Files
YellowLabTools/lib/screenshotHandler.js
T
2015-02-05 19:31:19 +01:00

135 lines
3.4 KiB
JavaScript

var debug = require('debug')('ylt:screenshotHandler');
var lwip = require('lwip');
var tmp = require('temporary');
var Q = require('q');
var fs = require('fs');
var path = require('path');
var screenshotHandler = function() {
this.getScreenshotTempFile = function() {
var screenshotTmpFolder = new tmp.Dir();
var tmpFilePath = path.join(screenshotTmpFolder.path, 'screenshot.jpg');
var that = this;
return {
getTmpFolder: function() {
return screenshotTmpFolder;
},
getTmpFilePath: function() {
return tmpFilePath;
},
toThumbnail: function(width) {
return that.optimize(tmpFilePath, width);
},
deleteTmpFile: function() {
return that.deleteTmpFileAndFolder(tmpFilePath, screenshotTmpFolder);
}
};
};
this.optimize = function(imagePath, width) {
var that = this;
debug('Starting screenshot transformation');
return this.openImage(imagePath)
.then(function(image) {
return that.resizeImage(image, width);
})
.then(this.toBuffer);
};
this.openImage = function(imagePath) {
var deferred = Q.defer();
lwip.open(imagePath, function(err, image){
if (err) {
debug('Could not open imagePath %s', imagePath);
debug(err);
deferred.reject(err);
} else {
debug('Image correctly open');
deferred.resolve(image);
}
});
return deferred.promise;
};
this.resizeImage = function(image, newWidth) {
var deferred = Q.defer();
var currentWidth = image.width();
var ratio = newWidth / currentWidth;
image.scale(ratio, function(err, image){
if (err) {
debug('Could not resize image');
debug(err);
deferred.reject(err);
} else {
debug('Image correctly resized');
deferred.resolve(image);
}
});
return deferred.promise;
};
this.toBuffer = function(image) {
var deferred = Q.defer();
image.toBuffer('jpg', {quality: 90}, function(err, buffer){
if (err) {
debug('Could not save image to buffer');
debug(err);
deferred.reject(err);
} else {
debug('Image correctly transformed to buffer');
deferred.resolve(buffer);
}
});
return deferred.promise;
};
this.deleteTmpFileAndFolder = function(tmpFilePath, screenshotTmpFolder) {
var deferred = Q.defer();
fs.unlink(tmpFilePath, function (err) {
if (err) {
debug('Screenshot file not found, could not be deleted. But it is not a problem.');
} else {
debug('Screenshot file deleted.');
}
screenshotTmpFolder.rmdir();
debug('Screenshot temp folder deleted');
deferred.resolve();
});
return deferred.promise;
};
};
module.exports = new screenshotHandler();