Java tutorial
/* * Copyright (C) 2010 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.preference; import android.annotation.StringRes; import android.annotation.UnsupportedAppUsage; import android.content.Context; import android.content.res.TypedArray; import android.util.AttributeSet; import android.view.View; import android.widget.Checkable; import android.widget.CompoundButton; import android.widget.Switch; /** * A {@link Preference} that provides a two-state toggleable option. * <p> * This preference will store a boolean into the SharedPreferences. * * @attr ref android.R.styleable#SwitchPreference_summaryOff * @attr ref android.R.styleable#SwitchPreference_summaryOn * @attr ref android.R.styleable#SwitchPreference_switchTextOff * @attr ref android.R.styleable#SwitchPreference_switchTextOn * @attr ref android.R.styleable#SwitchPreference_disableDependentsState */ public class SwitchPreference extends TwoStatePreference { @UnsupportedAppUsage private final Listener mListener = new Listener(); // Switch text for on and off states private CharSequence mSwitchOn; private CharSequence mSwitchOff; private class Listener implements CompoundButton.OnCheckedChangeListener { @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { if (!callChangeListener(isChecked)) { // Listener didn't like it, change it back. // CompoundButton will make sure we don't recurse. buttonView.setChecked(!isChecked); return; } SwitchPreference.this.setChecked(isChecked); } } /** * Construct a new SwitchPreference with the given style options. * * @param context The Context that will style this preference * @param attrs Style attributes that differ from the default * @param defStyleAttr An attribute in the current theme that contains a * reference to a style resource that supplies default values for * the view. Can be 0 to not look for defaults. * @param defStyleRes A resource identifier of a style resource that * supplies default values for the view, used only if * defStyleAttr is 0 or can not be found in the theme. Can be 0 * to not look for defaults. */ public SwitchPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { super(context, attrs, defStyleAttr, defStyleRes); TypedArray a = context.obtainStyledAttributes(attrs, com.android.internal.R.styleable.SwitchPreference, defStyleAttr, defStyleRes); setSummaryOn(a.getString(com.android.internal.R.styleable.SwitchPreference_summaryOn)); setSummaryOff(a.getString(com.android.internal.R.styleable.SwitchPreference_summaryOff)); setSwitchTextOn(a.getString(com.android.internal.R.styleable.SwitchPreference_switchTextOn)); setSwitchTextOff(a.getString(com.android.internal.R.styleable.SwitchPreference_switchTextOff)); setDisableDependentsState( a.getBoolean(com.android.internal.R.styleable.SwitchPreference_disableDependentsState, false)); a.recycle(); } /** * Construct a new SwitchPreference with the given style options. * * @param context The Context that will style this preference * @param attrs Style attributes that differ from the default * @param defStyleAttr An attribute in the current theme that contains a * reference to a style resource that supplies default values for * the view. Can be 0 to not look for defaults. */ public SwitchPreference(Context context, AttributeSet attrs, int defStyleAttr) { this(context, attrs, defStyleAttr, 0); } /** * Construct a new SwitchPreference with the given style options. * * @param context The Context that will style this preference * @param attrs Style attributes that differ from the default */ public SwitchPreference(Context context, AttributeSet attrs) { this(context, attrs, com.android.internal.R.attr.switchPreferenceStyle); } /** * Construct a new SwitchPreference with default style options. * * @param context The Context that will style this preference */ public SwitchPreference(Context context) { this(context, null); } @Override protected void onBindView(View view) { super.onBindView(view); View checkableView = view.findViewById(com.android.internal.R.id.switch_widget); if (checkableView != null && checkableView instanceof Checkable) { if (checkableView instanceof Switch) { final Switch switchView = (Switch) checkableView; switchView.setOnCheckedChangeListener(null); } ((Checkable) checkableView).setChecked(mChecked); if (checkableView instanceof Switch) { final Switch switchView = (Switch) checkableView; switchView.setTextOn(mSwitchOn); switchView.setTextOff(mSwitchOff); switchView.setOnCheckedChangeListener(mListener); } } syncSummaryView(view); } /** * Set the text displayed on the switch widget in the on state. * This should be a very short string; one word if possible. * * @param onText Text to display in the on state */ public void setSwitchTextOn(CharSequence onText) { mSwitchOn = onText; notifyChanged(); } /** * Set the text displayed on the switch widget in the off state. * This should be a very short string; one word if possible. * * @param offText Text to display in the off state */ public void setSwitchTextOff(CharSequence offText) { mSwitchOff = offText; notifyChanged(); } /** * Set the text displayed on the switch widget in the on state. * This should be a very short string; one word if possible. * * @param resId The text as a string resource ID */ public void setSwitchTextOn(@StringRes int resId) { setSwitchTextOn(getContext().getString(resId)); } /** * Set the text displayed on the switch widget in the off state. * This should be a very short string; one word if possible. * * @param resId The text as a string resource ID */ public void setSwitchTextOff(@StringRes int resId) { setSwitchTextOff(getContext().getString(resId)); } /** * @return The text that will be displayed on the switch widget in the on state */ public CharSequence getSwitchTextOn() { return mSwitchOn; } /** * @return The text that will be displayed on the switch widget in the off state */ public CharSequence getSwitchTextOff() { return mSwitchOff; } }