Added DPI support on macos-native. Fixed closing application on macos-native. (#298)

samples/SkiaMultiplatformSample/src/macosMain/kotlin/org/jetbrains/skiko/sample/App.macos.kt

@@ -6,11 +6,17 @@ import org.jetbrains.skia.*
 import org.jetbrains.skiko.*
 import kotlinx.cinterop.*
 import platform.Foundation.NSMakeRect
+import platform.darwin.NSObject
 
-fun makeApp() = BouncingBalls(true)
+fun makeApp() = Clocks()
 
 fun main() {
-    NSApplication.sharedApplication()
+    val app = NSApplication.sharedApplication()
+    app.delegate = object: NSObject(), NSApplicationDelegateProtocol {
+        override fun applicationShouldTerminateAfterLastWindowClosed(sender: NSApplication): Boolean {
+            return true
+        }
+    }
     val windowStyle = NSWindowStyleMaskTitled or
                 NSWindowStyleMaskMiniaturizable or
                 NSWindowStyleMaskClosable or
@@ -24,5 +30,5 @@ fun main() {
     skiaLayer.skikoView = GenericSkikoView(skiaLayer, makeApp())
     skiaLayer.attachTo(window)
     window.orderFrontRegardless()
-    NSApp?.run()
+    app.run()
 }

skiko/src/macosMain/kotlin/org/jetbrains/skiko/SkiaLayer.macos.kt

@@ -7,17 +7,19 @@ import org.jetbrains.skia.*
 import org.jetbrains.skiko.redrawer.Redrawer
 import platform.AppKit.*
 import platform.Foundation.NSMakeRect
+import platform.Foundation.NSNotification
 import platform.Foundation.NSNotificationCenter
 import platform.Foundation.NSSelectorFromString
 import platform.Foundation.addObserver
 import platform.darwin.NSObject
+import platform.CoreGraphics.CGRectMake
 
 actual open class SkiaLayer(
     private val properties: SkiaLayerProperties = makeDefaultSkiaLayerProperties()
 ) {
     actual var renderApi: GraphicsApi = GraphicsApi.OPENGL
     actual val contentScale: Float
-        get() = _contentScale
+        get() = if (this::nsView.isInitialized) nsView.window!!.backingScaleFactor.toFloat() else 1.0f
 
     actual var fullscreen: Boolean
         get() = false
@@ -32,7 +34,6 @@ actual open class SkiaLayer(
         }
 
     lateinit var nsView: NSView
-    var _contentScale: Float = 1.0f
 
     actual var skikoView: SkikoView? = null
 
@@ -123,8 +124,26 @@ actual open class SkiaLayer(
         val center = NSNotificationCenter.defaultCenter()
         center.addObserver(nsView, NSSelectorFromString("onWindowClose:"),
             NSWindowWillCloseNotification!!, window)
+        window.delegate = object : NSObject(), NSWindowDelegateProtocol {
+            override fun windowDidResize(notification: NSNotification) {
+                val (w, h) = window.contentView!!.frame.useContents {
+                    size.width to size.height
+                }
+                nsView.frame = CGRectMake(0.0, 0.0, w, h)
+                redrawer?.syncSize()
+                initedCanvas = false
+                redrawer?.redrawImmediately()
+            }
+
+            override fun windowDidChangeBackingProperties(notification: NSNotification) {
+                redrawer?.syncSize()
+                initedCanvas = false
+                redrawer?.redrawImmediately()
+            }
+        }
         window.contentView!!.addSubview(nsView)
         redrawer = createNativeRedrawer(this, GraphicsApi.OPENGL, properties).apply {
+            syncSize()
             needRedraw()
         }
     }

skiko/src/macosMain/kotlin/org/jetbrains/skiko/redrawer/OpenGLRedrawer.macos.kt

@@ -20,7 +20,11 @@ internal class MacOsOpenGLRedrawer(
     private val skiaLayer: SkiaLayer,
     private val properties: SkiaLayerProperties
 ) : Redrawer {
-    private val glLayer = MacosGLLayer(skiaLayer)
+    private val glLayer = MacosGLLayer()
+
+    init {
+        glLayer.init(skiaLayer)
+    }
 
     private val frameDispatcher = FrameDispatcher(SkikoDispatchers.Main) {
         redrawImmediately()
@@ -31,7 +35,7 @@ internal class MacOsOpenGLRedrawer(
     }
 
     override fun syncSize() {
-        // TODO: What do we really do here?
+        syncContentScale()
         skiaLayer.nsView.frame.useContents {
             glLayer.setFrame(
                 origin.x.toInt(),
@@ -42,6 +46,14 @@ internal class MacOsOpenGLRedrawer(
         }
     }
 
+    private fun syncContentScale() {
+        CATransaction.begin()
+        CATransaction.setDisableActions(true)
+        glLayer.contentsScale = skiaLayer.nsView.window!!.backingScaleFactor
+        CATransaction.commit()
+        CATransaction.flush()
+    }
+
     override fun needRedraw() {
         frameDispatcher.scheduleFrame()
     }
@@ -52,22 +64,29 @@ internal class MacOsOpenGLRedrawer(
     }
 }
 
-internal class MacosGLLayer(val layer: SkiaLayer) : CAOpenGLLayer() {
-    init {
+internal class MacosGLLayer : CAOpenGLLayer {
+    private lateinit var layer: SkiaLayer
+    @OverrideInit
+    constructor(): super()
+    @OverrideInit
+    constructor(layer: Any): super(layer)
+
+    fun init(layer: SkiaLayer) {
+        this.layer = layer
         this.setNeedsDisplayOnBoundsChange(true)
         this.removeAllAnimations()
         this.setAutoresizingMask(kCALayerWidthSizable or kCALayerHeightSizable )
         layer.nsView.layer = this
         layer.nsView.wantsLayer = true
+        this.contentsGravity = kCAGravityTopLeft;
     }
 
     fun setFrame(x: Int, y: Int, width: Int, height: Int) {
-        val newY = layer.nsView.frame.useContents { size.height } - y - height
-
         CATransaction.begin()
         CATransaction.setDisableActions(true)
-        this.frame = CGRectMake(x.toDouble(), newY, width.toDouble(), height.toDouble())
+        this.frame = CGRectMake(x.toDouble(), y.toDouble(), width.toDouble(), height.toDouble())
         CATransaction.commit()
+        CATransaction.flush()
     }
 
     fun dispose() {