Various Gradient Tool Improvements

- Fix Implementation of the "Toggle Gradient" button.
- Add confirmation popup for the clear gradient button.
- Move buttons to above gradient (thanks Cheerpipe!)

src/Artemis.UI.Shared/Screens/GradientEditor/GradientEditorView.xaml

@@ -60,8 +60,79 @@
         </StackPanel>
         <Separator Grid.Row="1" Margin="0 5" />
         <StackPanel Grid.Row="2" Margin="0 5" ClipToBounds="False">
+            <Grid>
                 <TextBlock Margin="0 5">Gradient</TextBlock>
-
+                <StackPanel Orientation="Horizontal" HorizontalAlignment="Right">
+                    <Button Style="{StaticResource MaterialDesignFlatButton}" 
+                        Margin="0 0 5 4"
+                        Padding="0"
+                        Command="{s:Action SpreadColorStops}" 
+                        ToolTip="Spread Stops" IsEnabled="{Binding HasMoreThanOneStop}" 
+                        HorizontalAlignment="Left"
+                        Height="25" Width="25">
+                        <materialDesign:PackIcon Kind="ArrowLeftRight"/>
+                    </Button>
+                    <Button Style="{StaticResource MaterialDesignFlatButton}" 
+                        Margin="0 0 5 4"
+                        Padding="0"
+                        Command="{s:Action ToggleSeam}" 
+                        ToolTip="Toggle Seamless" IsEnabled="{Binding HasMoreThanOneStop}" 
+                        HorizontalAlignment="Left"
+                        Height="25" Width="25">
+                        <materialDesign:PackIcon Kind="SineWave"/>
+                    </Button>
+                    <Button Style="{StaticResource MaterialDesignFlatButton}" 
+                        Margin="0 0 5 4"
+                        Padding="0"
+                        Command="{s:Action FlipColorStops}" 
+                        ToolTip="Flip Stops" IsEnabled="{Binding HasMoreThanOneStop}" 
+                        HorizontalAlignment="Left"
+                        Height="25" Width="25">
+                        <materialDesign:PackIcon Kind="FlipHorizontal"/>
+                    </Button>
+                    <Button Style="{StaticResource MaterialDesignFlatButton}" 
+                        Margin="0 0 5 4"
+                        Padding="0"
+                        Command="{s:Action RotateColorStops}" 
+                        ToolTip="Rotate Stops (shift to invert)" IsEnabled="{Binding HasMoreThanOneStop}" 
+                        HorizontalAlignment="Left"
+                        Height="25" Width="25">
+                        <materialDesign:PackIcon Kind="AxisZRotateCounterclockwise"/>
+                    </Button>
+                    <Button Style="{StaticResource MaterialDesignFlatButton}" 
+                        Margin="0 0 5 4"
+                        Padding="0"
+                        Command="{s:Action ShowClearGradientPopup}" 
+                        ToolTip="Clear All Color Stops" IsEnabled="{Binding HasMoreThanOneStop}" 
+                        HorizontalAlignment="Left"
+                        Height="25" Width="25"
+                        x:Name="ClearGradientButton">
+                        <StackPanel>
+                            <materialDesign:PackIcon Kind="DeleteSweep"/>
+                        </StackPanel>
+                    </Button>
+                    <Popup
+                        AllowsTransparency="True"
+                        Placement="Right"
+                        VerticalOffset="-25"
+                        HorizontalOffset="-5"
+                        CustomPopupPlacementCallback="{x:Static materialDesign:CustomPopupPlacementCallbackHelper.LargePopupCallback}"
+                        PlacementTarget="{Binding ElementName=ClearGradientButton}"
+                        StaysOpen="False"
+                        PopupAnimation="Fade"
+                        IsOpen="{Binding ClearGradientPopupOpen, Mode=OneWay}">
+                        <materialDesign:Card Margin="30" Padding="12" materialDesign:ShadowAssist.ShadowDepth="Depth4" >
+                            <StackPanel HorizontalAlignment="Center">
+                                <TextBlock Style="{StaticResource MaterialDesignSubtitle2TextBlock}" TextAlignment="Center" Margin="0 0 0 10">Clear Gradient?</TextBlock>
+                                <StackPanel Orientation="Horizontal">
