ebiten: add WindowResizingModeType and its constants and functions

This allows a new state to disallow resizing the window but allow
making the window fullscreen on macOS by a user.

This change adds the new type WindowResizingModeType. There are
these constants of this type:

 * WindowResizingModeDisabled
 * WindowResizingModeOnlyFullscreenEnabled
 * WindowResizingModeEnabled

Closes #1819

examples/windowsize/main.go

@@ -131,7 +131,7 @@ func (g *game) Update() error {
 	positionX, positionY := ebiten.WindowPosition()
 	g.transparent = ebiten.IsScreenTransparent()
 	floating := ebiten.IsWindowFloating()
-	resizable := ebiten.IsWindowResizable()
+	resizingMode := ebiten.WindowResizingMode()
 	screenCleared := ebiten.IsScreenClearedEveryFrame()
 
 	const d = 16
@@ -238,7 +238,16 @@ func (g *game) Update() error {
 		floating = !floating
 	}
 	if inpututil.IsKeyJustPressed(ebiten.KeyR) {
-		resizable = !resizable
+		switch resizingMode {
+		case ebiten.WindowResizingModeDisabled:
+			resizingMode = ebiten.WindowResizingModeOnlyFullscreenEnabled
+		case ebiten.WindowResizingModeOnlyFullscreenEnabled:
+			resizingMode = ebiten.WindowResizingModeEnabled
+		case ebiten.WindowResizingModeEnabled:
+			resizingMode = ebiten.WindowResizingModeDisabled
+		default:
+			panic("not reached")
+		}
 	}
 	if inpututil.IsKeyJustPressed(ebiten.KeyW) {
 		screenCleared = !screenCleared
@@ -275,7 +284,7 @@ func (g *game) Update() error {
 	}
 	ebiten.SetWindowFloating(floating)
 	ebiten.SetScreenClearedEveryFrame(screenCleared)
-	if maximize && ebiten.IsWindowResizable() {
+	if maximize && ebiten.WindowResizingMode() == ebiten.WindowResizingModeEnabled {
 		ebiten.MaximizeWindow()
 	}
 	if minimize {
@@ -284,7 +293,7 @@ func (g *game) Update() error {
 	if restore {
 		ebiten.RestoreWindow()
 	}
-	ebiten.SetWindowResizable(resizable)
+	ebiten.SetWindowResizingMode(resizingMode)
 
 	if inpututil.IsKeyJustPressed(ebiten.KeyI) {
 		ebiten.SetWindowIcon([]image.Image{createRandomIconImage()})
@@ -314,7 +323,7 @@ func (g *game) Draw(screen *ebiten.Image) {
 	}
 
 	var lines []string
-	if !ebiten.IsWindowMaximized() && ebiten.IsWindowResizable() {
+	if !ebiten.IsWindowMaximized() && ebiten.WindowResizingMode() == ebiten.WindowResizingModeEnabled {
 		lines = append(lines, "[M] Maximize the window (only for desktops)")
 	}
 	if !ebiten.IsWindowMinimized() {
@@ -325,7 +334,7 @@ func (g *game) Draw(screen *ebiten.Image) {
 	}
 	msgM := strings.Join(lines, "\n")
 
-	msgR := "[R] Switch the window resizable state (only for desktops)\n"
+	msgR := "[R] Switch the window resizing mode (only for desktops)\n"
 	fg := "Yes"
 	if !ebiten.IsFocused() {
 		fg = "No"
@@ -405,20 +414,20 @@ func main() {
 		ebiten.SetFullscreen(true)
 	}
 	if *flagResizable {
-		ebiten.SetWindowResizable(true)
+		ebiten.SetWindowResizingMode(ebiten.WindowResizingModeEnabled)
 	}
 	if *flagFloating {
 		ebiten.SetWindowFloating(true)
 	}
 	if *flagMaximize {
-		ebiten.SetWindowResizable(true)
+		ebiten.SetWindowResizingMode(ebiten.WindowResizingModeEnabled)
 		ebiten.MaximizeWindow()
 	}
 	if !*flagVsync {
 		ebiten.SetFPSMode(ebiten.FPSModeVsyncOffMaximum)
 	}
 	if *flagAutoAdjusting {
-		ebiten.SetWindowResizable(true)
+		ebiten.SetWindowResizingMode(ebiten.WindowResizingModeEnabled)
 	}
 
