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
17package android.widget;
18
19import android.content.Context;
20import android.content.res.TypedArray;
21import android.graphics.drawable.Drawable;
22import android.graphics.drawable.LayerDrawable;
23import android.util.AttributeSet;
24
25/**
26 * Displays checked/unchecked states as a button
27 * with a "light" indicator and by default accompanied with the text "ON" or "OFF".
28 *
29 * <p>See the <a href="{@docRoot}guide/topics/ui/controls/togglebutton.html">Toggle Buttons</a>
30 * guide.</p>
31 *
32 * @attr ref android.R.styleable#ToggleButton_textOn
33 * @attr ref android.R.styleable#ToggleButton_textOff
34 * @attr ref android.R.styleable#ToggleButton_disabledAlpha
35 */
36public class ToggleButton extends CompoundButton {
37    private CharSequence mTextOn;
38    private CharSequence mTextOff;
39
40    private Drawable mIndicatorDrawable;
41
42    private static final int NO_ALPHA = 0xFF;
43    private float mDisabledAlpha;
44
45    public ToggleButton(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
46        super(context, attrs, defStyleAttr, defStyleRes);
47
48        final TypedArray a = context.obtainStyledAttributes(
49                attrs, com.android.internal.R.styleable.ToggleButton, defStyleAttr, defStyleRes);
50        mTextOn = a.getText(com.android.internal.R.styleable.ToggleButton_textOn);
51        mTextOff = a.getText(com.android.internal.R.styleable.ToggleButton_textOff);
52        mDisabledAlpha = a.getFloat(com.android.internal.R.styleable.ToggleButton_disabledAlpha, 0.5f);
53        syncTextState();
54        a.recycle();
55    }
56
57    public ToggleButton(Context context, AttributeSet attrs, int defStyleAttr) {
58        this(context, attrs, defStyleAttr, 0);
59    }
60
61    public ToggleButton(Context context, AttributeSet attrs) {
62        this(context, attrs, com.android.internal.R.attr.buttonStyleToggle);
63    }
64
65    public ToggleButton(Context context) {
66        this(context, null);
67    }
68
69    @Override
70    public void setChecked(boolean checked) {
71        super.setChecked(checked);
72
73        syncTextState();
74    }
75
76    private void syncTextState() {
77        boolean checked = isChecked();
78        if (checked && mTextOn != null) {
79            setText(mTextOn);
80        } else if (!checked && mTextOff != null) {
81            setText(mTextOff);
82        }
83    }
84
85    /**
86     * Returns the text for when the button is in the checked state.
87     *
88     * @return The text.
89     */
90    public CharSequence getTextOn() {
91        return mTextOn;
92    }
93
94    /**
95     * Sets the text for when the button is in the checked state.
96     *
97     * @param textOn The text.
98     */
99    public void setTextOn(CharSequence textOn) {
100        mTextOn = textOn;
101    }
102
103    /**
104     * Returns the text for when the button is not in the checked state.
105     *
106     * @return The text.
107     */
108    public CharSequence getTextOff() {
109        return mTextOff;
110    }
111
112    /**
113     * Sets the text for when the button is not in the checked state.
114     *
115     * @param textOff The text.
116     */
117    public void setTextOff(CharSequence textOff) {
118        mTextOff = textOff;
119    }
120
121    @Override
122    protected void onFinishInflate() {
123        super.onFinishInflate();
124
125        updateReferenceToIndicatorDrawable(getBackground());
126    }
127
128    @Override
129    public void setBackgroundDrawable(Drawable d) {
130        super.setBackgroundDrawable(d);
131
132        updateReferenceToIndicatorDrawable(d);
133    }
134
135    private void updateReferenceToIndicatorDrawable(Drawable backgroundDrawable) {
136        if (backgroundDrawable instanceof LayerDrawable) {
137            LayerDrawable layerDrawable = (LayerDrawable) backgroundDrawable;
138            mIndicatorDrawable =
139                    layerDrawable.findDrawableByLayerId(com.android.internal.R.id.toggle);
140        } else {
141            mIndicatorDrawable = null;
142        }
143    }
144
145    @Override
146    protected void drawableStateChanged() {
147        super.drawableStateChanged();
148
149        if (mIndicatorDrawable != null) {
150            mIndicatorDrawable.setAlpha(isEnabled() ? NO_ALPHA : (int) (NO_ALPHA * mDisabledAlpha));
151        }
152    }
153
154    @Override
155    public CharSequence getAccessibilityClassName() {
156        return ToggleButton.class.getName();
157    }
158}
159