Merge pull request #1497 from kounoike/pr-textavatar

Add support auto-generated icon for default avatar.

src/main/scala/gitbucket/core/controller/AccountController.scala

@@ -150,17 +150,20 @@ trait AccountControllerBase extends AccountManagementControllerBase {
 
   get("/:userName/_avatar"){
     val userName = params("userName")
-    (for {
-      account <- getAccountByUserName(userName)
-      image <- account.image
-    } yield (account, image)) match {
-      case Some((account, image)) =>
-        response.setDateHeader("Last-Modified", account.updatedDate.getTime)
+    getAccountByUserName(userName).map{ account =>
+      response.setDateHeader("Last-Modified", account.updatedDate.getTime)
+      account.image.map{ image =>
         RawData(FileUtil.getMimeType(image), new java.io.File(getUserUploadDir(userName), image))
-      case None =>
+      }.getOrElse{
         contentType = "image/png"
-        response.setDateHeader("Last-Modified", (new Date(0)).getTime)
-        Thread.currentThread.getContextClassLoader.getResourceAsStream("noimage.png")
+        (if (account.isGroupAccount) {
+          TextAvatarUtil.textGroupAvatar(account.fullName)
+        } else {
+          TextAvatarUtil.textAvatar(account.fullName)
+        }).getOrElse(Thread.currentThread.getContextClassLoader.getResourceAsStream("noimage.png"))
+      }
+    }.getOrElse{
+      NotFound()
     }
   }
 

src/main/scala/gitbucket/core/util/TextAvatarUtil.scala

@@ -0,0 +1,127 @@
+package gitbucket.core.util
+
+import java.io.ByteArrayOutputStream
+import java.awt.image.BufferedImage
+import javax.imageio.ImageIO
+import java.awt.{Color, Font, Graphics2D, RenderingHints}
+import java.awt.font.{FontRenderContext, TextLayout}
+import java.awt.geom.AffineTransform
+
+
+object TextAvatarUtil {
+  private val iconSize = 200
+  private val fontSize = 180
+  private val roundSize = 60
+  private val shadowSize = 20
+  private val bgSaturation = 0.68f
+  private val bgBlightness = 0.73f
+  private val shadowBlightness = 0.23f
+  private val font = new Font(Font.SANS_SERIF, Font.PLAIN, fontSize)
+  private val transparent = new Color(0, 0, 0, 0)
+
+  // https://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef
+  private def relativeLuminance(c: Color): Double = {
+    val rgb = Seq(c.getRed, c.getGreen, c.getBlue).map{_/255.0}.map{x => if (x <= 0.03928) x / 12.92 else math.pow((x + 0.055) / 1.055, 2.4)}
+    0.2126 * rgb(0) + 0.7152 * rgb(1) + 0.0722 * rgb(2)
+  }
+
+  // https://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef
+  private def contrastRatio(c1: Color, c2: Color): Double = {
+    val l1 = relativeLuminance(c1)
+    val l2 = relativeLuminance(c2)
+    if (l1 > l2) (l1 + 0.05) / (l2 + 0.05) else (l2 + 0.05) / (l1 + 0.05)
+  }
+
+  private def goodContrastColor(base: Color, c1: Color, c2: Color): Color = {
+    if (contrastRatio(base, c1) > contrastRatio(base, c2)) c1 else c2
+  }
+
+  private def strToHue(text: String): Float = {
+    Integer.parseInt(StringUtil.md5(text).substring(0, 2), 16) / 256f
+  }
+
+  private def getCenterToDraw(drawText: String, font: Font, w: Int, h: Int): (Int, Int) = {
+    val context = new FontRenderContext(new AffineTransform(), true, true)
+    val txt = new TextLayout(drawText, font, context)
+
+    val bounds = txt.getBounds
+
+    val x: Int = ((w - bounds.getWidth) / 2 - bounds.getX).toInt
+    val y: Int = ((h - bounds.getHeight) / 2 - bounds.getY).toInt
+    (x, y)
+  }
+
+  private def textImage(drawText: String, bgColor: Color, fgColor: Color): Array[Byte] = {
+    val canvas = new BufferedImage(iconSize, iconSize, BufferedImage.TYPE_INT_ARGB)
+    val g = canvas.createGraphics()
+    val center = getCenterToDraw(drawText, font, iconSize, iconSize)
+
+    g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON)
+
+    g.setColor(transparent)
+    g.fillRect(0, 0, iconSize, iconSize)
+
+    g.setColor(bgColor)
+    g.fillRoundRect(0, 0, iconSize, iconSize, roundSize, roundSize)
+
+    g.setColor(fgColor)
+    g.setFont(font)
+    g.drawString(drawText, center._1, center._2)
+
+    g.dispose()
+
+    val stream = new ByteArrayOutputStream
+    ImageIO.write(canvas, "png", stream)
+    stream.toByteArray
+  }
+
+  def textAvatar(nameText: String): Option[Array[Byte]] = {
+    val drawText = nameText.substring(0, 1)
+
+    val bgHue = strToHue(nameText)
+    val bgColor = Color.getHSBColor(bgHue, bgSaturation, bgBlightness)
+    val fgColor = goodContrastColor(bgColor, Color.BLACK, Color.WHITE)
+
+    val font = new Font(Font.SANS_SERIF, Font.PLAIN, fontSize)
+    if (font.canDisplayUpTo(drawText) == -1) Some(textImage(drawText, bgColor, fgColor)) else None
+  }
+
+  private def textGroupImage(drawText: String, bgColor: Color, fgColor: Color, shadowColor: Color): Array[Byte] = {
+    val canvas = new BufferedImage(iconSize, iconSize, BufferedImage.TYPE_INT_ARGB)
+    val g = canvas.createGraphics()
+    val center = getCenterToDraw(drawText, font, iconSize - shadowSize, iconSize - shadowSize)
+
+    g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON)
+
+    g.setColor(transparent)
+    g.fillRect(0, 0, iconSize, iconSize)
+
+    g.setColor(shadowColor)
+    g.fillRect(shadowSize, shadowSize, iconSize, iconSize)
+
+    g.setColor(bgColor)
+    g.fillRect(0, 0, iconSize - shadowSize, iconSize - shadowSize)
+
+    g.setColor(fgColor)
+
+    g.setFont(font)
+    g.drawString(drawText, center._1, center._2)
+
+    g.dispose()
+
+    val stream = new ByteArrayOutputStream
+    ImageIO.write(canvas, "png", stream)
+    stream.toByteArray
+  }
+
+  def textGroupAvatar(nameText: String): Option[Array[Byte]] = {
+    val drawText = nameText.substring(0, 1)
+
+    val bgHue = strToHue(nameText)
+    val bgColor = Color.getHSBColor(bgHue, bgSaturation, bgBlightness)
+    val fgColor = goodContrastColor(bgColor, Color.BLACK, Color.WHITE)
+    val shadowColor = Color.getHSBColor(bgHue, bgSaturation, shadowBlightness)
+
+    if (font.canDisplayUpTo(drawText) == -1) Some(textGroupImage(drawText, bgColor, fgColor, shadowColor)) else None
+  }
+}