 	ebiten.SetInitFocused(*flagInitFocused)
@@ -438,7 +447,7 @@ func main() {
 	}
 	if minw >= 0 || minh >= 0 || maxw >= 0 || maxh >= 0 {
 		ebiten.SetWindowSizeLimits(minw, minh, maxw, maxh)
-		ebiten.SetWindowResizable(true)
+		ebiten.SetWindowResizingMode(ebiten.WindowResizingModeEnabled)
 	}
 
 	const title = "Window Size (Ebiten Demo)"

internal/ui/ui.go

@@ -68,3 +68,11 @@ const (
 	CursorShapeEWResize
 	CursorShapeNSResize
 )
+
+type WindowResizingMode int
+
+const (
+	WindowResizingModeDisabled WindowResizingMode = iota
+	WindowResizingModeOnlyFullscreenEnabled
+	WindowResizingModeEnabled
+)

internal/ui/ui_glfw.go

@@ -70,6 +70,7 @@ type UserInterface struct {
 	cursorShape          CursorShape
 	windowClosingHandled bool
 	windowBeingClosed    bool
+	windowResizingMode   WindowResizingMode
 
 	// setSizeCallbackEnabled must be accessed from the main thread.
 	setSizeCallbackEnabled bool
@@ -88,7 +89,6 @@ type UserInterface struct {
 	initFullscreen           bool
 	initCursorMode           CursorMode
 	initWindowDecorated      bool
-	initWindowResizable      bool
 	initWindowPositionXInDIP int
 	initWindowPositionYInDIP int
 	initWindowWidthInDIP     int
@@ -346,19 +346,6 @@ func (u *UserInterface) setRunnableOnUnfocused(runnableOnUnfocused bool) {
 	u.m.Unlock()
 }
 
-func (u *UserInterface) isInitWindowResizable() bool {
-	u.m.RLock()
-	v := u.initWindowResizable
-	u.m.RUnlock()
-	return v
-}
-
-func (u *UserInterface) setInitWindowResizable(resizable bool) {
-	u.m.Lock()
-	u.initWindowResizable = resizable
-	u.m.Unlock()
-}
-
 func (u *UserInterface) isInitScreenTransparent() bool {
 	u.m.RLock()
 	v := u.initScreenTransparent
@@ -873,7 +860,11 @@ func (u *UserInterface) init() error {
 
 	// Before creating a window, set it unresizable no matter what u.isInitWindowResizable() is (#1987).
 	// Making the window resizable here doesn't work correctly when switching to enable resizing.
-	glfw.WindowHint(glfw.Resizable, glfw.False)
+	resizable := glfw.False
+	if u.windowResizingMode == WindowResizingModeEnabled {
+		resizable = glfw.True
+	}
+	glfw.WindowHint(glfw.Resizable, resizable)
 
 	floating := glfw.False
 	if u.isInitWindowFloating() {
@@ -908,13 +899,13 @@ func (u *UserInterface) init() error {
 	u.setWindowPositionInDIP(wx, wy, u.initMonitor)
 	u.setWindowSizeInDIP(ww, wh, u.isFullscreen())
 
-	u.setWindowResizable(u.isInitWindowResizable())
-
 	// Maximizing a window requires a proper size and position. Call Maximize here (#1117).
 	if u.isInitWindowMaximized() {
 		u.window.Maximize()
 	}
 
+	u.setWindowResizingModeForOS(u.windowResizingMode)
+
 	u.window.Show()
 
 	if g, ok := Graphics().(interface{ SetWindow(uintptr) }); ok {
@@ -1520,8 +1511,12 @@ func (u *UserInterface) setWindowFloating(floating bool) {
 	u.window.SetAttrib(glfw.Floating, v)
 }
 
-// setWindowResizable must be called from the main thread.
+// setWindowResizingMode must be called from the main thread.
-func (u *UserInterface) setWindowResizable(resizable bool) {
+func (u *UserInterface) setWindowResizingMode(mode WindowResizingMode) {
+	if u.windowResizingMode == mode {
+		return
+	}
+
 	if u.setSizeCallbackEnabled {
 		u.setSizeCallbackEnabled = false
 		defer func() {
@@ -1529,11 +1524,14 @@ func (u *UserInterface) setWindowResizable(resizable bool) {
 		}()
 	}
 
+	u.windowResizingMode = mode
+
 	v := glfw.False
-	if resizable {
+	if mode == WindowResizingModeEnabled {
 		v = glfw.True
 	}
 	u.window.SetAttrib(glfw.Resizable, v)
+	u.setWindowResizingModeForOS(mode)
 }
 
 // setWindowPositionInDIP sets the window position.

