silverstripe-framework/filesystem/ImageManipulation.php

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<?php
namespace SilverStripe\Filesystem;
use Config;
use Convert;
use DBField;
use DBFile;
use HTMLText;
use Image_Backend;
use Injector;
use InvalidArgumentException;
use SilverStripe\Filesystem\Storage\AssetContainer;
use SilverStripe\Filesystem\Storage\AssetStore;
/**
* Provides image manipulation functionality.
* Provides limited thumbnail generation functionality for non-image files.
* Should only be applied to implementors of AssetContainer
*
* Allows raw images to be resampled via Resampled()
*
* Image scaling manipluations, including:
* - Fit()
* - FitMax()
* - ScaleWidth()
* - ScaleMaxWidth()
* - ScaleHeight()
* - ScaleMaxHeight()
* - ResizedImage()
*
* Image cropping manipulations, including:
* - CropHeight()
* - CropWidth()
* - Fill()
* - FillMax()
*
* Thumbnail generation methods including:
* - Icon()
* - CMSThumbnail()
*
* @mixin AssetContainer
*/
trait ImageManipulation {
/**
* @return string Data from the file in this container
*/
abstract public function getString();
/**
* @return resource Data stream to the asset in this container
*/
abstract public function getStream();
/**
* @param bool $grant Ensures that the url for any protected assets is granted for the current user.
* @return string public url to the asset in this container
*/
abstract public function getURL($grant = true);
/**
* @return string The absolute URL to the asset in this container
*/
abstract public function getAbsoluteURL();
/**
* Get metadata for this file
*
* @return array|null File information
*/
abstract public function getMetaData();
/**
* Get mime type
*
* @return string Mime type for this file
*/
abstract public function getMimeType();
/**
* Return file size in bytes.
*
* @return int
*/
abstract public function getAbsoluteSize();
/**
* Determine if this container has a valid value
*
* @return bool Flag as to whether the file exists
*/
abstract public function exists();
/**
* Get value of filename
*
* @return string
*/
abstract public function getFilename();
/**
* Get value of hash
*
* @return string
*/
abstract public function getHash();
/**
* Get value of variant
*
* @return string
*/
abstract public function getVariant();
/**
* Determine if a valid non-empty image exists behind this asset
*
* @return bool
*/
abstract public function getIsImage();
/**
* @config
* @var bool Force all images to resample in all cases
*/
private static $force_resample = true;
/**
* @config
* @var int The width of an image thumbnail in a strip.
*/
private static $strip_thumbnail_width = 50;
/**
* @config
* @var int The height of an image thumbnail in a strip.
*/
private static $strip_thumbnail_height = 50;
/**
* The width of an image thumbnail in the CMS.
*
* @config
* @var int
*/
private static $cms_thumbnail_width = 100;
/**
* The height of an image thumbnail in the CMS.
*
* @config
* @var int
*/
private static $cms_thumbnail_height = 100;
/**
* The width of an image preview in the Asset section
*
* This thumbnail is only sized to width.
*
* @config
* @var int
*/
private static $asset_preview_width = 400;
/**
* Fit image to specified dimensions and fill leftover space with a solid colour (default white). Use in templates with $Pad.
*
* @param integer $width The width to size to
* @param integer $height The height to size to
* @return AssetContainer
*/
public function Pad($width, $height, $backgroundColor = 'FFFFFF') {
if($this->isSize($width, $height)) {
return $this;
}
$variant = $this->variantName(__FUNCTION__, $width, $height, $backgroundColor);
return $this->manipulateImage(
$variant,
function(Image_Backend $backend) use($width, $height, $backgroundColor) {
return $backend->paddedResize($width, $height, $backgroundColor);
}
);
}
/**
* Forces the image to be resampled, if possible
*
* @return AssetContainer
*/
public function Resampled() {
// If image is already resampled, return self reference
$variant = $this->getVariant();
if($variant) {
return $this;
}
// Resample, but fallback to original object
$result = $this->manipulateImage(__FUNCTION__, function(Image_Backend $backend) {
return $backend;
});
if($result) {
return $result;
}
return $this;
}
/**
* Update the url to point to a resampled version if forcing
*
* @param string $url
*/
public function updateURL(&$url) {
// Skip if resampling is off, or is already resampled, or is not an image
if(!Config::inst()->get(get_class($this), 'force_resample') || $this->getVariant() || !$this->getIsImage()) {
return;
}
// Attempt to resample
$resampled = $this->Resampled();
if(!$resampled) {
return;
}
// Only update if resampled file is a smaller file size
if($resampled->getAbsoluteSize() < $this->getAbsoluteSize()) {
$url = $resampled->getURL();
}
}
/**
* Generate a resized copy of this image with the given width & height.
