[Linting] Some minor code purity stuff I came across (#10537)

* Centralize shift and control key detection (Unit multiselect now with right-shift too)

* Lint of an ugly curly brace placement - otherwise the original was fine

* Answer open question in comment

* Follow a Gdx 1.12 deprecation

* Another clarifying comment - on ScrollPane's built-in potential surprise that the constructor calls its own overridable public methods

core/src/com/unciv/UncivGame.kt

@@ -256,11 +256,7 @@ open class UncivGame(val isConsoleMode: Boolean = false) : Game(), PlatformSpeci
         throw UnsupportedOperationException("Use pushScreen or replaceCurrentScreen instead")
     }
 
-    override fun getScreen(): BaseScreen? {
+    override fun getScreen(): BaseScreen? = super.getScreen() as? BaseScreen
-        val curScreen = super.getScreen()
-        return if (curScreen == null) { null } else { curScreen as BaseScreen
-        }
-    }
 
     private fun setScreen(newScreen: BaseScreen) {
         debug("Setting new screen: %s, screenStack: %s", newScreen, screenStack)

core/src/com/unciv/ui/components/extensions/Scene2dExtensions.kt

@@ -366,6 +366,8 @@ object GdxKeyCodeFixes {
     }
 }
 
+fun Input.isShiftKeyPressed() = isKeyPressed(Input.Keys.SHIFT_LEFT) || isKeyPressed(Input.Keys.SHIFT_RIGHT)
+fun Input.isControlKeyPressed() = isKeyPressed(Input.Keys.CONTROL_LEFT) || isKeyPressed(Input.Keys.CONTROL_RIGHT)
 fun Input.areSecretKeysPressed() = isKeyPressed(Input.Keys.SHIFT_RIGHT) &&
         (isKeyPressed(Input.Keys.CONTROL_RIGHT) || isKeyPressed(Input.Keys.ALT_RIGHT))
 

core/src/com/unciv/ui/components/input/KeyShortcutListener.kt

@@ -1,11 +1,11 @@
 package com.unciv.ui.components.input
 
 import com.badlogic.gdx.Gdx
-import com.badlogic.gdx.Input
 import com.badlogic.gdx.scenes.scene2d.Actor
 import com.badlogic.gdx.scenes.scene2d.Group
 import com.badlogic.gdx.scenes.scene2d.InputEvent
 import com.badlogic.gdx.scenes.scene2d.InputListener
+import com.unciv.ui.components.extensions.isControlKeyPressed
 import com.unciv.ui.components.input.KeyShortcutDispatcherVeto.DispatcherVetoResult
 
 
@@ -20,7 +20,7 @@ import com.unciv.ui.components.input.KeyShortcutDispatcherVeto.DispatcherVetoRes
         val key = when {
             event == null ->
                 KeyCharAndCode.UNKNOWN
-            Gdx.input.isKeyPressed(Input.Keys.CONTROL_LEFT) || Gdx.input.isKeyPressed(Input.Keys.CONTROL_RIGHT) ->
+            Gdx.input.isControlKeyPressed() ->
                 KeyCharAndCode.ctrlFromCode(event.keyCode)
             else ->
                 KeyCharAndCode(event.keyCode)

core/src/com/unciv/ui/components/input/KeyboardPanningListener.kt

@@ -1,12 +1,12 @@
 package com.unciv.ui.components.input
 
 import com.badlogic.gdx.Gdx
-import com.badlogic.gdx.Input
 import com.badlogic.gdx.scenes.scene2d.InputEvent
 import com.badlogic.gdx.scenes.scene2d.InputListener
 import com.badlogic.gdx.scenes.scene2d.actions.Actions
 import com.badlogic.gdx.scenes.scene2d.actions.RepeatAction
 import com.badlogic.gdx.scenes.scene2d.ui.TextField
+import com.unciv.ui.components.extensions.isControlKeyPressed
 import com.unciv.ui.components.widgets.ZoomableScrollPane
 
 class KeyboardPanningListener(
@@ -40,9 +40,8 @@ class KeyboardPanningListener(
         if (event.target is TextField) return false
         if (keycode !in allowedKeys) return false
         // Without the following Ctrl-S would leave WASD map scrolling stuck
-        // Might be obsolete with keyboard shortcut refactoring
+        // _Not_ obsolete with keyboard shortcut refactoring
-        if (Gdx.input.isKeyPressed(Input.Keys.CONTROL_LEFT)) return false
+        if (Gdx.input.isControlKeyPressed()) return false
-        if (Gdx.input.isKeyPressed(Input.Keys.CONTROL_RIGHT)) return false
         pressedKeys.add(keycode)
         startLoop()
         return true

