Implement Image::sliceAnimation()

src/Collection.php

@@ -185,10 +185,31 @@ public function pushEach(array $data, ?callable $callback = null): CollectionInt
         return $this;
     }
 
+    /**
+     * {@inheritdoc}
+     *
+     * @see CollectionInterface::empty()
+     */
     public function empty(): CollectionInterface
     {
         $this->items = [];
 
         return $this;
     }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @see CollectionInterface::slice()
+     */
+    public function slice(int $offset, ?int $length = null): CollectionInterface
+    {
+        if ($offset >= count($this->items)) {
+            throw new RuntimeException('Offset exceeds the maximum value.');
+        }
+
+        $this->items = array_slice($this->items, $offset, $length);
+
+        return $this;
+    }
 }

src/Drivers/Gd/Modifiers/SliceAnimationModifier.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Intervention\Image\Drivers\Gd\Modifiers;
+
+use Intervention\Image\Drivers\DriverSpecializedModifier;
+use Intervention\Image\Interfaces\ImageInterface;
+
+/**
+ * @property int $offset
+ * @property null|int $length
+ */
+class SliceAnimationModifier extends DriverSpecializedModifier
+{
+    public function apply(ImageInterface $image): ImageInterface
+    {
+        $image->core()->slice($this->offset, $this->length);
+
+        return $image;
+    }
+}

src/Drivers/Imagick/Core.php

@@ -7,6 +7,7 @@
 use Iterator;
 use Intervention\Image\Interfaces\CoreInterface;
 use Intervention\Image\Exceptions\AnimationException;
+use Intervention\Image\Interfaces\CollectionInterface;
 use Intervention\Image\Interfaces\FrameInterface;
 
 class Core implements CoreInterface, Iterator
@@ -17,6 +18,98 @@ public function __construct(protected Imagick $imagick)
     {
     }
 
+    /**
+     * {@inheritdoc}
+     *
+     * @see CollectionInterface::has()
+     */
+    public function has(int|string $key): bool
+    {
+        try {
+            $result = $this->imagick->setIteratorIndex($key);
+        } catch (ImagickException) {
+            return false;
+        }
+
+        return $result;
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @see CollectionInterface::push()
+     */
+    public function push($item): CollectionInterface
+    {
+        return $this->add($item);
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @see CollectionInterface::get()
+     */
+    public function get(int|string $key, $default = null): mixed
+    {
+        try {
+            $this->imagick->setIteratorIndex($key);
+        } catch (ImagickException) {
+            return $default;
+        }
+
+        return new Frame($this->imagick->current());
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @see CollectionInterface::getAtPosition()
+     */
+    public function getAtPosition(int $key = 0, $default = null): mixed
+    {
+        return $this->get($key, $default);
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @see CollectionInterface::empty()
+     */
+    public function empty(): CollectionInterface
+    {
+        $this->imagick->clear();
+
+        return $this;
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @see CollectionInterface::slice()
+     */
+    public function slice(int $offset, ?int $length = null): CollectionInterface
+    {
+        $allowed_indexes = [];
+        $length = is_null($length) ? $this->count() : $length;
+        for ($i = $offset; $i < $offset + $length; $i++) {
+            $allowed_indexes[] = $i;
+        }
+
+        $sliced = new Imagick();
+        foreach ($this->imagick as $key => $native) {
+            if (in_array($key, $allowed_indexes)) {
+                $sliced->addImage($native->getImage());
+            }
+        }
+
+        $sliced = $sliced->coalesceImages();
+        $sliced->setImageIterations($this->imagick->getImageIterations());
+
+        $this->imagick = $sliced;
+
+        return $this;
+    }
+
     public function add(FrameInterface $frame): CoreInterface
     {
         $imagick = $frame->native();

src/Drivers/Imagick/Modifiers/SliceAnimationModifier.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Intervention\Image\Drivers\Imagick\Modifiers;
+
+use Intervention\Image\Drivers\DriverSpecializedModifier;
+use Intervention\Image\Interfaces\ImageInterface;
+
+/**
+ * @property int $offset
+ * @property null|int $length
+ */
+class SliceAnimationModifier extends DriverSpecializedModifier
+{
+    public function apply(ImageInterface $image): ImageInterface
+    {
+        $image->core()->slice($this->offset, $this->length);
+
+        return $image;
+    }
+}

src/Image.php

@@ -80,6 +80,7 @@
 use Intervention\Image\Modifiers\ScaleDownModifier;
 use Intervention\Image\Modifiers\ScaleModifier;
 use Intervention\Image\Modifiers\SharpenModifier;
+use Intervention\Image\Modifiers\SliceAnimationModifier;
 use Intervention\Image\Modifiers\TextModifier;
 use Intervention\Image\Typography\FontFactory;
 
@@ -190,6 +191,11 @@ public function removeAnimation(int|string $position = 0): ImageInterface
         return $this->modify(new RemoveAnimationModifier($position));
     }
 
+    public function sliceAnimation(int $offset = 0, ?int $length = null): ImageInterface
+    {
+        return $this->modify(new SliceAnimationModifier($offset, $length));
+    }
+
     /**
      * {@inheritdoc}
      *

src/Interfaces/CollectionInterface.php

@@ -67,4 +67,13 @@ public function count(): int;
      * @return CollectionInterface
      */
     public function empty(): CollectionInterface;
+
+    /**
+     * Keep a slice of items and remove the rest from the collection
+     *
+     * @param int $offset
+     * @param null|int $length
+     * @return CollectionInterface
+     */
+    public function slice(int $offset, ?int $length = 0): CollectionInterface;
 }

src/Interfaces/CoreInterface.php

@@ -2,9 +2,7 @@
 
 namespace Intervention\Image\Interfaces;
 
