我的Android进阶之旅------>自己写个Activity来调节Android系统背光亮度Brightness

今天终于算初步写好了一个调节系统背光亮度Brightness的代码，本来不看Android源代码以为可以直接调用某个Action来启动系统的那个调节Brightness的对话框，但是看了代码后发现系统调节Brightness的自定义组件BrightnessPreference继承了SeekBarDialogPreference，但是最终父类还是Preference，因此不能够单独启动，必须得将这个自定义的BrightnessPreference用某个Activity才能加载过来，毕竟最终还是一个组件。因此，将系统的BrightnessPreference改写成Activity的形式，然后将Activity的主题设置为对话框的主题即可。

下图是系统自带的对话框，我的Activity就是仿造这个界面做的。

下面是我改写完后的代码，可以和系统设置的背光设置进行同步，即数据同步，无论是使用自己的Activity还是系统自带的调节背光的亮度，都是一样的效果。代码在Eclipse中运行可能会报错，但是别怕，使用Android编译能通过，然后push到Android设备中去运行没有错误。

代码如下：BrightnessDialogActivity.java

import android.app.Activity;
import android.content.ContentResolver;
import android.database.ContentObserver;
import android.os.Bundle;
import android.os.Handler;
import android.os.IPowerManager;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.provider.Settings;
import android.provider.Settings.SettingNotFoundException;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.SeekBar;

import com.android.settings.R;
import com.canplay.systemui.QuickSettings;
import com.canplay.util.DLog;

/**
 * @author ouyangpeng
 */
public class BrightnessDialogActivity extends Activity implements
		SeekBar.OnSeekBarChangeListener, OnClickListener {
	private static String TAG="@@@@@@@@@@@@Brightness---->";
	private SeekBar mSeekBar;
	private CheckBox mCheckBox;
	private Button btnCancel;
	private Button btnSure;

	private int mOldBrightness;
	private int mOldAutomatic;

	private boolean mAutomaticAvailable;
	private boolean mAutomaticMode;

	private int mCurBrightness = -1;

	private boolean mRestoredOldState;

	// Backlight range is from 0 - 255. Need to make sure that user
	// doesn't set the backlight to 0 and get stuck

	private int mScreenBrightnessDim = android.os.PowerManager.BRIGHTNESS_DIM + 10;

	private static final int MAXIMUM_BACKLIGHT = android.os.PowerManager.BRIGHTNESS_ON;

	private static final int SEEK_BAR_RANGE = 10000;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.brightness_dialog_activity);

		getContentResolver().registerContentObserver(
				Settings.System.getUriFor(Settings.System.SCREEN_BRIGHTNESS),
				true, mBrightnessObserver);
		getContentResolver()
				.registerContentObserver(
						Settings.System
								.getUriFor(Settings.System.SCREEN_BRIGHTNESS_MODE),
						true, mBrightnessModeObserver);

		mRestoredOldState = false;

		mAutomaticAvailable = true;

		/*
		 * mAutomaticAvailable = getResources() .getBoolean(
		 * com.android.internal.R.bool.config_automatic_brightness_available);
		 */
		// mAutomaticAvailable=getBrightnessMode(0)==Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;

		mSeekBar = (SeekBar) findViewById(R.id.brightnessSeekbar);
		mSeekBar.setMax(SEEK_BAR_RANGE);

		mOldBrightness = getBrightness();
		mSeekBar.setProgress(mOldBrightness);

		mCheckBox = (CheckBox) findViewById(R.id.brightness_automatic_mode);
		// 重新读取配置信息
		// onBrightnessChanged();
		// onBrightnessModeChanged();

		if (mAutomaticAvailable) {
			mCheckBox
					.setOnCheckedChangeListener(new CheckBox.OnCheckedChangeListener() {
						@Override
						public void onCheckedChanged(CompoundButton buttonView,
								boolean isChecked) {
							setMode(isChecked ? Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC
									: Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
							mSeekBar.setProgress(getBrightness());
							mSeekBar.setEnabled(!mAutomaticMode);
							setBrightness(mSeekBar.getProgress(), false);
						}
					});
			mOldAutomatic = getBrightnessMode(0);
			mAutomaticMode = mOldAutomatic == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
			mCheckBox.setChecked(mAutomaticMode);
			mSeekBar.setEnabled(!mAutomaticMode);
		} else {
			mSeekBar.setEnabled(true);
		}

		mSeekBar.setOnSeekBarChangeListener(this);