+                                    <Button Command="{s:Action HideClearGradientPopup}" Style="{StaticResource MaterialDesignOutlinedButton}" Margin="0 0 10 0">No</Button>
+                                    <Button Command="{s:Action ClearGradientAndHide}">Yes</Button>
+                                </StackPanel>
+                            </StackPanel>
+                        </materialDesign:Card>
+                    </Popup>
+                </StackPanel>
+            </Grid>
             <Border Background="{StaticResource Checkerboard}">
                 <Rectangle x:Name="Preview" Height="40" shared:SizeObserver.Observe="True" shared:SizeObserver.ObservedWidth="{Binding PreviewWidth, Mode=OneWayToSource}">
                     <Rectangle.Fill>
@@ -90,67 +161,6 @@
                     </DataTemplate>
                 </ItemsControl.ItemTemplate>
             </ItemsControl>
-            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0">
-                <Button Style="{StaticResource MaterialDesignOutlinedButton}" 
-                    Margin="0 4 8 8"
-                    Command="{s:Action SpreadColorStops}" 
-                    ToolTip="Spread Stops" IsEnabled="{Binding HasMoreThanOneStop}" 
-                    HorizontalAlignment="Left"
-                    Height="25" Width="100">
-                    <StackPanel Orientation="Horizontal">
-                        <materialDesign:PackIcon Kind="DistributeHorizontalCenter"/>
-                        <TextBlock Margin="6 0 0 0">Spread</TextBlock>
-                    </StackPanel>
-                </Button>
-                <Button Style="{StaticResource MaterialDesignOutlinedButton}" 
-                    Margin="0 4 8 8"
-                    Command="{s:Action RotateColorStops}" 
-                    ToolTip="Rotate Stops" IsEnabled="{Binding HasMoreThanOneStop}" 
-                    HorizontalAlignment="Left"
-                    Height="25" Width="100">
-                    <StackPanel Orientation="Horizontal">
-                        <materialDesign:PackIcon Kind="AxisZRotateCounterclockwise" />
-                        <TextBlock Margin="6 0 0 0">Rotate</TextBlock>
-                    </StackPanel>
-                </Button>
-                <Button Style="{StaticResource MaterialDesignOutlinedButton}" 
-                    Margin="0 4 8 8"
-                    Command="{s:Action FlipColorStops}" 
-                    IsEnabled="{Binding HasMoreThanOneStop}" 
-                    HorizontalAlignment="Left"
-                    Height="25" Width="100" ToolTip="Flip Stops">
-                    <StackPanel Orientation="Horizontal">
-                        <materialDesign:PackIcon Kind="FlipHorizontal"/>
-                        <TextBlock Margin="6 0 0 0">Flip</TextBlock>
-                    </StackPanel>
-                </Button>
-            </StackPanel>
-            <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" Margin="0">
-                
-                <Button Style="{StaticResource MaterialDesignOutlinedButton}" 
-                    Margin="0 0 8 0"
-                    Command="{s:Action ToggleSeam}" 
-                    IsEnabled="{Binding HasMoreThanOneStop}" 
-                    HorizontalAlignment="Left"
-                    Height="25" Width="100" ToolTip="Toggle Seam">
-                    <StackPanel Orientation="Horizontal">
-                        <materialDesign:PackIcon Kind="ArrowSplitVertical"/>
-                        <TextBlock Margin="6 0 0 0">Seam</TextBlock>
-                    </StackPanel>
-                </Button>
-                <Button Style="{StaticResource MaterialDesignOutlinedButton}" 
-                    Margin="0 0 8 0"
-                    Command="{s:Action ClearGradient}" 
-                    IsEnabled="{Binding HasMoreThanOneStop}" 
-                    HorizontalAlignment="Left"
-                    Height="25" Width="100" ToolTip="Clear Gradient">
-                    <StackPanel Orientation="Horizontal">
-                        <materialDesign:PackIcon Kind="DeleteSweep"/>
-                        <TextBlock Margin="6 0 0 0">Clear</TextBlock>
-                    </StackPanel>
-                </Button>
-            </StackPanel>
-            
             <TextBlock Margin="0 6 0 0" FontWeight="Bold">Selected stop:</TextBlock>
 