core/src/com/unciv/ui/components/widgets/KeyCapturingButton.kt

@@ -11,6 +11,7 @@ import com.badlogic.gdx.scenes.scene2d.utils.ClickListener
 import com.badlogic.gdx.scenes.scene2d.utils.NinePatchDrawable
 import com.badlogic.gdx.utils.Align
 import com.unciv.ui.components.UncivTooltip.Companion.addTooltip
+import com.unciv.ui.components.extensions.isControlKeyPressed
 import com.unciv.ui.components.fonts.Fonts
 import com.unciv.ui.components.input.KeyCharAndCode
 import com.unciv.ui.images.ImageGetter
@@ -116,10 +117,6 @@ class KeyCapturingButton(
 
     // Instead of storing a button reference one could use `(event?.listenerActor as? KeyCapturingButton)?.`
     private class ButtonListener(private val myButton: KeyCapturingButton) : ClickListener() {
-        private fun controlDown() =
-                Gdx.input.isKeyPressed(Input.Keys.CONTROL_LEFT) ||
-                Gdx.input.isKeyPressed(Input.Keys.CONTROL_RIGHT)
-
         override fun enter(event: InputEvent?, x: Float, y: Float, pointer: Int, fromActor: Actor?) {
             if (myButton.stage == null) return
             myButton.savedFocus = myButton.stage.keyboardFocus
@@ -135,7 +132,7 @@ class KeyCapturingButton(
         override fun keyDown(event: InputEvent?, keycode: Int): Boolean {
             if (keycode == Input.Keys.ESCAPE || keycode == Input.Keys.UNKNOWN) return false
             if (keycode == Input.Keys.CONTROL_LEFT || keycode == Input.Keys.CONTROL_RIGHT) return false
-            myButton.handleKey(keycode, controlDown())
+            myButton.handleKey(keycode, Gdx.input.isControlKeyPressed())
             return true
         }
 

core/src/com/unciv/ui/components/widgets/UncivSlider.kt

@@ -1,7 +1,6 @@
 package com.unciv.ui.components.widgets
 
 import com.badlogic.gdx.Gdx
-import com.badlogic.gdx.Input
 import com.badlogic.gdx.graphics.Color
 import com.badlogic.gdx.math.Interpolation
 import com.badlogic.gdx.math.Vector2
@@ -21,10 +20,12 @@ import com.badlogic.gdx.utils.Timer
 import com.unciv.Constants
 import com.unciv.models.UncivSound
 import com.unciv.ui.audio.SoundPlayer
-import com.unciv.ui.images.IconCircleGroup
+import com.unciv.ui.components.extensions.isShiftKeyPressed
-import com.unciv.ui.components.input.onClick
 import com.unciv.ui.components.extensions.surroundWithCircle
 import com.unciv.ui.components.extensions.toLabel
+import com.unciv.ui.components.input.onClick
+import com.unciv.ui.components.widgets.UncivSlider.Companion.formatPercent
+import com.unciv.ui.images.IconCircleGroup
 import com.unciv.ui.screens.basescreen.BaseScreen
 import kotlin.math.abs
 import kotlin.math.sign
@@ -132,10 +133,10 @@ class UncivSlider (
         setPlusMinusEnabled()
     }
     /** Will make this slider snap to the specified values, if the knob is within the threshold. */
-    fun setSnapToValues(values: FloatArray?, threshold: Float) {
+    fun setSnapToValues(threshold: Float, vararg values: Float) {
         snapToValues = values       // make a copy so our plus/minus code can snap
         snapThreshold = threshold
-        slider.setSnapToValues(values, threshold)
+        slider.setSnapToValues(threshold, *values)
     }
 
