SystemUI: Cleanup BatteryMeter

/*

 * Copyright (C) 2015 The Android Open Source Project

 * Copyright (C) 2017 The LineageOS Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

import android.animation.ArgbEvaluator;

import android.annotation.Nullable;

import android.content.Context;

import android.content.pm.PackageManager;

import android.content.res.Resources;

import android.content.res.ThemeConfig;

import android.content.res.TypedArray;

import android.graphics.Color;

import android.graphics.ColorFilter;

import android.graphics.Paint;

import android.graphics.Path;

import android.graphics.PorterDuff;

import android.graphics.PorterDuffXfermode;

import android.graphics.Rect;

import android.graphics.RectF;

import android.graphics.Typeface;

import android.graphics.drawable.AnimatedVectorDrawable;

import android.graphics.drawable.BitmapDrawable;

import android.graphics.drawable.Drawable;

import android.graphics.drawable.LayerDrawable;

import android.net.Uri;

import android.os.Bundle;

import android.os.Handler;

import android.provider.Settings;

import android.util.Log;

import android.view.Gravity;

import android.view.View;

public class BatteryMeterDrawable extends Drawable implements

        BatteryController.BatteryStateChangeCallback {

    private static final float ASPECT_RATIO = 9.5f / 14.5f;

    public static final String TAG = BatteryMeterDrawable.class.getSimpleName();

    public static final String SHOW_PERCENT_SETTING = "status_bar_show_battery_percent";

    private static final boolean SINGLE_DIGIT_PERCENT = false;

    private static final int FULL = 96;

    private static final float BOLT_LEVEL_THRESHOLD = 0.3f;  // opaque bolt below this fraction

    // Values for the different battery styles

    public static final int BATTERY_STYLE_PORTRAIT  = 0;

    public static final int BATTERY_STYLE_CIRCLE    = 2;

    private final int mIntrinsicHeight;

    private boolean mShowPercent;

    private float mButtonHeightFraction;

    private float mSubpixelSmoothingLeft;

    private float mSubpixelSmoothingRight;

    private float mTextHeight, mWarningTextHeight;

    private int mIconTint = Color.WHITE;

    private float mOldDarkIntensity = 0f;

    private int mWidth;

    private String mWarningString;

    private final int mCriticalLevel;

    private int mChargeColor;

    private final Path mBoltPath = new Path();

    private final Path mPlusPath = new Path();

    private final RectF mFrame = new RectF();

    private final RectF mButtonFrame = new RectF();

    private final RectF mBoltFrame = new RectF();

    private final RectF mPlusFrame = new RectF();

    private final Path mShapePath = new Path();

    private final Path mClipPath = new Path();

    private final Path mTextPath = new Path();

    private BatteryController mBatteryController;

    private boolean mPowerSaveEnabled;

    private int mLevel = -1;

    private boolean mPluggedIn;

    private boolean mListening;

    private boolean mIsAnimating; // stores charge-animation status to remove callbacks

    private float mTextX, mTextY; // precalculated position for drawText() to appear centered

        mWarningString = context.getString(R.string.battery_meter_very_low_overlay_symbol);

        mCriticalLevel = mContext.getResources().getInteger(

                com.android.internal.R.integer.config_criticalBatteryWarningLevel);

        mButtonHeightFraction = context.getResources().getFraction(

                R.fraction.battery_button_height_fraction, 1, 1);

        mSubpixelSmoothingLeft = context.getResources().getFraction(

                R.fraction.battery_subpixel_smoothing_left, 1, 1);

        mSubpixelSmoothingRight = context.getResources().getFraction(

                R.fraction.battery_subpixel_smoothing_right, 1, 1);

        loadBatteryDrawables(res, style);

    }

    public void startListening() {

        mListening = true;

        mContext.getContentResolver().registerContentObserver(

                CMSettings.System.getUriFor(CMSettings.System.STATUS_BAR_SHOW_BATTERY_PERCENT),

                false, mSettingObserver);

    }

    public void stopListening() {

        mListening = false;

        mContext.getContentResolver().unregisterContentObserver(mSettingObserver);

        mBatteryController.removeStateChangedCallback(this);

    }

        mHeight = bottom - top;

        mWidth = right - left;

        mWarningTextPaint.setTextSize(mHeight * 0.75f);

        mWarningTextHeight = -mWarningTextPaint.getFontMetrics().ascent;

    }

    private void updateShowPercent() {

                checkBatteryMeterDrawableValid(res, style);

            } catch (BatteryMeterDrawableException e) {

                Log.w(TAG, "Invalid themed battery meter drawable, falling back to system", e);

/*              Disable until the theme engine is brought up

                PackageManager pm = mContext.getPackageManager();

                try {

                    res = pm.getThemedResourcesForApplication(mContext.getPackageName(),

                            ThemeConfig.SYSTEM_DEFAULT);

                } catch (PackageManager.NameNotFoundException nnfe) {

                    // Ignore; this should not happen

                }

*/

            }

        }

import android.content.res.TypedArray;

import android.os.Handler;

import android.util.ArraySet;

import android.os.UserHandle;

import android.provider.Settings;

import android.util.AttributeSet;

import android.view.View;

import android.widget.ImageView;