating(rating);
}
// A touch inside a star fill up to that fractional area (slightly more
// than 1 so boundaries round up).
mTouchProgressOffset = 1.1f;
}
public RatingBar(Context context, AttributeSet attrs) {
this(context, attrs, com.android.internal.R.attr.ratingBarStyle);
}
public RatingBar(Context context) {
this(context, null);
}
/**
* Sets the listener to be called when the rating changes.
*
* @param listener The listener.
*/
public void setOnRatingBarChangeListener(OnRatingBarChangeListener listener) {
mOnRatingBarChangeListener = listener;
}
/**
* @return The listener (may be null) that is listening for rating change
* events.
*/
public OnRatingBarChangeListener getOnRatingBarChangeListener() {
return mOnRatingBarChangeListener;
}
/**
* Whether this rating bar should only be an indicator (thus non-changeable
* by the user).
*
* @param isIndicator Whether it should be an indicator.
*
* @attr ref android.R.styleable#RatingBar_isIndicator
*/
public void setIsIndicator(boolean isIndicator) {
mIsUserSeekable = !isIndicator;
setFocusable(!isIndicator);
}
/**
* @return Whether this rating bar is only an indicator.
*
* @attr ref android.R.styleable#RatingBar_isIndicator
*/
public boolean isIndicator() {
return !mIsUserSeekable;
}
/**
* Sets the number of stars to show. In order for these to be shown
* properly, it is recommended the layout width of this widget be wrap
* content.
*
* @param numStars The number of stars.
*/
public void setNumStars(final int numStars) {
if (numStars <= 0) {
return;
}
mNumStars = numStars;
// This causes the width to change, so re-layout
requestLayout();
}
/**
* Returns the number of stars shown.
* @return The number of stars shown.
*/
public int getNumStars() {
return mNumStars;
}
/**
* Sets the rating (the number of stars filled).
*
* @param rating The rating to set.
*/
public void setRating(float rating) {
setProgress(Math.round(rating * getProgressPerStar()));
}
/**
* Gets the current rating (number of stars filled).
*
* @return The current rating.
*/
public float getRating() {
return getProgress() / getProgressPerStar();
}
/**
* Sets the step size (granularity) of this rating bar.
*
* @param stepSize The step size of this rating bar. For example, if
* half-star granularity is wanted, this would be 0.5.
*/
public void setStepSize(float stepSize) {
if (stepSize <= 0) {
return;
}
final float newMax = mNumStars / stepSize;
final int newProgress = (int) (newMax / getMax() * getProgress());
setMax((int) newMax);
setProgress(newProgress);
}
/**
* Gets the step size of this rating bar.
*
* @return The step size.
*/
public float getStepSize() {
return (float) getNumStars() / getMax();
}
/**
* @return The amount of progress that fits into a star
*/
private float getProgressPerStar() {
if (mNumStars > 0) {
return 1f * getMax() / mNumStars;
} else {
return 1;
}
}
@Override
Shape getDrawableShape() {
// TODO: Once ProgressBar's TODOs are fixed, this won't be needed
return new RectShape();
}
@Override
void onProgressRefresh(float scale, boolean fromUser) {
super.onProgressRefresh(scale, fromUser);
// Keep secondary progress in sync with primary
updateSecondaryProgress(getProgress());
if (!fromUser) {
// Callback for non-user rating changes
dispatchRatingChange(false);
}
}
/**
* The secondary progress is used to differentiate the background of a
* partially filled star. This method keeps the secondary progress in sync
* with the progress.
*
* @param progress The primary progress level.
*/
private void updateSecondaryProgress(int progress) {
final float ratio = getProgressPerStar();
if (ratio > 0) {
final float progressInStars = progress / ratio;
final int secondaryProgress = (int) (Math.ceil(progressInStars) * ratio);
setSecondaryProgress(secondaryProgress);
}
}
@Override
protected synchronized void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (mSampleTile != null) {
// TODO: Once ProgressBar's TODOs are gone, this can be done more
// cleanly than mSampleTile
final int width = mSampleTile.getWidth() * mNumStars;
setMeasuredDimension(resolveSizeAndState(width, widthMeasureSpec, 0),
getMeasuredHeight());
}
}
@Override
void onStartTrackingTouch() {
mProgressOnStartTracking = getProgress();
super.onStartTrackingTouch();
}
@Override
void onStopTrackingTouch() {
super.onStopTrackingTouch();
if (getProgress() != mProgressOnStartTracking) {
dispatchRatingChange(true);
}
}
@Override
void onKeyChange() {
super.onKeyChange();
dispatchRatingChange(true);
}
void dispatchRatingChange(boolean fromUser) {
if (mOnRatingBarChangeListener != null) {
mOnRatingBarChangeListener.onRatingChanged(this, getRating(),
fromUser);
}
}
@Override
public synchronized void setMax(int max) {
// Disallow max progress = 0
if (max <= 0) {
return;
}
super.setMax(max);
}
@Override
public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(event);
event.setClassName(RatingBar.class.getName());
}
@Override
public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
super.onInitializeAccessibilityNodeInfo(info);
info.setClassName(RatingBar.class.getName());
}
}
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