From dbfd4d84120731b5cfa1c95109ea9990799cac2c Mon Sep 17 00:00:00 2001
From: Emmanouil Papadeas <35376950+OverloadedOrama@users.noreply.github.com>
Date: Tue, 9 Apr 2024 02:30:50 +0300
Subject: [PATCH] When merging layers, automatically make the bottom layer
 visible

If the bottom layer is invisible, it becomes visible now. Consistent with behavior seen in Krita and Photopea.
---
 src/Classes/Layers/BaseLayer.gd      | 6 +++++-
 src/UI/Timeline/AnimationTimeline.gd | 2 +-
 src/UI/Timeline/LayerButton.gd       | 1 +
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/Classes/Layers/BaseLayer.gd b/src/Classes/Layers/BaseLayer.gd
index b5431e58f..aa5898d07 100644
--- a/src/Classes/Layers/BaseLayer.gd
+++ b/src/Classes/Layers/BaseLayer.gd
@@ -3,6 +3,7 @@ extends RefCounted
 ## Base class for layer properties. Different layer types extend from this class.
 
 signal name_changed  ## Emits when [member name] is changed.
+signal visibility_changed  ## Emits when [member visible] is changed.
 
 ## All currently supported layer blend modes between two layers. The upper layer
 ## is the blend layer, and the bottom layer is the base layer.
@@ -37,7 +38,10 @@ var name := "":  ## Name of the layer.
 var project: Project  ## The project the layer belongs to.
 var index: int  ## Index of layer in the timeline.
 var parent: BaseLayer  ## Parent of the layer.
-var visible := true  ## Sets visibility of the layer.
+var visible := true:  ## Sets visibility of the layer.
+	set(value):
+		visible = value
+		visibility_changed.emit()
 var locked := false  ## Images of a locked layer won't be overritten.
 var new_cels_linked := false  ## Determines if new cel of the layer should be linked or not.
 var blend_mode := BlendModes.NORMAL  ## Blend mode of the current layer.
diff --git a/src/UI/Timeline/AnimationTimeline.gd b/src/UI/Timeline/AnimationTimeline.gd
index ccc2466be..8c95c474a 100644
--- a/src/UI/Timeline/AnimationTimeline.gd
+++ b/src/UI/Timeline/AnimationTimeline.gd
@@ -948,7 +948,6 @@ func _on_MergeDownLayer_pressed() -> void:
 
 	project.undos += 1
 	project.undo_redo.create_action("Merge Layer")
-
 	for frame in project.frames:
 		var top_cel := frame.cels[top_layer.index]
 		top_cels.append(top_cel)  # Store for undo purposes
@@ -1000,6 +999,7 @@ func _on_MergeDownLayer_pressed() -> void:
 	project.undo_redo.add_undo_method(Global.undo_or_redo.bind(true))
 	project.undo_redo.add_do_method(Global.undo_or_redo.bind(false))
 	project.undo_redo.commit_action()
+	bottom_layer.visible = true
 
 
 func _on_OpacitySlider_value_changed(value: float) -> void:
diff --git a/src/UI/Timeline/LayerButton.gd b/src/UI/Timeline/LayerButton.gd
index 3fd616860..2d7344803 100644
--- a/src/UI/Timeline/LayerButton.gd
+++ b/src/UI/Timeline/LayerButton.gd
@@ -34,6 +34,7 @@ func _ready() -> void:
 	Global.cel_switched.connect(func(): z_index = 1 if button_pressed else 0)
 	var layer := Global.current_project.layers[layer_index]
 	layer.name_changed.connect(func(): label.text = layer.name)
+	layer.visibility_changed.connect(update_buttons)
 	if layer is PixelLayer:
 		linked_button.visible = true
 	elif layer is GroupLayer: