Add support for CSS4 alpha channels in hex notation

Author: raxbg

lib/Sabberworm/CSS/Parser.php

@@ -512,8 +512,15 @@ private function parseColorValue() {
 			$sValue = $this->parseIdentifier(false);
 			if ($this->strlen($sValue) === 3) {
 				$sValue = $sValue[0] . $sValue[0] . $sValue[1] . $sValue[1] . $sValue[2] . $sValue[2];
+			} else if ($this->strlen($sValue) === 4) {
+				$sValue = $sValue[0] . $sValue[0] . $sValue[1] . $sValue[1] . $sValue[2] . $sValue[2] . $sValue[3] . $sValue[3];
+			}
+
+			if ($this->strlen($sValue) === 8) {
+				$aColor = array('r' => new Size(intval($sValue[0] . $sValue[1], 16), null, true, $this->iLineNo), 'g' => new Size(intval($sValue[2] . $sValue[3], 16), null, true, $this->iLineNo), 'b' => new Size(intval($sValue[4] . $sValue[5], 16), null, true, $this->iLineNo), 'a' => new Size(round($this->mapRange(intval($sValue[6] . $sValue[7], 16), 0, 255, 0, 1), 2), null, true, $this->iLineNo));
+			} else {
+				$aColor = array('r' => new Size(intval($sValue[0] . $sValue[1], 16), null, true, $this->iLineNo), 'g' => new Size(intval($sValue[2] . $sValue[3], 16), null, true, $this->iLineNo), 'b' => new Size(intval($sValue[4] . $sValue[5], 16), null, true, $this->iLineNo));
 			}
-			$aColor = array('r' => new Size(intval($sValue[0] . $sValue[1], 16), null, true, $this->iLineNo), 'g' => new Size(intval($sValue[2] . $sValue[3], 16), null, true, $this->iLineNo), 'b' => new Size(intval($sValue[4] . $sValue[5], 16), null, true, $this->iLineNo));
 		} else {
 			$sColorMode = $this->parseIdentifier(false);
 			$this->consumeWhiteSpace();
@@ -800,4 +807,13 @@ private function strpos($sString, $sNeedle, $iOffset) {
 		}
 	}
 
+	private function mapRange($fVal, $fFromMin, $fFromMax, $fToMin, $fToMax) {
+		$fFromRange = $fFromMax - $fFromMin;
+		$fToRange = $fToMax - $fToMin;
+		$fMultiplier = $fToRange / $fFromRange;
+		$fNewVal = $fVal - $fFromMin;
+		$fNewVal *= $fMultiplier;
+		return $fNewVal + $fToMin;
+	}
+
 }

tests/Sabberworm/CSS/ParserTest.php

@@ -387,6 +387,13 @@ function testUrlInFile() {
 		$this->assertSame($sExpected, $oDoc->render());
 	}
 
+	function testHexAlphaInFile() {
+		$oDoc = $this->parsedStructureForFile('hex-alpha', Settings::create()->withMultibyteSupport(true));
+		$sExpected = 'div {background: rgba(17,34,51,.27);}
+div {background: rgba(17,34,51,.27);}';
+		$this->assertSame($sExpected, $oDoc->render());
+	}
+
 	function testCalcInFile() {
 		$oDoc = $this->parsedStructureForFile('calc', Settings::create()->withMultibyteSupport(true));
 		$sExpected = 'div {width: calc(100% / 4);}

tests/files/hex-alpha.css

@@ -0,0 +1,2 @@
+div { background: #1234; }
+div { background: #11223344; }