Merge pull request #1318 from tractorcow/3.1-api-image-resampling-compatible

API Better detection and prevention of image resampling

model/Image.php

@@ -192,30 +192,61 @@ class Image extends File {
 		}
 	}
 	
-	public function SetWidth($width) {
+	/**
-		return $this->getWidth() == $width ? $this : $this->getFormattedImage('SetWidth', $width);
+	 * Resize the image by preserving aspect ratio, keeping the image inside the
-	}
+	 * $width and $height
-	
+	 * 
-	public function SetHeight($height) {
+	 * @param integer $width The width to size within
-		return $this->getHeight() == $height ? $this : $this->getFormattedImage('SetHeight', $height);
+	 * @param integer $height The height to size within
-	}
+	 * @return Image
-	
+	 */
-	public function SetSize($width, $height) {
-		return (($this->getWidth() == $width) &&  ($this->getHeight() == $height)) 
-			? $this 
-			: $this->getFormattedImage('SetSize', $width, $height);
-	}
-	
 	public function SetRatioSize($width, $height) {
-		return $this->getFormattedImage('SetRatioSize', $width, $height);
+		
+		// Check if image is already sized to the correct dimension
+		$widthRatio = $width / $this->width;
+		$heightRatio = $height / $this->height;
+		if( $widthRatio < $heightRatio ) {
+			// Target is higher aspect ratio than image, so check width
+			if($this->isWidth($width)) return $this;
+		} else {
+			// Target is wider aspect ratio than image, so check height
+			if($this->isHeight($height)) return $this;
+		}
+		
+		// Item must be regenerated
+		return  $this->getFormattedImage('SetRatioSize', $width, $height);
 	}
 	
+	/**
+	 * Resize the image by preserving aspect ratio, keeping the image inside the
+	 * $width and $height
+	 * 
+	 * @param Image_Backend $backend
+	 * @param integer $width The width to size within
+	 * @param integer $height The height to size within
+	 * @return Image_Backend
+	 */
 	public function generateSetRatioSize(Image_Backend $backend, $width, $height) {
 		return $backend->resizeRatio($width, $height);
 	}
 	
 	/**
 	 * Resize this Image by width, keeping aspect ratio. Use in templates with $SetWidth.
+	 * 
+	 * @param integer $width The width to set
+	 * @return Image
+	 */
+	public function SetWidth($width) {
+		return $this->isWidth($width) 
+			? $this
+			: $this->getFormattedImage('SetWidth', $width);
+	}
+	
+	/**
+	 * Resize this Image by width, keeping aspect ratio. Use in templates with $SetWidth.
+	 * 
+	 * @param Image_Backend $backend
+	 * @param type $width The width to set
 	 * @return Image_Backend
 	 */
 	public function generateSetWidth(Image_Backend $backend, $width) {
@@ -224,6 +255,21 @@ class Image extends File {
 	
 	/**
 	 * Resize this Image by height, keeping aspect ratio. Use in templates with $SetHeight.
+	 * 
+	 * @param integer $height The height to set
+	 * @return Image
+	 */
+	public function SetHeight($height) {
+		return $this->isHeight($height)
+			? $this 
+			: $this->getFormattedImage('SetHeight', $height);
+	}
+	
+	/**
+	 * Resize this Image by height, keeping aspect ratio. Use in templates with $SetHeight.
+	 * 
+	 * @param Image_Backend $backend
+	 * @param integer $height The height to set
 	 * @return Image_Backend
 	 */
 	public function generateSetHeight(Image_Backend $backend, $height){
@@ -232,6 +278,24 @@ class Image extends File {
 	
 	/**
 	 * Resize this Image by both width and height, using padded resize. Use in templates with $SetSize.
+	 * @see Image::PaddedImage()
+	 * 
+	 * @param integer $width The width to size to
+	 * @param integer $height The height to size to
+	 * @return Image
+	 */
+	public function SetSize($width, $height) {
+		return $this->isSize($width, $height)
+			? $this 
+			: $this->getFormattedImage('SetSize', $width, $height);
+	}
+	
+	/**
+	 * Resize this Image by both width and height, using padded resize. Use in templates with $SetSize.
+	 * 
+	 * @param Image_Backend $backend
+	 * @param integer $width The width to size to
+	 * @param integer $height The height to size to
 	 * @return Image_Backend
 	 */
 	public function generateSetSize(Image_Backend $backend, $width, $height) {
@@ -274,10 +338,63 @@ class Image extends File {
 		return $backend->croppedResize($this->stat('strip_thumbnail_width'),$this->stat('strip_thumbnail_height'));
 	}
 	
+	/**
+	 * Resize this Image by both width and height, using padded resize. Use in templates with $PaddedImage.
+	 * @see Image::SetSize()
+	 * 
+	 * @param integer $width The width to size to
+	 * @param integer $height The height to size to
+	 * @return Image
+	 */
+	public function PaddedImage($width, $height) {
+		return $this->isSize($width, $height)
+			? $this 
+			: $this->getFormattedImage('PaddedImage', $width, $height);
+	}
+	
+	/**
+	 * Resize this Image by both width and height, using padded resize. Use in templates with $PaddedImage.
+	 * 
+	 * @param Image_Backend $backend
+	 * @param integer $width The width to size to
+	 * @param integer $height The height to size to
+	 * @return Image_Backend
+	 */
 	public function generatePaddedImage(Image_Backend $backend, $width, $height) {
 		return $backend->paddedResize($width, $height);
 	}
 	
+	/**
+	 * Determine if this image is of the specified size
+	 * 
+	 * @param integer $width Width to check
+	 * @param integer $height Height to check
+	 * @return boolean
+	 */
+	public function isSize($width, $height) {
+		return $this->isWidth($width) && $this->isHeight($height);
+	}
+	
+	/**
+	 * Determine if this image is of the specified width
+	 * 
+	 * @param integer $width Width to check
+	 * @return boolean
+	 */
+	public function isWidth($width) {
+		return !empty($width) && $this->getWidth() == $width;
+	}
+	
+	/**
+	 * Determine if this image is of the specified width
+	 * 
+	 * @param integer $height Height to check
+	 * @return boolean
+	 */
+	public function isHeight($height) {
+		return !empty($height) && $this->getHeight() == $height;
+	}
+
 	/**
 	 * Return an image object representing the image in the given format.
 	 * This image will be generated using generateFormattedImage().
@@ -321,6 +438,7 @@ class Image extends File {
 	 * Generate an image on the specified format. It will save the image
 	 * at the location specified by cacheFilename(). The image will be generated
 	 * using the specific 'generate' method for the specified format.
+	 * 
 	 * @param string $format Name of the format to generate.
 	 * @param string $arg1 Argument to pass to the generate method.
 	 * @param string $arg2 A second argument to pass to the generate method.
@@ -350,6 +468,25 @@ class Image extends File {
 	/**
 	 * Generate a resized copy of this image with the given width & height.
 	 * Use in templates with $ResizedImage.
+	 * 
+	 * @param integer $width Width to resize to
+	 * @param integer $height Height to resize to
+	 * @return Image
+	 */
+	public function ResizedImage($width, $height) {
+		return $this->isSize($width, $height)
+			? $this 
+			: $this->getFormattedImage('ResizedImage', $width, $height);
+	}
+	
+	/**
+	 * Generate a resized copy of this image with the given width & height.
+	 * Use in templates with $ResizedImage.
+	 * 
+	 * @param Image_Backend $backend
+	 * @param integer $width Width to resize to
+	 * @param integer $height Height to resize to
+	 * @return Image_Backend
 	 */
 	public function generateResizedImage(Image_Backend $backend, $width, $height) {
 		if(!$backend){
@@ -363,6 +500,25 @@ class Image extends File {
 	/**
 	 * Generate a resized copy of this image with the given width & height, cropping to maintain aspect ratio.
 	 * Use in templates with $CroppedImage
+	 * 
+	 * @param integer $width Width to crop to
+	 * @param integer $height Height to crop to
+	 * @return Image
+	 */
+	public function CroppedImage($width, $height) {
+		return $this->isSize($width, $height)
+			? $this 
+			: $this->getFormattedImage('CroppedImage', $width, $height);
+	}
+
+	/**
+	 * Generate a resized copy of this image with the given width & height, cropping to maintain aspect ratio.
+	 * Use in templates with $CroppedImage
+	 * 
+	 * @param Image_Backend $backend
+	 * @param integer $width Width to crop to
+	 * @param integer $height Height to crop to
+	 * @return Image_Backend
 	 */
 	public function generateCroppedImage(Image_Backend $backend, $width, $height) {
 		return $backend->croppedResize($width, $height);

tests/model/ImageTest.php

@@ -81,6 +81,9 @@ class ImageTest extends SapphireTest {
 		$this->assertEquals($expected, $actual);
 	}
 	
