Issue #15986092: Add power tracking of flashlight.

Also improve drawing of date markers to allow a middle
marker for really looong durations.

Change-Id: I0c12ec9b6de102360d9171627787462dfa58b7ef

res/values/strings.xml

@@ -3625,6 +3625,8 @@
 
     <!-- Label for power consumed by the screen -->
     <string name="power_screen">Screen</string>
+    <!-- Label for power consumed by the flashlight -->
+    <string name="power_flashlight">Flashlight</string>
     <!-- Label for power consumed by Wi-Fi -->
     <string name="power_wifi">Wi\u2011Fi</string>
     <!-- Label for power consumed by Bluetooth -->

src/com/android/settings/fuelgauge/BatteryEntry.java

@@ -150,6 +150,10 @@ public class BatteryEntry {
                 name = context.getResources().getString(R.string.power_screen);
                 iconId = R.drawable.ic_settings_display;
                 break;
+            case FLASHLIGHT:
+                name = context.getResources().getString(R.string.power_flashlight);
+                iconId = R.drawable.ic_settings_display;
+                break;
             case APP:
                 name = sipper.packageWithHighestDrain;
                 break;

src/com/android/settings/fuelgauge/BatteryHistoryChart.java

@@ -17,6 +17,7 @@
 package com.android.settings.fuelgauge;
 
 import android.content.Intent;
+import android.graphics.Bitmap;
 import android.graphics.DashPathEffect;
 import android.os.BatteryManager;
 import android.provider.Settings;
@@ -219,6 +220,9 @@ public class BatteryHistoryChart extends View {
     final ArrayList<TimeLabel> mTimeLabels = new ArrayList<TimeLabel>();
     final ArrayList<DateLabel> mDateLabels = new ArrayList<DateLabel>();
 
+    Bitmap mBitmap;
+    Canvas mCanvas;
+
     static class TextAttrs {
         ColorStateList textColor = null;
         int textSize = 15;
@@ -339,6 +343,8 @@ public class BatteryHistoryChart extends View {
     public BatteryHistoryChart(Context context, AttributeSet attrs) {
         super(context, attrs);
 
+        if (DEBUG) Log.d(TAG, "New BatteryHistoryChart!");
+
         mBatteryWarnLevel = mContext.getResources().getInteger(
                 com.android.internal.R.integer.config_lowBatteryWarningLevel);
         mBatteryCriticalLevel = mContext.getResources().getInteger(
@@ -468,6 +474,8 @@ public class BatteryHistoryChart extends View {
         mStats = stats;
         mBatteryBroadcast = broadcast;
 
+        if (DEBUG) Log.d(TAG, "Setting stats...");
+
         final long elapsedRealtimeUs = SystemClock.elapsedRealtime() * 1000;
 
         long uSecTime = mStats.computeBatteryRealtime(elapsedRealtimeUs,
@@ -687,8 +695,12 @@ public class BatteryHistoryChart extends View {
             return;
         }
 
+        if (DEBUG) Log.d(TAG, "Rebuilding chart for: " + w + "x" + h);
+
         mLastWidth = w;
         mLastHeight = h;
+        mBitmap = null;
+        mCanvas = null;
 
         int textHeight = mTextDescent - mTextAscent;
         if (h > ((textHeight*10)+mChartMinHeight)) {
@@ -1025,6 +1037,13 @@ public class BatteryHistoryChart extends View {
                 endRoundTime = calEnd.getTimeInMillis();
                 if (startRoundTime < endRoundTime) {
                     addDateLabel(calStart, mLevelLeft, mLevelRight, isDayFirst);
+                    Calendar calMid = Calendar.getInstance();
+                    calMid.setTimeInMillis(startRoundTime + ((endRoundTime - startRoundTime) / 2));
+                    calMid.set(Calendar.HOUR_OF_DAY, 0);
+                    long calMidMillis = calMid.getTimeInMillis();
+                    if (calMidMillis > startRoundTime && calMidMillis < endRoundTime) {
+                        addDateLabel(calMid, mLevelLeft, mLevelRight, isDayFirst);
+                    }
                 }
                 addDateLabel(calEnd, mLevelLeft, mLevelRight, isDayFirst);
             }
@@ -1067,8 +1086,27 @@ public class BatteryHistoryChart extends View {
         final int width = getWidth();
         final int height = getHeight();
 
-        if (DEBUG) Log.d(TAG, "onDraw: " + width + "x" + height);
+        //buildBitmap(width, height);
 
+        if (DEBUG) Log.d(TAG, "onDraw: " + width + "x" + height);
+        //canvas.drawBitmap(mBitmap, 0, 0, null);
+        drawChart(canvas, width, height);
+    }
+
+    void buildBitmap(int width, int height) {
+        if (mBitmap != null && width == mBitmap.getWidth() && height == mBitmap.getHeight()) {
+            return;
+        }
+
+        if (DEBUG) Log.d(TAG, "buildBitmap: " + width + "x" + height);
+
+        mBitmap = Bitmap.createBitmap(getResources().getDisplayMetrics(), width, height,
+                Bitmap.Config.ARGB_8888);
+        mCanvas = new Canvas(mBitmap);
+        drawChart(mCanvas, width, height);
+    }
+
+    void drawChart(Canvas canvas, int width, int height) {
         final boolean layoutRtl = isLayoutRtl();
         final int textStartX = layoutRtl ? width : 0;
         final int textEndX = layoutRtl ? 0 : width;