     // java format string for the value tip, set by changing stepSize
@@ -206,10 +207,7 @@ class UncivSlider (
         // un-snapping with Shift is taken from Slider source, and the loop mostly as well
         // with snap active, plus/minus buttons will go to the next snap position regardless of stepSize
         // this could be shorter if Slider.snap(), Slider.snapValues and Slider.threshold weren't protected
-        if (snapToValues?.isEmpty() != false ||
+        if (snapToValues?.isEmpty() != false || Gdx.input.isShiftKeyPressed()) {
-                Gdx.input.isKeyPressed(Input.Keys.SHIFT_LEFT) ||
-                Gdx.input.isKeyPressed(Input.Keys.SHIFT_RIGHT)
-        ) {
             value += delta
             onChange?.invoke(value)
             return

core/src/com/unciv/ui/components/widgets/ZoomableScrollPane.kt

@@ -15,8 +15,8 @@ import com.badlogic.gdx.scenes.scene2d.actions.TemporalAction
 import com.badlogic.gdx.scenes.scene2d.ui.ScrollPane
 import com.badlogic.gdx.scenes.scene2d.utils.ActorGestureListener
 import com.badlogic.gdx.scenes.scene2d.utils.Cullable
-import com.unciv.models.metadata.GameSettings
 import com.unciv.UncivGame
+import com.unciv.models.metadata.GameSettings
 import com.unciv.ui.components.ZoomGestureListener
 import com.unciv.ui.components.input.KeyboardPanningListener
 import java.lang.Float.max
@@ -70,6 +70,8 @@ open class ZoomableScrollPane(
         return if (group.hasChildren()) group.children[0] else null
     }
 
+    // This override will be called from ScrollPane's constructor to store the empty Group() we're passing,
+    // therefore super.getActor() _can_ return null.
     override fun setActor(content: Actor?) {
         val group: Group? = super.getActor() as Group?
         if (group != null) {

core/src/com/unciv/ui/popups/options/DisplayTab.kt

@@ -12,15 +12,15 @@ import com.unciv.models.metadata.GameSettings.ScreenSize
 import com.unciv.models.skins.SkinCache
 import com.unciv.models.tilesets.TileSetCache
 import com.unciv.models.translations.tr
-import com.unciv.ui.components.widgets.TranslatedSelectBox
-import com.unciv.ui.components.widgets.UncivSlider
-import com.unciv.ui.components.widgets.WrappableLabel
 import com.unciv.ui.components.extensions.addSeparator
 import com.unciv.ui.components.extensions.brighten
 import com.unciv.ui.components.extensions.toLabel
 import com.unciv.ui.components.extensions.toTextButton
 import com.unciv.ui.components.input.onChange
 import com.unciv.ui.components.input.onClick
+import com.unciv.ui.components.widgets.TranslatedSelectBox
+import com.unciv.ui.components.widgets.UncivSlider
+import com.unciv.ui.components.widgets.WrappableLabel
 import com.unciv.ui.images.ImageGetter
 import com.unciv.ui.popups.ConfirmPopup
 import com.unciv.ui.screens.basescreen.BaseScreen
@@ -169,7 +169,7 @@ private fun addPediaUnitArtSizeSlider(table: Table, settings: GameSettings, sele
         settings.pediaUnitArtSize = it
         GUI.setUpdateWorldOnNextRender()
     }
-    unitArtSizeSlider.setSnapToValues(floatArrayOf(0f, 32f, 48f, 64f, 96f, 120f, 180f, 240f, 360f), 60f)
+    unitArtSizeSlider.setSnapToValues(threshold = 60f, 0f, 32f, 48f, 64f, 96f, 120f, 180f, 240f, 360f)
     table.add(unitArtSizeSlider).minWidth(selectBoxMinWidth).pad(10f).row()
 }
 

core/src/com/unciv/ui/screens/mapeditorscreen/tabs/MapEditorViewTab.kt

@@ -16,16 +16,16 @@ import com.unciv.models.ruleset.nation.Nation
 import com.unciv.models.ruleset.tile.ResourceType
 import com.unciv.models.stats.Stats
 import com.unciv.models.translations.tr
-import com.unciv.ui.components.widgets.ExpanderTab
-import com.unciv.ui.components.widgets.TabbedPager
-import com.unciv.ui.components.widgets.UncivSlider
-import com.unciv.ui.components.widgets.WrappableLabel
 import com.unciv.ui.components.extensions.addSeparator
 import com.unciv.ui.components.extensions.darken
 import com.unciv.ui.components.extensions.pad
 import com.unciv.ui.components.extensions.toLabel
 import com.unciv.ui.components.extensions.toTextButton
 import com.unciv.ui.components.input.onClick
+import com.unciv.ui.components.widgets.ExpanderTab
+import com.unciv.ui.components.widgets.TabbedPager
+import com.unciv.ui.components.widgets.UncivSlider
+import com.unciv.ui.components.widgets.WrappableLabel
 import com.unciv.ui.popups.ToastPopup
 import com.unciv.ui.screens.basescreen.BaseScreen
 import com.unciv.ui.screens.civilopediascreen.CivilopediaScreen
@@ -230,7 +230,7 @@ class MapEditorViewTab(
                     editorScreen.updateTile(tile)
                     editorScreen.isDirty = true
                 }
-                slider.setSnapToValues(floatArrayOf(0f,1f,2f,3f,4f,5f,6f,7f,8f,9f,10f,12f,15f,20f,30f,40f), 5f)
+                slider.setSnapToValues(threshold = 5f, 0f,1f,2f,3f,4f,5f,6f,7f,8f,9f,10f,12f,15f,20f,30f,40f)
                 add(slider).right().minWidth(80f).fillX().padTop(15f)
             }).fillX()
         }

