Added a preview to the Resize Canvas dialog

CHANGELOG.md

@@ -37,7 +37,7 @@ Darshan Phaldesai (luiq54), Igor Santarek (jegor377), rob-a-bolton, Kinwailo
 - Fixed a rare issue with Undo/Redo not working while motion-drawing and making lines.
 - Grid and guides are now longer being displayed on previews. ([#205](https://github.com/Orama-Interactive/Pixelorama/issues/205))
 - Fixed a rare problem where the custom mouse cursor's image was failing to load.
-- Importing a non-palette json file no longer crashes the app.
+- Importing corrupted image files and non-palette json files no longer crash the app.
 <br><br>
 
 ## [v0.7] - 2020-05-16

src/UI/Dialogs/ResizeCanvas.gd

@@ -5,9 +5,35 @@ var width := 64
 var height := 64
 var offset_x := 0
 var offset_y := 0
+var image : Image
 
 onready var x_spinbox : SpinBox = $VBoxContainer/OptionsContainer/XSpinBox
 onready var y_spinbox : SpinBox = $VBoxContainer/OptionsContainer/YSpinBox
+onready var preview_rect : TextureRect = $VBoxContainer/Preview
+
+
+func _on_ResizeCanvas_about_to_show() -> void:
+	image = Image.new()
+	image.create(Global.current_project.size.x, Global.current_project.size.y, false, Image.FORMAT_RGBA8)
+	image.lock()
+	var layer_i := 0
+	for cel in Global.current_project.frames[Global.current_project.current_frame].cels:
+		if Global.current_project.layers[layer_i].visible:
+			var cel_image := Image.new()
+			cel_image.copy_from(cel.image)
+			cel_image.lock()
+			if cel.opacity < 1: # If we have cel transparency
+				for xx in cel_image.get_size().x:
+					for yy in cel_image.get_size().y:
+						var pixel_color := cel_image.get_pixel(xx, yy)
+						var alpha : float = pixel_color.a * cel.opacity
+						cel_image.set_pixel(xx, yy, Color(pixel_color.r, pixel_color.g, pixel_color.b, alpha))
+			image.blend_rect(cel_image, Rect2(Global.canvas.location, Global.current_project.size), Vector2.ZERO)
+		layer_i += 1
+	image.unlock()
+
+	update_preview()
+	preview_rect.get_node("TransparentChecker").rect_size = preview_rect.rect_size
 
 
 func _on_ResizeCanvas_confirmed() -> void:
@@ -19,6 +45,7 @@ func _on_WidthValue_value_changed(value : int) -> void:
 	x_spinbox.min_value = min(width - Global.current_project.size.x, 0)
 	x_spinbox.max_value = max(width - Global.current_project.size.x, 0)
 	x_spinbox.value = clamp(x_spinbox.value, x_spinbox.min_value, x_spinbox.max_value)
+	update_preview()
 
 
 func _on_HeightValue_value_changed(value : int) -> void:
@@ -26,16 +53,28 @@ func _on_HeightValue_value_changed(value : int) -> void:
 	y_spinbox.min_value = min(height - Global.current_project.size.y, 0)
 	y_spinbox.max_value = max(height - Global.current_project.size.y, 0)
 	y_spinbox.value = clamp(y_spinbox.value, y_spinbox.min_value, y_spinbox.max_value)
+	update_preview()
 
 
 func _on_XSpinBox_value_changed(value : int) -> void:
 	offset_x = value
+	update_preview()
 
 
 func _on_YSpinBox_value_changed(value : int) -> void:
 	offset_y = value
+	update_preview()
 
 
 func _on_CenterButton_pressed() -> void:
 	x_spinbox.value = (x_spinbox.min_value + x_spinbox.max_value) / 2
 	y_spinbox.value = (y_spinbox.min_value + y_spinbox.max_value) / 2
+
+
+func update_preview() -> void:
+	var preview_image := Image.new()
+	preview_image.create(width, height, false, Image.FORMAT_RGBA8)
+	preview_image.blend_rect(image, Rect2(Vector2.ZERO, Global.current_project.size), Vector2(offset_x, offset_y))
+	var preview_texture := ImageTexture.new()
+	preview_texture.create_from_image(preview_image, 0)
+	preview_rect.texture = preview_texture

src/UI/Dialogs/ResizeCanvas.tscn

@@ -1,6 +1,7 @@
-[gd_scene load_steps=2 format=2]
+[gd_scene load_steps=3 format=2]
 
 [ext_resource path="res://src/UI/Dialogs/ResizeCanvas.gd" type="Script" id=1]
+[ext_resource path="res://src/UI/TransparentChecker.tscn" type="PackedScene" id=2]
 
 [node name="ResizeCanvas" type="ConfirmationDialog"]
 margin_right = 200.0
@@ -10,20 +11,20 @@ script = ExtResource( 1 )
 [node name="VBoxContainer" type="VBoxContainer" parent="."]
 margin_left = 8.0
 margin_top = 8.0
-margin_right = 192.0
+margin_right = 208.0
-margin_bottom = 176.0
+margin_bottom = 380.0
 __meta__ = {
 "_edit_use_anchors_": false
 }
 
 [node name="ImageSize" type="Label" parent="VBoxContainer"]
-margin_right = 184.0
+margin_right = 200.0
 margin_bottom = 14.0
 text = "Canvas Size"
 
 [node name="OptionsContainer" type="GridContainer" parent="VBoxContainer"]
 margin_top = 18.0
-margin_right = 184.0
+margin_right = 200.0
 margin_bottom = 168.0
 custom_constants/vseparation = 4
 custom_constants/hseparation = 2
@@ -109,6 +110,18 @@ margin_top = 130.0
 margin_right = 54.0
 margin_bottom = 150.0
 text = "Center"
+
+[node name="Preview" type="TextureRect" parent="VBoxContainer"]
+margin_top = 172.0
+margin_right = 200.0
+margin_bottom = 372.0
+rect_min_size = Vector2( 200, 200 )
+expand = true
+stretch_mode = 6
+
+[node name="TransparentChecker" parent="VBoxContainer/Preview" instance=ExtResource( 2 )]
+show_behind_parent = true
+[connection signal="about_to_show" from="." to="." method="_on_ResizeCanvas_about_to_show"]
 [connection signal="confirmed" from="." to="." method="_on_ResizeCanvas_confirmed"]
 [connection signal="value_changed" from="VBoxContainer/OptionsContainer/WidthValue" to="." method="_on_WidthValue_value_changed"]
 [connection signal="value_changed" from="VBoxContainer/OptionsContainer/HeightValue" to="." method="_on_HeightValue_value_changed"]