Create a battery icon that loads paths

Create a new battery drawable that will load enough resources from
frameworks/base/core/res/res/ to allow for theming overlays. The current
things are overlayable:

- Perimeter path: the outer shape of the battery (including the
terminal)
- Fill mask: path defining the shape of the fill
- Bolt path: charging bolt path. draws with appropriate protection for
visibilty
- Powersave path: path of the plus sign that draws when in powersave
mode. also draws with protection

Test: visual; sysui demo mode
Bug: 123705805
Change-Id: I2bb15fd10e3fec63cb115a8f216794933b717404
diff --git a/packages/SettingsLib/Android.bp b/packages/SettingsLib/Android.bp
index caa928f..730e9e1 100644
--- a/packages/SettingsLib/Android.bp
+++ b/packages/SettingsLib/Android.bp
@@ -29,7 +29,7 @@
 
     resource_dirs: ["res"],
 
-    srcs: ["src/**/*.java"],
+    srcs: ["src/**/*.java", "src/**/*.kt"],
 
     min_sdk_version: "21",
 
diff --git a/packages/SettingsLib/src/com/android/settingslib/graph/ThemedBatteryDrawable.kt b/packages/SettingsLib/src/com/android/settingslib/graph/ThemedBatteryDrawable.kt
new file mode 100644
index 0000000..337106b
--- /dev/null
+++ b/packages/SettingsLib/src/com/android/settingslib/graph/ThemedBatteryDrawable.kt
@@ -0,0 +1,404 @@
+/*
+ * Copyright (C) 2019 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.settingslib.graph
+
+import android.content.Context
+import android.graphics.BlendMode
+import android.graphics.Canvas
+import android.graphics.Color
+import android.graphics.ColorFilter
+import android.graphics.Matrix
+import android.graphics.Paint
+import android.graphics.Path
+import android.graphics.PixelFormat
+import android.graphics.Rect
+import android.graphics.RectF
+import android.graphics.drawable.Drawable
+import android.util.PathParser
+import android.util.TypedValue
+
+import com.android.settingslib.R
+import com.android.settingslib.Utils
+
+/**
+ * A battery meter drawable that respects paths configured in
+ * frameworks/base/core/res/res/values/config.xml to allow for an easily overrideable battery icon
+ */
+open class ThemedBatteryDrawable(private val context: Context, frameColor: Int) : Drawable() {
+
+    // Need to load:
+    // 1. perimeter shape
+    // 2. fill mask (if smaller than perimeter, this would create a fill that
+    //    doesn't touch the walls
+    private val perimeterPath = Path()
+    private val scaledPerimeter = Path()
+    // Fill will cover the whole bounding rect of the fillMask, and be masked by the path
+    private val fillMask = Path()
+    private val scaledFill = Path()
+    // Based off of the mask, the fill will interpolate across this space
+    private val fillRect = RectF()
+    // Top of this rect changes based on level, 100% == fillRect
+    private val levelRect = RectF()
+    private val levelPath = Path()
+    // Updates the transform of the paths when our bounds change
+    private val scaleMatrix = Matrix()
+    private val padding = Rect()
+    // The net result of fill + perimeter paths
+    private val unifiedPath = Path()
+
+    // Bolt path (used while charging)
+    private val boltPath = Path()
+    private val scaledBolt = Path()
+
+    // Plus sign (used for power save mode)
+    private val plusPath = Path()
+    private val scaledPlus = Path()
+
+    private var intrinsicHeight: Int
+    private var intrinsicWidth: Int
+
+    // To implement hysteresis, keep track of the need to invert the interior icon of the battery
+    private var invertFillIcon = false
+
+    // Colors can be configured based on battery level (see res/values/arrays.xml)
+    private var colorLevels: IntArray
+
+    private var fillColor: Int = Color.MAGENTA
+    private var backgroundColor: Int = Color.MAGENTA
+    // updated whenever level changes
+    private var levelColor: Int = Color.MAGENTA
+
+    // Dual tone implies that battery level is a clipped overlay over top of the whole shape
+    private var dualTone = false
+
+    private val invalidateRunnable: () -> Unit = {
+        invalidateSelf()
+    }
+
+    open var criticalLevel: Int = 0
+
+    var charging = false
+        set(value) {
+            field = value
+            postInvalidate()
+        }
+
+    var powerSaveEnabled = false
+        set(value) {
+            field = value
+            postInvalidate()
+        }
+
+    private val fillColorStrokePaint: Paint by lazy {
+        val p = Paint(Paint.ANTI_ALIAS_FLAG)
+        p.color = frameColor
+        p.isDither = true
+        p.strokeWidth = 5f
+        p.style = Paint.Style.STROKE
+        p.blendMode = BlendMode.SRC
+        p.strokeMiter = 5f
+        p
+    }
+
+    private val fillColorStrokeProtection: Paint by lazy {
+        val p = Paint(Paint.ANTI_ALIAS_FLAG)
+        p.isDither = true