internal/ui/ui_glfw_darwin.go

@@ -22,6 +22,91 @@ package ui
 //
 // #import <AppKit/AppKit.h>
 //
+// @interface EbitenWindowDelegate : NSObject <NSWindowDelegate>
+// @end
+//
+// @implementation EbitenWindowDelegate {
+//   id<NSWindowDelegate> origDelegate_;
+//   bool origResizable_;
+// }
+//
+// - (instancetype)initWithOrigDelegate:(id<NSWindowDelegate>)origDelegate {
+//   self = [super init];
+//   if (self != nil) {
+//     origDelegate_ = origDelegate;
+//   }
+//   return self;
+// }
+//
+// // The method set of origDelegate_ must sync with GLFWWindowDelegate's implementation.
+// // See cocoa_window.m in GLFW.
+// - (BOOL)windowShouldClose:(id)sender {
+//   return [origDelegate_ windowShouldClose:sender];
+// }
+// - (void)windowDidResize:(NSNotification *)notification {
+//   [origDelegate_ windowDidResize:notification];
+// }
+// - (void)windowDidMove:(NSNotification *)notification {
+//   [origDelegate_ windowDidMove:notification];
+// }
+// - (void)windowDidMiniaturize:(NSNotification *)notification {
+//   [origDelegate_ windowDidMiniaturize:notification];
+// }
+// - (void)windowDidDeminiaturize:(NSNotification *)notification {
+//   [origDelegate_ windowDidDeminiaturize:notification];
+// }
+// - (void)windowDidBecomeKey:(NSNotification *)notification {
+//   [origDelegate_ windowDidBecomeKey:notification];
+// }
+// - (void)windowDidResignKey:(NSNotification *)notification {
+//   [origDelegate_ windowDidResignKey:notification];
+// }
+// - (void)windowDidChangeOcclusionState:(NSNotification* )notification {
+//   [origDelegate_ windowDidChangeOcclusionState:notification];
+// }
+//
+// - (void)pushResizableState:(NSWindow*)window {
+//   origResizable_ = window.styleMask & NSWindowStyleMaskResizable;
+//   if (!origResizable_) {
+//     window.styleMask |= NSWindowStyleMaskResizable;
+//   }
+// }
+//
+// - (void)popResizableState:(NSWindow*)window {
+//   if (!origResizable_) {
+//     window.styleMask &= ~NSWindowStyleMaskResizable;
+//   }
+//   origResizable_ = false;
+// }
+//
+// - (void)windowWillEnterFullScreen:(NSNotification *)notification {
+//   NSWindow* window = (NSWindow*)[notification object];
+//   [self pushResizableState:window];
+// }
+//
+// - (void)windowDidEnterFullScreen:(NSNotification *)notification {
+//   NSWindow* window = (NSWindow*)[notification object];
+//   [self popResizableState:window];
+// }
+//
+// - (void)windowWillExitFullScreen:(NSNotification *)notification {
+//   NSWindow* window = (NSWindow*)[notification object];
+//   [self pushResizableState:window];
+// }
+//
+// - (void)windowDidExitFullScreen:(NSNotification *)notification {
+//   NSWindow* window = (NSWindow*)[notification object];
+//   [self popResizableState:window];
+// }
+//
+// @end
+//
+// static void initializeWindow(uintptr_t windowPtr) {
+//   NSWindow* window = (NSWindow*)windowPtr;
+//   // This delegate is never released. This assumes that the window lives until the process lives.
+//   window.delegate = [[EbitenWindowDelegate alloc] initWithOrigDelegate:window.delegate];
+// }
+//
 // static void currentMonitorPos(uintptr_t windowPtr, int* x, int* y) {
 //   @autoreleasepool {
 //     NSScreen* screen = [NSScreen mainScreen];
@@ -55,6 +140,9 @@ package ui
 //   if (((window.styleMask & NSWindowStyleMaskFullScreen) != 0) == fullscreen) {
 //     return;
 //   }
+//
+//   // Even though EbitenWindowDelegate is used, this hack is still required.
+//   // toggleFullscreen doesn't work when the window is not resizable.
 //   bool origResizable = window.styleMask & NSWindowStyleMaskResizable;
 //   if (!origResizable) {
 //     window.styleMask |= NSWindowStyleMaskResizable;
@@ -126,6 +214,15 @@ package ui
 //   *x = (int)(location.x);
 //   *y = (int)(location.y);
 // }
+//
+// static void setAllowFullscreen(uintptr_t windowPtr, bool allowFullscreen) {
+//   NSWindow* window = (NSWindow*)windowPtr;
+//   if (allowFullscreen) {
+//     window.collectionBehavior |= NSWindowCollectionBehaviorFullScreenPrimary;
+//   } else {
+//     window.collectionBehavior &= ~NSWindowCollectionBehaviorFullScreenPrimary;
+//   }
+// }
 import "C"
 
 import (
@@ -225,5 +322,14 @@ func (u *UserInterface) adjustViewSize() {
 	C.adjustViewSize(C.uintptr_t(u.window.GetCocoaWindow()))
 }
 
