IOS: rotation support, dpi support, clocks sample. Partial commonization [SystemTheme]. (#284)

samples/SkiaMultiplatformSample/src/commonMain/kotlin/org/jetbrains/skiko/sample/Clocks.kt

+package org.jetbrains.skiko.sample
+
+import org.jetbrains.skia.*
+import org.jetbrains.skia.paragraph.FontCollection
+import org.jetbrains.skia.paragraph.ParagraphBuilder
+import org.jetbrains.skia.paragraph.ParagraphStyle
+import org.jetbrains.skia.paragraph.TextStyle
+import org.jetbrains.skiko.SkikoView
+import org.jetbrains.skiko.SkikoPointerEvent
+import org.jetbrains.skiko.isLeftClick
+import org.jetbrains.skiko.currentSystemTheme
+import kotlin.math.cos
+import kotlin.math.sin
+import kotlin.math.PI
+
+class Clocks: SkikoView {
+    private var frame = 0
+    private var xpos = 0.0
+    private var ypos = 0.0
+    private val fontCollection = FontCollection()
+        .setDefaultFontManager(FontMgr.default)
+
+    override fun onRender(canvas: Canvas, width: Int, height: Int, currentTimestamp: Long) {
+        val watchFill = Paint().apply { color = 0xFFFFFFFF.toInt() }
+        val watchStroke = Paint().apply {
+               color = 0xFF000000.toInt()
+               mode = PaintMode.STROKE
+               strokeWidth = 1f
+        }
+        val watchStrokeAA = Paint().apply {
+          color = 0xFF000000.toInt()
+          mode = PaintMode.STROKE
+          strokeWidth = 1f
+        }
+        val watchFillHover = Paint().apply { color = 0xFFE4FF01.toInt() }
+        for (x in 0 .. (width - 50) step 50) {
+            for (y in 20 .. (height - 50) step 50) {
+                val hover = xpos > x + 0 && xpos < x + 50 && ypos > y + 0 && ypos < y + 50
+                val fill = if (hover) watchFillHover else watchFill
+                val stroke = if (x > width / 2) watchStrokeAA else watchStroke
+                canvas.drawOval(Rect.makeXYWH(x + 5f, y + 5f, 40f, 40f), fill)
+                canvas.drawOval(Rect.makeXYWH(x + 5f, y + 5f, 40f, 40f), stroke)
+                var angle = 0f
+                while (angle < 2f * PI) {
+                    canvas.drawLine(
+                            (x + 25 - 17 * sin(angle)),
+                            (y + 25 + 17 * cos(angle)),
+                            (x + 25 - 20 * sin(angle)),
+                            (y + 25 + 20 * cos(angle)),
+                            stroke
+                    )
+                    angle += (2.0 * PI / 12.0).toFloat()
+                }
+                val time = (currentTimestamp / 1E6) % 60000 +
+                        (x.toFloat() / width * 5000).toLong() +
+                        (y.toFloat() / width * 5000).toLong()
+
+                val angle1 = (time.toFloat() / 5000 * 2f * PI).toFloat()
+                canvas.drawLine(x + 25f, y + 25f,
+                        x + 25f - 15f * sin(angle1),
+                        y + 25f + 15 * cos(angle1),
+                        stroke)
+
+                val angle2 = (time / 60000 * 2f * PI).toFloat()
+                canvas.drawLine(x + 25f, y + 25f,
+                        x + 25f - 10f * sin(angle2),
+                        y + 25f + 10f * cos(angle2),
+                        stroke)
+            }
+        }
+
+
+        val style = ParagraphStyle()
+        val title = ParagraphBuilder(style, fontCollection)
+            .pushStyle(TextStyle().setColor(0xFF000000.toInt()))
+            .addText("Graphics API: Metal ✿ﾟ $currentSystemTheme")
+            .popStyle()
+            .build()
+        title.layout(Float.POSITIVE_INFINITY)
+        title.paint(canvas, 5f, 5f)
+
+        val frames = ParagraphBuilder(style, fontCollection)
+            .pushStyle(TextStyle().setColor(0xFFFFAA0A.toInt()).setFontSize(25f))
+            .addText("Frames: ${frame++}")
+            .popStyle()
+            .build()
+        frames.layout(Float.POSITIVE_INFINITY)
+        frames.paint(canvas, xpos.toFloat(), ypos.toFloat())
+    }
+
+    override fun onPointerEvent(event: SkikoPointerEvent) {
+        if (event.isLeftClick) {
+            xpos = event.x
+            ypos = event.y
+        }
+    }
+}
\ No newline at end of file

samples/SkiaMultiplatformSample/src/iosMain/kotlin/org/jetbrains/skiko/sample/App.ios.kt

@@ -8,7 +8,7 @@ import org.jetbrains.skiko.SkikoViewController
 import platform.UIKit.*
 import platform.Foundation.*
 