-use Traversable;
-
-interface CoreInterface extends Traversable
+interface CoreInterface extends CollectionInterface
 {
     /**
      * return driver's representation of the image core.
@@ -60,5 +58,10 @@ public function loops(): int;
      */
     public function setLoops(int $loops): CoreInterface;
 
+    /**
+     * Get first frame in core
+     *
+     * @return FrameInterface
+     */
     public function first(): FrameInterface;
 }

src/Interfaces/ImageInterface.php

@@ -112,6 +112,15 @@ public function isAnimated(): bool;
      */
     public function removeAnimation(int|string $position = 0): ImageInterface;
 
+    /**
+     * Keep a slice of the animated frame and remove the rest
+     *
+     * @param int $offset
+     * @param null|int $length
+     * @return ImageInterface
+     */
+    public function sliceAnimation(int $offset = 0, ?int $length = null): ImageInterface;
+
     /**
      * Return loop count of animated image
      *

src/Modifiers/SliceAnimationModifier.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace Intervention\Image\Modifiers;
+
+class SliceAnimationModifier extends AbstractModifier
+{
+    public function __construct(public int $offset = 0, public ?int $length = null)
+    {
+    }
+}

tests/CollectionTest.php

@@ -3,6 +3,7 @@
 namespace Intervention\Image\Tests;
 
 use Intervention\Image\Collection;
+use Intervention\Image\Exceptions\RuntimeException;
 
 /**
  * @covers \Intervention\Image\Collection
@@ -144,4 +145,28 @@ public function testEmpty(): void
         $this->assertEquals(0, $collection->count());
         $this->assertEquals(0, $result->count());
     }
+
+    public function testSlice(): void
+    {
+        $collection = new Collection(['a', 'b', 'c', 'd', 'e', 'f']);
+        $this->assertEquals(6, $collection->count());
+        $result = $collection->slice(0, 3);
+        $this->assertEquals(['a', 'b', 'c'], $collection->toArray());
+        $this->assertEquals(['a', 'b', 'c'], $result->toArray());
+        $this->assertEquals('a', $result->get(0));
+        $this->assertEquals('b', $result->get(1));
+        $this->assertEquals('c', $result->get(2));
+
+        $result = $collection->slice(2, 1);
+        $this->assertEquals(['c'], $collection->toArray());
+        $this->assertEquals(['c'], $result->toArray());
+        $this->assertEquals('c', $result->get(0));
+    }
+
+    public function testSliceOutOfBounds(): void
+    {
+        $this->expectException(RuntimeException::class);
+        $collection = new Collection(['a', 'b', 'c']);
+        $collection->slice(6);
+    }
 }

tests/Drivers/Imagick/CoreTest.php

@@ -66,4 +66,77 @@ public function testSetGetLoops(): void
         $this->assertEquals(12, $core->loops());
         $this->assertInstanceOf(Core::class, $result);
     }
+
+    public function testHas(): void
+    {
+        $imagick = new Imagick();
+        $imagick->newImage(100, 100, new ImagickPixel('red'));
+        $imagick->addImage(clone $imagick);
+        $core = new Core($imagick);
+        $this->assertTrue($core->has(0));
+        $this->assertTrue($core->has(1));
+        $this->assertFalse($core->has(2));
+    }
+
+    public function testPush(): void
+    {
+        $imagick = new Imagick();
+        $imagick->newImage(100, 100, new ImagickPixel('red'));
+        $imagick->addImage(clone $imagick);
+        $core = new Core($imagick);
+        $this->assertEquals(2, $core->count());
+
+        $im = new Imagick();
+        $im->newImage(100, 100, new ImagickPixel('green'));
+        $result = $core->push(new Frame($im));
+        $this->assertEquals(3, $core->count());
+        $this->assertEquals(3, $result->count());
+    }
+
+    public function testGet(): void
+    {
+        $imagick = new Imagick();
+        $imagick->newImage(100, 100, new ImagickPixel('red'));
+        $imagick->addImage(clone $imagick);
+        $core = new Core($imagick);
+        $this->assertInstanceOf(Frame::class, $core->get(0));
+        $this->assertInstanceOf(Frame::class, $core->get(1));
+        $this->assertNull($core->get(2));
+        $this->assertEquals('foo', $core->get(2, 'foo'));
+    }
+
+    public function testEmpty(): void
+    {
+        $imagick = new Imagick();
+        $imagick->newImage(100, 100, new ImagickPixel('red'));
+        $imagick->addImage(clone $imagick);
+        $core = new Core($imagick);
+        $this->assertEquals(2, $core->count());
+        $result = $core->empty();
+        $this->assertEquals(0, $core->count());
+        $this->assertEquals(0, $result->count());
+    }
+
+    public function testSlice(): void
+    {
+        $imagick = new Imagick();
+
+        $im = new Imagick();
+        $im->newImage(10, 10, new ImagickPixel('red'));
+        $imagick->addImage($im);
+
+        $im = new Imagick();
+        $im->newImage(10, 10, new ImagickPixel('green'));
+        $imagick->addImage($im);
+
+        $im = new Imagick();
+        $im->newImage(10, 10, new ImagickPixel('blue'));
+        $imagick->addImage($im);
+
+        $core = new Core($imagick);
+        $this->assertEquals(3, $core->count());
+        $result = $core->slice(1, 2);
+        $this->assertEquals(2, $core->count());
+        $this->assertEquals(2, $result->count());
+    }
 }