-func initializeWindowAfterCreation(w *glfw.Window) {
+func (u *UserInterface) setWindowResizingModeForOS(mode WindowResizingMode) {
+	allowFullscreen := mode == WindowResizingModeOnlyFullscreenEnabled ||
+		mode == WindowResizingModeEnabled
+	C.setAllowFullscreen(C.uintptr_t(u.window.GetCocoaWindow()), C.bool(allowFullscreen))
+}
+
+func initializeWindowAfterCreation(w *glfw.Window) {
+	// TODO: Register NSWindowWillEnterFullScreenNotification and so on.
+	// Enable resizing temporary before making the window fullscreen.
+	C.initializeWindow(C.uintptr_t(w.GetCocoaWindow()))
 }

internal/ui/ui_glfw_unix.go

@@ -189,6 +189,9 @@ func (u *UserInterface) setNativeFullscreen(fullscreen bool) {
 func (u *UserInterface) adjustViewSize() {
 }
 
+func (u *UserInterface) setWindowResizingModeForOS(mode WindowResizingMode) {
+}
+
 func initializeWindowAfterCreation(w *glfw.Window) {
 	// Show the window once before getting the position of the window.
 	// On Linux/Unix, the window position is not reliable before showing.

internal/ui/ui_glfw_windows.go

@@ -203,5 +203,8 @@ func (u *UserInterface) setNativeFullscreen(fullscreen bool) {
 func (u *UserInterface) adjustViewSize() {
 }
 
+func (u *UserInterface) setWindowResizingModeForOS(mode WindowResizingMode) {
+}
+
 func initializeWindowAfterCreation(w *glfw.Window) {
 }

internal/ui/window_glfw.go

@@ -53,27 +53,32 @@ func (w *Window) SetDecorated(decorated bool) {
 	})
 }
 
-func (w *Window) IsResizable() bool {
+func (w *Window) ResizingMode() WindowResizingMode {
 	if !w.ui.isRunning() {
-		return w.ui.isInitWindowResizable()
+		w.ui.m.Lock()
+		mode := w.ui.windowResizingMode
+		w.ui.m.Unlock()
+		return mode
 	}
-	v := false
+	var mode WindowResizingMode
 	w.ui.t.Call(func() {
-		v = w.ui.window.GetAttrib(glfw.Resizable) == glfw.True
+		mode = w.ui.windowResizingMode
 	})
-	return v
+	return mode
 }
 
-func (w *Window) SetResizable(resizable bool) {
+func (w *Window) SetResizingMode(mode WindowResizingMode) {
 	if !w.ui.isRunning() {
-		w.ui.setInitWindowResizable(resizable)
+		w.ui.m.Lock()
+		w.ui.windowResizingMode = mode
+		w.ui.m.Unlock()
 		return
 	}
 	w.ui.t.Call(func() {
 		if w.ui.isNativeFullscreen() {
 			return
 		}
-		w.ui.setWindowResizable(resizable)
+		w.ui.setWindowResizingMode(mode)
 	})
 }
 
@@ -105,7 +110,7 @@ func (w *Window) IsMaximized() bool {
 	if !w.ui.isRunning() {
 		return w.ui.isInitWindowMaximized()
 	}
-	if !w.IsResizable() {
+	if w.ResizingMode() != WindowResizingModeEnabled {
 		return false
 	}
 	var v bool
@@ -119,7 +124,7 @@ func (w *Window) Maximize() {
 	// Do not allow maximizing the window when the window is not resizable.
 	// On Windows, it is possible to restore the window from being maximized by mouse-dragging,
 	// and this can be an unexpected behavior.
-	if !w.IsResizable() {
+	if w.ResizingMode() != WindowResizingModeEnabled {
 		panic("ui: a window to maximize must be resizable")
 	}
 	if !w.ui.isRunning() {

internal/ui/window_null.go

@@ -30,11 +30,11 @@ func (*Window) IsDecorated() bool {
 func (*Window) SetDecorated(decorated bool) {
 }
 
