From f9f1a0aa07e43fd0ea0ca211f04bc28d6f71ba44 Mon Sep 17 00:00:00 2001
From: Brice Dutheil <brice.dutheil@gmail.com>
Date: Sat, 21 Sep 2024 00:31:22 +0200
Subject: [PATCH] IJPL-155932 SVG Image support via ImageReaderSpi (detect SVG)

closes #2850

GitOrigin-RevId: 1674cb6711fa8e2744c09dcdd58963051d331f3c
---
 images/intellij.platform.images.iml           |   1 +
 .../services/javax.imageio.spi.ImageReaderSpi |   3 +-
 .../images/util/imageio/svg/SvgImageReader.kt | 144 +++++++++++++++
 .../util/imageio/svg/SvgImageReaderSpi.kt     | 143 +++++++++++++++
 .../util/imageio/svg/SvgImageReaderSpiTest.kt | 170 ++++++++++++++++++
 5 files changed, 460 insertions(+), 1 deletion(-)
 create mode 100644 images/src/org/intellij/images/util/imageio/svg/SvgImageReader.kt
 create mode 100644 images/src/org/intellij/images/util/imageio/svg/SvgImageReaderSpi.kt
 create mode 100644 images/test/org/intellij/images/util/imageio/svg/SvgImageReaderSpiTest.kt

diff --git a/images/intellij.platform.images.iml b/images/intellij.platform.images.iml
index 345b5be762d6..e59d92929370 100644
--- a/images/intellij.platform.images.iml
+++ b/images/intellij.platform.images.iml
@@ -42,5 +42,6 @@
     <orderEntry type="library" name="kotlinx-serialization-json" level="project" />
     <orderEntry type="module" module-name="intellij.xml.frontback" />
     <orderEntry type="module" module-name="intellij.platform.ui.jcef" />
+    <orderEntry type="library" name="jsvg" level="project" />
   </component>
 </module>
\ No newline at end of file
diff --git a/images/resources/META-INF/services/javax.imageio.spi.ImageReaderSpi b/images/resources/META-INF/services/javax.imageio.spi.ImageReaderSpi
index c22125678d82..52a4d9483612 100644
--- a/images/resources/META-INF/services/javax.imageio.spi.ImageReaderSpi
+++ b/images/resources/META-INF/services/javax.imageio.spi.ImageReaderSpi
@@ -1 +1,2 @@
-org.intellij.images.util.imageio.CommonsImagingImageReaderSpi
\ No newline at end of file
+org.intellij.images.util.imageio.CommonsImagingImageReaderSpi
+org.intellij.images.util.imageio.svg.SvgImageReaderSpi
\ No newline at end of file
diff --git a/images/src/org/intellij/images/util/imageio/svg/SvgImageReader.kt b/images/src/org/intellij/images/util/imageio/svg/SvgImageReader.kt
new file mode 100644
index 000000000000..ade4111a071a
--- /dev/null
+++ b/images/src/org/intellij/images/util/imageio/svg/SvgImageReader.kt
@@ -0,0 +1,144 @@
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package org.intellij.images.util.imageio.svg
+
+import com.github.weisj.jsvg.attributes.font.SVGFont
+import com.github.weisj.jsvg.geometry.size.Length
+import com.github.weisj.jsvg.nodes.SVG
+import com.intellij.ui.paint.PaintUtil
+import com.intellij.ui.scale.ScaleContext
+import com.intellij.ui.svg.createJSvgDocument
+import com.intellij.util.ui.ImageUtil
+import java.awt.image.BufferedImage
+import java.io.IOException
+import java.io.InputStream
+import javax.imageio.ImageReadParam
+import javax.imageio.ImageReader
+import javax.imageio.ImageTypeSpecifier
+import javax.imageio.stream.ImageInputStream
+import kotlin.math.max
+
+class SvgImageReader(svgImageReaderSpi: SvgImageReaderSpi) : ImageReader(svgImageReaderSpi) {
+  private var height: Length? = null
+  private var width: Length? = null
+  private var jSvgDocument: SVG? = null
+  override fun setInput(input: Any?, seekForwardOnly: Boolean, ignoreMetadata: Boolean) {
+    super.setInput(input, seekForwardOnly, ignoreMetadata)
+    reset()
+  }
+
+  override fun getWidth(imageIndex: Int): Int {
+    loadInfoIfNeeded()
+    return width?.raw()?.toInt() ?: throw IOException("SVG document not loaded")
+  }
+