+        p.strokeWidth = 5f
+        p.style = Paint.Style.STROKE
+        p.blendMode = BlendMode.CLEAR
+        p.strokeMiter = 5f
+        p
+    }
+
+    private val fillPaint: Paint by lazy {
+        val p = Paint(Paint.ANTI_ALIAS_FLAG)
+        p.color = frameColor
+        p.alpha = 255
+        p.isDither = true
+        p.strokeWidth = 0f
+        p.style = Paint.Style.FILL_AND_STROKE
+        p
+    }
+
+    // Only used if dualTone is set to true
+    private val dualToneBackgroundFill: Paint by lazy {
+        val p = Paint(Paint.ANTI_ALIAS_FLAG)
+        p.color = frameColor
+        p.alpha = 255
+        p.isDither = true
+        p.strokeWidth = 0f
+        p.style = Paint.Style.FILL_AND_STROKE
+        p
+    }
+
+    init {
+        val density = context.resources.displayMetrics.density
+        intrinsicHeight = (Companion.HEIGHT * density).toInt()
+        intrinsicWidth = (Companion.WIDTH * density).toInt()
+
+        val res = context.resources
+        val levels = res.obtainTypedArray(R.array.batterymeter_color_levels)
+        val colors = res.obtainTypedArray(R.array.batterymeter_color_values)
+        val N = levels.length()
+        colorLevels = IntArray(2 * N)
+        for (i in 0 until N) {
+            colorLevels[2 * i] = levels.getInt(i, 0)
+            if (colors.getType(i) == TypedValue.TYPE_ATTRIBUTE) {
+                colorLevels[2 * i + 1] = Utils.getColorAttrDefaultColor(context,
+                        colors.getThemeAttributeId(i, 0))
+            } else {
+                colorLevels[2 * i + 1] = colors.getColor(i, 0)
+            }
+        }
+        levels.recycle()
+        colors.recycle()
+
+        criticalLevel = context.resources.getInteger(
+                com.android.internal.R.integer.config_criticalBatteryWarningLevel)
+
+        loadPaths()
+    }
+
+    override fun draw(c: Canvas) {
+        unifiedPath.reset()
+        levelPath.reset()
+        levelRect.set(fillRect)
+        val fillFraction = level / 100f
+        val fillTop =
+                if (level >= 95)
+                    fillRect.top
+                else
+                    fillRect.top + (fillRect.height() * (1 - fillFraction))
+
+        levelRect.top = Math.floor(fillTop.toDouble()).toFloat()
+        levelPath.addRect(levelRect, Path.Direction.CCW)
+
+        // The perimeter should never change
+        unifiedPath.addPath(scaledPerimeter)
+        // IF drawing dual tone, the level is used only to clip the whole drawable path
+        if (!dualTone) {
+            unifiedPath.op(levelPath, Path.Op.UNION)
+        }
+
+        fillPaint.color = levelColor
+
+        // Deal with unifiedPath clipping before it draws
+        if (charging) {
+            // Clip out the bolt shape
+            unifiedPath.op(scaledBolt, Path.Op.DIFFERENCE)
+            if (!invertFillIcon) {
+                c.drawPath(scaledBolt, fillPaint)
+            }
+        } else if (powerSaveEnabled) {
+            // Clip out the plus shape
+            unifiedPath.op(scaledPlus, Path.Op.DIFFERENCE)
+            if (!invertFillIcon) {
+                c.drawPath(scaledPlus, fillPaint)
+            }
+        }
+
+        if (dualTone) {
+            // Dual tone means we draw the shape again, clipped to the charge level
+            c.drawPath(unifiedPath, dualToneBackgroundFill)
+            c.save()
+            c.clipRect(0f,
+                    bounds.bottom - bounds.height() * fillFraction,
+                    bounds.right.toFloat(),
+                    bounds.bottom.toFloat())
+            c.drawPath(unifiedPath, fillPaint)
+            c.restore()
+        } else {
+            // Non dual-tone means we draw the perimeter (with the level fill), and potentially
+            // draw the fill again with a critical color
+            fillPaint.color = fillColor
+            c.drawPath(unifiedPath, fillPaint)
+            fillPaint.color = levelColor
+
+            // Show colorError below this level
+            if (level <= Companion.CRITICAL_LEVEL && !charging) {
+                c.save()
+                c.clipPath(scaledFill)
+                c.drawPath(levelPath, fillPaint)
+                c.restore()
+            }
+        }
+
+        if (charging) {
+            c.clipOutPath(scaledBolt)
+            if (invertFillIcon) {
+                c.drawPath(scaledBolt, fillColorStrokePaint)
+            } else {
+                c.drawPath(scaledBolt, fillColorStrokeProtection)
+            }
+        } else if (powerSaveEnabled) {
+            c.clipOutPath(scaledPlus)
+            if (invertFillIcon) {
+                c.drawPath(scaledPlus, fillColorStrokePaint)
+            } else {
+                c.drawPath(scaledPlus, fillColorStrokeProtection)
+            }
+        }
+    }
+
+    private fun batteryColorForLevel(level: Int): Int {