		btnSure = (Button) findViewById(R.id.btnSure);
		btnSure.setOnClickListener(this);
		btnCancel = (Button) findViewById(R.id.btnCancel);
		btnCancel.setOnClickListener(this);
	}

	private ContentObserver mBrightnessObserver = new ContentObserver(
			new Handler()) {
		@Override
		public void onChange(boolean selfChange) {
			mCurBrightness = -1;
			onBrightnessChanged();
		}
	};

	private ContentObserver mBrightnessModeObserver = new ContentObserver(
			new Handler()) {
		@Override
		public void onChange(boolean selfChange) {
			onBrightnessModeChanged();
		}
	};

	private void onBrightnessChanged() {
		mSeekBar.setProgress(getBrightness());
	}

	private void onBrightnessModeChanged() {
		boolean checked = getBrightnessMode(0) == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
		mCheckBox.setChecked(checked);
		mSeekBar.setProgress(getBrightness());
		mSeekBar.setEnabled(!checked);
	}

	private int getBrightnessMode(int defaultValue) {
		int brightnessMode = defaultValue;
		try {
			brightnessMode = Settings.System.getInt(getContentResolver(),
					Settings.System.SCREEN_BRIGHTNESS_MODE);
		} catch (SettingNotFoundException snfe) {
		}
		return brightnessMode;
	}

	private int getBrightness() {
		int mode = getBrightnessMode(0);
		float brightness = 0;
		if (mode == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC) {
			brightness = Settings.System.getFloat(getContentResolver(),
					Settings.System.SCREEN_AUTO_BRIGHTNESS_ADJ, 0);
			brightness = (brightness + 1) / 2;
		} else {
			if (mCurBrightness < 0) {
				brightness = Settings.System.getInt(getContentResolver(),
						Settings.System.SCREEN_BRIGHTNESS, 100);
			} else {
				brightness = mCurBrightness;
			}
			brightness = (brightness - mScreenBrightnessDim)
					/ (MAXIMUM_BACKLIGHT - mScreenBrightnessDim);
		}
		return (int) (brightness * SEEK_BAR_RANGE);
	}

	@Override
	public void onProgressChanged(SeekBar seekBar, int progress,
			boolean fromUser) {
		setBrightness(progress, false);
	}

	@Override
	public void onStartTrackingTouch(SeekBar seekBar) {

	}

	@Override
	public void onStopTrackingTouch(SeekBar seekBar) {

	}

	private void setMode(int mode) {
		mAutomaticMode = mode == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
		Settings.System.putInt(getContentResolver(),
				Settings.System.SCREEN_BRIGHTNESS_MODE, mode);
	}

	private void setBrightness(int brightness, boolean write) {
		if (mAutomaticMode) {
				float valf = (((float) brightness * 2) / SEEK_BAR_RANGE) - 1.0f;
				try {
					IPowerManager power = IPowerManager.Stub
							.asInterface(ServiceManager.getService("power"));
					if (power != null) {
						power.setAutoBrightnessAdjustment(valf);
					}
					if (write) {
						final ContentResolver resolver = getContentResolver();
						Settings.System.putFloat(resolver,
								Settings.System.SCREEN_AUTO_BRIGHTNESS_ADJ,
								valf);
					}
				} catch (RemoteException doe) {
				}
		} else {
			int range = (MAXIMUM_BACKLIGHT - mScreenBrightnessDim);
			brightness = (brightness * range) / SEEK_BAR_RANGE
					+ mScreenBrightnessDim;
			try {
				IPowerManager power = IPowerManager.Stub
						.asInterface(ServiceManager.getService("power"));
				if (power != null) {
					power.setBacklightBrightness(brightness);
				}
				if (write) {
					mCurBrightness = -1;
					final ContentResolver resolver = getContentResolver();
					Settings.System.putInt(resolver,
							Settings.System.SCREEN_BRIGHTNESS, brightness);
				} else {
					mCurBrightness = brightness;
				}
			} catch (RemoteException doe) {
			}
		}
	}

	private void restoreOldState() {
		if (mRestoredOldState)
			return;

		if (mAutomaticAvailable) {
			setMode(mOldAutomatic);
		}
		setBrightness(mOldBrightness, false);
		mRestoredOldState = true;
		mCurBrightness = -1;
	}

	@Override
	public void onClick(View v) {
		final ContentResolver resolver = getContentResolver();
		if (v == findViewById(R.id.btnSure)) {
			setBrightness(mSeekBar.getProgress(), true);
			this.finish();
		} else if (v == findViewById(R.id.btnCancel)) {
			restoreOldState();
			this.finish();
		}
		resolver.unregisterContentObserver(mBrightnessObserver);
		resolver.unregisterContentObserver(mBrightnessModeObserver);
	}
}

