Battery meter: remove bolt color compromise & improve pct.

 - Bolt remains opaque (white) below a threshold level, otherwise
   transparent.
 - Draw the entire shape using a path, removing the need for a
   software layer.
 - Use a similar approach to make the percentage text readable,
   but this still requires a software layer (since text is involved).

Bug: 12131168
Change-Id: Ifde5e99121155bf1be171f44b2c80c116b17c9e7

2 files changed, 94 insertions, 57 deletions

diff --git a/packages/SystemUI/res/values/colors.xml b/packages/SystemUI/res/values/colors.xml
index 3a35de5..9301618 100644
--- a/packages/SystemUI/res/values/colors.xml
+++ b/packages/SystemUI/res/values/colors.xml
@@ -34,7 +34,7 @@
     <color name="notification_panel_scrim_color">#B0000000</color>
     <color name="batterymeter_frame_color">#66FFFFFF</color><!-- 40% white -->
     <color name="batterymeter_charge_color">#FFFFFFFF</color>
-    <color name="batterymeter_bolt_color">#B2000000</color><!-- 70% black -->
+    <color name="batterymeter_bolt_color">#FFFFFFFF</color>
     <color name="status_bar_clock_color">#FFFFFFFF</color>
     <drawable name="notification_item_background_color">#ff111111</drawable>
     <drawable name="notification_item_background_color_pressed">#ff454545</drawable>
diff --git a/packages/SystemUI/src/com/android/systemui/BatteryMeterView.java b/packages/SystemUI/src/com/android/systemui/BatteryMeterView.java
index 1c64fb4..5579e19 100755
--- a/packages/SystemUI/src/com/android/systemui/BatteryMeterView.java
+++ b/packages/SystemUI/src/com/android/systemui/BatteryMeterView.java
@@ -39,20 +39,20 @@ public class BatteryMeterView extends View implements DemoMode {
     public static final String TAG = BatteryMeterView.class.getSimpleName();
     public static final String ACTION_LEVEL_TEST = "com.android.systemui.BATTERY_LEVEL_TEST";
 
-    public static final boolean ENABLE_PERCENT = true;
-    public static final boolean SINGLE_DIGIT_PERCENT = false;
-    public static final boolean SHOW_100_PERCENT = false;
+    private static final boolean ENABLE_PERCENT = true;
+    private static final boolean SINGLE_DIGIT_PERCENT = false;
+    private static final boolean SHOW_100_PERCENT = false;
 
-    public static final int FULL = 96;
-    public static final int EMPTY = 4;
+    private static final int FULL = 96;
+    private static final int EMPTY = 4;
 
-    public static final float SUBPIXEL = 0.4f;  // inset rects for softer edges
+    private static final float SUBPIXEL = 0.4f;  // inset rects for softer edges
+    private static final float BOLT_LEVEL_THRESHOLD = 0.3f;  // opaque bolt below this fraction
 
-    int[] mColors;
+    private final int[] mColors;
 
     boolean mShowPercent = true;
-    Paint mFramePaint, mBatteryPaint, mWarningTextPaint, mTextPaint, mBoltPaint;
-    int mButtonHeight;
+    private final Paint mFramePaint, mBatteryPaint, mWarningTextPaint, mTextPaint, mBoltPaint;
     private float mTextHeight, mWarningTextHeight;
 
     private int mHeight;
@@ -64,9 +64,11 @@ public class BatteryMeterView extends View implements DemoMode {
 
     private final RectF mFrame = new RectF();
     private final RectF mButtonFrame = new RectF();
-    private final RectF mClipFrame = new RectF();
     private final RectF mBoltFrame = new RectF();
 
+    private final Path mShapePath = new Path();
+    private final Path mClipPath = new Path();
+
     private class BatteryTracker extends BroadcastReceiver {
         public static final int UNKNOWN_LEVEL = -1;
 
