Move underline thickness and position computation to Paint

Also, in TextLine, fix underline color and thickness to come from the
underline info rather than the TextPaint object.

Bug: 32907446
Bug: 62353930
Test: Manual
Test: cts-tradefed run cts-dev --module CtsTextTestCases
Test: cts-tradefed run cts-dev --module CtsWidgetTestCases
Change-Id: I259e9cf635a7056ccd367baa77c03100c69e3b98

3 files changed, 37 insertions, 7 deletions

diff --git a/core/java/android/text/TextLine.java b/core/java/android/text/TextLine.java
index 97e281894395..e4ed62a1ead9 100644
--- a/core/java/android/text/TextLine.java
+++ b/core/java/android/text/TextLine.java
@@ -705,9 +705,8 @@ class TextLine {
     }
 
     private static void drawUnderline(TextPaint wp, Canvas c, int color, float thickness,
-            float xleft, float xright, int baseline) {
-        // kStdUnderline_Offset = 1/9, defined in SkTextFormatParams.h
-        final float underlineTop = baseline + wp.baselineShift + (1.0f / 9.0f) * wp.getTextSize();
+            float xleft, float xright, float baseline) {
+        final float underlineTop = baseline + wp.baselineShift + wp.getUnderlinePosition();
 
         final int previousColor = wp.getColor();
         final Paint.Style previousStyle = wp.getStyle();
@@ -802,8 +801,6 @@ class TextLine {
             }
 
             if (numUnderlines != 0) {
-                // kStdUnderline_Thickness = 1/18, defined in SkTextFormatParams.h
-                final float defaultThickness = (1.0f / 18.0f) * wp.getTextSize();
                 for (int i = 0; i < numUnderlines; i++) {
                     final UnderlineInfo info = underlines.get(i);
 
@@ -826,11 +823,11 @@ class TextLine {
                     // setUnderLineText() are called. For backward compatibility, we need to draw
                     // both underlines, the one with custom color first.
                     if (info.underlineColor != 0) {
-                        drawUnderline(wp, c, wp.underlineColor, wp.underlineThickness,
+                        drawUnderline(wp, c, info.underlineColor, info.underlineThickness,
                                 underlineXLeft, underlineXRight, y);
                     }
                     if (info.isUnderlineText) {
-                        drawUnderline(wp, c, wp.getColor(), defaultThickness,
+                        drawUnderline(wp, c, wp.getColor(), ((Paint) wp).getUnderlineThickness(),
                                 underlineXLeft, underlineXRight, y);
                     }
                 }
diff --git a/core/java/android/text/TextPaint.java b/core/java/android/text/TextPaint.java
index 1b062cf8adcf..5234fa9a594b 100644
--- a/core/java/android/text/TextPaint.java
+++ b/core/java/android/text/TextPaint.java
@@ -102,4 +102,16 @@ public class TextPaint extends Paint {
         underlineColor = color;
         underlineThickness = thickness;
     }
+
+    /**
+     * @hide
+     */
+    @Override
+    public float getUnderlineThickness() {
+        if (underlineColor != 0) { // Return custom thickness only if underline color is set.
+            return underlineThickness;
+        } else {
+            return super.getUnderlineThickness();
+        }
+    }
 }
diff --git a/graphics/java/android/graphics/Paint.java b/graphics/java/android/graphics/Paint.java
index eb33ca857095..adc4369ba2ec 100644
--- a/graphics/java/android/graphics/Paint.java
+++ b/graphics/java/android/graphics/Paint.java
@@ -816,6 +816,27 @@ public class Paint {
     }
 
     /**
+     * Distance from top of the underline to the baseline. Positive values mean below the baseline.
+     * This method returns where the underline should be drawn independent of if the underlineText
+     * bit is set at the moment.
+     * @hide
+     */
+    public float getUnderlinePosition() {
+        // kStdUnderline_Offset = 1/9, defined in SkTextFormatParams.h
+        // TODO: replace with position from post and MVAR tables (b/62353930).
+        return (1.0f / 9.0f) * getTextSize();
+    }
+
+    /**
+     * @hide
+     */
+    public float getUnderlineThickness() {
+        // kStdUnderline_Thickness = 1/18, defined in SkTextFormatParams.h
+        // TODO: replace with thickness from post and MVAR tables (b/62353930).
+        return (1.0f / 18.0f) * getTextSize();
+    }
+
+    /**
      * Helper for setFlags(), setting or clearing the UNDERLINE_TEXT_FLAG bit
      *
      * @param underlineText true to set the underlineText bit in the paint's