Fix issues with link state

- Scrolling will now clear the link renderer
- Refreshing a single line will now recalculate only that line

Fixes #959
Fixes #960

src/input/Interfaces.ts

@@ -5,7 +5,7 @@
 
 export interface IMouseZoneManager {
   add(zone: IMouseZone): void;
-  clearAll(): void;
+  clearAll(start?: number, end?: number): void;
 }
 
 export interface IMouseZone {

src/input/MouseZoneManager.ts

@@ -44,9 +44,28 @@ export class MouseZoneManager implements IMouseZoneManager {
     }
   }
 
-  public clearAll(): void {
-    this._zones.length = 0;
-    this._deactivate();
+  public clearAll(start?: number, end?: number): void {
+    // Exit if there's nothing to clear
+    if (this._zones.length === 0) {
+      return;
+    }
+
+    // Iterate through zones and clear them out if they're within the range
+    for (let i = 0; i < this._zones.length; i++) {
+      const zone = this._zones[i];
+      if (zone.y >= start && zone.y <= end) {
+        if (this._currentZone && this._currentZone === zone) {
+          this._currentZone.leaveCallback();
+          this._currentZone = null;
+        }
+        this._zones.splice(i--, 1);
+      }
+    }
+
+    // Deactivate the mouse zone manager if all the zones have been removed
+    if (this._zones.length === 0) {
+      this._deactivate();
+    }
   }
 
   private _activate(): void {