+  override fun getHeight(imageIndex: Int): Int {
+    loadInfoIfNeeded()
+    return height?.raw()?.toInt() ?: throw IOException("SVG document not loaded")
+  }
+
+  @Throws(IOException::class)
+  private fun loadInfoIfNeeded() {
+    val input = input
+    if (jSvgDocument == null && input is ImageInputStream) {
+
+      try {
+        // Not using ByteArray to avoid potential humongous allocation
+        ImageInputStreamAdapter(input).buffered().use {
+          jSvgDocument = createJSvgDocument(it).also { svg ->
+            width = svg.width
+            height = svg.height
+          }
+        }
+      } catch (e: IOException) {
+        // could not read the SVG document
+      }
+    }
+  }
+
+  @Throws(IOException::class)
+  override fun read(imageIndex: Int, param: ImageReadParam?): BufferedImage {
+    loadInfoIfNeeded()
+    jSvgDocument ?: throw IOException("SVG document not loaded")
+
+    val sourceRenderSize = param?.sourceRenderSize
+
+    val width =  sourceRenderSize?.width?.toDouble() ?: width!!.raw().toDouble()
+    val height = sourceRenderSize?.height?.toDouble() ?: height!!.raw().toDouble()
+
+    // how to have an hidpi aware image?
+    val bi = ImageUtil.createImage(
+      ScaleContext.create(),
+      width,
+      height,
+      BufferedImage.TYPE_INT_ARGB,
+      PaintUtil.RoundingMode.ROUND
+    )
+    val g = bi.createGraphics()
+
+    ImageUtil.applyQualityRenderingHints(g)
+
+    jSvgDocument?.renderWithSize(
+      width.toFloat(),
+      height.toFloat(),
+      SVGFont.defaultFontSize(),
+      g,
+    )
+    return bi
+  }
+
+  override fun reset() {
+    jSvgDocument = null
+    height = null
+    width = null
+  }
+
+  override fun dispose() {
+    reset()
+  }
+
+  override fun getNumImages(allowSearch: Boolean): Int {
+    return if (jSvgDocument != null) 1 else 0
+  }
+
+  override fun getImageTypes(imageIndex: Int): Iterator<ImageTypeSpecifier> {
+    return listOf<ImageTypeSpecifier>(ImageTypeSpecifier.createFromBufferedImageType(BufferedImage.TYPE_INT_ARGB)).iterator()
+  }
+
+  override fun getStreamMetadata() = null
+
+  override fun getImageMetadata(imageIndex: Int) = null
+
+}
+
+private class ImageInputStreamAdapter(private val imageInputStream: ImageInputStream) : InputStream() {
+  private var closed = false
+
+  @Throws(IOException::class)
+  override fun close() {
+    closed = true
+  }
+
+  @Throws(IOException::class)
+  override fun read(): Int {
+    if(closed) throw IOException("stream closed")
+    return imageInputStream.read()
+  }
+
+  @Throws(IOException::class)
+  override fun read(b: ByteArray, off: Int, len: Int): Int {
+    if(closed) throw IOException("stream closed")
+    if (len <= 0) {
+      return 0
+    }
+    return imageInputStream.read(b, off, max(len.toLong(), 0).toInt())
+  }
+
+  @Throws(IOException::class)
+  override fun skip(n: Long): Long {
+    if(closed) throw IOException("stream closed")
+    if (n <= 0) {
+      return 0
+    }
+    return imageInputStream.skipBytes(n)
+  }
+}
\ No newline at end of file
diff --git a/images/src/org/intellij/images/util/imageio/svg/SvgImageReaderSpi.kt b/images/src/org/intellij/images/util/imageio/svg/SvgImageReaderSpi.kt
new file mode 100644
index 000000000000..7d2d5f6164c2
--- /dev/null
+++ b/images/src/org/intellij/images/util/imageio/svg/SvgImageReaderSpi.kt
@@ -0,0 +1,143 @@
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package org.intellij.images.util.imageio.svg
+
+import java.io.EOFException
+import java.util.*
+import javax.imageio.ImageReader
+import javax.imageio.spi.ImageReaderSpi
+import javax.imageio.stream.ImageInputStream
+import kotlin.experimental.and
+
+/**
+ * ImageReaderSpi for SVG images.
