delboy1978uk / image

src/Image/Strategy/GifStrategy.php

<?php


declare(strict_types=1);


namespace Del\Image\Strategy;


use GdImage;


class GifStrategy implements ImageTypeStrategyInterface

{

    public function create(string $filename): GdImage

    {

        return \imagecreatefromgif($filename);

The expression return imagecreatefromgif($filename) could return the type resource which is incompatible with the type-hinted return GdImage. Consider adding an additional type-check to rule them out.

    }


    public function save(GdImage $resource, string $filename, int $compression = 100): void

    {

        \imagegif($resource, $filename);

    }


    public function getContentType(): string

    {

        return 'image/gif';

    }


    public function render(GdImage $resource): void

    {

        \imagegif($resource);

    }


    public function handleTransparency(GdImage $newImage, GdImage $image): void

    {

        // Get transparency color's index number

        $transparency = $this->getTransparencyIndex($image);


        // Is a strange index other than -1 set?

        if ($transparency >= 0) {

            $this->prepWithCustomTransparencyIndex($newImage, $image, $transparency);

        }

    }


    private function prepWithCustomTransparencyIndex(GdImage $newImage, GdImage $image, int $index): void

    {

        // Get the array of RGB vals for the transparency index

        $transparentColor = \imagecolorsforindex($image, $index);


        // Now allocate the color

        $transparency = \imagecolorallocate($newImage, $transparentColor['red'], $transparentColor['green'], $transparentColor['blue']);


        // Fill the background with the color

        \imagefill($newImage, 0, 0, $transparency);


        // And set that color as the transparent one

        \imagecolortransparent($newImage, $transparency);

    }


    private function getTransparencyIndex(GdImage $image): int

    {

        return \imagecolortransparent($image);

    }

}