Allow holding the cargo pickup & dropoff key (#10859)

Allow holding down the cargo pickup & cargo drop keys to repeatedly pick up or drop off payloads. This takes effect after a short delay so that tapping to pick up or drop off individual payloads is still reliable.

core/assets/contributors

@@ -181,3 +181,4 @@ IchMagSchokolade
 MonoChronos
 RushieWashie
 ITY
+Iniquit

core/src/mindustry/input/DesktopInput.java

@@ -56,6 +56,11 @@ public class DesktopInput extends InputHandler{
     /** Time of most recent control group selection */
     public long lastCtrlGroupSelectMillis;
 
+    /** Time of most recent payload pickup/drop key press*/
+    public long lastPayloadKeyTapMillis;
+    /** Time of most recent payload pickup/drop key hold*/
+    public long lastPayloadKeyHoldMillis;
+
     private float buildPlanMouseOffsetX, buildPlanMouseOffsetY;
     private boolean changedCursor;
 
@@ -970,10 +975,26 @@ public class DesktopInput extends InputHandler{
         if(unit instanceof Payloadc){
             if(Core.input.keyTap(Binding.pickupCargo)){
                 tryPickupPayload();
+                lastPayloadKeyTapMillis = Time.millis();
+            }
+
+            if(Core.input.keyDown(Binding.pickupCargo)
+            && Time.timeSinceMillis(lastPayloadKeyHoldMillis) > 20
+            && Time.timeSinceMillis(lastPayloadKeyTapMillis) > 200){
+                tryPickupPayload();
+                lastPayloadKeyHoldMillis = Time.millis();
             }
 
             if(Core.input.keyTap(Binding.dropCargo)){
                 tryDropPayload();
+                lastPayloadKeyTapMillis = Time.millis();
+            }
+
+            if(Core.input.keyDown(Binding.dropCargo)
+            && Time.timeSinceMillis(lastPayloadKeyHoldMillis) > 20
+            && Time.timeSinceMillis(lastPayloadKeyTapMillis) > 200){
+                tryDropPayload();
+                lastPayloadKeyHoldMillis = Time.millis();
             }
         }
     }