Introduce UIResourceManager & add Nunito font

src/com/reco1l/andengine/UIEngine.kt

@@ -22,6 +22,10 @@ class UIEngine(val context: Activity, options: EngineOptions) : Engine(options)
      */
     val overlay = HUD()
 
+    /**
+     * The resource manager for loading and accessing UI resources (fonts, textures, etc).
+     */
+    val resources = UIResourceManager(context)
 
     /**
      * The current focused entity.

src/com/reco1l/andengine/UIResourceManager.kt

@@ -0,0 +1,77 @@
+@file:Suppress("ConstPropertyName")
+
+package com.reco1l.andengine
+
+import android.content.Context
+import android.graphics.Color
+import android.graphics.Typeface
+import android.util.Log
+import com.reco1l.andengine.component.UIComponent
+import org.anddev.andengine.opengl.font.Font
+import org.anddev.andengine.opengl.texture.TextureOptions
+import org.anddev.andengine.opengl.texture.atlas.bitmap.BitmapTextureAtlas
+import org.anddev.andengine.opengl.util.GLHelper
+import java.lang.ref.WeakReference
+
+class UIResourceManager(private val context: Context) {
+
+    private val fonts = mutableMapOf<String, Font>()
+    private val fontSubscribers = mutableMapOf<Font, MutableList<WeakReference<UIComponent>>>()
+
+
+    fun getOrStoreFont(size: Float, family: String): Font {
+
+        val fontIdentifier = "${family}-${size}"
+
+        val fetchedFont = fonts[fontIdentifier]
+        if (fetchedFont != null) {
+            return fetchedFont
+        }
+
+        Log.i("UIResourceManager", "Loading font: $fontIdentifier with texture size ${GLHelper.GlMaxTextureWidth / 2}x${GLHelper.GlMaxTextureWidth / 2}")
+
+        val texture = BitmapTextureAtlas(
+            GLHelper.GlMaxTextureWidth / 2,
+            GLHelper.GlMaxTextureWidth / 2,
+            TextureOptions.BILINEAR_PREMULTIPLYALPHA
+        )
+        val typeface = Typeface.createFromAsset(context.assets, "fonts/${family}")
+        val font = Font(texture, typeface, size, true, Color.WHITE)
+
+        UIEngine.current.apply {
+            textureManager.loadTexture(texture)
+            fontManager.loadFont(font)
+
+            fonts[fontIdentifier] = font
+        }
+
+        return font
+    }
+
+    fun subscribeToFont(font: Font, component: UIComponent) {
+        val subscribers = fontSubscribers.getOrPut(font) { mutableListOf() }
+        if (subscribers.none { it.get() === component }) {
+            subscribers.add(WeakReference(component))
+        }
+    }
+
+    fun unsubscribeFromFont(font: Font, component: UIComponent) {
+
+        val subscribers = fontSubscribers[font] ?: return
+        subscribers.removeAll { it.get() === component || it.get() == null }
+
+        if (subscribers.isEmpty()) {
+            val fontKey = fonts.entries.find { it.value == font }?.key
+            Log.i("UIResourceManager", "Unloading font: $fontKey")
+
+            fonts.remove(fontKey)
+            fontSubscribers.remove(font)
+
+            UIEngine.current.apply {
+                fontManager.unloadFont(font)
+                textureManager.unloadTexture(font.texture)
+            }
+        }
+    }
+
+}

src/com/reco1l/andengine/theme/Font.kt

@@ -0,0 +1,7 @@
+@file:Suppress("ConstPropertyName")
+
+package com.reco1l.andengine.theme
+
+object Fonts {
+    const val NunitoMedium = "nunito-medium.ttf"
+}