From f6d5a3c9b9ef97fac6888ca6ab1a88a590befb47 Mon Sep 17 00:00:00 2001
From: v-shift-bit <308126563+v-shift-bit@users.noreply.github.com>
Date: Mon, 14 Sep 2026 20:47:47 +0300
Subject: [PATCH] Add playback speed control and timeline seek hotkeys to
 VideoViewer

---
 .../QuickLook.Plugin.VideoViewer/Styles.xaml  |  40 +++++
 .../Translations.config                       |   2 +
 .../ViewerPanel.xaml                          |   7 +
 .../ViewerPanel.xaml.cs                       | 165 ++++++++++++++++++
 4 files changed, 214 insertions(+)

diff --git a/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/Styles.xaml b/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/Styles.xaml
index e9da23920..1d0864a61 100644
--- a/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/Styles.xaml
+++ b/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/Styles.xaml
@@ -50,6 +50,46 @@
         </Style.Triggers>
     </Style>
 
+    <Style x:Key="SpeedButtonStyle"
+           BasedOn="{StaticResource CaptionButtonBaseStyle}"
+           TargetType="Button">
+        <Setter Property="Width" Value="46" />
+        <Setter Property="Height" Value="22" />
+        <Setter Property="Margin" Value="2,0,0,0" />
+        <Setter Property="Padding" Value="3,0" />
+        <Setter Property="Background" Value="{DynamicResource CardBackground}" />
+        <Setter Property="BorderBrush" Value="{DynamicResource CardBorderBrush}" />
+        <Setter Property="BorderThickness" Value="1" />
+        <Setter Property="FontSize" Value="11" />
+        <Setter Property="FontWeight" Value="SemiBold" />
+        <Setter Property="Foreground" Value="{DynamicResource CaptionButtonIconForeground}" />
+        <Setter Property="HorizontalContentAlignment" Value="Center" />
+        <Setter Property="VerticalContentAlignment" Value="Center" />
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="{x:Type Button}">
+                    <Border Background="{TemplateBinding Background}"
+                            BorderBrush="{TemplateBinding BorderBrush}"
+                            BorderThickness="{TemplateBinding BorderThickness}"
+                            SnapsToDevicePixels="True">
+                        <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
+                                          VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
+                    </Border>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+        <Style.Triggers>
+            <Trigger Property="IsMouseOver" Value="True">
+                <Setter Property="Background" Value="{DynamicResource CardBackground}" />
+                <Setter Property="BorderBrush" Value="{DynamicResource CardBorderBrush}" />
+            </Trigger>
+            <Trigger Property="IsPressed" Value="True">
+                <Setter Property="Background" Value="{DynamicResource CardBackground}" />
+                <Setter Property="BorderBrush" Value="{DynamicResource CardBorderBrush}" />
+            </Trigger>
+        </Style.Triggers>
+    </Style>
+
     <!--  Postion Slider Control  -->
     <ControlTemplate x:Key="PositionSliderThumbTemplate" TargetType="{x:Type Thumb}">
         <Grid HorizontalAlignment="Center"
diff --git a/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/Translations.config b/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/Translations.config
index d212581ff..d18b7679d 100644
--- a/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/Translations.config
+++ b/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/Translations.config
@@ -54,6 +54,7 @@
     <BTN_PlayPause>Play/Pause</BTN_PlayPause>
     <BTN_Loop>Loop</BTN_Loop>
     <BTN_HardwareAcceleration>Hardware/Software Decoding</BTN_HardwareAcceleration>
+    <BTN_Speed>Playback Speed (click to cycle, right-click to reset; +/- and 0 also work)</BTN_Speed>
     <BTN_Volume>Volume</BTN_Volume>
     <BTN_Time>Time Elapsed/Remaining</BTN_Time>
   </en>
@@ -124,6 +125,7 @@
     <BTN_PlayPause>Play/Pause</BTN_PlayPause>
     <BTN_Loop>Loop</BTN_Loop>
     <BTN_HardwareAcceleration>Hardware/Software Decoding</BTN_HardwareAcceleration>
+    <BTN_Speed>Скорость воспроизведения (клик — переключить, ПКМ — сбросить; также +/- и 0)</BTN_Speed>
     <BTN_Volume>Volume</BTN_Volume>
     <BTN_Time>Time Elapsed/Remaining</BTN_Time>
   </ru-RU>
diff --git a/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/ViewerPanel.xaml b/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/ViewerPanel.xaml
index c7aa2c371..52c622ed6 100644
--- a/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/ViewerPanel.xaml
+++ b/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/ViewerPanel.xaml
@@ -212,6 +212,13 @@
                         </TextBlock.Style>
                     </TextBlock>
                 </Button>
+                <Button x:Name="buttonSpeed"
+                        DockPanel.Dock="Left"
+                        Style="{StaticResource SpeedButtonStyle}"
+                        ToolTip="Playback Speed (+/- to change, 0 to reset)">
+                    <TextBlock VerticalAlignment="Center"
+                               Text="{Binding PlaybackSpeed, ElementName=viewerPanel, StringFormat={}{0:0.##}x}" />
+                </Button>
                 <Button x:Name="buttonMute"
                         DockPanel.Dock="Right"
                         ToolTip="Volume">
diff --git a/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/ViewerPanel.xaml.cs b/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/ViewerPanel.xaml.cs
index 6d7c5a489..775ca65e2 100644
--- a/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/ViewerPanel.xaml.cs
+++ b/QuickLook.Plugin/QuickLook.Plugin.VideoViewer/ViewerPanel.xaml.cs
@@ -56,6 +56,17 @@ public partial class ViewerPanel : UserControl, IDisposable, INotifyPropertyChan
     private bool _wasPlaying;
     private bool _shouldLoop;
     private bool _useHardwareAcceleration;
+    private double _playbackSpeed = 1.0d;
+
+    // Preset playback speeds cycled through by the speed button and the +/- hotkeys.
+    private static readonly double[] SpeedPresets = [0.25d, 0.5d, 0.75d, 1.0d, 1.25d, 1.5d, 1.75d, 2.0d];
+
+    // Seek step sizes (in 100ns ticks, same unit as MediaPosition/MediaDuration) used by the
+    // timeline hotkeys: Shift+Left/Right for a short seek, Ctrl+Left/Right for a long seek.
+    // Plain arrow keys are intentionally left untouched: QuickLook's global hotkey dispatcher
+    // already uses them to switch between files in Explorer.
+    private static readonly long ShortSeekTicks = TimeSpan.FromSeconds(5).Ticks;
+    private static readonly long LongSeekTicks = TimeSpan.FromSeconds(30).Ticks;
 
