press tab to bring up the game menu

src/net/torvald/terrarum/ui/Movement.kt

@@ -1,6 +1,7 @@
 package net.torvald.terrarum.ui
 
 import com.jme3.math.FastMath
+import net.torvald.terrarum.sqr
 
 /**
  * Created by minjaesong on 2016-03-22.
@@ -26,5 +27,19 @@ object Movement{
             if (scale < 0f) start
             else if (scale > 1f) end
             else (start - end) * FastMath.cos2(0.5f * FastMath.PI * scale) + end
-
+    fun moveQuick(start: Float, end: Float, timer: Float, duration: Float) =
+            (start - end) * ((timer / duration) - 1).sqr() + end
+    fun moveLinear(start: Float, end: Float, timer: Float, duration: Float): Float {
+        val scale = timer / duration
+        if (start == end) {
+            return start
+        }
+        if (scale <= 0f) {
+            return start
+        }
+        if (scale >= 1f) {
+            return end
+        }
+        return ((1f - scale) * start) + (scale * end)
+    }
 }

src/net/torvald/terrarum/ui/UIHandler.kt

@@ -24,12 +24,13 @@ import net.torvald.terrarum.modulebasegame.TerrarumIngame
  * Created by minjaesong on 2015-12-31.
  */
 class UIHandler(//var UI: UICanvas,
-                var toggleKeyLiteral: Int? = null,
-                var toggleButtonLiteral: Int? = null,
+        var toggleKeyLiteral: Int? = null,
+        var toggleButtonLiteral: Int? = null,
                 // UI positions itself? (you must g.flush() yourself after the g.translate(Int, Int))
-                var customPositioning: Boolean = false, // mainly used by vital meter
-                var doNotWarnConstant: Boolean = false,
-                internal var allowESCtoClose: Boolean = false
+        var customPositioning: Boolean = false, // mainly used by vital meter
+        var doNotWarnConstant: Boolean = false,
+        internal var allowESCtoClose: Boolean = false,
+        var uiTogglerFunctionDefault: ((UIHandler) -> Unit)? = null
 ): Disposable {
 
     companion object {
@@ -128,6 +129,21 @@ void main() {
     private val toggleButton: Int?; get() = toggleButtonLiteral // to support in-screen keybind changing
 
 
+    val toggleKeyExtra: ArrayList<() -> Int> = arrayListOf()
+
+    /**
+     * Takes a function that works with UIHandler.
+     * For the function, try starting from the:
+     * ```
+     * if (it.isClosed)
+     *     it.setAsOpen()
+     * else if (it.isOpened)
+     *     setAsClose()
+     * ```
+     */
+    val toggleKeyExtraAction: ArrayList<(UIHandler) -> Unit> = arrayListOf()
+
+
     val subUIs = ArrayList<UICanvas>()
 
     val mouseUp: Boolean
@@ -165,15 +181,30 @@ void main() {
         // some UIs will pause the game, and they still need to be closed
         if (!uiToggleLocked && (Terrarum.ingame?.consoleOpened == false && (Terrarum.ingame?.paused == false || isOpened))) {
             if (toggleKey != null && Gdx.input.isKeyJustPressed(toggleKey!!)) {
-                if (isClosed)
-                    setAsOpen()
-                else if (isOpened)
-                    setAsClose()
+                if (uiTogglerFunctionDefault == null) {
+                    if (isClosed)
+                        setAsOpen()
+                    else if (isOpened)
+                        setAsClose()
+                }
+                else uiTogglerFunctionDefault!!.invoke(this)
 
                 // for the case of intermediate states, do nothing.
             }
-            if (toggleButton != null) {
-                /* */
+            if (toggleButton != null && Gdx.input.isButtonJustPressed(toggleButton!!)) {
+                if (uiTogglerFunctionDefault == null) {
+                    if (isClosed)
+                        setAsOpen()
+                    else if (isOpened)
+                        setAsClose()
+                }
+                else uiTogglerFunctionDefault!!.invoke(this)
+            }
+
+            toggleKeyExtra.forEachIndexed { index, getKey ->
+                if (Gdx.input.isKeyJustPressed(getKey())) {
+                    toggleKeyExtraAction[0].invoke(this)
+                }
             }
 
             // ESC is a master key for closing

src/net/torvald/terrarum/ui/UIItemList.kt

@@ -63,7 +63,7 @@ class UIItemList<Item: UIItem>(
             highlighterMoveTimer += delta
 
             if (selectedIndex != null) {
-                highlightY = UIUtils.moveQuick(
+                highlightY = Movement.moveQuick(
                         highlighterYStart!!,
                         highlighterYEnd!!,
                         highlighterMoveTimer,

src/net/torvald/terrarum/ui/UIItemTextButtonList.kt

@@ -183,7 +183,7 @@ class UIItemTextButtonList(
             highlighterMoveTimer += delta
 
             if (selectedIndex != null) {
-                highlightY = UIUtils.moveQuick(
+                highlightY = Movement.moveQuick(
                         highlighterYStart!!,
                         highlighterYEnd!!,
                         highlighterMoveTimer.toFloat(),

src/net/torvald/terrarum/ui/UIItemTransitionContainer.kt

@@ -37,6 +37,14 @@ open class UIItemTransitionContainer(
         }
     }
 
+    fun forcePosition(target: Int) {
+        transitionOngoing = false
+        transitionRequested = false
+        transitionTimer = 0f
+        currentPosition = target.toFloat()
+        onTransition(currentPosition, uis)
+    }
+
     override fun update(delta: Float) {
         super.update(delta)
         uis.forEachIndexed { index, ui -> if (timeToUpdate(index)) ui.update(delta) }
@@ -56,7 +64,7 @@ open class UIItemTransitionContainer(
         if (transitionOngoing) {
             transitionTimer += Gdx.graphics.deltaTime
 
-            currentPosition = UIUtils.moveLinear(transitionReqSource, transitionReqTarget, transitionTimer, transitionLength)
+            currentPosition = Movement.moveLinear(transitionReqSource, transitionReqTarget, transitionTimer, transitionLength)
 
             if (transitionTimer > transitionLength) {
                 transitionOngoing = false

src/net/torvald/terrarum/ui/UIUtils.kt

@@ -1,24 +0,0 @@
-package net.torvald.terrarum.ui
-
-import net.torvald.terrarum.sqr
-
-/**
- * Created by minjaesong on 2017-03-14.
- */
-object UIUtils {
-    fun moveQuick(start: Float, end: Float, timer: Float, duration: Float) =
-            (start - end) * ((timer / duration) - 1).sqr() + end
-    fun moveLinear(start: Float, end: Float, timer: Float, duration: Float): Float {
-        val scale = timer / duration
-        if (start == end) {
-            return start
-        }
-        if (scale <= 0f) {
-            return start
-        }
-        if (scale >= 1f) {
-            return end
-        }
-        return ((1f - scale) * start) + (scale * end)
-    }
-}