Add new horizontal masonry and image height allocation

- Move image templates to content/image sub-folder

src/Content/Post/Collection/PostMedias.php

@@ -42,4 +42,16 @@ class PostMedias extends BaseCollection
 	{
 		return parent::current();
 	}
+
+	/**
+	 * Determine whether all the collection's item have at least one set of dimensions provided
+	 *
+	 * @return bool
+	 */
+	public function haveDimensions(): bool
+	{
+		return array_reduce($this->getArrayCopy(), function (bool $carry, Entity\PostMedia $item) {
+			return $carry && $item->hasDimensions();
+		}, true);
+	}
 }

src/Content/Post/Entity/PostMedia.php

@@ -188,6 +188,30 @@ class PostMedia extends BaseEntity
 
 	}
 
+	/**
+	 * Computes the allocated height value used in the content/image/single_with_height_allocation.tpl template
+	 *
+	 * Either base or preview dimensions need to be set at runtime.
+	 *
+	 * @return string
+	 */
+	public function getAllocatedHeight(): string
+	{
+		if (!$this->hasDimensions()) {
+			throw new \RangeException('Either width and height or previewWidth and previewHeight must be defined to use this method.');
+		}
+
+		if ($this->width && $this->height) {
+			$width  = $this->width;
+			$height = $this->height;
+		} else {
+			$width  = $this->previewWidth;
+			$height = $this->previewHeight;
+		}
+
+		return (100 * $height / $width) . '%';
+	}
+
 	/**
 	 * Return a new PostMedia entity with a different preview URI and an optional proxy size name.
 	 * The new entity preview's width and height are rescaled according to the provided size.
@@ -263,4 +287,14 @@ class PostMedia extends BaseEntity
 			$this->id,
 		);
 	}
+
+	/**
+	 * Checks the media has at least one full set of dimensions, needed for the height allocation feature
+	 *
+	 * @return bool
+	 */
+	public function hasDimensions(): bool
+	{
+		return $this->width && $this->height || $this->previewWidth && $this->previewHeight;
+	}
 }