* This can be used in templates with $ResizedImage but should be avoided,
* as it's the only image manipulation function which can skew an image.
*
* @param integer $width Width to resize to
* @param integer $height Height to resize to
* @return AssetContainer
*/
public function ResizedImage($width, $height) {
if($this->isSize($width, $height)) {
return $this;
}
$variant = $this->variantName(__FUNCTION__, $width, $height);
return $this->manipulateImage($variant, function(Image_Backend $backend) use ($width, $height) {
return $backend->resize($width, $height);
});
}
/**
* Scale image proportionally to fit within the specified bounds
*
* @param integer $width The width to size within
* @param integer $height The height to size within
* @return AssetContainer
*/
public function Fit($width, $height) {
// Prevent divide by zero on missing/blank file
if(!$this->getWidth() || !$this->getHeight()) {
return null;
}
// Check if image is already sized to the correct dimension
$widthRatio = $width / $this->getWidth();
$heightRatio = $height / $this->getHeight();
if( $widthRatio < $heightRatio ) {
// Target is higher aspect ratio than image, so check width
if($this->isWidth($width)) {
return $this;
}
} else {
// Target is wider or same aspect ratio as image, so check height
if($this->isHeight($height)) {
return $this;
}
}
// Item must be regenerated
$variant = $this->variantName(__FUNCTION__, $width, $height);
return $this->manipulateImage($variant, function(Image_Backend $backend) use ($width, $height) {
return $backend->resizeRatio($width, $height);
});
}
/**
* Proportionally scale down this image if it is wider or taller than the specified dimensions.
* Similar to Fit but without up-sampling. Use in templates with $FitMax.
*
* @uses ScalingManipulation::Fit()
* @param integer $width The maximum width of the output image
* @param integer $height The maximum height of the output image
* @return AssetContainer
*/
public function FitMax($width, $height) {
return $this->getWidth() > $width || $this->getHeight() > $height
? $this->Fit($width,$height)
: $this;
}
/**
* Scale image proportionally by width. Use in templates with $ScaleWidth.
*
* @param integer $width The width to set
* @return AssetContainer
*/
public function ScaleWidth($width) {
if($this->isWidth($width)) {
return $this;
}
$variant = $this->variantName(__FUNCTION__, $width);
return $this->manipulateImage($variant, function(Image_Backend $backend) use ($width) {
return $backend->resizeByWidth($width);
});
}
/**
* Proportionally scale down this image if it is wider than the specified width.
* Similar to ScaleWidth but without up-sampling. Use in templates with $ScaleMaxWidth.
*
* @uses ScalingManipulation::ScaleWidth()
* @param integer $width The maximum width of the output image
* @return AssetContainer
*/
public function ScaleMaxWidth($width) {
return $this->getWidth() > $width
? $this->ScaleWidth($width)
: $this;
}
/**
* Scale image proportionally by height. Use in templates with $ScaleHeight.
*
* @param int $height The height to set
* @return AssetContainer
*/
public function ScaleHeight($height) {
if($this->isHeight($height)) {
return $this;
}
$variant = $this->variantName(__FUNCTION__, $height);
return $this->manipulateImage($variant, function(Image_Backend $backend) use ($height) {
return $backend->resizeByHeight($height);
});
}
/**
* Proportionally scale down this image if it is taller than the specified height.
* Similar to ScaleHeight but without up-sampling. Use in templates with $ScaleMaxHeight.
*
* @uses ScalingManipulation::ScaleHeight()
* @param integer $height The maximum height of the output image
* @return AssetContainer
*/
public function ScaleMaxHeight($height) {
return $this->getHeight() > $height
? $this->ScaleHeight($height)
: $this;
}
/**
* Crop image on X axis if it exceeds specified width. Retain height.
* Use in templates with $CropWidth. Example: $Image.ScaleHeight(100).$CropWidth(100)
*
* @uses CropManipulation::Fill()
* @param integer $width The maximum width of the output image
* @return AssetContainer
*/
public function CropWidth($width) {
return $this->getWidth() > $width
? $this->Fill($width, $this->getHeight())
: $this;
}
/**
* Crop image on Y axis if it exceeds specified height. Retain width.