+ *
+ * @author Brice Dutheil
+ */
+class SvgImageReaderSpi : ImageReaderSpi() {
+  init {
+    vendorName = "weisj/jsvg & JetBrains"
+    suffixes = arrayOf("svg")
+    MIMETypes = arrayOf("image/svg+xml")
+    names = arrayOf("SVG Image Reader")
+    pluginClassName = SvgImageReaderSpi::class.java.name
+    inputTypes = arrayOf<Class<*>>(ImageInputStream::class.java)
+  }
+
+  override fun getDescription(locale: Locale?) = "SVG Image Reader"
+
+  override fun canDecodeInput(source: Any?): Boolean {
+    if (source !is ImageInputStream) return false
+    return canDecode(source)
+  }
+
+  private fun canDecode(imageInputStream: ImageInputStream): Boolean {
+    // NOTE: This test is quite quick as it does not involve any parsing,
+    // however, it may not recognize all kinds of SVG documents.
+
+    try {
+      // We need to read the first few bytes to determine if this is an SVG file,
+      // then reset the stream at the marked position
+      imageInputStream.mark()
+
+      // SVG file can starts with an XML declaration, then possibly followed by comments, whitespaces
+      // \w.*(<?xml version="1.0" encoding="UTF-8" ?>)?
+      // (\w|(<!--.*-->))*
+
+      // Then either the doctype gives the hint possibly surrounded by comments and/or whitespaces
+      // <!DOCTYPE svg ...
+      // (\w|(<!--.*-->))*
+
+      // Or the root tag is svg, possibly preceding comments and/or whitespaces
+      // <svg ...
+
+      // Handles first whitespaces if any
+      val lastReadByte = imageInputStream.readFirstAfterWhitespaces()
+
+      // The next byte should be '<' (comments, doctype XML declaration or the root tag)
+      if (lastReadByte != '<'.code) {
+        return false
+      }
+
+      val window = ByteArray(4)
+      while (true) {
+        imageInputStream.readFully(window)
+
+        when {
+          // `<?` Handles the XML declaration
+          window.startsWith('?') -> imageInputStream.skipUntil('?', '>')
+          //buffer[0] == '?'.code.toByte() -> imageInputStream.skipUntil('?', '>')
+
+          // `<!--` Handles a comment
+          window.startsWith('!', '-', '-') -> imageInputStream.skipUntil('-', '-', '>')
+
+          // `<!DOCTYPE` Handles the DOCTYPE declaration
+          window.startsWith('!', 'D', 'O', 'C') && imageInputStream.readNextEquals(charArrayOf('T', 'Y', 'P', 'E')) -> {
+            val lastReadChar = imageInputStream.readFirstAfterWhitespaces()
+            return lastReadChar == 's'.code && imageInputStream.readNextEquals(charArrayOf('v', 'g'))
+          }
+
+          // `<svg` Handles the root tag
+          window.startsWith('s', 'v', 'g') && (Char(window[3].toUShort()).isWhitespace() || window[3] == ':'.code.toByte()) -> {
+            return true
+          }
+
+          // not an SVG file or not handled
+          else -> return false
+        }
+
+        //while ((imageInputStream.readByte() and 0xFF.toByte()).toInt().toChar() != '<') {
+        //  // Skip over, until next begin tag or EOF
+        //}
+        // Skip over, until next begin tag or EOF
+        imageInputStream.skipUntil('<')
+      }
+    } catch (ignore: EOFException) {
+      // Possible for small files...
