icon placeholder

src/PixiEditor.UI.Common/Fonts/PixiPerfectIcons.axaml

@@ -129,6 +129,7 @@
             <system:String x:Key="icon-pause">&#xE980;</system:String>
             <system:String x:Key="icon-timeline">&#xE983;</system:String>
             <system:String x:Key="icon-swatches">&#xE982;</system:String>
+            <system:String x:Key="icon-onion-skin">&#x25AF;</system:String>
         </ResourceDictionary>
     </Styles.Resources>
     

src/PixiEditor/Styles/Templates/Timeline.axaml

@@ -76,7 +76,7 @@
                                     ui1:Translator.TooltipKey="DUPLICATE_FRAME"
                                     Command="{TemplateBinding DuplicateKeyFrameCommand}" />
                             <ToggleButton Classes="pixi-icon"
-                                    Content="onion-skining"
+                                    Content="{DynamicResource icon-onion-skin}"
                                     ui1:Translator.TooltipKey="TOGGLE_ONION_SKINNING"
                                     Command="{TemplateBinding ToggleOnionSkinningCommand}" 
                                     CommandParameter="{Binding Path=IsChecked, RelativeSource={RelativeSource Self}}"