feat: Customizable shortcuts/hotkeys (#439)

This implements the logic for allowing hotkeys with modifiers.
Implemented globalhotkeys and videocontrol hotkeys
Also implements saving the forward backwards seconds to the user.

Co-authored-by: PartyDonut <PartyDonut@users.noreply.github.com>

lib/util/input_handler.dart

@@ -1,27 +1,36 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 
-class InputHandler extends StatefulWidget {
+import 'package:fladder/models/settings/key_combinations.dart';
+
+class InputHandler<T> extends StatefulWidget {
   final bool autoFocus;
   final KeyEventResult Function(FocusNode node, KeyEvent event)? onKeyEvent;
+  final bool Function(T result)? keyMapResult;
+  final Map<T, KeyCombination>? keyMap;
   final Widget child;
   const InputHandler({
     required this.child,
     this.autoFocus = true,
     this.onKeyEvent,
+    this.keyMapResult,
+    this.keyMap,
     super.key,
   });
 
   @override
-  State<InputHandler> createState() => _InputHandlerState();
+  State<InputHandler> createState() => _InputHandlerState<T>();
 }
 
-class _InputHandlerState extends State<InputHandler> {
+class _InputHandlerState<T> extends State<InputHandler<T>> {
   final focusNode = FocusNode();
 
+  LogicalKeyboardKey? pressedModifier;
+
   @override
   void initState() {
     super.initState();
-    //Focus on start
+    // Focus on start
     focusNode.requestFocus();
   }
 
@@ -35,8 +44,38 @@ class _InputHandlerState extends State<InputHandler> {
           focusNode.requestFocus();
         }
       },
-      onKeyEvent: widget.onKeyEvent,
+      onKeyEvent: (node, event) => _onKey(event),
       child: widget.child,
     );
   }
+
+  KeyEventResult _onKey(KeyEvent value) {
+    final keyMap = widget.keyMap?.entries.nonNulls.toList() ?? [];
+    if (value is KeyDownEvent || value is KeyRepeatEvent) {
+      if (KeyCombination.modifierKeys.contains(value.logicalKey)) {
+        pressedModifier = value.logicalKey;
+      }
+
+      for (var entry in keyMap) {
+        final hotKey = entry.key;
+        final keyCombination = entry.value;
+
+        bool isMainKeyPressed = value.logicalKey == keyCombination.key;
+        bool isModifierKeyPressed = pressedModifier == keyCombination.modifier;
+
+        if (isMainKeyPressed && isModifierKeyPressed) {
+          if (widget.keyMapResult?.call(hotKey) ?? false) {
+            return KeyEventResult.handled;
+          } else {
+            return KeyEventResult.ignored;
+          }
+        }
+      }
+    } else if (value is KeyUpEvent) {
+      if (KeyCombination.modifierKeys.contains(value.logicalKey)) {
+        pressedModifier = null;
+      }
+    }
+    return KeyEventResult.ignored;
+  }
 }