* Use in templates with $CropHeight. Example: $Image.ScaleWidth(100).CropHeight(100)
*
* @uses CropManipulation::Fill()
* @param integer $height The maximum height of the output image
* @return AssetContainer
*/
public function CropHeight($height) {
return $this->getHeight() > $height
? $this->Fill($this->getWidth(), $height)
: $this;
}
/**
* Crop this image to the aspect ratio defined by the specified width and height,
* then scale down the image to those dimensions if it exceeds them.
* Similar to Fill but without up-sampling. Use in templates with $FillMax.
*
* @uses ImageManipulation::Fill()
* @param integer $width The relative (used to determine aspect ratio) and maximum width of the output image
* @param integer $height The relative (used to determine aspect ratio) and maximum height of the output image
* @return AssetContainer
*/
public function FillMax($width, $height) {
// Prevent divide by zero on missing/blank file
if(!$this->getWidth() || !$this->getHeight()) {
return null;
}
// Is the image already the correct size?
if ($this->isSize($width, $height)) {
return $this;
}
// If not, make sure the image isn't upsampled
$imageRatio = $this->getWidth() / $this->getHeight();
$cropRatio = $width / $height;
// If cropping on the x axis compare heights
if ($cropRatio < $imageRatio && $this->getHeight() < $height) {
return $this->Fill($this->getHeight() * $cropRatio, $this->getHeight());
}
// Otherwise we're cropping on the y axis (or not cropping at all) so compare widths
if ($this->getWidth() < $width) {
return $this->Fill($this->getWidth(), $this->getWidth() / $cropRatio);
}
return $this->Fill($width, $height);
}
/**
* Resize and crop image to fill specified dimensions.
* Use in templates with $Fill
*
* @param integer $width Width to crop to
* @param integer $height Height to crop to
* @return AssetContainer
*/
public function Fill($width, $height) {
if($this->isSize($width, $height)) {
return $this;
}
// Resize
$variant = $this->variantName(__FUNCTION__, $width, $height);
return $this->manipulateImage($variant, function(Image_Backend $backend) use ($width, $height) {
return $backend->croppedResize($width, $height);
});
}
/**
* Default CMS thumbnail
*
* @return DBFile|HTMLText Either a resized thumbnail, or html for a thumbnail icon
*/
public function CMSThumbnail() {
$width = Config::inst()->get(get_class($this), 'cms_thumbnail_width');
$height = Config::inst()->get(get_class($this), 'cms_thumbnail_height');
return $this->ThumbnailIcon($width, $height);
}
/**
* Generates a thumbnail for use in the gridfield view
*
* @return AssetContainer|HTMLText Either a resized thumbnail, or html for a thumbnail icon
*/
public function StripThumbnail() {
$width = Config::inst()->get(get_class($this), 'strip_thumbnail_width');
$height = Config::inst()->get(get_class($this), 'strip_thumbnail_height');
return $this->ThumbnailIcon($width, $height);
}
/**
* Get preview for this file
*
* @return AssetContainer|HTMLText Either a resized thumbnail, or html for a thumbnail icon
*/
public function PreviewThumbnail() {
$width = Config::inst()->get(get_class($this), 'asset_preview_width');
return $this->ScaleWidth($width) ?: $this->IconTag();
}
/**
* Default thumbnail generation for Images
*
* @param int $width
* @param int $height
* @return AssetContainer
*/
public function Thumbnail($width, $height) {
return $this->Pad($height, $height);
}
/**
* Thubnail generation for all file types.
*
* Resizes images, but returns an icon <img /> tag if this is not a resizable image
*
* @param int $width
* @param int $height
* @return AssetContainer|HTMLText
*/
public function ThumbnailIcon($width, $height) {
return $this->Thumbnail($width, $height) ?: $this->IconTag();
}
/**
* Get HTML for img containing the icon for this file
*
* @return type
*/
public function IconTag() {
return DBField::create_field(
'HTMLText',
'<img src="' . Convert::raw2att($this->getIcon()) . '" />'
);
}
/**
* Get URL to thumbnail of the given size.
*
* May fallback to default icon
*
* @param int $width
* @param int $height
* @return string
*/
public function ThumbnailURL($width, $height) {
$thumbnail = $this->Thumbnail($width, $height);
if($thumbnail) {
return $thumbnail->getURL();
}
return $this->getIcon();
}
/**
* Return the relative URL of an icon for the file type,
* based on the {@link appCategory()} value.
* Images are searched for in "framework/images/app_icons/".
