penpot/frontend/src/uxbox/main/ui/workspace/scroll.cljs

68 lines
2.4 KiB
Clojure

;; This Source Code Form is subject to the terms of the Mozilla Public
;; License, v. 2.0. If a copy of the MPL was not distributed with this
;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
;;
;; Copyright (c) 2015-2017 Andrey Antukh <niwi@niwi.nz>
;; Copyright (c) 2015-2017 Juan de la Cruz <delacruzgarciajuan@gmail.com>
(ns uxbox.main.ui.workspace.scroll
"Workspace scroll events handling."
(:require [beicon.core :as rx]
[potok.core :as ptk]
[uxbox.main.refs :as refs]
[uxbox.util.mixins :as mx :include-macros true]
[uxbox.util.dom :as dom]
[uxbox.util.geom.point :as gpt]))
;; FIXME: revisit this ns in order to find a better location for its functions
(defn set-scroll-position
[dom position]
(set! (.-scrollLeft dom) (:x position))
(set! (.-scrollTop dom) (:y position)))
(defn set-scroll-center
[dom center]
(let [viewport-width (.-offsetWidth dom)
viewport-height (.-offsetHeight dom)
position-x (- (* (:x center) @refs/selected-zoom) (/ viewport-width 2))
position-y (- (* (:y center) @refs/selected-zoom) (/ viewport-height 2))
position (gpt/point position-x position-y)]
(set-scroll-position dom position)))
(defn scroll-to-page-center
[dom page]
(let [page-width (get-in page [:metadata :width])
page-height (get-in page [:metadata :height])
center (gpt/point (+ 1200 (/ page-width 2)) (+ 1200 (/ page-height 2)))]
(set-scroll-center dom center)))
(defn get-current-center
[dom]
(let [viewport-width (.-offsetWidth dom)
viewport-height (.-offsetHeight dom)
scroll-left (.-scrollLeft dom)
scroll-top (.-scrollTop dom)]
(gpt/point
(+ (/ viewport-width 2) scroll-left)
(+ (/ viewport-height 2) scroll-top))))
(defn get-current-center-absolute
[dom]
(gpt/divide (get-current-center dom) @refs/selected-zoom))
(defn get-current-position
[dom]
(let [scroll-left (.-scrollLeft dom)
scroll-top (.-scrollTop dom)]
(gpt/point scroll-left scroll-top)))
(defn get-current-position-absolute
[dom]
(gpt/divide (get-current-position dom) @refs/selected-zoom))
(defn scroll-to-point
[dom point position]
(let [viewport-offset (gpt/subtract point position)
new-scroll-position (gpt/subtract (gpt/multiply point @refs/selected-zoom) (gpt/multiply viewport-offset @refs/selected-zoom))]
(set-scroll-position dom new-scroll-position)))