Add auto-width calculation for float and inline-block elements

Plus:

 * Fix style specificity based on the origin of the stylesheet.
 * Add :focus psudo-class to stylesheet parser.
 * Fix 'content' css property being set to 'normal' for all :before/:after
   selectors before determining their specificity.
 * Add extra check to prevent Helpers::build_url() from throwing a warning
   for URIs of 1 character (eg: '#').

Closes #1158
Addresses #627, addresses #371
Partially addresses #631 and #26
Fixes #1074, fixes #1031
Partial fix for #672

... and many more

lib/res/html.css

@@ -373,10 +373,13 @@ input[type=reset],
 input[type=file],
 button {
   background: #CCC;
-  width: 8em;
   text-align: center;
 }
 
+input[type=file] {
+  width: 8em;
+}
+
 input[type=text]:before,
 input[type=button]:before,
 input[type=submit]:before,

src/Css/Style.php

@@ -781,6 +781,32 @@ function __get($prop)
         return $this->_prop_cache[$prop] = $this->_props[$prop];
     }
 
+    /**
+     * Similar to __get() without storing the result. Useful for accessing
+     * properties while loading stylesheets.
+     *
+     * @return string
+     */
+    function get_prop($prop)
+    {
+        if (!isset(self::$_defaults[$prop])) {
+            throw new Exception("'$prop' is not a valid CSS2 property.");
+        }
+
+        $method = "get_$prop";
+
+        // Fall back on defaults if property is not set
+        if (!isset($this->_props[$prop])) {
+            return self::$_defaults[$prop];
+        }
+
+        if (method_exists($this, $method)) {
+            return $this->$method();
+        }
+
+        return $this->_props[$prop];
+    }
+
     function get_font_family_raw()
     {
         return trim($this->_props["font_family"], " \t\n\r\x0B\"'");

src/Css/Stylesheet.php

@@ -612,6 +612,7 @@ private function _css_selector_to_xpath($selector, $first_pass = false)
                         case "first-letter": // TODO
 
                             // N/A
+                        case "focus":
                         case "active":
                         case "hover":
                         case "visited":
@@ -861,7 +862,7 @@ function apply_styles(FrameTree $tree)
                         continue;
                     }
 
-                    if (($src = $this->_image($style->content)) !== "none") {
+                    if (($src = $this->_image($style->get_prop('content'))) !== "none") {
                         $new_node = $node->ownerDocument->createElement("img_generated");
                         $new_node->setAttribute("src", $src);
                     } else {
@@ -896,7 +897,7 @@ function apply_styles(FrameTree $tree)
                 $id = $node->getAttribute("frame_id");
 
                 // Assign the current style to the scratch array
-                $spec = $this->_specificity($selector);
+                $spec = $this->_specificity($selector, $style->get_origin());
                 $styles[$id][$spec][] = $style;
             }
         }

src/Frame.php

@@ -770,6 +770,18 @@ public function is_block()
         return $this->_is_cache["block"] = in_array($this->get_style()->display, Style::$BLOCK_TYPES);
     }
 
+    /**
+     * @return bool
+     */
+    public function is_inline_block()
+    {
+        if (isset($this->_is_cache["inline_block"])) {
+            return $this->_is_cache["inline_block"];
+        }
+
+        return $this->_is_cache["inline_block"] = ($this->get_style()->display === 'inline-block');
+    }
+
     /**
      * @return bool
      */

src/FrameDecorator/AbstractFrameDecorator.php

@@ -805,4 +805,14 @@ final function get_min_max_width()
     {
         return $this->_reflower->get_min_max_width();
     }
+
+    /**
+     * Determine current frame width based on contents
+     *
+     * @return float
+     */
+    final function calculate_auto_width()
+    {
+        return $this->_reflower->calculate_auto_width();
+    }
 }

src/FrameReflower/AbstractFrameReflower.php

@@ -68,7 +68,8 @@ protected function _collapse_margins()
         $cb = $frame->get_containing_block();
         $style = $frame->get_style();
 
-        if (!$frame->is_in_flow()) {
+        // Margins of float/absolutely positioned/inline-block elements do not collapse.
+        if (!$frame->is_in_flow() || $frame->is_inline_block()) {
             return;
         }
 
@@ -436,7 +437,7 @@ protected function _set_content()
             $frame->increment_counters($increment);
         }
 
-        if ($style->content && !$frame->get_first_child() && $frame->get_node()->nodeName === "dompdf_generated") {
+        if ($style->content && /*!$frame->get_first_child() && */$frame->get_node()->nodeName === "dompdf_generated") {
             $content = $this->_parse_content();
             // add generated content to the font subset
             // FIXME: This is currently too late because the font subset has already been generated.
@@ -457,4 +458,14 @@ protected function _set_content()
             $frame->append_child($new_frame);
         }
     }
+
+    /**
+     * Determine current frame width based on contents
+     *
+     * @return float
+     */
+    public function calculate_auto_width()
+    {
+        return $this->_frame->get_margin_width();
+    }
 }

src/FrameReflower/Block.php

@@ -753,11 +753,12 @@ function reflow(BlockFrameDecorator $block = null)
         $style->top = $top;
         $style->bottom = $bottom;
 