+      ignore.printStackTrace()
+      return false
+    } finally {
+      imageInputStream.reset()
+    }
+  }
+
+  private fun ImageInputStream.readFirstAfterWhitespaces(): Int {
+    var lastReadByte: Int
+    while ((read().also { lastReadByte = it }).toChar().isWhitespace()) {
+      // skip whitespaces if any
+    }
+    return lastReadByte
+  }
+
+  private fun ImageInputStream.skipUntil(vararg expected: Char) {
+    while (!readNextEquals(expected)) {
+      // skip until expected chars or EOF
+    }
+  }
+
+  private fun ImageInputStream.readNextEquals(expected: CharArray): Boolean {
+    // first char is read with readByte()
+    require(expected.isNotEmpty())
+    val first = (readByte() and 0xFF.toByte()).toInt().toChar()
+    if (first != expected[0]) return false
+
+    // next can be read with read()
+    expected.forEachIndexed { index, it ->
+      if (index == 0) return@forEachIndexed
+      val read = read()
+      if (read != it.code) return false
+    }
+    return true
+  }
+
+  private fun ByteArray.startsWith(vararg expected: Char): Boolean {
+    expected.forEachIndexed { index, c ->
+      if (this[index] != c.code.toByte()) return false
+    }
+    return true
+  }
+
+  override fun createReaderInstance(extension: Any?): ImageReader {
+    return SvgImageReader(this)
+  }
+}
+
diff --git a/images/test/org/intellij/images/util/imageio/svg/SvgImageReaderSpiTest.kt b/images/test/org/intellij/images/util/imageio/svg/SvgImageReaderSpiTest.kt
new file mode 100644
index 000000000000..9e615f7b097b
--- /dev/null
+++ b/images/test/org/intellij/images/util/imageio/svg/SvgImageReaderSpiTest.kt
@@ -0,0 +1,170 @@
+package org.intellij.images.util.imageio.svg
+
+import org.junit.jupiter.api.Assertions.*
+import org.junit.jupiter.api.Test
+import javax.imageio.stream.MemoryCacheImageInputStream
+
+class SvgImageReaderSpiTest {
+  @Test
+  fun `can read svg with xml header`() {
+    val svg = """
+    <?xml version="1.0" encoding="UTF-8" ?>
+    <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"> </svg>
+    """.trimIndent()
+
+    MemoryCacheImageInputStream(svg.byteInputStream()).use { stream ->
+      assertTrue(SvgImageReaderSpi().canDecodeInput(stream))
+    }
+  }
+
+  @Test
+  fun `cannot read svg with broken xml header`() {
+    val svg = """
+    <?xml version="1.0" encoding="UTF-8" // broken
+    <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"> </svg>
+    """.trimIndent()
+
+    MemoryCacheImageInputStream(svg.byteInputStream()).use { stream ->
+      assertFalse(SvgImageReaderSpi().canDecodeInput(stream))
+    }
+  }
+
+  @Test
+  fun `cannot read svg with broken truncated file`() {
+    val svg = """
+    <?xml version="1.0" encoding="UTF-8" // broken
+    """.trimIndent()
+
+    MemoryCacheImageInputStream(svg.byteInputStream()).use { stream ->
+      assertFalse(SvgImageReaderSpi().canDecodeInput(stream))
+    }
+  }
+
+  @Test
+  fun `can read svg with whitespace before xml header`() {
+    val svg = """
+                                                 
+                                                 
+    <?xml version="1.0" encoding="UTF-8" ?>
+    <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"> </svg>
+    """.trimIndent()
+
+    MemoryCacheImageInputStream(svg.byteInputStream()).use { stream ->
+      assertTrue(SvgImageReaderSpi().canDecodeInput(stream))
+    }
+  }
+  @Test
+  fun `can read svg with comment after xml header`() {
+    val svg = """
+    <?xml version="1.0" encoding="UTF-8" ?>
+    <!-- comment -->
