align widget and some fixes

src/main/kotlin/com/neptuneclient/voidui/widgets/Align.kt

@@ -0,0 +1,81 @@
+package com.neptuneclient.voidui.widgets
+
+import com.neptuneclient.voidui.framework.BoxConstraints
+import com.neptuneclient.voidui.framework.Offset
+import com.neptuneclient.voidui.framework.Size
+import com.neptuneclient.voidui.framework.Widget
+
+/**
+ * A widget which aligns a child at a relative position.
+ * It stretches itself to the maximum size of the constraints.
+ *
+ * @param child The child which will be aligned.
+ * @param alignment The alignment factor.
+ */
+class Align(
+    private val child: Widget,
+    private val alignment: Alignment = Alignment.topLeft
+) : Widget() {
+
+    override fun layout(constraints: BoxConstraints) {
+        child.layout(constraints)
+        size = Size(constraints.maxWidth, constraints.maxHeight)
+    }
+
+    override fun postLayoutInit(parentOffset: Offset, parent: Widget) {
+        super.postLayoutInit(parentOffset + alignment.align(size, child.size), parent)
+        offset = parentOffset
+    }
+
+    override fun build(): Widget {
+        return child
+    }
+
+}
+
+/**
+ * A data class to hold values about the relative alignment of a widget inside its parent.
+ *
+ * @param x The x-axis alignment.
+ * @param y The y-axis alignment.
+ */
+data class Alignment(val x: Double, val y: Double) {
+
+    companion object {
+        val topLeft = Alignment(-1.0, -1.0)
+
+        val topCenter = Alignment(0.0, -1.0)
+
+        val topRight = Alignment(1.0, -1.0)
+
+        val centerLeft = Alignment(-1.0, 0.0)
+
+        val center = Alignment(0.0, 0.0)
+
+        val centerRight = Alignment(1.0, 0.0)
+
+        val bottomLeft = Alignment(-1.0, 1.0)
+
+        val bottomCenter = Alignment(0.0, 1.0)
+
+        val bottomRight = Alignment(1.0, 1.0)
+    }
+
+    /**
+     * Aligns a child size within the parent's size according to [x] and [y].
+     *
+     * @param baseSize The larger size which acts as a container for the smaller size.
+     * @param childSize The smaller size which will be aligned.
+     *
+     * @return The aligned offset from the top left corner of the base size.
+     */
+    fun align(baseSize: Size, childSize: Size): Offset {
+        // x and y values between 0 and 1
+        val relX = (x + 1) / 2f
+        val relY = (y + 1) / 2f
+        val size = baseSize - childSize
+
+        return Offset(size.width * relX.toFloat(), size.height * relY.toFloat())
+    }
+
+}

src/main/kotlin/com/neptuneclient/voidui/widgets/Container.kt

@@ -41,11 +41,9 @@ class Container(
                 border = border,
                 cornerRadius = cornerRadius,
                 child = if (width != null || height != null) {
-                    val w = width ?: 0f
-                    val h = height ?: 0f
                     SizedBox(
-                        width = w,
-                        height = h,
+                        width = width,
+                        height = height,
                         child = Padding(padding, child)
                     )
                 } else {

src/main/kotlin/com/neptuneclient/voidui/widgets/SizedBox.kt

@@ -3,7 +3,6 @@ package com.neptuneclient.voidui.widgets
 import com.neptuneclient.voidui.framework.BoxConstraints
 import com.neptuneclient.voidui.framework.Size
 import com.neptuneclient.voidui.framework.Widget
-import kotlin.math.max
 
 /**
  * A widget which has a fixed size.
@@ -14,14 +13,20 @@ import kotlin.math.max
  */
 class SizedBox(
     private val child: Widget,
-    private val width: Float = 0f,
-    private val height: Float = 0f,
+    private val width: Float? = null,
+    private val height: Float? = null,
 ) : Widget() {
 
     override fun layout(constraints: BoxConstraints) {
-        child.layout(constraints)
+        val childConstraints = BoxConstraints(
+            constraints.minWidth,
+            width ?: constraints.maxWidth,
+            constraints.minHeight,
+            height ?: constraints.maxHeight
+        )
+        child.layout(childConstraints)
 
-        val s = Size(max(width, child.size.width), max(height, child.size.height))
+        val s = Size(width ?: child.size.width, height ?: child.size.height)
         size = constraints.constrain(s)
     }
 

src/test/kotlin/com/neptuneclient/voidui/tests/ScreenTest.kt

@@ -7,6 +7,7 @@ import com.neptuneclient.voidui.event.MouseClickedEvent
 import com.neptuneclient.voidui.event.MouseReleasedEvent
 import com.neptuneclient.voidui.framework.Offset
 import com.neptuneclient.voidui.framework.Screen
+import com.neptuneclient.voidui.framework.Size
 import com.neptuneclient.voidui.framework.Widget
 import com.neptuneclient.voidui.objects.Border
 import com.neptuneclient.voidui.objects.CornerRadius
@@ -21,10 +22,15 @@ fun EpicButton(label: String): Widget {
         color = Color(140, 60, 255),
         cornerRadius = CornerRadius.all(10f),
         border = Border(1f, Color(255, 255, 255, 100)),
+        width = 300f,
+        height = 39f,
 
-        child = Padding(
-            padding = EdgeInsets.symmetric(10f, 50f),
-            child = Text(label)
+        child = Align(
+            alignment = Alignment.center,
+            child = Padding(
+                padding = EdgeInsets.symmetric(10f, 0f),
+                child = Text(label)
+            )
         )
     )
 }
@@ -34,11 +40,17 @@ class TestScreen(voidUI: VoidUI) : Screen(voidUI) {
     override fun build(): Widget {
         return Positioned(
             position = Offset(300f, 300f),
-            child = Column(
-                gap = 20f,
-                children = arrayOf(
-                    EpicButton("Singleplayer"),
-                    EpicButton("Multiplayer")
+            child = Container(
+                color = Color(16, 14, 20),
+                cornerRadius = CornerRadius.all(10f),
+                padding = EdgeInsets.all(20f),
+
+                child = Column(
+                    gap = 20f,
+                    children = arrayOf(
+                        EpicButton("Singleplayer"),
+                        EpicButton("Multiplayer")
+                    )
                 )
             )
         )