Last active
March 4, 2018 17:48
-
-
Save DimitryDushkin/e2eb5d7cd7129c804cf0bfa7376809a3 to your computer and use it in GitHub Desktop.
Code from Yandex Zen narrative editor
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
type DraggerPosition = 'top-left' | 'top-right' | 'bottom-left' | 'bottom-right'; | |
const computeGeometryWhileDragging = ( | |
position: DraggerPosition, | |
preserveAspectRatio: boolean, | |
initialGeometry: SlideElementGeometry, | |
currentGeometry: SlideElementGeometry, | |
dx: number, | |
dy: number | |
): SlideElementGeometry => { | |
const startWidth = initialGeometry.width; | |
const startHeight = initialGeometry.height; | |
const startX = initialGeometry.x; | |
const startY = initialGeometry.y; | |
// Необходимо умножать на (startWidth / startHeight) и (startHeight / startWidth), | |
// чтобы привести смещения к единой шкале измерения | |
const isScalingByWidth = (startWidth - dx) * startWidth / startHeight | |
> (startHeight - dy) * startHeight / startWidth; | |
const geometry = {}; | |
if (position === 'top-left') { | |
if (preserveAspectRatio) { | |
if (isScalingByWidth) { | |
geometry.width = startWidth - dx; | |
geometry.height = startHeight / startWidth * geometry.width; | |
} else { | |
geometry.height = startHeight - dy; | |
geometry.width = startWidth / startHeight * geometry.height; | |
} | |
} else { | |
geometry.width = startWidth - dx; | |
geometry.height = startHeight - dy; | |
} | |
geometry.x = startX + startWidth - geometry.width; | |
geometry.y = startY + startHeight - geometry.height; | |
} else if (position === 'top-right') { | |
if (preserveAspectRatio) { | |
if (isScalingByWidth) { | |
geometry.width = startWidth + dx; | |
geometry.height = startHeight / startWidth * geometry.width; | |
} else { | |
geometry.height = startHeight - dy; | |
geometry.width = startWidth / startHeight * geometry.height; | |
} | |
geometry.y = startY + startHeight - geometry.height; | |
} else { | |
geometry.width = startWidth + dx; | |
geometry.height = startHeight - dy; | |
geometry.y = startY + dy; | |
} | |
} else if (position === 'bottom-left') { | |
if (preserveAspectRatio) { | |
if (isScalingByWidth) { | |
geometry.width = startWidth - dx; | |
geometry.height = startHeight / startWidth * geometry.width; | |
} else { | |
geometry.height = startHeight + dy; | |
geometry.width = startWidth / startHeight * geometry.height; | |
} | |
geometry.x = startX + startWidth - geometry.width; | |
} else { | |
geometry.width = startWidth - dx; | |
geometry.height = startHeight + dy; | |
geometry.x = startX + dx; | |
} | |
} else if (position === 'bottom-right') { | |
if (preserveAspectRatio) { | |
if (isScalingByWidth) { | |
geometry.width = startWidth + dx; | |
geometry.height = startHeight / startWidth * geometry.width; | |
} else { | |
geometry.height = startHeight + dy; | |
geometry.width = startWidth / startHeight * geometry.height; | |
} | |
} else { | |
geometry.width = startWidth + dx; | |
geometry.height = startHeight + dy; | |
} | |
} | |
if (geometry.width < MIN_WIDTH || geometry.height < MIN_HEIGHT) { | |
return currentGeometry; | |
} | |
return geometry; | |
}; |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment