app,gpu,op: [android,ios,macos,windows] add ExternalOp paint for external views

app/GioView.java

@@ -16,6 +16,7 @@
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Matrix;
+import android.graphics.PixelFormat;
 import android.graphics.Rect;
 import android.os.Build;
 import android.os.Bundle;
@@ -55,6 +56,8 @@
 import android.view.accessibility.AccessibilityNodeInfo;
 import android.view.accessibility.AccessibilityEvent;
 import android.view.accessibility.AccessibilityManager;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
 
 import java.io.UnsupportedEncodingException;
 
@@ -84,9 +87,12 @@ public GioView(Context context, AttributeSet attrs) {
 		// Late initialization of the Go runtime to wait for a valid context.
 		Gio.init(context.getApplicationContext());
 
+		setZOrderOnTop(true);
+
 		// Set background color to transparent to avoid a flickering
 		// issue on ChromeOS.
 		setBackgroundColor(Color.argb(0, 0, 0, 0));
+		getHolder().setFormat(PixelFormat.TRANSPARENT);
 
 		ViewConfiguration conf = ViewConfiguration.get(context);
 		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
@@ -153,6 +159,22 @@ public GioView(Context context, AttributeSet attrs) {
 			requestUnbufferedDispatch(event);
 		}
 
+		// Check if touch event should be handled by Gio or passed through
+		// to external views. Only check at the beginning of a trace so drags
+		// crossing over external regions are not truncated.
+		if (nhandle != 0) {
+			int action = event.getActionMasked();
+			if (action == MotionEvent.ACTION_DOWN || action == MotionEvent.ACTION_POINTER_DOWN) {
+				int idx = event.getActionIndex();
+				float x = event.getX(idx);
+				float y = event.getY(idx);
+				if (!hitTest(nhandle, x, y)) {
+					// Event is on an external view, don't consume it.
+					return false;
+				}
+			}
+		}
+
 		dispatchMotionEvent(event);
 		return true;
 	}
@@ -549,6 +571,62 @@ void updateCaret(float m00, float m01, float m02, float m10, float m11, float m1
 		imm.updateCursorAnchorInfo(this, inf);
 	}
 
+	boolean setEmbedViewPosition(View view, int x, int y, int w, int h, int zOrder) {
+		ViewGroup parent = (ViewGroup) this.getParent();
+		boolean isLayoutUpdated = false;
+
+		if (zOrder == 0) {
+			view.setVisibility(View.GONE);
+			view.requestLayout();
+			return true;
+		}
+
+		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+			// On API 21+: use Z for draw ordering without mutating the view
+			// hierarchy, so GioView's SurfaceView surface is never destroyed.
+			if (view.getVisibility() != View.VISIBLE) {
+				view.setVisibility(View.VISIBLE);
+				isLayoutUpdated = true;
+			}
+			if (view.getZ() != (float) zOrder) {
+				// Suppress any outline-based drop shadow the Z value would produce.
+				view.setOutlineProvider(null);
+				view.setZ((float) zOrder);
+				isLayoutUpdated = true;
+			}
+		}
+
+		ViewGroup.LayoutParams lp = view.getLayoutParams();
+		if (lp == null || lp.width != w || lp.height != h) {
+			view.setLayoutParams(new FrameLayout.LayoutParams(w, h));
+			isLayoutUpdated = true;
+		}
+
+		int oldX = (int) view.getX();
+		int oldY = (int) view.getY();
+		if (oldX != x || oldY != y) {
+			view.setX(x);
+			view.setY(y);
+			isLayoutUpdated = true;
+		}
+
+		if (isLayoutUpdated) {
+			view.invalidate();
+			view.requestLayout();
+			this.invalidate();
+		}
+
+		return isLayoutUpdated;
+	}
+
+	public void updateLayout() {
+		ViewGroup parent = (ViewGroup) this.getParent();
+		if (parent != null) {
+			parent.bringChildToFront(this);
+			parent.forceLayout();
+		}
+	}
+
 	static private native long onCreateView(GioView view);
 	static private native void onDestroyView(long handle);
 	static private native void onStartView(long handle);
@@ -583,6 +661,9 @@ void updateCaret(float m00, float m01, float m02, float m10, float m11, float m1
 	static private native int imeToRunes(long handle, int chars);
 	// imeToUTF16 converts the rune index into Java characters.
 	static private native int imeToUTF16(long handle, int runes);
+	// hitTest returns true if the point should be handled by Gio,
+	// false if it should be passed through to external views.
+	static private native boolean hitTest(long handle, float x, float y);
 
 	private class GioInputConnection implements InputConnection {
 		private int batchDepth;

app/gl_ios.m

@@ -41,7 +41,9 @@ CFTypeRef gio_createGLLayer(void) {
 		return nil;
 	}
 	layer.drawableProperties = @{kEAGLDrawablePropertyColorFormat: kEAGLColorFormatSRGBA8};
-	layer.opaque = YES;
+	// Enable transparency for external views.
+	layer.opaque = NO;
+	layer.backgroundColor = [UIColor clearColor].CGColor;
 	layer.anchorPoint = CGPointMake(0, 0);
 	return CFBridgingRetain(layer);
 }

app/gl_macos.m

@@ -9,7 +9,11 @@
 
 CALayer *gio_layerFactory(BOOL presentWithTrans) {
 	@autoreleasepool {
-		return [CALayer layer];
+		CALayer *l = [CALayer layer];
+		// Enable transparency for external views.
+		l.opaque = NO;
+		l.backgroundColor = [NSColor clearColor].CGColor;
+		return l;
 	}
 }
 

app/internal/windows/windows.go

@@ -208,7 +208,10 @@ const (
 	CFS_CANDIDATEPOS = 0x0040
 
 	HWND_TOPMOST = ^(uint32(1) - 1) // -1
+	HWND_TOP     = 0
+	HWND_BOTTOM  = 1
 
+	HTTRANSPARENT = ^uintptr(0) // -1, pass through to underlying window
 	HTCAPTION     = 2
 	HTCLIENT      = 1
 	HTLEFT        = 10
@@ -220,6 +223,15 @@ const (
 	HTBOTTOMLEFT  = 16
 	HTBOTTOMRIGHT = 17
 
+	// Region operations for CombineRgn
+	RGN_AND   = 1
+	RGN_OR    = 2
+	RGN_XOR   = 3
+	RGN_DIFF  = 4
+	RGN_COPY  = 5
+	RGN_NULL  = 1
+	RGN_ERROR = 0
+
 	IDC_APPSTARTING = 32650 // Standard arrow and small hourglass
 	IDC_ARROW       = 32512 // Standard arrow
 	IDC_CROSS       = 32515 // Crosshair
@@ -259,8 +271,10 @@ const (
 	SW_SHOWMAXIMIZED = 3
 	SW_SHOWNORMAL    = 1
 	SW_SHOW          = 5
+	SW_HIDE          = 0
 
 	SWP_FRAMECHANGED  = 0x0020
+	SWP_NOACTIVATE    = 0x0010
 	SWP_NOMOVE        = 0x0002
 	SWP_NOOWNERZORDER = 0x0200
 	SWP_NOSIZE        = 0x0001
@@ -378,6 +392,7 @@ const (
 	WS_THICKFRAME  = 0x00040000
 	WS_MINIMIZEBOX = 0x00020000
 	WS_MAXIMIZEBOX = 0x00010000
+	WS_CHILD       = 0x40000000
 
 	WS_EX_APPWINDOW  = 0x00040000
 	WS_EX_WINDOWEDGE = 0x00000100
@@ -472,6 +487,7 @@ var (
 	_SetWindowLong32             = user32.NewProc("SetWindowLongW")
 	_SetWindowPlacement          = user32.NewProc("SetWindowPlacement")
 	_SetWindowPos                = user32.NewProc("SetWindowPos")
+	_SetWindowRgn                = user32.NewProc("SetWindowRgn")
 	_SetWindowText               = user32.NewProc("SetWindowTextW")
 	_TranslateMessage            = user32.NewProc("TranslateMessage")
 	_UnregisterClass             = user32.NewProc("UnregisterClassW")
@@ -482,6 +498,9 @@ var (
 
 	gdi32          = syscall.NewLazySystemDLL("gdi32")
 	_GetDeviceCaps = gdi32.NewProc("GetDeviceCaps")
+	_CreateRectRgn = gdi32.NewProc("CreateRectRgn")
+	_CombineRgn    = gdi32.NewProc("CombineRgn")
+	_DeleteObject  = gdi32.NewProc("DeleteObject")
 
 	imm32                    = syscall.NewLazySystemDLL("imm32")
 	_ImmGetContext           = imm32.NewProc("ImmGetContext")
@@ -993,3 +1012,32 @@ func (p *WindowPlacement) Set(Left, Top, Right, Bottom int) {
 	p.rcNormalPosition.Right = int32(Right)
 	p.rcNormalPosition.Bottom = int32(Bottom)
 }
+
+// CreateRectRgn creates a rectangular region.
+func CreateRectRgn(left, top, right, bottom int32) syscall.Handle {
+	r, _, _ := _CreateRectRgn.Call(uintptr(left), uintptr(top), uintptr(right), uintptr(bottom))
+	return syscall.Handle(r)
+}
+
+// CombineRgn combines two regions.
+func CombineRgn(dst, src1, src2 syscall.Handle, mode int) int {
+	r, _, _ := _CombineRgn.Call(uintptr(dst), uintptr(src1), uintptr(src2), uintptr(mode))
+	return int(r)
+}
+
+// DeleteObject deletes a GDI object.
+func DeleteObject(h syscall.Handle) bool {
+	r, _, _ := _DeleteObject.Call(uintptr(h))
+	return r != 0
+}
+
+// SetWindowRgn sets the window region for hit testing.
+// Pass 0 as hRgn to reset to the full window rect.
+func SetWindowRgn(hwnd syscall.Handle, hRgn syscall.Handle, redraw bool) bool {
+	var redrawInt uintptr
+	if redraw {
+		redrawInt = 1
+	}
+	r, _, _ := _SetWindowRgn.Call(uintptr(hwnd), uintptr(hRgn), redrawInt)
+	return r != 0
+}

app/metal_ios.go

@@ -23,6 +23,9 @@ static CFTypeRef getMetalLayer(CFTypeRef viewRef) {
 		CAMetalLayer *l = (CAMetalLayer *)view.layer;
 		l.needsDisplayOnBoundsChange = YES;
 		l.presentsWithTransaction = YES;
+		// Enable transparency for external views.
+		l.opaque = NO;
+		l.backgroundColor = [UIColor clearColor].CGColor;
 		return CFBridgingRetain(l);
 	}
 }

app/metal_macos.go

@@ -18,6 +18,9 @@ CALayer *gio_layerFactory(BOOL presentWithTrans) {
 		l.autoresizingMask = kCALayerHeightSizable|kCALayerWidthSizable;
 		l.needsDisplayOnBoundsChange = YES;
 		l.presentsWithTransaction = presentWithTrans;
+		// Enable transparency for external views.
+		l.opaque = NO;
+		l.backgroundColor = [NSColor clearColor].CGColor;
 		return l;
 	}
 }

app/os_android.go

@@ -138,6 +138,7 @@ import (
 
 	"gioui.org/io/transfer"
 
+	"gioui.org/gpu"
 	"gioui.org/internal/f32color"
 	"gioui.org/op"
 
@@ -176,30 +177,35 @@ type window struct {
 		focusID input.SemanticID
 		diffs   []input.SemanticID
 	}
+
+	// embedRegions tracks areas for hit testing.
+	embedRegions gpu.EmbedRegions
 }
 
 // gioView hold cached JNI methods for GioView.
 var gioView struct {
-	once               sync.Once
-	getDensity         C.jmethodID
-	getFontScale       C.jmethodID
-	showTextInput      C.jmethodID
-	hideTextInput      C.jmethodID
-	setInputHint       C.jmethodID
-	postFrameCallback  C.jmethodID
-	invalidate         C.jmethodID // requests draw, called from UI thread
-	setCursor          C.jmethodID
-	setOrientation     C.jmethodID
-	setNavigationColor C.jmethodID
-	setStatusColor     C.jmethodID
-	setFullscreen      C.jmethodID
-	unregister         C.jmethodID
-	sendA11yEvent      C.jmethodID
-	sendA11yChange     C.jmethodID
-	isA11yActive       C.jmethodID
-	restartInput       C.jmethodID
-	updateSelection    C.jmethodID
-	updateCaret        C.jmethodID
+	once                 sync.Once
+	getDensity           C.jmethodID
+	getFontScale         C.jmethodID
+	showTextInput        C.jmethodID
+	hideTextInput        C.jmethodID
+	setInputHint         C.jmethodID
+	postFrameCallback    C.jmethodID
+	invalidate           C.jmethodID // requests draw, called from UI thread
+	setCursor            C.jmethodID
+	setOrientation       C.jmethodID
+	setNavigationColor   C.jmethodID
+	setStatusColor       C.jmethodID
+	setFullscreen        C.jmethodID
+	unregister           C.jmethodID
+	sendA11yEvent        C.jmethodID
+	sendA11yChange       C.jmethodID
+	isA11yActive         C.jmethodID
+	restartInput         C.jmethodID
+	updateSelection      C.jmethodID
+	updateCaret          C.jmethodID
+	updateLayout         C.jmethodID
+	setEmbedViewPosition C.jmethodID
 }
 
 type pixelInsets struct {
@@ -486,6 +492,8 @@ func Java_org_gioui_GioView_onCreateView(env *C.JNIEnv, class C.jclass, view C.j
 		m.restartInput = getMethodID(env, class, "restartInput", "()V")
 		m.updateSelection = getMethodID(env, class, "updateSelection", "()V")
 		m.updateCaret = getMethodID(env, class, "updateCaret", "(FFFFFFFFFF)V")
+		m.updateLayout = getMethodID(env, class, "updateLayout", "()V")
+		m.setEmbedViewPosition = getMethodID(env, class, "setEmbedViewPosition", "(Landroid/view/View;IIIII)Z")
 	})
 	view = C.jni_NewGlobalRef(env, view)
 	wopts := <-mainWindow.out
@@ -910,6 +918,23 @@ func (w *window) draw(env *C.JNIEnv, sync bool) {
 			callVoidMethod(env, w.view, gioView.sendA11yChange, jvalue(w.virtualIDFor(id)))
 		}
 	}
+
+	currentRegions, lostRegions := w.callbacks.EmbeddedRegions()
+	var needsUpdate bool
+	for index, region := range currentRegions.Views {
+		if ok, _ := callBooleanMethod(env, w.view, gioView.setEmbedViewPosition, jvalue(region.View), jvalue(region.Area.Min.X), jvalue(region.Area.Min.Y), jvalue(region.Area.Dx()), jvalue(region.Area.Dy()), jvalue(index+1)); ok {
+			needsUpdate = true
+		}
+	}
+	for _, lost := range lostRegions {
+		if ok, _ := callBooleanMethod(env, w.view, gioView.setEmbedViewPosition, jvalue(lost.View), jvalue(0), jvalue(0), jvalue(0), jvalue(0), jvalue(0)); ok {
+			needsUpdate = true
+		}
+	}
+	if needsUpdate {
+		callVoidMethod(env, w.view, gioView.updateLayout)
+	}
+	w.embedRegions = currentRegions
 }
 
 func runInJVM(jvm *C.JavaVM, f func(env *C.JNIEnv)) {
@@ -984,6 +1009,15 @@ func Java_org_gioui_GioView_onKeyEvent(env *C.JNIEnv, class C.jclass, handle C.j
 	}
 }
 
+//export Java_org_gioui_GioView_hitTest
+func Java_org_gioui_GioView_hitTest(env *C.JNIEnv, class C.jclass, handle C.jlong, x, y C.jfloat) C.jboolean {
+	w := cgo.Handle(handle).Value().(*window)
+	if w.embedRegions.Contains(f32.Point{X: float32(x), Y: float32(y)}) {
+		return C.JNI_FALSE
+	}
+	return C.JNI_TRUE
+}
+
 //export Java_org_gioui_GioView_onTouchEvent
 func Java_org_gioui_GioView_onTouchEvent(env *C.JNIEnv, class C.jclass, handle C.jlong, action, pointerID, tool C.jint, x, y, scrollX, scrollY C.jfloat, jbtns C.jint, t C.jlong) {
 	w := cgo.Handle(handle).Value().(*window)