Improve use handling

src/Svg/Document.php

@@ -23,6 +23,7 @@
 use Svg\Tag\Polyline;
 use Svg\Tag\Rect;
 use Svg\Tag\Stop;
+use Svg\Tag\Symbol;
 use Svg\Tag\Text;
 use Svg\Tag\StyleTag;
 use Svg\Tag\UseTag;
@@ -322,10 +323,14 @@ private function _tagStart($parser, $name, $attributes)
                 break;
 
             case 'g':
-            case 'symbol':
                 $tag = new Group($this, $name);
                 break;
 
+            case 'symbol':
+                $this->inDefs = true;
+                $tag = new Symbol($this, $name);
+                break;
+
             case 'clippath':
                 $tag = new ClipPath($this, $name);
                 break;
@@ -378,6 +383,11 @@ function _tagEnd($parser, $name)
                 $this->inDefs = false;
                 return;
 
+            case 'symbol':
+                $this->inDefs = false;
+                $tag = array_pop($this->stack);
+                break;
+
             case 'svg':
             case 'path':
             case 'rect':
@@ -393,7 +403,6 @@ function _tagEnd($parser, $name)
             case 'style':
             case 'text':
             case 'g':
-            case 'symbol':
             case 'clippath':
             case 'use':
             case 'a':

src/Svg/Tag/AbstractTag.php

@@ -189,6 +189,97 @@ protected function applyTransform($attributes)
         }
     }
 
+    /**
+     * Apply a viewBox transform to the element
+     *
+     * @param array $attributes
+     */
+    protected function applyViewbox($attributes) {
+        if (!isset($attributes["viewbox"])) {
+            return;
+        }
+
+        $surface = $this->document->getSurface();
+        $viewBox = preg_split('/[\s,]+/is', trim($attributes['viewbox']));
+        if (count($viewBox) != 4) {
+            return;
+        }
+
+        // Computing the equivalent transform of an SVG viewport
+        // https://svgwg.org/svg2-draft/coords.html#ComputingAViewportsTransform
+
+        // 1. Let vb-x, vb-y, vb-width, vb-height be the min-x, min-y, width and height values of the viewBox attribute respectively.
+        [$vbX, $vbY, $vbWidth, $vbHeight] = $viewBox;
+
+        if ($vbWidth < 0 || $vbHeight < 0) {
+            return;
+        }
+
+        // correct solution is to not render, for now scaling to 0 below
+        //if ($vbWidth == 0 || $vbHeight == 0) {
+        //}
+
+        // 2. Let e-x, e-y, e-width, e-height be the position and size of the element respectively.
+        $eX = $attributes["x"] ?? 0;
+        $eY = $attributes["y"] ?? 0;
+        $eWidth = $attributes["width"] ?? $this->document->getWidth();
+        $eHeight = $attributes["height"] ?? $this->document->getHeight();
+
+        // 3. Let align be the align value of preserveAspectRatio, or 'xMidYMid' if preserveAspectRatio is not defined.
+        $preserveAspectRatio = explode(" ", $attributes["preserveAspectRatio"] ?? "xMidYMid meet");
+        $align = $preserveAspectRatio[0];
+
+        // 4. Let meetOrSlice be the meetOrSlice value of preserveAspectRatio, or 'meet' if preserveAspectRatio is not defined or if meetOrSlice is missing from this value.
+        $meetOrSlice = $meetOrSlice ?? "meet";
+
+        // 5. Initialize scale-x to e-width/vb-width.
+        $scaleX = $vbWidth == 0 ? 0 : ($eWidth / $vbWidth);
+
+        // 6. Initialize scale-y to e-height/vb-height.
+        $scaleY = $vbHeight == 0 ? 0 : ($eHeight / $vbHeight);
+
+        // 7. If align is not 'none' and meetOrSlice is 'meet', set the larger of scale-x and scale-y to the smaller.
+        if ($align !== "none" && $meetOrSlice === "meet") {
+            $scaleX = min($scaleX, $scaleY);
+            $scaleY = min($scaleX, $scaleY);
+        }
+
+        // 8. Otherwise, if align is not 'none' and meetOrSlice is 'slice', set the smaller of scale-x and scale-y to the larger.
+        elseif ($align !== "none" && $meetOrSlice === "slice") {
+            $scaleX = max($scaleX, $scaleY);
+            $scaleY = max($scaleX, $scaleY);
+        }
+
+        // 9. Initialize translate-x to e-x - (vb-x * scale-x).
+        $translateX = $eX - ($vbX * $scaleX);
+
+        // 10. Initialize translate-y to e-y - (vb-y * scale-y)
+        $translateY = $eY - ($vbY * $scaleY);
+
+        // 11. If align contains 'xMid', add (e-width - vb-width * scale-x) / 2 to translate-x.
+        if (strpos($align, "xMid") !== false) {
+            $translateX += ($eWidth - $vbWidth * $scaleX) / 2;
+        }
+
+        // 12. If align contains 'xMax', add (e-width - vb-width * scale-x) to translate-x.
+        if (strpos($align, "xMax") !== false) {
+            $translateX += ($eWidth - $vbWidth * $scaleX);
+        }
+
+        // 13. If align contains 'yMid', add (e-height - vb-height * scale-y) / 2 to translate-y.
+        if (strpos($align, "yMid") !== false) {
+            $translateX += ($eHeight - $vbHeight * $scaleY) / 2;
+        }
+
+        // 14. If align contains 'yMax', add (e-height - vb-height * scale-y) to translate-y.
+        if (strpos($align, "yMid") !== false) {
+            $translateX += ($eHeight - $vbHeight * $scaleY);
+        }
+
+        $surface->translate($translateX, $translateY);
+        $surface->scale($scaleX, $scaleY);
+    }
+
     /**
      * Convert the given size for the context of this current tag.
      * Takes a pixel-based reference, which is usually specific to the context of the size,

