add command to move cursor proportionally to the track duration

src/core/support/Playback.cpp

@@ -78,6 +78,16 @@ namespace musik {
                 playback.SetPosition(playback.GetPosition() - 10.0f);
             }
 
+            void SeekForwardProportional(IPlaybackService& playback) {
+                double moveBy = 0.05f * playback.GetDuration();
+                playback.SetPosition(playback.GetPosition() + moveBy);
+            }
+
+            void SeekBackProportional(IPlaybackService& playback) {
+                double moveBy = 0.05f * playback.GetDuration();
+                playback.SetPosition(playback.GetPosition() - moveBy);
+            }
+
             void LoadPlaybackContext(Prefs prefs, ILibraryPtr library, PlaybackService& playback) {
                 if (prefs->GetBool(keys::SaveSessionOnExit, true)) {
                     auto query = std::shared_ptr<PersistedPlayQueueQuery>(

src/core/support/Playback.h

@@ -44,6 +44,8 @@ namespace musik {
             void VolumeDown(musik::core::audio::ITransport& transport);
             void SeekForward(musik::core::sdk::IPlaybackService& playback);
             void SeekBack(musik::core::sdk::IPlaybackService& playback);
+            void SeekForwardProportional(musik::core::sdk::IPlaybackService& playback);
+            void SeekBackProportional(musik::core::sdk::IPlaybackService& playback);
             void PauseOrResume(musik::core::audio::ITransport& transport);
 
             void LoadPlaybackContext(

src/musikcube/app/util/GlobalHotkeys.cpp

@@ -92,6 +92,14 @@ bool GlobalHotkeys::Handle(const std::string& kn) {
         core::playback::SeekForward(this->playback);
         return true;
     }
+    else if (Hotkeys::Is(Hotkeys::SeekForwardProportional, kn)) {
+        core::playback::SeekForwardProportional(this->playback);
+        return true;
+    }
+    else if (Hotkeys::Is(Hotkeys::SeekBackProportional, kn)) {
+        core::playback::SeekBackProportional(this->playback);
+        return true;
+    }
     else if (Hotkeys::Is(Hotkeys::ToggleRepeat, kn)) {
         this->playback.ToggleRepeatMode();
         return true;

src/musikcube/app/util/Hotkeys.cpp

@@ -100,6 +100,8 @@ static std::unordered_map<std::string, Id> NAME_TO_ID = {
     { "playback_volume_up", Id::VolumeUp },
     { "playback_volume_down", Id::VolumeDown },
     { "playback_seek_forward", Id::SeekForward },
+    { "playback_seek_forward_proportional", Id::SeekForwardProportional },
+    { "playback_seek_back_proportional", Id::SeekBackProportional },
     { "playback_seek_back", Id::SeekBack },
     { "playback_toggle_repeat", Id::ToggleRepeat },
     { "playback_toggle_shuffle", Id::ToggleShuffle },
@@ -176,6 +178,8 @@ static std::unordered_map<Id, std::string, EnumHasher> ID_TO_DEFAULT = {
     { Id::VolumeDown, "k" },
     { Id::SeekForward, "o" },
     { Id::SeekBack, "u" },
+    { Id::SeekForwardProportional, "p" },
+    { Id::SeekBackProportional, "y" },
     { Id::ToggleRepeat, "." },
     { Id::ToggleShuffle, "," },
     { Id::Stop, "^X" },

src/musikcube/app/util/Hotkeys.h

@@ -82,6 +82,8 @@ namespace musik {
                     VolumeUp,
                     VolumeDown,
                     SeekForward,
+                    SeekForwardProportional,
+                    SeekBackProportional,
                     SeekBack,
                     ToggleRepeat,
                     ToggleShuffle,