相应的布局文件如下：brightness_dialog_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center_horizontal"
        android:orientation="vertical"
        android:paddingBottom="20dip" >

        <ImageView
            android:id="@android:id/icon"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:contentDescription="@null"
            android:paddingTop="20dip"
            android:visibility="gone" />

        <CheckBox
            android:id="@+id/brightness_automatic_mode"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginLeft="20dip"
            android:layout_marginRight="20dip"
            android:layout_marginTop="6dip"
            android:text="@string/automatic_brightness"
            android:textAppearance="?android:attr/textAppearanceSmall" />

        <SeekBar
            android:id="@+id/brightness_seekbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:padding="20dip" />

        <LinearLayout
            xmlns:android="http://schemas.android.com/apk/res/android"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="horizontal" >

            <Button
                android:id="@+id/btn_cancel"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:text="@string/cancel"
                android:layout_gravity="center" />

            <Button
                  android:id="@+id/btn_sure"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:text="@string/sure"
                android:layout_gravity="center" />
        </LinearLayout>
    </LinearLayout>

</ScrollView>

注册Activity的时候使用下面的主题

 android:theme="@android:style/Theme.Holo.Dialog"

但是有个bug，即调用系统的应用调节背光的时候，Seekbar的值和复选框是否被勾中在我的自定义Activity中的Seekbar的值和复选框是否被勾中同步，但是反过来就不行了。

再次读取系统的BrightnessPreference发现是因为没有去进行更新操作。因此得修改Android的源代码，重新编译后才能达到两边数据随便那边修改后，两边的数据都同步。

修改如下所示，修改前BrightnessPreference.showDialog(Bundle state)

   @Override
    protected void showDialog(Bundle state) {
        super.showDialog(state);

        getContext().getContentResolver().registerContentObserver(
                Settings.System.getUriFor(Settings.System.SCREEN_BRIGHTNESS), true,
                mBrightnessObserver);

        getContext().getContentResolver().registerContentObserver(
                Settings.System.getUriFor(Settings.System.SCREEN_BRIGHTNESS_MODE), true,
                mBrightnessModeObserver);
        mRestoredOldState = false;
    }

修改后BrightnessPreference.showDialog(Bundle state)，即打开对话框的时候重新去读取数据库里面的Brightness的值和复选框是否被选中的值。

    @Override
    protected void showDialog(Bundle state) {
        super.showDialog(state);

        getContext().getContentResolver().registerContentObserver(
                Settings.System.getUriFor(Settings.System.SCREEN_BRIGHTNESS), true,
                mBrightnessObserver);

        getContext().getContentResolver().registerContentObserver(
                Settings.System.getUriFor(Settings.System.SCREEN_BRIGHTNESS_MODE), true,
                mBrightnessModeObserver);
        onBrightnessChanged();
        onBrightnessModeChanged();
        mRestoredOldState = false;
    }

====================================================================================

  作者：欧阳鹏  欢迎转载，与人分享是进步的源泉！

  转载请保留原文地址：http://blog.csdn.net/ouyang_peng

===================================================================================

最后附上系统调节Brightness的代码

/*
 * Copyright (C) 2008 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 com.android.settings;

import android.content.ContentResolver;
import android.content.Context;
import android.database.ContentObserver;
import android.os.Bundle;
import android.os.Handler;
import android.os.IPowerManager;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.preference.SeekBarDialogPreference;
import android.provider.Settings;
import android.provider.Settings.SettingNotFoundException;
import android.util.AttributeSet;
import android.view.View;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.SeekBar;

public class BrightnessPreference extends SeekBarDialogPreference implements
        SeekBar.OnSeekBarChangeListener, CheckBox.OnCheckedChangeListener {

    private SeekBar mSeekBar;
    private CheckBox mCheckBox;

    private int mOldBrightness;
    private int mOldAutomatic;

    private boolean mAutomaticAvailable;
    private boolean mAutomaticMode;

    private int mCurBrightness = -1;

    private boolean mRestoredOldState;

