From 429f1969c3dd97e178ee6786df1169256bc27281 Mon Sep 17 00:00:00 2001
From: Mikael Sand <msand@abo.fi>
Date: Mon, 30 Jul 2018 05:45:50 +0300
Subject: [PATCH] Implement basic support for unicode emoji

---
 .../java/com/horcrux/svg/TSpanShadowNode.java | 23 +++++++++---
 ios/Text/RNSVGTSpan.m                         | 36 ++++++++++++++++---
 2 files changed, 50 insertions(+), 9 deletions(-)

diff --git a/android/src/main/java/com/horcrux/svg/TSpanShadowNode.java b/android/src/main/java/com/horcrux/svg/TSpanShadowNode.java
index 01f74352..027dfce0 100644
--- a/android/src/main/java/com/horcrux/svg/TSpanShadowNode.java
+++ b/android/src/main/java/com/horcrux/svg/TSpanShadowNode.java
@@ -672,6 +672,7 @@ class TSpanShadowNode extends TextShadowNode {
         final Matrix end = new Matrix();
 
         final float[] startPointMatrixData = new float[9];
+        final float[] midPointMatrixData = new float[9];
         final float[] endPointMatrixData = new float[9];
 
         for (int index = 0; index < length; index++) {
@@ -729,7 +730,7 @@ class TSpanShadowNode extends TextShadowNode {
             double dy = gc.nextDeltaY();
             double r = gc.nextRotation();
 
-            if (alreadyRenderedGraphemeCluster) {
+            if (alreadyRenderedGraphemeCluster || isWordSeparator) {
                 // Skip rendering other grapheme clusters of ligatures (already rendered),
                 // But, make sure to increment index positions by making gc.next() calls.
                 continue;
@@ -852,8 +853,20 @@ class TSpanShadowNode extends TextShadowNode {
             } else {
                 glyph = bag.getOrCreateAndCache(currentChar, current);
             }
-            glyph.transform(mid);
-            path.addPath(glyph);
+            RectF bounds = new RectF();
+            glyph.computeBounds(bounds, true);
+            float width = bounds.width();
+            if (width == 0) { // Render unicode emoji
+                mid.getValues(midPointMatrixData);
+                double midX = midPointMatrixData[MTRANS_X];
+                double midY = midPointMatrixData[MTRANS_Y];
+                canvas.rotate((float) r, (float)midX, (float)midY);
+                canvas.drawText(current, (float)midX, (float)midY, paint);
+                canvas.rotate((float) -r, (float)midX, (float)midY);
+            } else {
+                glyph.transform(mid);
+                path.addPath(glyph);
+            }
         }
 
         return path;
@@ -929,8 +942,8 @@ class TSpanShadowNode extends TextShadowNode {
         paint.setTextAlign(Paint.Align.LEFT);
 
         // Do these have any effect for anyone? Not for me (@msand) at least.
-        paint.setUnderlineText(underlineText);
-        paint.setStrikeThruText(strikeThruText);
+        // paint.setUnderlineText(underlineText);
+        // paint.setStrikeThruText(strikeThruText);
     }
 
     private void setupTextPath() {
diff --git a/ios/Text/RNSVGTSpan.m b/ios/Text/RNSVGTSpan.m
index e55862ba..decd8d52 100644
--- a/ios/Text/RNSVGTSpan.m
+++ b/ios/Text/RNSVGTSpan.m
@@ -82,7 +82,7 @@ static double RNSVGTSpan_radToDeg = 180 / M_PI;
 
     [self pushGlyphContext];
 
-    CGMutablePathRef path = [self getLinePath:text];
+    CGMutablePathRef path = [self getLinePath:text context:context];
 
     _cache = CGPathRetain(CFAutorelease(CGPathCreateCopy(path)));
 
@@ -91,7 +91,7 @@ static double RNSVGTSpan_radToDeg = 180 / M_PI;
     return (CGPathRef)CFAutorelease(path);
 }
 
-- (CGMutablePathRef)getLinePath:(NSString *)str
+- (CGMutablePathRef)getLinePath:(NSString *)str context:(CGContextRef)context
 {
     // Create a dictionary for this font
     CTFontRef fontRef = [self getFontFromContext];
@@ -720,6 +720,10 @@ static double RNSVGTSpan_radToDeg = 180 / M_PI;
             double dy = [gc nextDeltaY];
             double r = [[gc nextRotation] doubleValue] / RNSVGTSpan_radToDeg;
 
+            if (isWordSeparator) {
+                continue;
+            }
+
             CFIndex endIndex = g + 1 == runGlyphCount ? currIndex : indices[g + 1];
             while (++currIndex < endIndex) {
                 // Skip rendering other grapheme clusters of ligatures (already rendered),
@@ -805,8 +809,32 @@ static double RNSVGTSpan_radToDeg = 180 / M_PI;
                 transform = CGAffineTransformConcat(CGAffineTransformMakeRotation(r), transform);
             }
 
-            transform = CGAffineTransformScale(transform, 1.0, -1.0);
-            CGPathAddPath(path, &transform, glyphPath);
+            CGRect box = CGPathGetBoundingBox(glyphPath);
+            CGFloat width = box.size.width;
+
+            if (width == 0) { // Render unicode emoji
+                UILabel *label = [[UILabel alloc] init];
+                CFIndex startIndex = indices[g];
+                NSString* currChars = [str substringWithRange:NSMakeRange(startIndex, MAX(1, endIndex - startIndex))];
+                label.text = currChars;
+                label.opaque = NO;
+                label.backgroundColor = UIColor.clearColor;
+                CGSize measuredSize = [currChars sizeWithAttributes:
+                                       @{NSFontAttributeName: [UIFont systemFontOfSize:17.0f]}];
+                label.frame = CGRectMake(0, 0, ceilf(measuredSize.width), ceilf(measuredSize.height));
+
+                CGFloat fontScale = 34;
+                CGContextConcatCTM(context, transform);
+                CGContextScaleCTM(context, fontSize / fontScale, fontSize / fontScale);
+                CGContextTranslateCTM(context, 0, -measuredSize.height);
+                [label.layer renderInContext:context];
+                CGContextTranslateCTM(context, 0, measuredSize.height);
+                CGContextScaleCTM(context, fontScale / fontSize, fontScale / fontSize);
+                CGContextConcatCTM(context, CGAffineTransformInvert(transform));
+            } else {
+                transform = CGAffineTransformScale(transform, 1.0, -1.0);
+                CGPathAddPath(path, &transform, glyphPath);
+            }
             CGPathRelease(glyphPath);
         }
     }