Implement build autopausing (#1017)

Automatically pause building after current build queue is empty

core/src/io/anuke/mindustry/entities/type/Player.java

@@ -52,6 +52,7 @@ public class Player extends Unit implements BuilderMinerTrait, ShooterTrait{
     public @Nullable
     String uuid, usid;
     public boolean isAdmin, isTransferring, isShooting, isBoosting, isMobile, isTyping, isBuilding = true;
+    public boolean buildWasAutoPaused = false;
     public float boostHeat, shootHeat, destructTime;
     public boolean achievedFlight;
     public Color color = new Color();

core/src/io/anuke/mindustry/input/DesktopInput.java

@@ -267,6 +267,12 @@ public class DesktopInput extends InputHandler{
         int cursorY = tileY(Core.input.mouseY());
         int rawCursorX = world.toTile(Core.input.mouseWorld().x), rawCursorY = world.toTile(Core.input.mouseWorld().y);
 
+        // automatically pause building if the current build queue is empty
+        if(Core.settings.getBool("buildautopause") && player.isBuilding && !player.isBuilding()){
+            player.isBuilding = false;
+            player.buildWasAutoPaused = true;
+        }
+
         if(!selectRequests.isEmpty()){
             int shiftX = rawCursorX - schematicX, shiftY = rawCursorY - schematicY;
 
@@ -337,6 +343,7 @@ public class DesktopInput extends InputHandler{
 
         if(Core.input.keyTap(Binding.pause_building)){
             player.isBuilding = !player.isBuilding;
+            player.buildWasAutoPaused = false;
         }
 
         if((cursorX != lastLineX || cursorY != lastLineY) && isPlacing() && mode == placing){

core/src/io/anuke/mindustry/ui/dialogs/SettingsMenuDialog.java

@@ -228,6 +228,9 @@ public class SettingsMenuDialog extends SettingsDialog{
         game.checkPref("blockreplace", true);
         game.checkPref("conveyorpathfinding", true);
         game.checkPref("hints", true);
+        if(!mobile){
+            game.checkPref("buildautopause", false);
+        }
 
         if(steam && !Version.modifier.contains("beta")){
             game.checkPref("publichost", false, i -> {

core/src/io/anuke/mindustry/world/blocks/BuildBlock.java

@@ -144,6 +144,9 @@ public class BuildBlock extends Block{
 
         //if the target is constructible, begin constructing
         if(entity.cblock != null){
+            if(player.buildWasAutoPaused && !player.isBuilding){
+                player.isBuilding = true;
+            }
             //player.clearBuilding();
             player.addBuildRequest(new BuildRequest(tile.x, tile.y, tile.rotation(), entity.cblock), false);
         }