     public ViewerPanel(ContextObject context)
     {
@@ -88,12 +99,19 @@ public ViewerPanel(ContextObject context)
         buttonPlayPause.ToolTip = TranslationHelper.Get("BTN_PlayPause", translationFile, failsafe: "Play/Pause");
         buttonLoop.ToolTip = TranslationHelper.Get("BTN_Loop", translationFile, failsafe: "Loop");
         buttonHardwareAcceleration.ToolTip = TranslationHelper.Get("BTN_HardwareAcceleration", translationFile, failsafe: "Hardware/Software Decoding");
+        buttonSpeed.ToolTip = TranslationHelper.Get("BTN_Speed", translationFile, failsafe: "Playback Speed (+/- to change, 0 to reset)");
         buttonMute.ToolTip = TranslationHelper.Get("BTN_Volume", translationFile, failsafe: "Volume");
         buttonTime.ToolTip = TranslationHelper.Get("BTN_Time", translationFile, failsafe: "Time Elapsed/Remaining");
 
         buttonPlayPause.Click += TogglePlayPause;
         buttonLoop.Click += ToggleShouldLoop;
         buttonHardwareAcceleration.Click += ToggleHardwareAcceleration;
+        buttonSpeed.Click += (_, _) => CycleSpeed(1);
+        buttonSpeed.MouseRightButtonUp += (_, e) =>
+        {
+            PlaybackSpeed = 1.0d;
+            e.Handled = true;
+        };
         buttonTime.Click += (_, _) => buttonTime.Tag = (string)buttonTime.Tag == "Time" ? "Length" : "Time";
         buttonMute.Click += (_, _) => volumeSliderLayer.Visibility = Visibility.Visible;
         volumeSliderLayer.MouseDown += (_, _) => volumeSliderLayer.Visibility = Visibility.Collapsed;
@@ -109,6 +127,14 @@ public ViewerPanel(ContextObject context)
         };
 