@@ -188,7 +190,9 @@ public class BatteryMeterView extends View implements DemoMode {
         colors.recycle();
         mShowPercent = ENABLE_PERCENT && 0 != Settings.System.getInt(
                 context.getContentResolver(), "status_bar_show_battery_percent", 0);
-
+        if (mShowPercent) {
+            setLayerType(View.LAYER_TYPE_SOFTWARE, null);
+        }
         mWarningString = context.getString(R.string.battery_meter_very_low_overlay_symbol);
 
         mFramePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
@@ -196,7 +200,6 @@ public class BatteryMeterView extends View implements DemoMode {
         mFramePaint.setDither(true);
         mFramePaint.setStrokeWidth(0);
         mFramePaint.setStyle(Paint.Style.FILL_AND_STROKE);
-        mFramePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_ATOP));
 
         mBatteryPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
         mBatteryPaint.setDither(true);
@@ -204,8 +207,7 @@ public class BatteryMeterView extends View implements DemoMode {
         mBatteryPaint.setStyle(Paint.Style.FILL_AND_STROKE);
 
         mTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
-        mTextPaint.setColor(0xFFFFFFFF);
-        Typeface font = Typeface.create("sans-serif-condensed", Typeface.NORMAL);
+        Typeface font = Typeface.create("sans-serif-condensed", Typeface.BOLD);
         mTextPaint.setTypeface(font);
         mTextPaint.setTextAlign(Paint.Align.CENTER);
 
@@ -217,11 +219,9 @@ public class BatteryMeterView extends View implements DemoMode {
 
         mChargeColor = getResources().getColor(R.color.batterymeter_charge_color);
 
-        mBoltPaint = new Paint();
-        mBoltPaint.setAntiAlias(true);
+        mBoltPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
         mBoltPaint.setColor(res.getColor(R.color.batterymeter_bolt_color));
         mBoltPoints = loadBoltPoints(res);
-        setLayerType(View.LAYER_TYPE_SOFTWARE, null);
     }
 
     private static float[] loadBoltPoints(Resources res) {
@@ -269,36 +269,34 @@ public class BatteryMeterView extends View implements DemoMode {
         final int pl = getPaddingLeft();
         final int pr = getPaddingRight();
         final int pb = getPaddingBottom();
-        int height = mHeight - pt - pb;
-        int width = mWidth - pl - pr;
+        final int height = mHeight - pt - pb;
+        final int width = mWidth - pl - pr;
 
-        mButtonHeight = (int) (height * 0.12f);
+        final int buttonHeight = (int) (height * 0.12f);
 
         mFrame.set(0, 0, width, height);
         mFrame.offset(pl, pt);
 
+        // button-frame: area above the battery body
         mButtonFrame.set(
                 mFrame.left + width * 0.25f,
                 mFrame.top,
                 mFrame.right - width * 0.25f,
-                mFrame.top + mButtonHeight + 5 /*cover frame border of intersecting area*/);
+                mFrame.top + buttonHeight);
 
         mButtonFrame.top += SUBPIXEL;
         mButtonFrame.left += SUBPIXEL;
         mButtonFrame.right -= SUBPIXEL;
 
-        mFrame.top += mButtonHeight;
+        // frame: battery body area
+        mFrame.top += buttonHeight;
         mFrame.left += SUBPIXEL;
         mFrame.top += SUBPIXEL;
         mFrame.right -= SUBPIXEL;
         mFrame.bottom -= SUBPIXEL;
 
-        // first, draw the battery shape
-        c.drawRect(mFrame, mFramePaint);
-
-        // fill 'er up
-        final int color = tracker.plugged ? mChargeColor : getColorForLevel(level);
-        mBatteryPaint.setColor(color);
+        // set the battery charging color
+        mBatteryPaint.setColor(tracker.plugged ? mChargeColor : getColorForLevel(level));
 
         if (level >= FULL) {
             drawFrac = 1f;
@@ -306,18 +304,23 @@ public class BatteryMeterView extends View implements DemoMode {
             drawFrac = 0f;
         }
 
-        c.drawRect(mButtonFrame, drawFrac == 1f ? mBatteryPaint : mFramePaint);
-
-        mClipFrame.set(mFrame);
-        mClipFrame.top += (mFrame.height() * (1f - drawFrac));
-
-        c.save(Canvas.CLIP_SAVE_FLAG);
-        c.clipRect(mClipFrame);
-        c.drawRect(mFrame, mBatteryPaint);
-        c.restore();
+        final float levelTop = drawFrac == 1f ? mButtonFrame.top
+                : (mFrame.top + (mFrame.height() * (1f - drawFrac)));
+
+        // define the battery shape
+        mShapePath.reset();
+        mShapePath.moveTo(mButtonFrame.left, mButtonFrame.top);
+        mShapePath.lineTo(mButtonFrame.right, mButtonFrame.top);
+        mShapePath.lineTo(mButtonFrame.right, mFrame.top);
+        mShapePath.lineTo(mFrame.right, mFrame.top);
+        mShapePath.lineTo(mFrame.right, mFrame.bottom);
+        mShapePath.lineTo(mFrame.left, mFrame.bottom);
+        mShapePath.lineTo(mFrame.left, mFrame.top);
+        mShapePath.lineTo(mButtonFrame.left, mFrame.top);
+        mShapePath.lineTo(mButtonFrame.left, mButtonFrame.top);
 