    // Backlight range is from 0 - 255. Need to make sure that user
    // doesn't set the backlight to 0 and get stuck
    private int mScreenBrightnessDim =
	    getContext().getResources().getInteger(com.android.internal.R.integer.config_screenBrightnessDim);
    private static final int MAXIMUM_BACKLIGHT = android.os.PowerManager.BRIGHTNESS_ON;

    private static final int SEEK_BAR_RANGE = 10000;

    private ContentObserver mBrightnessObserver = new ContentObserver(new Handler()) {
        @Override
        public void onChange(boolean selfChange) {
            mCurBrightness = -1;
            onBrightnessChanged();
        }
    };

    private ContentObserver mBrightnessModeObserver = new ContentObserver(new Handler()) {
        @Override
        public void onChange(boolean selfChange) {
            onBrightnessModeChanged();
        }
    };

    public BrightnessPreference(Context context, AttributeSet attrs) {
        super(context, attrs);

        mAutomaticAvailable = context.getResources().getBoolean(
                com.android.internal.R.bool.config_automatic_brightness_available);

        setDialogLayoutResource(R.layout.preference_dialog_brightness);
        setDialogIcon(R.drawable.ic_settings_display);
    }

    @Override
    protected void showDialog(Bundle state) {
        super.showDialog(state);

        getContext().getContentResolver().registerContentObserver(
                Settings.System.getUriFor(Settings.System.SCREEN_BRIGHTNESS), true,
                mBrightnessObserver);

        getContext().getContentResolver().registerContentObserver(
                Settings.System.getUriFor(Settings.System.SCREEN_BRIGHTNESS_MODE), true,
                mBrightnessModeObserver);
        onBrightnessChanged();
        onBrightnessModeChanged();
        mRestoredOldState = false;
    }

    @Override
    protected void onBindDialogView(View view) {
        super.onBindDialogView(view);

        mSeekBar = getSeekBar(view);
        mSeekBar.setMax(SEEK_BAR_RANGE);
        mOldBrightness = getBrightness();
        mSeekBar.setProgress(mOldBrightness);

        mCheckBox = (CheckBox)view.findViewById(R.id.automatic_mode);
        if (mAutomaticAvailable) {
            mCheckBox.setOnCheckedChangeListener(this);
            mOldAutomatic = getBrightnessMode(0);
            mAutomaticMode = mOldAutomatic == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
            mCheckBox.setChecked(mAutomaticMode);
            mSeekBar.setEnabled(!mAutomaticMode);
        } else {
            mSeekBar.setEnabled(true);
        }
        mSeekBar.setOnSeekBarChangeListener(this);
    }

    public void onProgressChanged(SeekBar seekBar, int progress,
            boolean fromTouch) {
        setBrightness(progress, false);
    }

    public void onStartTrackingTouch(SeekBar seekBar) {
        // NA
    }

    public void onStopTrackingTouch(SeekBar seekBar) {
        // NA
    }

    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        setMode(isChecked ? Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC
                : Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
        mSeekBar.setProgress(getBrightness());
        mSeekBar.setEnabled(!mAutomaticMode);
        setBrightness(mSeekBar.getProgress(), false);
    }

    private int getBrightness() {
        int mode = getBrightnessMode(0);
        float brightness = 0;
        if (false && mode == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC) {
            brightness = Settings.System.getFloat(getContext().getContentResolver(),
                    Settings.System.SCREEN_AUTO_BRIGHTNESS_ADJ, 0);
            brightness = (brightness+1)/2;
        } else {
            if (mCurBrightness < 0) {
                brightness = Settings.System.getInt(getContext().getContentResolver(),
                        Settings.System.SCREEN_BRIGHTNESS, 100);
            } else {
                brightness = mCurBrightness;
            }
            brightness = (brightness - mScreenBrightnessDim)
                    / (MAXIMUM_BACKLIGHT - mScreenBrightnessDim);
        }
        return (int)(brightness*SEEK_BAR_RANGE);
    }

    private int getBrightnessMode(int defaultValue) {
        int brightnessMode = defaultValue;
        try {
            brightnessMode = Settings.System.getInt(getContext().getContentResolver(),
                    Settings.System.SCREEN_BRIGHTNESS_MODE);
        } catch (SettingNotFoundException snfe) {
        }
        return brightnessMode;
    }

    private void onBrightnessChanged() {
        mSeekBar.setProgress(getBrightness());
    }

    private void onBrightnessModeChanged() {
        boolean checked = getBrightnessMode(0)
                == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
        mCheckBox.setChecked(checked);
        mSeekBar.setProgress(getBrightness());
        mSeekBar.setEnabled(!checked);
    }

