Add ->get_quality() method to WP_Image_Editor class.

Adds unit tests.

Props markoheijnen.
Fixes #28154.

Built from https://develop.svn.wordpress.org/trunk@28879


git-svn-id: http://core.svn.wordpress.org/trunk@28678 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-image-editor-gd.php

@@ -114,7 +114,7 @@ class WP_Image_Editor_GD extends WP_Image_Editor {
 		$this->update_size( $size[0], $size[1] );
 		$this->mime_type = $size['mime'];
 
-		return $this->set_quality( $this->quality );
+		return true;
 	}
 
 	/**
@@ -394,7 +394,7 @@ class WP_Image_Editor_GD extends WP_Image_Editor {
 			}
 		}
 		elseif ( 'image/jpeg' == $mime_type ) {
-			if ( ! $this->make_image( $filename, 'imagejpeg', array( $image, $filename, $this->quality ) ) )
+			if ( ! $this->make_image( $filename, 'imagejpeg', array( $image, $filename, $this->get_quality() ) ) )
 				return new WP_Error( 'image_save_error', __('Image Editor Save Failed') );
 		}
 		else {
@@ -442,7 +442,7 @@ class WP_Image_Editor_GD extends WP_Image_Editor {
 				return imagegif( $this->image );
 			default:
 				header( 'Content-Type: image/jpeg' );
-				return imagejpeg( $this->image, null, $this->quality );
+				return imagejpeg( $this->image, null, $this->get_quality() );
 		}
 	}
 

wp-includes/class-wp-image-editor-imagick.php

@@ -143,7 +143,7 @@ class WP_Image_Editor_Imagick extends WP_Image_Editor {
 		if ( is_wp_error( $updated_size ) )
 				return $updated_size;
 
-		return $this->set_quality( $this->quality );
+		return true;
 	}
 
 	/**
@@ -160,7 +160,7 @@ class WP_Image_Editor_Imagick extends WP_Image_Editor {
 		if ( is_wp_error( $quality_result ) ) {
 			return $quality_result;
 		} else {
-			$quality = $this->quality;
+			$quality = $this->get_quality();
 		}
 
 		try {

wp-includes/class-wp-image-editor.php

@@ -16,7 +16,8 @@ abstract class WP_Image_Editor {
 	protected $size = null;
 	protected $mime_type = null;
 	protected $default_mime_type = 'image/jpeg';
-	protected $quality = 90;
+	protected $quality = false;
+	protected $default_quality = 90;
 
 	/**
 	 * Each instance handles a single file.
@@ -202,6 +203,49 @@ abstract class WP_Image_Editor {
 		return true;
 	}
 
+	/**
+	 * Gets the Image Compression quality on a 1-100% scale.
+	 *
+	 * @since 4.0.0
+	 * @access public
+	 *
+	 * @return int $quality Compression Quality. Range: [1,100]
+	 */
+	public function get_quality() {
+		if ( ! $this->quality ) {
+			/**
+			 * Filter the default image compression quality setting.
+			 *
+			 * @since 3.5.0
+			 *
+			 * @param int    $quality   Quality level between 1 (low) and 100 (high).
+			 * @param string $mime_type Image mime type.
+			 */
+			$quality = apply_filters( 'wp_editor_set_quality', $this->default_quality, $this->mime_type );
+
+			if ( 'image/jpeg' == $this->mime_type ) {
+				/**
+				 * Filter the JPEG compression quality for backward-compatibility.
+				 *
+				 * The filter is evaluated under two contexts: 'image_resize', and 'edit_image',
+				 * (when a JPEG image is saved to file).
+				 *
+				 * @since 2.5.0
+				 *
+				 * @param int    $quality Quality level between 0 (low) and 100 (high) of the JPEG.
+				 * @param string $context Context of the filter.
+				 */
+				$quality = apply_filters( 'jpeg_quality', $quality, 'image_resize' );
+
+				if ( ! $this->set_quality( $quality ) ) {
+					$this->quality = $this->default_quality;
+				}
+			}
+		}
+
+		return $this->quality;
+	}
+
 	/**
 	 * Sets Image Compression quality on a 1-100% scale.
 	 *
@@ -212,41 +256,12 @@ abstract class WP_Image_Editor {
 	 * @return boolean|WP_Error True if set successfully; WP_Error on failure.
 	 */
 	public function set_quality( $quality = null ) {
-		if ( $quality == null ) {
+		// Allow 0, but squash to 1 due to identical images in GD, and for backwards compatibility.
-			$quality = $this->quality;
+		if ( $quality == 0 ) {
+			$quality = 1;
 		}
 
-		/**
+		if ( ( $quality >= 1 ) && ( $quality <= 100 ) ) {
-		 * Filter the default image compression quality setting.
-		 *
-		 * @since 3.5.0
-		 *
-		 * @param int    $quality   Quality level between 1 (low) and 100 (high).
-		 * @param string $mime_type Image mime type.
-		 */
-		$quality = apply_filters( 'wp_editor_set_quality', $quality, $this->mime_type );
-
-		if ( 'image/jpeg' == $this->mime_type ) {
-			/**
-			 * Filter the JPEG compression quality for backward-compatibility.
-			 *
-			 * The filter is evaluated under two contexts: 'image_resize', and 'edit_image',
-			 * (when a JPEG image is saved to file).
-			 *
-			 * @since 2.5.0
-			 *
-			 * @param int    $quality Quality level between 0 (low) and 100 (high) of the JPEG.
-			 * @param string $context Context of the filter.
-			 */
-			$quality = apply_filters( 'jpeg_quality', $quality, 'image_resize' );
-
-			// Allow 0, but squash to 1 due to identical images in GD, and for backwards compatibility.
-			if ( $quality == 0 ) {
-				$quality = 1;
-			}
-		}
-
-		if ( ( $quality >= 1 ) && ( $quality <= 100 ) ){
 			$this->quality = $quality;
 			return true;
 		} else {