         if (tracker.plugged) {
-            // draw the bolt
+            // define the bolt shape
             final float bl = mFrame.left + mFrame.width() / 4.5f;
             final float bt = mFrame.top + mFrame.height() / 6f;
             final float br = mFrame.right - mFrame.width() / 7f;
@@ -338,24 +341,58 @@ public class BatteryMeterView extends View implements DemoMode {
                         mBoltFrame.left + mBoltPoints[0] * mBoltFrame.width(),
                         mBoltFrame.top + mBoltPoints[1] * mBoltFrame.height());
             }
-            c.drawPath(mBoltPath, mBoltPaint);
-        } else if (level <= EMPTY) {
-            final float x = mWidth * 0.5f;
-            final float y = (mHeight + mWarningTextHeight) * 0.48f;
-            c.drawText(mWarningString, x, y, mWarningTextPaint);
-        } else if (mShowPercent && !(tracker.level == 100 && !SHOW_100_PERCENT)) {
-            mTextPaint.setTextSize(height *
-                    (SINGLE_DIGIT_PERCENT ? 0.75f
-                            : (tracker.level == 100 ? 0.38f : 0.5f)));
-            mTextHeight = -mTextPaint.getFontMetrics().ascent;
-
-            final String str = String.valueOf(SINGLE_DIGIT_PERCENT ? (level/10) : level);
-            final float x = mWidth * 0.5f;
-            final float y = (mHeight + mTextHeight) * 0.47f;
-            c.drawText(str,
-                    x,
-                    y,
-                    mTextPaint);
+
+            float boltPct = (mBoltFrame.bottom - levelTop) / (mBoltFrame.bottom - mBoltFrame.top);
+            boltPct = Math.min(Math.max(boltPct, 0), 1);
+            if (boltPct <= BOLT_LEVEL_THRESHOLD) {
+                // draw the bolt if opaque
+                c.drawPath(mBoltPath, mBoltPaint);
+            } else {
+                // otherwise cut the bolt out of the overall shape
+                mShapePath.op(mBoltPath, Path.Op.DIFFERENCE);
+            }
+        }
+
+        // draw the battery shape background
+        c.drawPath(mShapePath, mFramePaint);
+
+        // draw the battery shape, clipped to charging level
+        mFrame.top = levelTop;
+        mClipPath.reset();
+        mClipPath.addRect(mFrame,  Path.Direction.CCW);
+        mShapePath.op(mClipPath, Path.Op.INTERSECT);
+        c.drawPath(mShapePath, mBatteryPaint);
+
+        if (!tracker.plugged) {
+            if (level <= EMPTY) {
+                // draw the warning text
+                final float x = mWidth * 0.5f;
+                final float y = (mHeight + mWarningTextHeight) * 0.48f;
+                c.drawText(mWarningString, x, y, mWarningTextPaint);
+            } else if (mShowPercent && !(tracker.level == 100 && !SHOW_100_PERCENT)) {
+                // draw the percentage text
+                mTextPaint.setColor(getColorForLevel(level));
+                mTextPaint.setTextSize(height *
+                        (SINGLE_DIGIT_PERCENT ? 0.75f
+                                : (tracker.level == 100 ? 0.38f : 0.5f)));
+                mTextHeight = -mTextPaint.getFontMetrics().ascent;
+
+                final String str = String.valueOf(SINGLE_DIGIT_PERCENT ? (level/10) : level);
+                final float x = mWidth * 0.5f;
+                final float y = (mHeight + mTextHeight) * 0.47f;
+
+                boolean opaque = levelTop > y;
+                if (opaque) {
+                    mTextPaint.setXfermode(null);
+                } else {
+                    mTextPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
+                }
+
+                c.drawText(str,
+                        x,
+                        y,
+                        mTextPaint);
+            }
         }
     }