             <Grid Margin="0 5">
@@ -170,7 +180,7 @@
 
                     <Label HorizontalAlignment="Center">Location:</Label>
                     <TextBox Width="30"
-                             Text="{Binding SelectedColorStopViewModel.OffsetPercent}"
+                             Text="{Binding SelectedColorStopViewModel.OffsetPercent, UpdateSourceTrigger=PropertyChanged}"
                              IsEnabled="{Binding HasSelectedColorStopViewModel}"
                              materialDesign:HintAssist.Hint="0"
                              Margin="5 0 0 0" />
@@ -184,6 +194,9 @@
                         Command="{s:Action RemoveColorStop}"
                         CommandParameter="{Binding SelectedColorStopViewModel}"
                         ToolTip="Delete Selected Stop">
+                    <Button.Resources>
+                        <SolidColorBrush x:Key="PrimaryHueMidBrush" Color="#c94848"/>
+                    </Button.Resources>
                     <StackPanel Orientation="Horizontal">
                         <materialDesign:PackIcon Kind="Delete"/>
                         <TextBlock Margin="4 0 0 0">Delete</TextBlock>

src/Artemis.UI.Shared/Screens/GradientEditor/GradientEditorViewModel.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.ComponentModel;
 using System.Linq;
@@ -44,6 +45,8 @@ namespace Artemis.UI.Shared.Screens.GradientEditor
 
         public bool HasSelectedColorStopViewModel => SelectedColorStopViewModel != null;
         public bool HasMoreThanOneStop => ColorStopViewModels.Count > 1;
+        private bool popupOpen = false;
+        public bool ClearGradientPopupOpen => popupOpen;
 
         public ColorGradient ColorGradient { get; }
 
@@ -91,6 +94,7 @@ namespace Artemis.UI.Shared.Screens.GradientEditor
             NotifyOfPropertyChange(nameof(HasMoreThanOneStop));
         }
 
+        #region Gradient Tools
         public void SpreadColorStops()
         {
             List<ColorStopViewModel> stops = ColorStopViewModels.OrderBy(x => x.OffsetFloat).ToList();
@@ -129,39 +133,67 @@ namespace Artemis.UI.Shared.Screens.GradientEditor
             if (ColorGradient.IsSeamless())
             {
                 // Remove the last stop
-                ColorStopViewModel? stop = ColorStopViewModels.OrderBy(x => x.OffsetFloat).Last();
+                ColorStopViewModel? stopToRemove = ColorStopViewModels.OrderBy(x => x.OffsetFloat).Last();
 
-                if (stop == SelectedColorStopViewModel) SelectColorStop(null);
+                if (stopToRemove == SelectedColorStopViewModel) SelectColorStop(null);
+
+                ColorStopViewModels.Remove(stopToRemove);
+                ColorGradient.Remove(stopToRemove.ColorStop);
+
+                // Uncompress the stops if there is still more than one
+                List<ColorStopViewModel> stops = ColorStopViewModels.OrderBy(x => x.OffsetFloat).ToList();
+
+                if (stops.Count >= 2)
+                {
+                    float multiplier = stops.Count/(stops.Count - 1f);
+                    foreach (ColorStopViewModel stop in stops)
+                        stop.OffsetFloat = Math.Min(stop.OffsetFloat * multiplier, 100f);
+                }
                 
-                ColorStopViewModels.Remove(stop);
-                ColorGradient.Remove(stop.ColorStop);
 
-                // Distribute the stops if there is still more than one
-                if (ColorGradient.Count > 1)
-                    SpreadColorStops();
             }
             else
             {
+                // Compress existing stops to the left
+                List<ColorStopViewModel> stops = ColorStopViewModels.OrderBy(x => x.OffsetFloat).ToList();
+
+                float multiplier = (stops.Count - 1f)/stops.Count;
+                foreach (ColorStopViewModel stop in stops)
+                    stop.OffsetFloat *= multiplier;
+
                 // Add a stop to the end that is the same color as the first stop
-                ColorGradientStop stop = new(ColorGradient.First().Color, 100);
+                ColorGradientStop newStop = new(ColorGradient.First().Color, 1f);
-                ColorGradient.Add(stop);
+                ColorGradient.Add(newStop);
 
-                ColorStopViewModel viewModel = new(this, stop);
+                int index = ColorGradient.IndexOf(newStop);
-                ColorStopViewModels.Add(viewModel);
+                ColorStopViewModel viewModel = new(this, newStop);
-
+                ColorStopViewModels.Insert(index, viewModel);
-                NotifyOfPropertyChange(nameof(HasMoreThanOneStop));
-
-                // Distribute the stops
-                SpreadColorStops();
             }
         }
 
+        public void ShowClearGradientPopup()
+        {
+            popupOpen = true;
+            NotifyOfPropertyChange(nameof(ClearGradientPopupOpen));
+        }
+        public void HideClearGradientPopup()
+        {
+            popupOpen = false;
+            NotifyOfPropertyChange(nameof(ClearGradientPopupOpen));
+        }
+        public void ClearGradientAndHide()
+        {
+            ClearGradient();
+            HideClearGradientPopup();
+        }
         public void ClearGradient()
         {
             ColorGradient.Clear();
             ColorStopViewModels.Clear();
         }
 
+        #endregion
+
         public Point GetPositionInPreview(object sender, MouseEventArgs e)
         {
             Canvas? parent = VisualTreeUtilities.FindParent<Canvas>((DependencyObject) sender, null);