+	/**
+	 * Tests that multiple image manipulations may be performed on a single Image
+	 */
 	public function testMultipleGenerateManipulationCalls() {
 		$image = $this->objFromFixture('Image', 'imageWithoutTitle');
 		
@@ -98,6 +101,78 @@ class ImageTest extends SapphireTest {
 		$this->assertEquals($expected, $actual);
 	}
 	
+	/**
+	 * Tests that image manipulations that do not affect the resulting dimensions
+	 * of the output image do not resample the file.
+	 */
+	public function testReluctanceToResampling() {
+		 
+		$image = $this->objFromFixture('Image', 'imageWithoutTitle');
+		$this->assertTrue($image->isSize(300, 300));
+		
+		// Set width to 50 pixels
+		$imageSetWidth = $image->SetWidth(300);
+		$this->assertEquals($imageSetWidth->getWidth(), 300);
+		$this->assertEquals($image->Filename, $imageSetWidth->Filename);
+		
+		// Set height to 300 pixels
+		$imageSetHeight = $image->SetHeight(300);
+		$this->assertEquals($imageSetHeight->getHeight(), 300);
+		$this->assertEquals($image->Filename, $imageSetHeight->Filename);
+		
+		// Crop image to 300 x 300
+		$imageCropped = $image->CroppedImage(300, 300);
+		$this->assertTrue($imageCropped->isSize(300, 300));
+		$this->assertEquals($image->Filename, $imageCropped->Filename);
+		
+		// Resize (padded) to 300 x 300
+		$imageSized = $image->SetSize(300, 300);
+		$this->assertTrue($imageSized->isSize(300, 300));
+		$this->assertEquals($image->Filename, $imageSized->Filename);
+		
+		// Padded image 300 x 300 (same as above)
+		$imagePadded = $image->PaddedImage(300, 300);
+		$this->assertTrue($imagePadded->isSize(300, 300));
+		$this->assertEquals($image->Filename, $imagePadded->Filename);
+		
+		// Resized (stretched) to 300 x 300
+		$imageStretched = $image->ResizedImage(300, 300);
+		$this->assertTrue($imageStretched->isSize(300, 300));
+		$this->assertEquals($image->Filename, $imageStretched->Filename);
+		
+		// SetRatioSize (various options)
+		$imageSetRatioSize = $image->SetRatioSize(300, 600);
+		$this->assertTrue($imageSetRatioSize->isSize(300, 300));
+		$this->assertEquals($image->Filename, $imageSetRatioSize->Filename);
+		$imageSetRatioSize = $image->SetRatioSize(600, 300);
+		$this->assertTrue($imageSetRatioSize->isSize(300, 300));
+		$this->assertEquals($image->Filename, $imageSetRatioSize->Filename);
+		$imageSetRatioSize = $image->SetRatioSize(300, 300);
+		$this->assertTrue($imageSetRatioSize->isSize(300, 300));
+		$this->assertEquals($image->Filename, $imageSetRatioSize->Filename);
+	}
+	
+	public function testImageResize() {
+		$image = $this->objFromFixture('Image', 'imageWithoutTitle');
+		$this->assertTrue($image->isSize(300, 300));
+		
+		// Test normal resize
+		$resized = $image->SetSize(150, 100);
+		$this->assertTrue($resized->isSize(150, 100));
+		
+		// Test cropped resize
+		$cropped = $image->CroppedImage(100, 200);
+		$this->assertTrue($cropped->isSize(100, 200));
+		
+		// Test padded resize
+		$padded = $image->PaddedImage(200, 100);
+		$this->assertTrue($padded->isSize(200, 100));
+		
+		// Test SetRatioSize
+		$ratio = $image->SetRatioSize(80, 160);
+		$this->assertTrue($ratio->isSize(80, 80));
+	}
+	
 	public function testGeneratedImageDeletion() {
 		$image = $this->objFromFixture('Image', 'imageWithMetacharacters');
 		$image_generated = $image->SetWidth(200);