Fix position of cursor on empty line (#208)

JetBrains · Nov 16, 2022 · 02b65f7 · 02b65f7
1 parent 8644417
commit 02b65f7
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Showing 3 changed files with 21 additions and 2 deletions.
diff --git a/compose/ui/ui-text/src/skikoMain/kotlin/androidx/compose/ui/text/SkiaParagraph.skiko.kt b/compose/ui/ui-text/src/skikoMain/kotlin/androidx/compose/ui/text/SkiaParagraph.skiko.kt
@@ -212,11 +212,22 @@ internal class SkiaParagraph(
     // workaround for https://bugs.chromium.org/p/skia/issues/detail?id=11321 :(
     private val lineMetrics: Array<LineMetrics>
         get() = if (text == "") {
-            val height = layouter.defaultHeight.toDouble()
+            val metrics = layouter.defaultFont.metrics
+            val ascent = -metrics.ascent.toDouble()
+            val descent = metrics.descent.toDouble()
+            val baseline = para.alphabeticBaseline.toDouble()
+            val height = with(layouter.paragraphStyle.strutStyle) {
+                if (isEnabled && !isHeightForced && isHeightOverridden && fontSize > 0.0f) {
+                    (height * fontSize).toDouble()
+                } else {
+                    ascent + descent
+                }
+            }
+
             arrayOf(
                 LineMetrics(
                     0, 0, 0, 0, true,
-                    height, 0.0, height, height, 0.0, 0.0, height, 0
+                    ascent, descent, ascent, height, 0.0, 0.0, baseline, 0
                 )
             )
         } else {
@@ -291,6 +302,7 @@ internal class SkiaParagraph(
         }
     }
 
+    // TODO(b/229518449): Implement an alternative to paint function that takes a brush.
     override fun paint(
         canvas: Canvas,
         color: Color,

diff --git a/...ui-text/src/skikoMain/kotlin/androidx/compose/ui/text/platform/ParagraphLayouter.skiko.kt b/...ui-text/src/skikoMain/kotlin/androidx/compose/ui/text/platform/ParagraphLayouter.skiko.kt
@@ -71,6 +71,8 @@ class ParagraphLayouter(
     private var width: Float = -1f
 
     val defaultHeight get() = builder.defaultHeight
+    val defaultFont get() = builder.defaultFont
+    val paragraphStyle get() = builder.paragraphStyle
 
     fun layoutParagraph(
         width: Float = this.width,

diff --git a/.../ui/ui-text/src/skikoMain/kotlin/androidx/compose/ui/text/platform/SkiaParagraph.skiko.kt b/.../ui/ui-text/src/skikoMain/kotlin/androidx/compose/ui/text/platform/SkiaParagraph.skiko.kt
@@ -31,6 +31,7 @@ import org.jetbrains.skia.paragraph.Shadow as SkShadow
 import org.jetbrains.skia.paragraph.StrutStyle
 import org.jetbrains.skia.paragraph.TextBox
 import org.jetbrains.skia.paragraph.TextStyle as SkTextStyle
+import org.jetbrains.skia.paragraph.Rect as SkRect
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.Shadow
 import androidx.compose.ui.graphics.isSpecified
@@ -289,6 +290,8 @@ internal class ParagraphBuilder(
 ) {
     private lateinit var initialStyle: SpanStyle
     private lateinit var defaultStyle: ComputedStyle
+    internal lateinit var paragraphStyle: ParagraphStyle
+        private set
     private lateinit var ops: List<Op>
 
     /**
@@ -312,6 +315,7 @@ internal class ParagraphBuilder(
 
         var pos = 0
         val ps = textStyleToParagraphStyle(textStyle, defaultStyle)
+        paragraphStyle = ps
 
         if (maxLines != Int.MAX_VALUE) {
             ps.maxLinesCount = maxLines
@@ -524,6 +528,7 @@ internal class ParagraphBuilder(
                 else -> error("Unexpected size in textStyleToParagraphStyle")
             }
             strutStyle.height = lineHeight / fontSize
+            strutStyle.fontSize = fontSize
             pStyle.strutStyle = strutStyle
         }
         pStyle.direction = textDirection.toSkDirection()