+        $orig_style = $this->_frame->get_original_style();
+
         $needs_reposition = ($style->position === "absolute" && ($style->right !== "auto" || $style->bottom !== "auto"));
 
         // Absolute positioning measurement
         if ($needs_reposition) {
-            $orig_style = $this->_frame->get_original_style();
             if ($orig_style->width === "auto" && ($orig_style->left === "auto" || $orig_style->right === "auto")) {
                 $width = 0;
                 foreach ($this->_frame->get_line_boxes() as $line) {
@@ -770,6 +771,25 @@ function reflow(BlockFrameDecorator $block = null)
             $style->right = $orig_style->right;
         }
 
+        // Calculate inline-block / float auto-widths
+        if (($style->display === "inline-block" || $style->float !== 'none') && $orig_style->width === 'auto') {
+            $width = 0;
+
+            foreach ($this->_frame->get_line_boxes() as $line) {
+                $line->recalculate_width();
+
+                $width = max($line->w, $width);
+            }
+
+            if ($width === 0) {
+                foreach ($this->_frame->get_children() as $child) {
+                    $width += $child->calculate_auto_width();
+                }
+            }
+
+            $style->width = $width;
+        }
+
         $this->_text_align();
         $this->vertical_align();
 
@@ -790,4 +810,32 @@ function reflow(BlockFrameDecorator $block = null)
             }
         }
     }
+
+    /**
+     * Determine current frame width based on contents
+     *
+     * @return float
+     */
+    public function calculate_auto_width()
+    {
+        $width = 0;
+
+        foreach ($this->_frame->get_line_boxes() as $line) {
+            $line_width = 0;
+
+            foreach ($line->get_frames() as $frame) {
+                if ($frame->get_original_style()->width == 'auto') {
+                    $line_width += $frame->calculate_auto_width();
+                } else {
+                    $line_width += $frame->get_margin_width();
+                }
+            }
+
+            $width = max($line_width, $width);
+        }
+
+        $this->_frame->get_style()->width = $width;
+
+        return $this->_frame->get_margin_width();
+    }
 }

src/FrameReflower/Inline.php

@@ -73,4 +73,26 @@ function reflow(BlockFrameDecorator $block = null)
             $child->reflow($block);
         }
     }
+
+    /**
+     * Determine current frame width based on contents
+     *
+     * @return float
+     */
+    public function calculate_auto_width()
+    {
+        $width = 0;
+
+        foreach ($this->_frame->get_children() as $child) {
+            if ($child->get_original_style()->width == 'auto') {
+                $width += $child->calculate_auto_width();
+            } else {
+                $width += $child->get_margin_width();
+            }
+        }
+
+        $this->_frame->get_style()->width = $width;
+
+        return $this->_frame->get_margin_width();
+    }
 }

src/FrameReflower/Text.php

@@ -484,4 +484,14 @@ public function getFontMetrics()
     {
         return $this->fontMetrics;
     }
+
+    /**
+     * Determine current frame width based on contents
+     *
+     * @return float
+     */
+    public function calculate_auto_width()
+    {
+        return $this->_frame->recalculate_width();
+    }
 }

src/Helpers.php

@@ -72,7 +72,7 @@ public static function build_url($protocol, $host, $base_path, $url)
             //drive: followed by a relative path would be a drive specific default folder.
             //not known in php app code, treat as abs path
             //($url[1] !== ':' || ($url[2]!=='\\' && $url[2]!=='/'))
-            if ($url[0] !== '/' && (strtoupper(substr(PHP_OS, 0, 3)) !== 'WIN' || ($url[0] !== '\\' && $url[1] !== ':'))) {
+            if ($url[0] !== '/' && (strtoupper(substr(PHP_OS, 0, 3)) !== 'WIN' || (mb_strlen($url) > 1 && $url[0] !== '\\' && $url[1] !== ':'))) {
                 // For rel path and local acess we ignore the host, and run the path through realpath()
                 $ret .= realpath($base_path) . '/';
             }

src/LineBox.php

@@ -234,6 +234,22 @@ function add_frame(Frame $frame)
         $this->_frames[] = $frame;
     }
 
+    /**
+     * Recalculate LineBox width based on the contained frames total width.
+     *
+     * @return float
+     */
+    public function recalculate_width()
+    {
+        $width = 0;
+
+        foreach ($this->get_frames() as $frame) {
+            $width += $frame->calculate_auto_width();
+        }
+
+        return $this->w = $width;
+    }
+
     function __toString()
     {
         $props = array("wc", "y", "w", "h", "left", "right", "br");