From 442c151b8d0800a3f30cdfc0bbfd40af524dcf7a Mon Sep 17 00:00:00 2001
From: Siyamed Sinir <siyamed@google.com>
Date: Mon, 24 Jul 2017 12:18:27 -0700
Subject: [PATCH] Fix EditText line spacing

DynamicLayout did not include the line spacing for the newly added
lines. This CL updates StaticLayout with a parameter to force addition
of line spacing to the last line, and updates DynamicLayout to use this
parameter. With this change the last line will have the line spacing
applied, and it will provide a consistent UX.

Test: Manual/Visual test
Test: bit -t FrameworksCoreTests:android.text.StaticLayoutTest
Test: bit -t FrameworksCoreTests:android.text.StaticLayoutTextMeasuringTest
Test: bit -t FrameworksCoreTests:android.text.StaticLayoutLineBreakingTest
Test: bit -t FrameworksCoreTests:android.text.DynamicLayoutTest
Test: bit -t FrameworksCoreTests:android.text.DynamicLayoutBlocksTest
Test: bit -t CtsTextTestCases:android.text.cts.StaticLayoutTest
Test: bit -t CtsTextTestCases:android.text.cts.DynamicLayoutTest

Bug: 25194907
Change-Id: I52497fbd108538729758e842072f3ce87c6bbfdd
---
 core/java/android/text/DynamicLayout.java |  5 +++--
 core/java/android/text/StaticLayout.java  | 23 ++++++++++++++++++-----
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/core/java/android/text/DynamicLayout.java b/core/java/android/text/DynamicLayout.java
index 91d8290999176..e63f5ddc9af0e 100644
--- a/core/java/android/text/DynamicLayout.java
+++ b/core/java/android/text/DynamicLayout.java
@@ -303,8 +303,9 @@ public class DynamicLayout extends Layout
                 .setEllipsize(mEllipsizeAt)
                 .setBreakStrategy(mBreakStrategy)
                 .setHyphenationFrequency(mHyphenationFrequency)
-                .setJustificationMode(mJustificationMode);
-        reflowed.generate(b, false, true);
+                .setJustificationMode(mJustificationMode)
+                .setAddLastLineLineSpacing(true);
+        reflowed.generate(b, false /*includepad*/, true /*trackpad*/);
         int n = reflowed.getLineCount();
         // If the new layout has a blank line at the end, but it is not
         // the very end of the buffer, then we already have a line that
diff --git a/core/java/android/text/StaticLayout.java b/core/java/android/text/StaticLayout.java
index dc5553ee4fe5c..4eb74a738b63f 100644
--- a/core/java/android/text/StaticLayout.java
+++ b/core/java/android/text/StaticLayout.java
@@ -334,6 +334,17 @@ public class StaticLayout extends Layout {
             return this;
         }
 
+        /**
+         * Sets whether the line spacing should be applied for the last line. Default value is
+         * {@code false}.
+         *
+         * @hide
+         */
+        /* package */ Builder setAddLastLineLineSpacing(boolean value) {
+            mAddLastLineLineSpacing = value;
+            return this;
+        }
+
         private long[] getHyphenators(LocaleList locales) {
             final int length = locales.size();
             final long[] result = new long[length];
@@ -430,6 +441,7 @@ public class StaticLayout extends Layout {
         int[] mLeftIndents;
         int[] mRightIndents;
         int mJustificationMode;
+        boolean mAddLastLineLineSpacing;
 
         Paint.FontMetricsInt mFontMetricsInt = new Paint.FontMetricsInt();
 
@@ -599,6 +611,7 @@ public class StaticLayout extends Layout {
         float spacingadd = b.mSpacingAdd;
         float ellipsizedWidth = b.mEllipsizedWidth;
         TextUtils.TruncateAt ellipsize = b.mEllipsize;
+        final boolean addLastLineSpacing = b.mAddLastLineLineSpacing;
         LineBreaks lineBreaks = new LineBreaks();  // TODO: move to builder to avoid allocation costs
         // store span end locations
         int[] spanEndCache = new int[4];
@@ -849,8 +862,8 @@ public class StaticLayout extends Layout {
                             fmAscent, fmDescent, fmTop, fmBottom,
                             v, spacingmult, spacingadd, chooseHt, chooseHtv, fm, flags[breakIndex],
                             needMultiply, chdirs, dir, easy, bufEnd, includepad, trackpad,
-                            chs, widths, paraStart, ellipsize, ellipsizedWidth,
-                            lineWidths[breakIndex], paint, moreChars);
+                            addLastLineSpacing, chs, widths, paraStart, ellipsize,
+                            ellipsizedWidth, lineWidths[breakIndex], paint, moreChars);
 
                     if (endPos < spanEnd) {
                         // preserve metrics for current span
@@ -890,7 +903,7 @@ public class StaticLayout extends Layout {
                     spacingmult, spacingadd, null,
                     null, fm, 0,
                     needMultiply, measured.mLevels, measured.mDir, measured.mEasy, bufEnd,
-                    includepad, trackpad, null,
+                    includepad, trackpad, addLastLineSpacing, null,
                     null, bufStart, ellipsize,
                     ellipsizedWidth, 0, paint, false);
         }
@@ -903,7 +916,7 @@ public class StaticLayout extends Layout {
                       Paint.FontMetricsInt fm, int flags,
                       boolean needMultiply, byte[] chdirs, int dir,
                       boolean easy, int bufEnd, boolean includePad,
-                      boolean trackPad, char[] chs,
+                      boolean trackPad, boolean addLastLineLineSpacing, char[] chs,
                       float[] widths, int widthStart, TextUtils.TruncateAt ellipsize,
                       float ellipsisWidth, float textWidth,
                       TextPaint paint, boolean moreChars) {
@@ -992,7 +1005,7 @@ public class StaticLayout extends Layout {
             }
         }
 
-        if (needMultiply && !lastLine) {
+        if (needMultiply && (addLastLineLineSpacing || !lastLine)) {
             double ex = (below - above) * (spacingmult - 1) + spacingadd;
             if (ex >= 0) {
                 extra = (int)(ex + EXTRA_ROUNDING);