+        return when {
+            charging || powerSaveEnabled -> fillPaint.color
+            else -> getColorForLevel(level)
+        }
+    }
+
+    private fun getColorForLevel(level: Int): Int {
+        var thresh: Int
+        var color = 0
+        var i = 0
+        while (i < colorLevels.size) {
+            thresh = colorLevels[i]
+            color = colorLevels[i + 1]
+            if (level <= thresh) {
+
+                // Respect tinting for "normal" level
+                return if (i == colorLevels.size - 2) {
+                    fillColor
+                } else {
+                    color
+                }
+            }
+            i += 2
+        }
+        return color
+    }
+
+    /**
+     * Alpha is unused internally, and should be defined in the colors passed to {@link setColors}.
+     * Further, setting an alpha for a dual tone battery meter doesn't make sense without bounds
+     * defining the minimum background fill alpha. This is because fill + background must be equal
+     * to the net alpha passed in here.
+     */
+    override fun setAlpha(alpha: Int) {
+    }
+
+    override fun setColorFilter(colorFilter: ColorFilter?) {
+        fillPaint.colorFilter = colorFilter
+        fillColorStrokePaint.colorFilter = colorFilter
+        dualToneBackgroundFill.colorFilter = colorFilter
+    }
+
+    /**
+     * Deprecated, but required by Drawable
+     */
+    override fun getOpacity(): Int {
+        return PixelFormat.OPAQUE
+    }
+
+    override fun getIntrinsicHeight(): Int {
+        return intrinsicHeight
+    }
+
+    override fun getIntrinsicWidth(): Int {
+        return intrinsicWidth
+    }
+
+    /**
+     * Set the fill level
+     */
+    public open fun setBatteryLevel(l: Int) {
+        invertFillIcon = if (l >= 67) true else if (l <= 33) false else invertFillIcon
+        level = l
+        levelColor = batteryColorForLevel(level)
+        invalidateSelf()
+    }
+
+    public fun getBatteryLevel(): Int {
+        return level
+    }
+
+    override fun onBoundsChange(bounds: Rect?) {
+        super.onBoundsChange(bounds)
+        updateSize()
+    }
+
+    fun setPadding(left: Int, top: Int, right: Int, bottom: Int) {
+        padding.left = left
+        padding.top = top
+        padding.right = right
+        padding.bottom = bottom
+
+        updateSize()
+    }
+
+    fun setColors(fgColor: Int, bgColor: Int, singleToneColor: Int) {
+        fillColor = if (dualTone) fgColor else singleToneColor
+
+        fillPaint.color = fillColor
+        fillColorStrokePaint.color = fillColor
+
+        backgroundColor = bgColor
+        dualToneBackgroundFill.color = bgColor
+
+        invalidateSelf()
+    }
+
+    private fun postInvalidate() {
+        unscheduleSelf(invalidateRunnable)
+        scheduleSelf(invalidateRunnable, 0)
+    }
+
+    private fun updateSize() {
+        val b = bounds
+        if (b.isEmpty) {
+            scaleMatrix.setScale(1f, 1f)
+        } else {
+            scaleMatrix.setScale((b.right / Companion.WIDTH), (b.bottom / Companion.HEIGHT))
+        }
+
+        perimeterPath.transform(scaleMatrix, scaledPerimeter)
+        fillMask.transform(scaleMatrix, scaledFill)
+        scaledFill.computeBounds(fillRect, true)
+        boltPath.transform(scaleMatrix, scaledBolt)
+        plusPath.transform(scaleMatrix, scaledPlus)
+    }
+
+    private fun loadPaths() {
+        val pathString = context.resources.getString(
+                com.android.internal.R.string.config_batterymeterPerimeterPath)
+        perimeterPath.set(PathParser.createPathFromPathData(pathString))
+        val b = RectF()
+        perimeterPath.computeBounds(b, true)
+
+        val fillMaskString = context.resources.getString(
+                com.android.internal.R.string.config_batterymeterFillMask)
+        fillMask.set(PathParser.createPathFromPathData(fillMaskString))
+        // Set the fill rect so we can calculate the fill properly
+        fillMask.computeBounds(fillRect, true)
+
+        val boltPathString = context.resources.getString(
+                com.android.internal.R.string.config_batterymeterBoltPath)
+        boltPath.set(PathParser.createPathFromPathData(boltPathString))
+
+        val plusPathString = context.resources.getString(
+                com.android.internal.R.string.config_batterymeterPowersavePath)
+        plusPath.set(PathParser.createPathFromPathData(plusPathString))
+
+        dualTone = context.resources.getBoolean(
+                com.android.internal.R.bool.config_batterymeterDualTone)
+    }
+
+    companion object {
+        private const val TAG = "ThemedBatteryDrawable"
+        private const val WIDTH = 12f
+        private const val HEIGHT = 20f
+        private const val CRITICAL_LEVEL = 15
+    }
+}