    @Override
    protected void onDialogClosed(boolean positiveResult) {
        super.onDialogClosed(positiveResult);

        final ContentResolver resolver = getContext().getContentResolver();

        if (positiveResult) {
            setBrightness(mSeekBar.getProgress(), true);
        } else {
            restoreOldState();
        }

        resolver.unregisterContentObserver(mBrightnessObserver);
        resolver.unregisterContentObserver(mBrightnessModeObserver);
    }

    private void restoreOldState() {
        if (mRestoredOldState) return;

        if (mAutomaticAvailable) {
            setMode(mOldAutomatic);
        }
        setBrightness(mOldBrightness, false);
        mRestoredOldState = true;
        mCurBrightness = -1;
    }

    private void setBrightness(int brightness, boolean write) {
        if (mAutomaticMode) {
            if (false) {
                float valf = (((float)brightness*2)/SEEK_BAR_RANGE) - 1.0f;
                try {
                    IPowerManager power = IPowerManager.Stub.asInterface(
                            ServiceManager.getService("power"));
                    if (power != null) {
                        power.setAutoBrightnessAdjustment(valf);
                    }
                    if (write) {
                        final ContentResolver resolver = getContext().getContentResolver();
                        Settings.System.putFloat(resolver,
                                Settings.System.SCREEN_AUTO_BRIGHTNESS_ADJ, valf);
                    }
                } catch (RemoteException doe) {
                }
            }
        } else {
            int range = (MAXIMUM_BACKLIGHT - mScreenBrightnessDim);
            brightness = (brightness*range)/SEEK_BAR_RANGE + mScreenBrightnessDim;
            try {
                IPowerManager power = IPowerManager.Stub.asInterface(
                        ServiceManager.getService("power"));
                if (power != null) {
                    power.setBacklightBrightness(brightness);
                }
                if (write) {
                    mCurBrightness = -1;
                    final ContentResolver resolver = getContext().getContentResolver();
                    Settings.System.putInt(resolver,
                            Settings.System.SCREEN_BRIGHTNESS, brightness);
                } else {
                    mCurBrightness = brightness;
                }
            } catch (RemoteException doe) {
            }
        }
    }

    private void setMode(int mode) {
        mAutomaticMode = mode == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
        Settings.System.putInt(getContext().getContentResolver(),
                Settings.System.SCREEN_BRIGHTNESS_MODE, mode);
    }

    @Override
    protected Parcelable onSaveInstanceState() {
        final Parcelable superState = super.onSaveInstanceState();
        if (getDialog() == null || !getDialog().isShowing()) return superState;

        // Save the dialog state
        final SavedState myState = new SavedState(superState);
        myState.automatic = mCheckBox.isChecked();
        myState.progress = mSeekBar.getProgress();
        myState.oldAutomatic = mOldAutomatic == 1;
        myState.oldProgress = mOldBrightness;
        myState.curBrightness = mCurBrightness;

        // Restore the old state when the activity or dialog is being paused
        restoreOldState();
        return myState;
    }

    @Override
    protected void onRestoreInstanceState(Parcelable state) {
        if (state == null || !state.getClass().equals(SavedState.class)) {
            // Didn't save state for us in onSaveInstanceState
            super.onRestoreInstanceState(state);
            return;
        }

        SavedState myState = (SavedState) state;
        super.onRestoreInstanceState(myState.getSuperState());
        mOldBrightness = myState.oldProgress;
        mOldAutomatic = myState.oldAutomatic ? 1 : 0;
        setMode(myState.automatic ? 1 : 0);
        setBrightness(myState.progress, false);
        mCurBrightness = myState.curBrightness;
    }

    private static class SavedState extends BaseSavedState {

        boolean automatic;
        boolean oldAutomatic;
        int progress;
        int oldProgress;
        int curBrightness;

        public SavedState(Parcel source) {
            super(source);
            automatic = source.readInt() == 1;
            progress = source.readInt();
            oldAutomatic = source.readInt() == 1;
            oldProgress = source.readInt();
            curBrightness = source.readInt();
        }

        @Override
        public void writeToParcel(Parcel dest, int flags) {
            super.writeToParcel(dest, flags);
            dest.writeInt(automatic ? 1 : 0);
            dest.writeInt(progress);
            dest.writeInt(oldAutomatic ? 1 : 0);
            dest.writeInt(oldProgress);
            dest.writeInt(curBrightness);
        }

        public SavedState(Parcelable superState) {
            super(superState);
        }

        public static final Parcelable.Creator<SavedState> CREATOR =
                new Parcelable.Creator<SavedState>() {

            public SavedState createFromParcel(Parcel in) {
                return new SavedState(in);
            }

            public SavedState[] newArray(int size) {
                return new SavedState[size];
            }
        };
    }
}