penpot/frontend/src/app/main/data/workspace/undo.cljs
2023-03-07 09:11:51 +01:00

131 lines
4.5 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) KALEIDOS INC
(ns app.main.data.workspace.undo
(:require
[app.common.data :as d]
[app.common.pages.changes-spec :as pcs]
[app.common.spec :as us]
[cljs.spec.alpha :as s]
[potok.core :as ptk]))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Undo / Redo
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(s/def ::undo-changes ::pcs/changes)
(s/def ::redo-changes ::pcs/changes)
(s/def ::undo-entry
(s/keys :req-un [::undo-changes ::redo-changes]))
(def MAX-UNDO-SIZE 50)
(defn- conj-undo-entry
[undo data]
(let [undo (conj undo data)
cnt (count undo)]
(if (> cnt MAX-UNDO-SIZE)
(subvec undo (- cnt MAX-UNDO-SIZE))
undo)))
;; TODO: Review the necessity of this method
(defn materialize-undo
[_changes index]
(ptk/reify ::materialize-undo
ptk/UpdateEvent
(update [_ state]
(-> state
(assoc-in [:workspace-undo :index] index)))))
(defn- add-undo-entry
[state entry]
(if (and entry
(not-empty (:undo-changes entry))
(not-empty (:redo-changes entry)))
(let [index (get-in state [:workspace-undo :index] -1)
items (get-in state [:workspace-undo :items] [])
items (->> items (take (inc index)) (into []))
items (conj-undo-entry items entry)]
(-> state
(update :workspace-undo assoc :items items
:index (min (inc index)
(dec MAX-UNDO-SIZE)))))
state))
(defn- stack-undo-entry
[state {:keys [undo-changes redo-changes] :as entry}]
(let [index (get-in state [:workspace-undo :index] -1)]
(if (>= index 0)
(update-in state [:workspace-undo :items index]
(fn [item]
(-> item
(update :undo-changes #(into undo-changes %))
(update :redo-changes #(into % redo-changes)))))
(add-undo-entry state entry))))
(defn- accumulate-undo-entry
[state {:keys [undo-changes redo-changes group-id]}]
(-> state
(update-in [:workspace-undo :transaction :undo-changes] #(into undo-changes %))
(update-in [:workspace-undo :transaction :redo-changes] #(into % redo-changes))
(assoc-in [:workspace-undo :transaction :group-id] group-id)))
(defn append-undo
[entry stack?]
(us/assert ::undo-entry entry)
(ptk/reify ::append-undo
ptk/UpdateEvent
(update [_ state]
(cond
(and (get-in state [:workspace-undo :transaction])
(or (d/not-empty? (get-in state [:workspace-undo :transaction :undo-changes]))
(d/not-empty? (get-in state [:workspace-undo :transaction :redo-changes]))))
(accumulate-undo-entry state entry)
stack?
(stack-undo-entry state entry)
:else
(add-undo-entry state entry)))))
(def empty-tx
{:undo-changes [] :redo-changes []})
(defn start-undo-transaction [id]
(ptk/reify ::start-undo-transaction
ptk/UpdateEvent
(update [_ state]
;; We commit the old transaction before starting the new one
(let [current-tx (get-in state [:workspace-undo :transaction])
pending-tx (get-in state [:workspace-undo :transactions-pending])]
(cond-> state
(nil? current-tx) (assoc-in [:workspace-undo :transaction] empty-tx)
(nil? pending-tx) (assoc-in [:workspace-undo :transactions-pending] #{id})
(some? pending-tx) (update-in [:workspace-undo :transactions-pending] conj id))))))
(defn discard-undo-transaction []
(ptk/reify ::discard-undo-transaction
ptk/UpdateEvent
(update [_ state]
(update state :workspace-undo dissoc :transaction :transactions-pending))))
(defn commit-undo-transaction [id]
(ptk/reify ::commit-undo-transaction
ptk/UpdateEvent
(update [_ state]
(let [state (update-in state [:workspace-undo :transactions-pending] disj id)]
(if (empty? (get-in state [:workspace-undo :transactions-pending]))
(-> state
(add-undo-entry (get-in state [:workspace-undo :transaction]))
(update :workspace-undo dissoc :transaction))
state)))))
(def reinitialize-undo
(ptk/reify ::reset-undo
ptk/UpdateEvent
(update [_ state]
(assoc state :workspace-undo {}))))