-func (*Window) IsResizable() bool {
+func (*Window) ResizingMode() WindowResizingMode {
-	return false
+	return WindowResizingModeDisabled
 }
 
-func (*Window) SetResizable(resizable bool) {
+func (*Window) SetResizingMode(mode WindowResizingMode) {
 }
 
 func (*Window) Position() (int, int) {

window.go

@@ -21,6 +21,27 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/ui"
 )
 
+// WindowResizingModeType represents a mode in which a user resizes the window.
+//
+// Regardless of the resizing mode, an Ebiten application can still change the window size or make
+// the window fullscreen by calling Ebiten functions.
+type WindowResizingModeType = ui.WindowResizingMode
+
+// WindowResizingModeTypes
+const (
+	// WindowResizingModeDisabled indicates the mode to disallow resizing the window by a user.
+	WindowResizingModeDisabled WindowResizingModeType = WindowResizingModeType(ui.WindowResizingModeDisabled)
+
+	// WindowResizingModeDisabled indicates the mode to disallow resizing the window,
+	// but allow to make the window fullscreen by a user.
+	// This works only on macOS so far.
+	// On the other platforms, this is the same as WindowResizingModeDisabled.
+	WindowResizingModeOnlyFullscreenEnabled WindowResizingModeType = WindowResizingModeType(ui.WindowResizingModeOnlyFullscreenEnabled)
+
+	// WindowResizingModeEnabled indicates the mode to allow resizing the window by a user.
+	WindowResizingModeEnabled WindowResizingModeType = WindowResizingModeType(ui.WindowResizingModeEnabled)
+)
+
 // IsWindowDecorated reports whether the window is decorated.
 //
 // IsWindowDecorated is concurrent-safe.
@@ -42,24 +63,42 @@ func SetWindowDecorated(decorated bool) {
 	ui.Get().Window().SetDecorated(decorated)
 }
 
+// WindowResizingMode returns the current mode in which a user resizes the window.
+//
+// The default mode is WindowResizingModeDisabled.
+//
+// WindowResizingMode is concurrent-safe.
+func WindowResizingMode() WindowResizingModeType {
+	return WindowResizingModeType(ui.Get().Window().ResizingMode())
+}
+
+// SetWindowResizingMode sets the mode in which a user resizes the window.
+//
+// SetWindowResizingMode does nothing on macOS when the window is fullscreened.
+//
+// SetWindowResizingMode is concurrent-safe.
+func SetWindowResizingMode(mode WindowResizingModeType) {
+	ui.Get().Window().SetResizingMode(ui.WindowResizingMode(mode))
+}
+
 // IsWindowResizable reports whether the window is resizable by the user's dragging on desktops.
 // On the other environments, IsWindowResizable always returns false.
 //
-// IsWindowResizable is concurrent-safe.
+// Deprecated: as of v2.2. Use WindowResizingMode instead.
 func IsWindowResizable() bool {
-	return ui.Get().Window().IsResizable()
+	return ui.Get().Window().ResizingMode() == ui.WindowResizingModeEnabled
 }
 
 // SetWindowResizable sets whether the window is resizable by the user's dragging on desktops.
 // On the other environments, SetWindowResizable does nothing.
 //
-// The window is not resizable by default.
+// Deprecated: as of v2.2, Use SetWindowResizingMode instead.
-//
-// SetWindowResizable does nothing on macOS when the window is fullscreened.
-//
-// SetWindowResizable is concurrent-safe.
 func SetWindowResizable(resizable bool) {
-	ui.Get().Window().SetResizable(resizable)
+	mode := ui.WindowResizingModeDisabled
+	if resizable {
+		mode = ui.WindowResizingModeEnabled
+	}
+	ui.Get().Window().SetResizingMode(mode)
 }
 
 // SetWindowTitle sets the title of the window.
@@ -200,7 +239,7 @@ func SetWindowFloating(float bool) {
 
 // MaximizeWindow maximizes the window.
 //
-// MaximizeWindow panics when the window is not resizable.
+// MaximizeWindow panics when the window is not resizable (WindowResizingModeEnabled).
 //
 // MaximizeWindow does nothing on browsers or mobiles.
 //
@@ -211,7 +250,7 @@ func MaximizeWindow() {
 
 // IsWindowMaximized reports whether the window is maximized or not.
 //
-// IsWindowMaximized returns false when the window is not resizable.
+// IsWindowMaximized returns false when the window is not resizable (WindowResizingModeEnabled).
 //
 // IsWindowMaximized always returns false on browsers and mobiles.
 //