-fun makeApp(): SkikoView = BouncingBalls()
+fun makeApp(): SkikoView = Clocks()
 
 fun main() {
     val args = emptyArray<String>()

skiko/src/commonMain/kotlin/org/jetbrains/skiko/SystemTheme.kt

+package org.jetbrains.skiko
+
+enum class SystemTheme {
+    DARK,
+    LIGHT,
+    UNKNOWN
+}
\ No newline at end of file

skiko/src/iosMain/kotlin/org/jetbrains/skiko/SkiaLayer.ios.kt

@@ -22,7 +22,7 @@ actual open class SkiaLayer(
         set(value) { throw UnsupportedOperationException() }
 
     actual val contentScale: Float
-        get() = 1.0f
+        get() = view.contentScaleFactor.toFloat()
 
     actual var fullscreen: Boolean
         get() = true
@@ -88,8 +88,11 @@ actual open class SkiaLayer(
     private val contextHandler = MetalContextHandler(this)
 
     fun update(nanoTime: Long) {
-        val pictureWidth = (width * contentScale).coerceAtLeast(0.0F)
-        val pictureHeight = (height * contentScale).coerceAtLeast(0.0F)
+        val (w, h) = view.frame.useContents {
+            size.width to size.height
+        }
+        val pictureWidth = (w.toFloat() * contentScale).coerceAtLeast(0.0F)
+        val pictureHeight = (h.toFloat() * contentScale).coerceAtLeast(0.0F)
 
         val bounds = Rect.makeWH(pictureWidth, pictureHeight)
         val canvas = pictureRecorder.beginRecording(bounds)

skiko/src/iosMain/kotlin/org/jetbrains/skiko/SkikoViewController.kt

@@ -8,6 +8,7 @@ import platform.UIKit.UIEvent
 import platform.UIKit.UIScreen
 import platform.UIKit.UIViewController
 import platform.UIKit.setFrame
+import platform.UIKit.contentScaleFactor
 
 @ExportObjCClass
 class SkikoViewController : UIViewController {
@@ -41,6 +42,7 @@ class SkikoViewController : UIViewController {
         val layer = SkiaLayer().apply {
             skikoView = appFactory(this)
         }
+        view.contentScaleFactor = UIScreen.mainScreen.scale
         view.setFrame(CGRectMake(0.0, 0.0, width, height))
         layer.attachTo(this.view)
     }

skiko/src/iosMain/kotlin/org/jetbrains/skiko/SystemTheme.ios.kt

+package org.jetbrains.skiko
+
+import platform.UIKit.*
+import platform.UIKit.UIUserInterfaceStyle.*
+
+val currentSystemTheme: SystemTheme
+    get() = when (UITraitCollection.currentTraitCollection.userInterfaceStyle) {
+        UIUserInterfaceStyleDark -> SystemTheme.DARK
+        UIUserInterfaceStyleLight -> SystemTheme.LIGHT
+        else -> SystemTheme.UNKNOWN
+    }

skiko/src/iosMain/kotlin/org/jetbrains/skiko/context/MetalContextHandler.kt

 package org.jetbrains.skiko.context
 
+import kotlinx.cinterop.useContents
 import org.jetbrains.skia.ColorSpace
 import org.jetbrains.skia.Surface
 import org.jetbrains.skia.SurfaceColorFormat
@@ -23,12 +24,27 @@ internal class MetalContextHandler(layer: SkiaLayer) : ContextHandler(layer) {
         return true
     }
 
+    private var currentWidth = 0
+    private var currentHeight = 0
+    private fun isSizeChanged(width: Int, height: Int): Boolean {
+        if (width != currentWidth || height != currentHeight) {
+            currentWidth = width
+            currentHeight = height
+            return true
+        }
+        return false
+    }
+
     override fun initCanvas() {
         disposeCanvas()
-
         val scale = layer.contentScale
-        val w = (layer.width * scale).toInt().coerceAtLeast(0)
-        val h = (layer.height * scale).toInt().coerceAtLeast(0)
+        val (w, h) = layer.view.frame.useContents {
+            (size.width * scale).toInt().coerceAtLeast(0) to (size.height * scale).toInt().coerceAtLeast(0)
+        }
+
+        if (isSizeChanged(w, h)) {
+            metalRedrawer.syncSize()
+        }
 
         renderTarget = metalRedrawer.makeRenderTarget(w, h)
 

skiko/src/iosMain/kotlin/org/jetbrains/skiko/redrawer/MetalRedrawer.ios.kt

@@ -4,6 +4,7 @@ import kotlinx.cinterop.addressOf
 import kotlinx.cinterop.autoreleasepool
 import kotlinx.cinterop.objcPtr
 import kotlinx.cinterop.usePinned
+import kotlinx.cinterop.useContents
 import org.jetbrains.skia.BackendRenderTarget
 import org.jetbrains.skia.DirectContext
 import org.jetbrains.skiko.*
@@ -17,6 +18,7 @@ import platform.QuartzCore.CAMetalDrawableProtocol
 import platform.QuartzCore.CAMetalLayer
 import platform.QuartzCore.kCAGravityTopLeft
 import kotlin.system.getTimeNanos
+import platform.CoreGraphics.CGSizeMake
 