core/src/com/unciv/ui/screens/newgamescreen/GameOptionsTable.kt

@@ -338,7 +338,7 @@ class GameOptionsTable(
         }
         slider.isDisabled = locked
         val snapValues = floatArrayOf(100f,150f,200f,250f,300f,350f,400f,450f,500f,550f,600f,650f,700f,750f,800f,900f,1000f,1250f,1500f)
-        slider.setSnapToValues(snapValues, 125f)
+        slider.setSnapToValues(threshold = 125f, *snapValues)
         return slider
     }
 

core/src/com/unciv/ui/screens/worldscreen/WorldMapHolder.kt

@@ -2,7 +2,6 @@ package com.unciv.ui.screens.worldscreen
 
 import com.badlogic.gdx.Application
 import com.badlogic.gdx.Gdx
-import com.badlogic.gdx.Input
 import com.badlogic.gdx.graphics.Color
 import com.badlogic.gdx.graphics.g2d.Batch
 import com.badlogic.gdx.math.Vector2
@@ -35,6 +34,7 @@ import com.unciv.ui.components.MiscArrowTypes
 import com.unciv.ui.components.extensions.center
 import com.unciv.ui.components.extensions.colorFromRGB
 import com.unciv.ui.components.extensions.darken
+import com.unciv.ui.components.extensions.isShiftKeyPressed
 import com.unciv.ui.components.extensions.surroundWithCircle
 import com.unciv.ui.components.extensions.toLabel
 import com.unciv.ui.components.input.ActivationTypes
@@ -423,7 +423,7 @@ class WorldMapHolder(
             if (unit.currentMovement == 0f) unitGroup.color.a = 0.66f
             unitGroup.touchable = Touchable.enabled
             unitGroup.onClick {
-                worldScreen.bottomUnitTable.selectUnit(unit, Gdx.input.isKeyPressed(Input.Keys.SHIFT_LEFT))
+                worldScreen.bottomUnitTable.selectUnit(unit, Gdx.input.isShiftKeyPressed())
                 worldScreen.shouldUpdate = true
                 removeUnitActionOverlay()
             }

core/src/com/unciv/ui/screens/worldscreen/unit/UnitTable.kt

@@ -1,7 +1,6 @@
 package com.unciv.ui.screens.worldscreen.unit
 
 import com.badlogic.gdx.Gdx
-import com.badlogic.gdx.Input
 import com.badlogic.gdx.graphics.Color
 import com.badlogic.gdx.scenes.scene2d.Actor
 import com.badlogic.gdx.scenes.scene2d.Touchable
@@ -16,6 +15,7 @@ import com.unciv.models.translations.tr
 import com.unciv.ui.components.extensions.addSeparator
 import com.unciv.ui.components.extensions.center
 import com.unciv.ui.components.extensions.darken
+import com.unciv.ui.components.extensions.isShiftKeyPressed
 import com.unciv.ui.components.extensions.toImageButton
 import com.unciv.ui.components.extensions.toLabel
 import com.unciv.ui.components.input.onClick
@@ -352,7 +352,7 @@ class UnitTable(val worldScreen: WorldScreen) : Table() {
             selectedTile.isCityCenter() &&
                     (selectedTile.getOwner() == worldScreen.viewingCiv || worldScreen.viewingCiv.isSpectator()) ->
                 citySelected(selectedTile.getCity()!!)
-            nextUnit != null -> selectUnit(nextUnit, Gdx.input.isKeyPressed(Input.Keys.SHIFT_LEFT))
+            nextUnit != null -> selectUnit(nextUnit, Gdx.input.isShiftKeyPressed())
             selectedTile == previouslySelectedUnit?.currentTile -> {
                 selectUnit()
                 isVisible = false