Watermark Media Action (#3308)

* added gregwar merge media action and watermark media function

* remove the dump left by accident

* added scaling to the watermark

Co-authored-by: Ricardo <ricardo@urbansquid.london>
Co-authored-by: Andy Miller <1084697+rhukster@users.noreply.github.com>

system/config/system.yaml

@@ -162,6 +162,12 @@ images:
     retina_scale: 1                              # scale to adjust auto-sizes for better handling of HiDPI resolutions
   defaults:
     loading: auto                                # Let browser pick [auto|lazy|eager]
+  watermark:
+    image: 'system://images/watermark.png'       # Path to a watermark image
+    position_y: 'center'                         # top|center|bottom
+    position_x: 'center'                         # left|center|right
+    scale: 33                                    # percentage of watermark scale
+    watermark_all: false                         # automatically watermark all images
 
 media:
   enable_media_timestamp: false                  # Enable media timestamps

system/src/Grav/Common/Media/Traits/ImageMediaTrait.php

@@ -50,6 +50,8 @@ trait ImageMediaTrait
     /** @var integer */
     protected $retina_scale;
 
+    /** @var bool */
+    protected $watermark;
 
     /** @var array */
     public static $magic_actions = [
@@ -379,6 +381,8 @@ trait ImageMediaTrait
         $this->aspect_ratio = $config->get('system.images.cls.aspect_ratio', false);
         $this->retina_scale = $config->get('system.images.cls.retina_scale', 1);
 
+        $this->watermark = $config->get('system.images.watermark.watermark_all', false);
+
         return $this;
     }
 
@@ -415,6 +419,10 @@ trait ImageMediaTrait
             $this->image->merge(ImageFile::open($overlay));
         }
 
+        if ($this->watermark) {
+            $this->watermark();
+        }
+
         return $this->image->cacheFile($this->format, $this->quality, false, [$this->get('width'), $this->get('height'), $this->get('modified')]);
     }
 }

system/src/Grav/Common/Page/Medium/ImageMedium.php

@@ -17,6 +17,7 @@ use Grav\Common\Media\Interfaces\MediaLinkInterface;
 use Grav\Common\Media\Traits\ImageLoadingTrait;
 use Grav\Common\Media\Traits\ImageMediaTrait;
 use Grav\Common\Utils;
+use Gregwar\Image\Image;
 use RocketTheme\Toolbox\ResourceLocator\UniformResourceLocator;
 use function func_get_args;
 use function in_array;
@@ -325,6 +326,67 @@ class ImageMedium extends Medium implements ImageMediaInterface, ImageManipulate
         return $this;
     }
 
+    public function watermark($image = null, $position = null, $scale = null)
+    {
+        $grav = $this->getGrav();
+
+        $locator = $grav['locator'];
+        $config = $grav['config'];
+
+        $args = func_get_args();
+
+        $file = $args[0] ?? '1'; // using '1' because of markdown. doing ![](image.jpg?watermark) returns $args[0]='1';
+        $file = $file === '1' ? $config->get('system.images.watermark.image') : $args[0];
+
+        $watermark = $locator->findResource($file);
+        $watermark = ImageFile::open($watermark);
+
+        // Scaling operations
+        $scale     = ($scale ?? $config->get('system.images.watermark.scale', 100)) / 100;
+        $wwidth    = $this->get('width')  * $scale;
+        $wheight   = $this->get('height') * $scale;
+        $watermark->resize($wwidth, $wheight);
+
+        // Position operations
+        $position = !empty($args[1]) ? explode('-',  $args[1]) : ['center', 'center']; // todo change to config
+        $positionY = $position[0] ?? $config->get('system.images.watermark.position_y', 'center');
+        $positionX = $position[1] ?? $config->get('system.images.watermark.position_x', 'center');
+
+        switch ($positionY)
+        {
+            case 'top':
+                $positionY = 0;
+                break;
+
+            case 'bottom':
+                $positionY = $this->get('height')-$wheight;
+                break;
+
+            case 'center':
+                $positionY = ($this->get('height')/2) - ($wheight/2);
+                break;
+        }
+
+        switch ($positionX)
+        {
+            case 'left':
+                $positionX = 0;
+                break;
+
+            case 'right':
+                $positionX = $this->get('width')-$wwidth;
+                break;
+
+            case 'center':
+                $positionX = ($this->get('width')/2) - ($wwidth/2);
+                break;
+        }
+
+        $this->__call('merge', [$watermark,$positionX, $positionY]);
+
+        return $this;
+    }
+
     /**
      * Handle this commonly used variant
      *