         PreviewMouseWheel += (_, e) => ChangeVolume(e.Delta / 120d * 0.04d);
+
+        // Keyboard hotkeys for seeking the timeline and changing playback speed.
+        // Keep keyboard focus on the panel itself: every child control in this panel
+        // (buttons, sliders) is Focusable="False" by design, so focus otherwise stays
+        // on the host window and PreviewKeyDown here would not fire on it.
+        Focusable = true;
+        Loaded += (_, _) => Focus();
+        PreviewKeyDown += ViewerPanel_PreviewKeyDown;
     }
 
     private partial void LoadAndInsertGlassLayer();
@@ -157,6 +183,27 @@ private set
         }
     }
 
+    /// <summary>
+    /// The current playback speed multiplier (1.0 = normal speed). Backed by the
+    /// underlying <see cref="mediaElement"/>'s DirectShow SpeedRatio (IMediaSeeking.SetRate).
+    /// </summary>
+    public double PlaybackSpeed
+    {
+        get => _playbackSpeed;
+        set
+        {
+            var clamped = Math.Max(SpeedPresets[0], Math.Min(SpeedPresets[SpeedPresets.Length - 1], value));
+            if (Math.Abs(clamped - _playbackSpeed) < 0.0001d) return;
+
+            _playbackSpeed = clamped;
+
+            if (mediaElement != null)
+                mediaElement.SpeedRatio = _playbackSpeed;
+
+            OnPropertyChanged();
+        }
+    }
+
     public BitmapSource CoverArt
     {
         get => _coverArt;
@@ -175,6 +222,7 @@ public void Dispose()
         SettingHelper.Set("VolumeDouble", LinearVolume, "QuickLook.Plugin.VideoViewer");
         SettingHelper.Set("ShouldLoop", ShouldLoop, "QuickLook.Plugin.VideoViewer");
         SettingHelper.Set("UseHardwareAcceleration", UseHardwareAcceleration, "QuickLook.Plugin.VideoViewer");
+        SettingHelper.Set("PlaybackSpeed", PlaybackSpeed, "QuickLook.Plugin.VideoViewer");
 
         try
         {
@@ -200,6 +248,10 @@ public void Dispose()
 
     private void Panel_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
     {
+        // Make sure the panel (not the window) owns keyboard focus, so that the
+        // seek/speed hotkeys keep working after the user interacts with the mouse.
+        Focus();
+
         if (e.LeftButton == MouseButtonState.Pressed)
         {
             var wnd = Window.GetWindow(this);
@@ -211,6 +263,118 @@ private void Panel_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
         }
     }
 