 internal class MetalRedrawer(
     private val layer: SkiaLayer,
@@ -26,7 +28,11 @@ internal class MetalRedrawer(
     internal val device = MTLCreateSystemDefaultDevice()!!
     private val queue = device.newCommandQueue()!!
     private var currentDrawable: CAMetalDrawableProtocol? = null
-    private val metalLayer = MetalLayer(this.layer, device)
+    private val metalLayer = MetalLayer()
+
+    init {
+        metalLayer.init(this.layer, device)
+    }
 
     private val frameDispatcher = FrameDispatcher(SkikoDispatchers.Main) {
         if (layer.isShowing()) {
@@ -48,7 +54,13 @@ internal class MetalRedrawer(
     }
 
     override fun syncSize() {
-        println("TODO: implement syncSize()")
+        metalLayer.contentsScale = layer.contentScale.toDouble()
+        val (w, h) = layer.view.frame.useContents {
+            size.width to size.height
+        }
+        metalLayer.frame = layer.view.frame
+        metalLayer.init(layer, device)
+        metalLayer.drawableSize = CGSizeMake(w * metalLayer.contentsScale, h * metalLayer.contentsScale)
     }
 
     override fun needRedraw() {
@@ -88,11 +100,15 @@ internal class MetalRedrawer(
     }
 }
 
-class MetalLayer(
-    private val skiaLayer: SkiaLayer,
-    theDevice: MTLDeviceProtocol
-) : CAMetalLayer() {
-    init {
+class MetalLayer : CAMetalLayer {
+    private lateinit var skiaLayer: SkiaLayer
+
+    @OverrideInit
+    constructor(): super()
+    @OverrideInit
+    constructor(layer: Any): super(layer)
+
+    fun init(skiaLayer: SkiaLayer, theDevice: MTLDeviceProtocol) {
         this.setNeedsDisplayOnBoundsChange(true)
         this.removeAllAnimations()
         // TODO: looks like a bug in K/N interop.

skiko/src/jvmMain/cpp/linux/drawlayer.cc

@@ -88,7 +88,7 @@ extern "C"
         return (float) getDpiScaleByDisplay(dsi_x11->display);
     }
 
-    JNIEXPORT jint JNICALL Java_org_jetbrains_skiko_SystemThemeKt_getCurrentSystemTheme(JNIEnv *env, jobject topLevel)
+    JNIEXPORT jint JNICALL Java_org_jetbrains_skiko_SystemTheme_1jvmKt_getCurrentSystemTheme(JNIEnv *env, jobject topLevel)
     {
        // Unknown.
        return 2;

skiko/src/jvmMain/cpp/windows/drawlayer.cc

@@ -28,7 +28,7 @@ extern "C"
         return (jlong) dsi_win->hwnd;
     }
 
-    JNIEXPORT jint JNICALL Java_org_jetbrains_skiko_SystemThemeKt_getCurrentSystemTheme(JNIEnv *env, jobject topLevel)
+    JNIEXPORT jint JNICALL Java_org_jetbrains_skiko_SystemTheme_1jvmKt_getCurrentSystemTheme(JNIEnv *env, jobject topLevel)
     {
         auto subkey = L"Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize";
         auto name = L"AppsUseLightTheme";

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/SystemTheme.kt → skiko/src/jvmMain/kotlin/org/jetbrains/skiko/SystemTheme.jvm.kt

 package org.jetbrains.skiko
 
-enum class SystemTheme {
-    DARK,
-    LIGHT,
-    UNKNOWN
-}
-
 val currentSystemTheme: SystemTheme
     get() = when (getCurrentSystemTheme()) {
         0 -> SystemTheme.LIGHT

skiko/src/jvmMain/objectiveC/macos/Drawlayer.mm

@@ -188,7 +188,7 @@ JNIEXPORT void JNICALL Java_org_jetbrains_skiko_PlatformOperationsKt_osxDisableT
     });
 }
 
-JNIEXPORT jint JNICALL Java_org_jetbrains_skiko_SystemThemeKt_getCurrentSystemTheme(JNIEnv *env, jobject topLevel)
+JNIEXPORT jint JNICALL Java_org_jetbrains_skiko_SystemTheme_1jvmKt_getCurrentSystemTheme(JNIEnv *env, jobject topLevel)
 {
     NSString *osxMode = [[NSUserDefaults standardUserDefaults] stringForKey:@"AppleInterfaceStyle"];
     if ([@"Dark" isEqualToString:osxMode]) {