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      1 /*
      2  * Copyright (C) 2007 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package android.widget;
     18 
     19 import android.annotation.FloatRange;
     20 import android.content.Context;
     21 import android.content.res.TypedArray;
     22 import android.graphics.drawable.Drawable;
     23 import android.graphics.drawable.LayerDrawable;
     24 import android.util.AttributeSet;
     25 import android.view.inspector.InspectableProperty;
     26 
     27 /**
     28  * Displays checked/unchecked states as a button
     29  * with a "light" indicator and by default accompanied with the text "ON" or "OFF".
     30  *
     31  * <p>See the <a href="{@docRoot}guide/topics/ui/controls/togglebutton.html">Toggle Buttons</a>
     32  * guide.</p>
     33  *
     34  * @attr ref android.R.styleable#ToggleButton_textOn
     35  * @attr ref android.R.styleable#ToggleButton_textOff
     36  * @attr ref android.R.styleable#ToggleButton_disabledAlpha
     37  */
     38 public class ToggleButton extends CompoundButton {
     39     private CharSequence mTextOn;
     40     private CharSequence mTextOff;
     41 
     42     private Drawable mIndicatorDrawable;
     43 
     44     private static final int NO_ALPHA = 0xFF;
     45     private float mDisabledAlpha;
     46 
     47     public ToggleButton(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
     48         super(context, attrs, defStyleAttr, defStyleRes);
     49 
     50         final TypedArray a = context.obtainStyledAttributes(
     51                 attrs, com.android.internal.R.styleable.ToggleButton, defStyleAttr, defStyleRes);
     52         saveAttributeDataForStyleable(context, com.android.internal.R.styleable.ToggleButton,
     53                 attrs, a, defStyleAttr, defStyleRes);
     54         mTextOn = a.getText(com.android.internal.R.styleable.ToggleButton_textOn);
     55         mTextOff = a.getText(com.android.internal.R.styleable.ToggleButton_textOff);
     56         mDisabledAlpha = a.getFloat(com.android.internal.R.styleable.ToggleButton_disabledAlpha, 0.5f);
     57         syncTextState();
     58         a.recycle();
     59     }
     60 
     61     public ToggleButton(Context context, AttributeSet attrs, int defStyleAttr) {
     62         this(context, attrs, defStyleAttr, 0);
     63     }
     64 
     65     public ToggleButton(Context context, AttributeSet attrs) {
     66         this(context, attrs, com.android.internal.R.attr.buttonStyleToggle);
     67     }
     68 
     69     public ToggleButton(Context context) {
     70         this(context, null);
     71     }
     72 
     73     @Override
     74     public void setChecked(boolean checked) {
     75         super.setChecked(checked);
     76 
     77         syncTextState();
     78     }
     79 
     80     private void syncTextState() {
     81         boolean checked = isChecked();
     82         if (checked && mTextOn != null) {
     83             setText(mTextOn);
     84         } else if (!checked && mTextOff != null) {
     85             setText(mTextOff);
     86         }
     87     }
     88 
     89     /**
     90      * Returns the text for when the button is in the checked state.
     91      *
     92      * @return The text.
     93      */
     94     @InspectableProperty
     95     public CharSequence getTextOn() {
     96         return mTextOn;
     97     }
     98 
     99     /**
    100      * Sets the text for when the button is in the checked state.
    101      *
    102      * @param textOn The text.
    103      */
    104     public void setTextOn(CharSequence textOn) {
    105         mTextOn = textOn;
    106     }
    107 
    108     /**
    109      * Returns the text for when the button is not in the checked state.
    110      *
    111      * @return The text.
    112      */
    113     @InspectableProperty
    114     public CharSequence getTextOff() {
    115         return mTextOff;
    116     }
    117 
    118     /**
    119      * Sets the text for when the button is not in the checked state.
    120      *
    121      * @param textOff The text.
    122      */
    123     public void setTextOff(CharSequence textOff) {
    124         mTextOff = textOff;
    125     }
    126 
    127     /**
    128      * Returns the alpha value of the button when it is disabled
    129      *
    130      * @return the alpha value, 0.0-1.0
    131      */
    132     @InspectableProperty
    133     @FloatRange(from = 0.0, to = 1.0)
    134     public float getDisabledAlpha() {
    135         return mDisabledAlpha;
    136     }
    137 
    138     @Override
    139     protected void onFinishInflate() {
    140         super.onFinishInflate();
    141 
    142         updateReferenceToIndicatorDrawable(getBackground());
    143     }
    144 
    145     @Override
    146     public void setBackgroundDrawable(Drawable d) {
    147         super.setBackgroundDrawable(d);
    148 
    149         updateReferenceToIndicatorDrawable(d);
    150     }
    151 
    152     private void updateReferenceToIndicatorDrawable(Drawable backgroundDrawable) {
    153         if (backgroundDrawable instanceof LayerDrawable) {
    154             LayerDrawable layerDrawable = (LayerDrawable) backgroundDrawable;
    155             mIndicatorDrawable =
    156                     layerDrawable.findDrawableByLayerId(com.android.internal.R.id.toggle);
    157         } else {
    158             mIndicatorDrawable = null;
    159         }
    160     }
    161 
    162     @Override
    163     protected void drawableStateChanged() {
    164         super.drawableStateChanged();
    165 
    166         if (mIndicatorDrawable != null) {
    167             mIndicatorDrawable.setAlpha(isEnabled() ? NO_ALPHA : (int) (NO_ALPHA * mDisabledAlpha));
    168         }
    169     }
    170 
    171     @Override
    172     public CharSequence getAccessibilityClassName() {
    173         return ToggleButton.class.getName();
    174     }
    175 }
    176