+    /// <summary>
+    /// Handles keyboard shortcuts for timeline seeking and playback speed.
+    ///
+    /// Plain Left/Right/Up/Down are deliberately NOT used here: QuickLook's global
+    /// low-level keyboard hook (see QuickLook.KeystrokeDispatcher) already reuses those
+    /// keys system-wide to switch between files in Explorer, and it never marks the
+    /// keystroke as handled, so it would still reach this handler too. Using modifier
+    /// combinations avoids fighting over the same keys:
+    ///   Shift+Left / Shift+Right  - seek 5 seconds backward/forward
+    ///   Ctrl+Left  / Ctrl+Right   - seek 30 seconds backward/forward
+    ///   Home / End                - jump to the start/end of the media
+    ///   +/-  (OemPlus/OemMinus)   - increase/decrease playback speed
+    ///   0    (D0/NumPad0)         - reset playback speed to 1.0x
+    /// </summary>
+    private void ViewerPanel_PreviewKeyDown(object sender, KeyEventArgs e)
+    {
+        if (mediaElement?.Source == null)
+            return;
+
+        var modifiers = Keyboard.Modifiers;
+
+        switch (e.Key)
+        {
+            case Key.Left when modifiers == ModifierKeys.Shift:
+                Seek(-ShortSeekTicks);
+                e.Handled = true;
+                break;
+
+            case Key.Right when modifiers == ModifierKeys.Shift:
+                Seek(ShortSeekTicks);
+                e.Handled = true;
+                break;
+
+            case Key.Left when modifiers == ModifierKeys.Control:
+                Seek(-LongSeekTicks);
+                e.Handled = true;
+                break;
+
+            case Key.Right when modifiers == ModifierKeys.Control:
+                Seek(LongSeekTicks);
+                e.Handled = true;
+                break;
+
+            case Key.Home when modifiers == ModifierKeys.None:
+                SeekTo(0L);
+                e.Handled = true;
+                break;
+
+            case Key.End when modifiers == ModifierKeys.None:
+                SeekTo(mediaElement.MediaDuration);
+                e.Handled = true;
+                break;
+
+            case Key.OemPlus or Key.Add when modifiers == ModifierKeys.None:
+                CycleSpeed(1);
+                e.Handled = true;
+                break;
+
+            case Key.OemMinus or Key.Subtract when modifiers == ModifierKeys.None:
+                CycleSpeed(-1);
+                e.Handled = true;
+                break;
+
+            case Key.D0 or Key.NumPad0 when modifiers == ModifierKeys.None:
+                PlaybackSpeed = 1.0d;
+                e.Handled = true;
+                break;
+        }
+    }
+
+    /// <summary>Seeks the timeline by a relative amount of 100ns ticks (same unit as MediaPosition).</summary>
+    private void Seek(long deltaTicks)
+    {
+        if (mediaElement == null)
+            return;
+
+        SeekTo(mediaElement.MediaPosition + deltaTicks);
+    }
+
+    /// <summary>Seeks the timeline to an absolute position, clamped to the media's duration.</summary>
+    private void SeekTo(long positionTicks)
+    {
+        if (mediaElement == null)
+            return;
+
+        var duration = mediaElement.MediaDuration;
+        var clamped = duration > 0
+            ? Math.Max(0L, Math.Min(duration, positionTicks))
+            : Math.Max(0L, positionTicks);
+
+        mediaElement.MediaPosition = clamped;
+    }
+
+    /// <summary>Moves the playback speed to the next/previous preset in <see cref="SpeedPresets"/>.</summary>
+    private void CycleSpeed(int direction)
+    {
+        var index = 3; // default: land on 1.0x if the current speed isn't an exact preset match
+        var smallestDelta = double.MaxValue;
+        for (var i = 0; i < SpeedPresets.Length; i++)
+        {
+            var delta = Math.Abs(SpeedPresets[i] - PlaybackSpeed);
+            if (delta < smallestDelta)
+            {
+                smallestDelta = delta;
+                index = i;
+            }
+        }
+
+        index = Math.Max(0, Math.Min(SpeedPresets.Length - 1, index + direction));
+        PlaybackSpeed = SpeedPresets[index];
+    }
+
     public event PropertyChangedEventHandler PropertyChanged;
 
     private void MediaOpened(object o, RoutedEventArgs args)
@@ -483,6 +647,7 @@ public void LoadAndPlay(string path, MediaInfoNative info)
         mediaElement.Source = new Uri(path);
         // old plugin use an int-typed "Volume" config key ranged from 0 to 100. Let's use a new one here.
         LinearVolume = Math.Max(0d, Math.Min(1d, SettingHelper.Get("VolumeDouble", 1d, "QuickLook.Plugin.VideoViewer")));
+        PlaybackSpeed = SettingHelper.Get("PlaybackSpeed", 1d, "QuickLook.Plugin.VideoViewer");
 
         mediaElement.Play();
     }