From 3a9cc83e788e21ec443750295e12249a465ab625 Mon Sep 17 00:00:00 2001
From: Noah Petherbridge <root@kirsle.net>
Date: Mon, 11 Oct 2021 16:10:04 -0700
Subject: [PATCH] Bugfix: Undo/Redo works for the Doodad Editor

Changed dependencies around so the undo/redo feature works on doodads as
well as levels.
---
 pkg/doodads/doodad.go      |  7 ++++++-
 pkg/uix/canvas.go          |  2 ++
 pkg/uix/canvas_editable.go |  2 ++
 pkg/uix/canvas_strokes.go  | 26 ++++++++++++++++++--------
 4 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/pkg/doodads/doodad.go b/pkg/doodads/doodad.go
index 10d07ad..51a3788 100644
--- a/pkg/doodads/doodad.go
+++ b/pkg/doodads/doodad.go
@@ -2,6 +2,7 @@ package doodads
 
 import (
 	"git.kirsle.net/apps/doodle/pkg/balance"
+	"git.kirsle.net/apps/doodle/pkg/drawtool"
 	"git.kirsle.net/apps/doodle/pkg/level"
 	"git.kirsle.net/apps/doodle/pkg/log"
 	"git.kirsle.net/go/render"
@@ -17,6 +18,9 @@ type Doodad struct {
 	Hitbox   render.Rect       `json:"hitbox"`
 	Layers   []Layer           `json:"layers"`
 	Tags     map[string]string `json:"data"` // arbitrary key/value data storage
+
+	// Undo history, temporary live data not persisted to the level file.
+	UndoHistory *drawtool.History `json:"-" msgpack:"-"`
 }
 
 // Layer holds a layer of drawing data for a Doodad.
@@ -43,7 +47,8 @@ func New(size int) *Doodad {
 				Chunker: level.NewChunker(size),
 			},
 		},
-		Tags: map[string]string{},
+		Tags:        map[string]string{},
+		UndoHistory: drawtool.NewHistory(balance.UndoHistory),
 	}
 }
 
diff --git a/pkg/uix/canvas.go b/pkg/uix/canvas.go
index 2cede8c..fc8eb43 100644
--- a/pkg/uix/canvas.go
+++ b/pkg/uix/canvas.go
@@ -54,6 +54,7 @@ type Canvas struct {
 	// Underlying chunk data for the drawing.
 	level    *level.Level
 	chunks   *level.Chunker
+	doodad   *doodads.Doodad
 	modified bool // set to True when the drawing has been modified, like in Editor Mode.
 
 	// Actors to superimpose on top of the drawing.
@@ -179,6 +180,7 @@ func (w *Canvas) LoadLevel(level *level.Level) {
 // LoadDoodad initializes a Canvas from a Doodad object.
 func (w *Canvas) LoadDoodad(d *doodads.Doodad) {
 	// TODO more safe
+	w.doodad = d
 	w.Load(d.Palette, d.Layers[0].Chunker)
 }
 
diff --git a/pkg/uix/canvas_editable.go b/pkg/uix/canvas_editable.go
index 14b1d88..f72f519 100644
--- a/pkg/uix/canvas_editable.go
+++ b/pkg/uix/canvas_editable.go
@@ -106,6 +106,8 @@ func (w *Canvas) commitStroke(tool drawtool.Tool, addHistory bool) {
 	// Add the stroke to level history.
 	if w.level != nil && addHistory {
 		w.level.UndoHistory.AddStroke(w.currentStroke)
+	} else if w.doodad != nil && addHistory {
+		w.doodad.UndoHistory.AddStroke(w.currentStroke)
 	}
 
 	w.RemoveStroke(w.currentStroke)
diff --git a/pkg/uix/canvas_strokes.go b/pkg/uix/canvas_strokes.go
index fc575e8..350b415 100644
--- a/pkg/uix/canvas_strokes.go
+++ b/pkg/uix/canvas_strokes.go
@@ -42,12 +42,17 @@ func (w *Canvas) RemoveStroke(stroke *drawtool.Stroke) bool {
 // added to the level. Returns false and emits a warning to the log if the
 // canvas has no level loaded properly.
 func (w *Canvas) UndoStroke() bool {
-	if w.level == nil {
-		log.Error("Canvas.UndoStroke: no Level currently available to the canvas")
+	var undoer *drawtool.History
+	if w.level != nil {
+		undoer = w.level.UndoHistory
+	} else if w.doodad != nil {
+		undoer = w.doodad.UndoHistory
+	} else {
+		log.Error("Canvas.UndoStroke: no Level or Doodad currently available to the canvas")
 		return false
 	}
 
-	latest := w.level.UndoHistory.Latest()
+	latest := undoer.Latest()
 	if latest != nil {
 		// TODO: only single-thickness lines will restore the original color;
 		// thick lines just delete their pixels from the world due to performance.
@@ -93,23 +98,28 @@ func (w *Canvas) UndoStroke() bool {
 
 		}
 	}
-	return w.level.UndoHistory.Undo()
+	return undoer.Undo()
 }
 
 // RedoStroke rolls the level's UndoHistory forwards again and replays the
 // recently undone changes.
 func (w *Canvas) RedoStroke() bool {
-	if w.level == nil {
-		log.Error("Canvas.UndoStroke: no Level currently available to the canvas")
+	var undoer *drawtool.History
+	if w.level != nil {
+		undoer = w.level.UndoHistory
+	} else if w.doodad != nil {
+		undoer = w.doodad.UndoHistory
+	} else {
+		log.Error("Canvas.UndoStroke: no Level or Doodad currently available to the canvas")
 		return false
 	}
 
-	ok := w.level.UndoHistory.Redo()
+	ok := undoer.Redo()
 	if !ok {
 		return false
 	}
 
-	latest := w.level.UndoHistory.Latest()
+	latest := undoer.Latest()
 
 	// We stored the ActiveSwatch on this stroke as we drew it. Recover it
 	// and place the pixels back down.