*
* @return string URL to icon
*/
public function getIcon() {
$filename = $this->getFilename();
$ext = pathinfo($filename, PATHINFO_EXTENSION);
return \File::get_icon_for_extension($ext);
}
/**
* Get Image_Backend instance for this image
*
* @return Image_Backend
*/
public function getImageBackend() {
if(!$this->getIsImage()) {
return null;
}
// Create backend for this object
return Injector::inst()->createWithArgs('Image_Backend', array($this));
}
/**
* Get the dimensions of this Image.
*
* @param string $dim One of the following:
* - "string": return the dimensions in string form
* - "array": it'll return the raw result
* - 0: return the height
* - 1: return the width
* @return string|int|array|null
*/
public function getDimensions($dim = "string") {
if(!$this->getIsImage()) {
return null;
}
$content = $this->getString();
if(!$content) {
return null;
}
// Get raw content
$size = getimagesizefromstring($content);
if($size === false) {
return null;
}
if($dim === 'array') {
return $size;
}
// Get single dimension
if(is_numeric($dim)) {
return $size[$dim];
}
return "$size[0]x$size[1]";
}
/**
* Get the width of this image.
*
* @return int
*/
public function getWidth() {
return $this->getDimensions(0);
}
/**
* Get the height of this image.
*
* @return int
*/
public function getHeight() {
return $this->getDimensions(1);
}
/**
* Get the orientation of this image.
*
* @return ORIENTATION_SQUARE | ORIENTATION_PORTRAIT | ORIENTATION_LANDSCAPE
*/
public function getOrientation() {
$width = $this->getWidth();
$height = $this->getHeight();
if($width > $height) {
return Image_Backend::ORIENTATION_LANDSCAPE;
} elseif($height > $width) {
return Image_Backend::ORIENTATION_PORTRAIT;
} else {
return Image_Backend::ORIENTATION_SQUARE;
}
}
/**
* 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) {
if(empty($width) || !is_numeric($width)) {
throw new InvalidArgumentException("Invalid value for width");
}
return $this->getWidth() == $width;
}
/**
* Determine if this image is of the specified width
*
* @param integer $height Height to check
* @return boolean
*/
public function isHeight($height) {
if(empty($height) || !is_numeric($height)) {
throw new InvalidArgumentException("Invalid value for height");
}
return $this->getHeight() == $height;
}
/**
* Wrapper for manipulate that passes in and stores Image_Backend objects instead of tuples
*
* @param string $variant
* @param callable $callback Callback which takes an Image_Backend object, and returns an Image_Backend result
* @return DBFile The manipulated file
*/
public function manipulateImage($variant, $callback) {
return $this->manipulate(
$variant,
function(AssetStore $store, $filename, $hash, $variant) use ($callback) {
$backend = $this->getImageBackend();
if(!$backend) {
return null;
}
$backend = $callback($backend);
if(!$backend) {
return null;
}
return $backend->writeToStore(
$store, $filename, $hash, $variant,
array('conflict' => AssetStore::CONFLICT_USE_EXISTING)
);
}
);
}
/**
* Generate a new DBFile instance using the given callback if it hasn't been created yet, or
* return the existing one if it has.
*
* @param string $variant name of the variant to create
* @param callable $callback Callback which should return a new tuple as an array.
* This callback will be passed the backend, filename, hash, and variant
* This will not be called if the file does not
* need to be created.
* @return DBFile The manipulated file
*/
public function manipulate($variant, $callback) {
// Verify this manipulation is applicable to this instance
if(!$this->exists()) {
return null;
}
// Build output tuple
$filename = $this->getFilename();
$hash = $this->getHash();
$existingVariant = $this->getVariant();
if($existingVariant) {
$variant = $existingVariant . '_' . $variant;
}
// Skip empty files (e.g. Folder does not have a hash)
if(empty($filename) || empty($hash)) {
return null;
}
// Create this asset in the store if it doesn't already exist,
// otherwise use the existing variant
$store = Injector::inst()->get('AssetStore');
$result = null;
if(!$store->exists($filename, $hash, $variant)) {
$result = call_user_func($callback, $store, $filename, $hash, $variant);
} else {
$result = array(
'Filename' => $filename,
'Hash' => $hash,
'Variant' => $variant
);
}
// Callback may fail to perform this manipulation (e.g. resize on text file)
if(!$result) {
return null;
}
// Store result in new DBFile instance
return DBField::create_field('DBFile', $result)
->setOriginal($this);
}
/**
* Name a variant based on a format with arbitrary parameters
*
* @param string $format The format name.
* @param mixed ...$args Additional arguments
* @return string
* @throws InvalidArgumentException
*/
public function variantName($format) {
$args = func_get_args();
array_shift($args);
return $format . Convert::base64url_encode($args);
}
}