src/Svg/Tag/Symbol.php

@@ -0,0 +1,34 @@
+<?php
+/**
+ * @package php-svg-lib
+ * @link    http://github.com/PhenX/php-svg-lib
+ * @author  Fabien Ménager <[email protected]>
+ * @license GNU LGPLv3+ http://www.gnu.org/copyleft/lesser.html
+ */
+
+namespace Svg\Tag;
+
+use Svg\Style;
+
+class Symbol extends AbstractTag
+{
+    protected function before($attributes)
+    {
+        $surface = $this->document->getSurface();
+
+        $surface->save();
+
+        $style = $this->makeStyle($attributes);
+
+        $this->setStyle($style);
+        $surface->setStyle($style);
+
+        $this->applyViewbox($attributes);
+        $this->applyTransform($attributes);
+    }
+
+    protected function after()
+    {
+        $this->document->getSurface()->restore();
+    }
+}

src/Svg/Tag/UseTag.php

@@ -48,10 +48,6 @@ protected function before($attributes)
         $link = $attributes["href"] ?? $attributes["xlink:href"];
         $this->reference = $document->getDef($link);
 
-        if ($this->reference) {
-            $this->reference->before($attributes);
-        }
-
         $surface = $document->getSurface();
         $surface->save();
 
@@ -63,11 +59,6 @@ protected function after() {
             return;
         }
         parent::after();
-
-        if ($this->reference) {
-            $this->reference->after();
-        }
-
         $this->getDocument()->getSurface()->restore();
     }
 
@@ -84,19 +75,22 @@ public function handle($attributes)
             return;
         }
 
+        $originalAttributes = array_merge($this->reference->attributes);
+        $originalStyle = $this->reference->getStyle();
         $mergedAttributes = $this->reference->attributes;
-        $attributesToNotMerge = ['x', 'y', 'width', 'height', 'href', 'xlink:href', 'id'];
+        $attributesToNotMerge = ['x', 'y', 'width', 'height', 'href', 'xlink:href', 'id', 'style'];
         foreach ($attributes as $attrKey => $attrVal) {
             if (!in_array($attrKey, $attributesToNotMerge) && !isset($mergedAttributes[$attrKey])) {
                 $mergedAttributes[$attrKey] = $attrVal;
             }
         }
+        $mergedAttributes['style'] = ($attributes['style'] ?? '') . ';' . ($mergedAttributes['style'] ?? '');
 
-        $this->reference->handle($mergedAttributes);
+        $this->_handle($this->reference, $mergedAttributes);
 
-        foreach ($this->reference->children as $_child) {
-            $_attributes = array_merge($_child->attributes, $mergedAttributes);
-            $_child->handle($_attributes);
+        $this->reference->attributes = $originalAttributes;
+        if ($originalStyle !== null) {
+            $this->reference->setStyle($originalStyle);
         }
     }
 
@@ -107,16 +101,32 @@ public function handleEnd()
             return;
         }
 
+        if ($this->reference) {
+            $this->_handleEnd($this->reference);
+        }
+
         parent::handleEnd();
+    }
 
-        if (!$this->reference) {
-            return;
+    private function _handle($tag, $attributes) {
+        $tag->handle($attributes);
+        foreach ($tag->children as $child) {
+            $originalAttributes = array_merge($child->attributes);
+            $originalStyle = $child->getStyle();
+            $mergedAttributes = $child->attributes;
+            $mergedAttributes['style'] = ($attributes['style'] ?? '') . ';' . ($mergedAttributes['style'] ?? '');
+            $this->_handle($child, $mergedAttributes);
+            $child->attributes = $originalAttributes;
+            if ($originalStyle !== null) {
+                $child->setStyle($originalStyle);
+            }
         }
+    }
 
-        $this->reference->handleEnd();
-
-        foreach ($this->reference->children as $_child) {
-            $_child->handleEnd();
+    private function _handleEnd($tag) {
+        foreach ($tag->children as $child) {
+            $this->_handleEnd($child);
         }
+        $tag->handleEnd();
     }
 }