+    <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"> </svg>
+    """.trimIndent()
+
+    MemoryCacheImageInputStream(svg.byteInputStream()).use { stream ->
+      assertTrue(SvgImageReaderSpi().canDecodeInput(stream))
+    }
+  }
+
+  @Test
+  fun `can read svg with DOCTYPE after xml header`() {
+    val svg = """
+    <?xml version="1.0" standalone="no"?>
+    <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 20010904//EN"
+      "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+    <!-- comment -->
+    <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"> </svg>
+    """.trimIndent()
+
+    MemoryCacheImageInputStream(svg.byteInputStream()).use { stream ->
+      assertTrue(SvgImageReaderSpi().canDecodeInput(stream))
+    }
+  }
+
+  @Test
+  fun `can read svg with comment before DOCTYPE`() {
+    val svg = """
+    <!-- comment -->
+    <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 20010904//EN"
+      "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+    <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"> </svg>
+    """.trimIndent()
+
+    MemoryCacheImageInputStream(svg.byteInputStream()).use { stream ->
+      assertTrue(SvgImageReaderSpi().canDecodeInput(stream))
+    }
+  }
+
+  @Test
+  fun `can read svg starting with DOCTYPE`() {
+    val svg = """
+    <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 20010904//EN"
+      "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+    <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"> </svg>
+    """.trimIndent()
+
+    MemoryCacheImageInputStream(svg.byteInputStream()).use { stream ->
+      assertTrue(SvgImageReaderSpi().canDecodeInput(stream))
+    }
+  }
+
+  @Test
+  fun `can read svg starting with DOCTYPE having spaces`() {
+    val svg = """
+    <!DOCTYPE        svg   PUBLIC "-//W3C//DTD SVG 20010904//EN"
+      "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
+    <!-- comment -->
+    <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"> </svg>
+    """.trimIndent()
+
+    MemoryCacheImageInputStream(svg.byteInputStream()).use { stream ->
+      assertTrue(SvgImageReaderSpi().canDecodeInput(stream))
+    }
+  }
+
+  @Test
+  fun `can read svg starting with SVG root tag`() {
+    val svg = """
+    <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"> </svg>
+    """.trimIndent()
+
+    MemoryCacheImageInputStream(svg.byteInputStream()).use { stream ->
+      assertTrue(SvgImageReaderSpi().canDecodeInput(stream))
+    }
+  }
+
+  @Test
+  fun `can read svg starting with comment then SVG root tag`() {
+    val svg = """
+    <!-- comment -->
+    <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"> </svg>
+    """.trimIndent()
+
+    MemoryCacheImageInputStream(svg.byteInputStream()).use { stream ->
+      assertTrue(SvgImageReaderSpi().canDecodeInput(stream))
+    }
+  }
+
+  @Test
+  fun `cannot read svg with broken comment`() {
+    val svg = """
+    <!-- comment -- // broken
+    <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"> </svg>
+    """.trimIndent()
+
+    MemoryCacheImageInputStream(svg.byteInputStream()).use { stream ->
+      assertFalse(SvgImageReaderSpi().canDecodeInput(stream))
+    }
+  }
+  @Test
+  fun `cannot read svg with broken root tag`() {
+    val svg = """
+    <!-- comment -->
+    <sv xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"> </svg>
+    """.trimIndent()
+
+    MemoryCacheImageInputStream(svg.byteInputStream()).use { stream ->
+      assertFalse(SvgImageReaderSpi().canDecodeInput(stream))
+    }
+  }
+}
\ No newline at end of file