From d94e810977eb0bcd63c6271c06072ae779808c9a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Przemys=C5=82aw=20Pluta?=
 <noreply.git@mx.bartlomiejpluta.com>
Date: Thu, 4 Feb 2021 09:22:41 +0100
Subject: [PATCH] [Editor] Create basic undo/redo system

---
 .../base/editor/command/model/Command.kt      |  5 ++
 .../editor/command/model/SimpleCommand.kt     | 21 +++++++
 .../base/editor/command/model/Undoable.kt     |  7 +++
 .../command/service/DefaultUndoRedoService.kt | 61 +++++++++++++++++++
 .../editor/command/service/UndoRedoService.kt | 15 +++++
 5 files changed, 109 insertions(+)
 create mode 100755 editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/model/Command.kt
 create mode 100755 editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/model/SimpleCommand.kt
 create mode 100755 editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/model/Undoable.kt
 create mode 100755 editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/service/DefaultUndoRedoService.kt
 create mode 100755 editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/service/UndoRedoService.kt

diff --git a/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/model/Command.kt b/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/model/Command.kt
new file mode 100755
index 00000000..998f5033
--- /dev/null
+++ b/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/model/Command.kt
@@ -0,0 +1,5 @@
+package com.bartlomiejpluta.base.editor.command.model
+
+interface Command {
+    fun execute()
+}
\ No newline at end of file
diff --git a/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/model/SimpleCommand.kt b/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/model/SimpleCommand.kt
new file mode 100755
index 00000000..633608e6
--- /dev/null
+++ b/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/model/SimpleCommand.kt
@@ -0,0 +1,21 @@
+package com.bartlomiejpluta.base.editor.command.model
+
+class SimpleCommand<T>(
+    override val commandName: String,
+    private val formerValue: T,
+    private val value: T,
+    private val execute: (T) -> Unit
+) : Undoable, Command {
+
+    override fun undo() {
+        execute(formerValue)
+    }
+
+    override fun redo() {
+        execute()
+    }
+
+    override fun execute() {
+        execute(value)
+    }
+}
\ No newline at end of file
diff --git a/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/model/Undoable.kt b/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/model/Undoable.kt
new file mode 100755
index 00000000..c9470f59
--- /dev/null
+++ b/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/model/Undoable.kt
@@ -0,0 +1,7 @@
+package com.bartlomiejpluta.base.editor.command.model
+
+interface Undoable {
+    fun undo()
+    fun redo()
+    val commandName: String
+}
\ No newline at end of file
diff --git a/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/service/DefaultUndoRedoService.kt b/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/service/DefaultUndoRedoService.kt
new file mode 100755
index 00000000..4da0b061
--- /dev/null
+++ b/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/service/DefaultUndoRedoService.kt
@@ -0,0 +1,61 @@
+package com.bartlomiejpluta.base.editor.command.service
+
+import com.bartlomiejpluta.base.editor.command.model.Undoable
+import org.springframework.stereotype.Service
+import java.util.*
+
+@Service
+class DefaultUndoRedoService : UndoRedoService {
+    private val undo: Deque<Undoable> = ArrayDeque()
+    private val redo: Deque<Undoable> = ArrayDeque()
+
+    override var sizeMax = 30
+        set(value) {
+            if(value >= 0) {
+                for(i in 0 until undo.size - value) {
+                    undo.removeLast()
+                }
+
+                field = value
+            }
+        }
+
+    override fun push(undoable: Undoable) {
+        if(undo.size == sizeMax) {
+            undo.removeLast()
+        }
+
+        undo.push(undoable)
+        redo.clear()
+    }
+
+    override fun undo() {
+        if(undo.isNotEmpty()) {
+            undo.pop().let {
+                it.undo()
+                redo.push(it)
+            }
+        }
+    }
+
+    override fun redo() {
+        if(redo.isNotEmpty()) {
+            redo.pop().let {
+                it.redo()
+                undo.push(it)
+            }
+        }
+    }
+
+    override val lastUndoable: Undoable?
+        get() = undo.last
+
+    override val lastRedoable: Undoable?
+        get() = redo.last
+
+    override val undoCommandName: String
+        get() = undo.last?.commandName ?: ""
+
+    override val redoCommandName: String
+        get() = redo.last?.commandName ?: ""
+}
\ No newline at end of file
diff --git a/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/service/UndoRedoService.kt b/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/service/UndoRedoService.kt
new file mode 100755
index 00000000..cd896473
--- /dev/null
+++ b/editor/src/main/kotlin/com/bartlomiejpluta/base/editor/command/service/UndoRedoService.kt
@@ -0,0 +1,15 @@
+package com.bartlomiejpluta.base.editor.command.service
+
+import com.bartlomiejpluta.base.editor.command.model.Undoable
+
+interface UndoRedoService {
+    fun push(undoable: Undoable)
+    fun undo()
+    fun redo()
+
+    val lastUndoable: Undoable?
+    val lastRedoable: Undoable?
+    val undoCommandName: String
+    val redoCommandName: String
+    var sizeMax: Int
+}
\ No newline at end of file