Add screen support

Co-authored-by: Oleg Gulevskyy <43781031+oleggulevskyy@users.noreply.github.com>

exp/examples/window/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	_ "embed"
+	"fmt"
 	"log"
 	"math/rand"
 	"strconv"
@@ -169,7 +170,37 @@ func main() {
 			w.SetURL("https://wails.io")
 		})
 	})
-
+	stateMenu.Add("Get Primary Screen").OnClick(func(ctx *application.Context) {
+		screen, err := app.GetPrimaryScreen()
+		if err != nil {
+			app.NewErrorDialog().SetTitle("Error").SetMessage(err.Error()).Show()
+			return
+		}
+		msg := fmt.Sprintf("Screen: %+v", screen)
+		app.NewInfoDialog().SetTitle("Primary Screen").SetMessage(msg).Show()
+	})
+	stateMenu.Add("Get Screens").OnClick(func(ctx *application.Context) {
+		screens, err := app.GetScreens()
+		if err != nil {
+			app.NewErrorDialog().SetTitle("Error").SetMessage(err.Error()).Show()
+			return
+		}
+		for _, screen := range screens {
+			msg := fmt.Sprintf("Screen: %+v", screen)
+			app.NewInfoDialog().SetTitle(fmt.Sprintf("Screen %s", screen.ID)).SetMessage(msg).Show()
+		}
+	})
+	stateMenu.Add("Get Screen for Window").OnClick(func(ctx *application.Context) {
+		currentWindow(func(w *application.Window) {
+			screen, err := w.GetScreen()
+			if err != nil {
+				app.NewErrorDialog().SetTitle("Error").SetMessage(err.Error()).Show()
+				return
+			}
+			msg := fmt.Sprintf("Screen: %+v", screen)
+			app.NewInfoDialog().SetTitle(fmt.Sprintf("Screen %s", screen.ID)).SetMessage(msg).Show()
+		})
+	})
 	app.NewWindow()
 
 	app.SetMenu(menu)

exp/pkg/application/application.go

@@ -362,6 +362,14 @@ func (a *App) NewSaveFileDialog() *SaveFileDialog {
 	return newSaveFileDialog()
 }
 
+func (a *App) GetPrimaryScreen() (*Screen, error) {
+	return getPrimaryScreen()
+}
+
+func (a *App) GetScreens() ([]*Screen, error) {
+	return getScreens()
+}
+
 func (a *App) Clipboard() *Clipboard {
 	if a.clipboard == nil {
 		a.clipboard = newClipboard()

exp/pkg/application/screen.go

@@ -0,0 +1,26 @@
+package application
+
+type Screen struct {
+	ID        string  // A unique identifier for the display
+	Name      string  // The name of the display
+	Scale     float32 // The scale factor of the display
+	X         int     // The x-coordinate of the top-left corner of the rectangle
+	Y         int     // The y-coordinate of the top-left corner of the rectangle
+	Size      Size    // The size of the display
+	Bounds    Rect    // The bounds of the display
+	WorkArea  Rect    // The work area of the display
+	IsPrimary bool    // Whether this is the primary display
+	Rotation  float32 // The rotation of the display
+}
+
+type Rect struct {
+	X      int
+	Y      int
+	Width  int
+	Height int
+}
+
+type Size struct {
+	Width  int
+	Height int
+}

exp/pkg/application/screen_darwin.go

@@ -0,0 +1,151 @@
+//go:build darwin
+
+package application
+
+/*
+#cgo CFLAGS: -x objective-c
+#cgo LDFLAGS: -framework Foundation -framework Cocoa -framework WebKit -framework AppKit
+#import <Foundation/Foundation.h>
+#import <CoreGraphics/CoreGraphics.h>
+#import <Cocoa/Cocoa.h>
+#import <AppKit/AppKit.h>
+#include <stdlib.h>
+
+typedef struct Screen {
+	const char* id;
+	const char* name;
+	int p_width;
+	int p_height;
+	int width;
+	int height;
+	int x;
+	int y;
+	int w_width;
+	int w_height;
+	int w_x;
+	int w_y;
+	float scale;
+	double rotation;
+	bool isPrimary;
+} Screen;
+
+
+int GetNumScreens(){
+	return [[NSScreen screens] count];
+}
+
+Screen processScreen(NSScreen* screen){
+	Screen returnScreen;
+	returnScreen.scale = screen.backingScaleFactor;
+
+	// screen bounds
+	returnScreen.height = screen.frame.size.height;
+	returnScreen.width = screen.frame.size.width;
+	returnScreen.x = screen.frame.origin.x;
+	returnScreen.y = screen.frame.origin.y;
+
+	// work area
+	NSRect workArea = [screen visibleFrame];
+	returnScreen.w_height = workArea.size.height;
+	returnScreen.w_width = workArea.size.width;
+	returnScreen.w_x = workArea.origin.x;
+	returnScreen.w_y = workArea.origin.y;
+
+
+	// adapted from https://stackoverflow.com/a/1237490/4188138
+	NSDictionary* screenDictionary = [screen deviceDescription];
+	NSNumber* screenID = [screenDictionary objectForKey:@"NSScreenNumber"];
+	CGDirectDisplayID displayID = [screenID unsignedIntValue];
+	returnScreen.id = [[NSString stringWithFormat:@"%d", displayID] UTF8String];
+
+	// Get physical monitor size
+	NSValue *sizeValue = [screenDictionary objectForKey:@"NSDeviceSize"];
+	NSSize physicalSize = sizeValue.sizeValue;
+	returnScreen.p_height = physicalSize.height;
+	returnScreen.p_width = physicalSize.width;
+
+	// Get the rotation
+	double rotation = CGDisplayRotation(displayID);
+	returnScreen.rotation = rotation;
+
+	if( @available(macOS 10.15, *) ){
+		returnScreen.name = [screen.localizedName UTF8String];
+	}
+
+	return returnScreen;
+}
+
+// Get primary screen
+Screen GetPrimaryScreen(){
+	// Get primary screen
+	NSScreen *mainScreen = [NSScreen mainScreen];
+	return processScreen(mainScreen);
+}
+
+Screen* getAllScreens() {
+	NSArray<NSScreen *> *screens = [NSScreen screens];
+	Screen* returnScreens = malloc(sizeof(Screen) * screens.count);
+	for (int i = 0; i < screens.count; i++) {
+		NSScreen* screen = [screens objectAtIndex:i];
+		returnScreens[i] = processScreen(screen);
+	}
+	return returnScreens;
+}
+
+Screen getScreenForWindow(void* window){
+	NSScreen* screen = ((NSWindow*)window).screen;
+	return processScreen(screen);
+}
+
+*/
+import "C"
+import "unsafe"
+
+func cScreenToScreen(screen C.Screen) *Screen {
+
+	return &Screen{
+		Size: Size{
+			Width:  int(screen.p_width),
+			Height: int(screen.p_height),
+		},
+		Bounds: Rect{
+			X:      int(screen.x),
+			Y:      int(screen.y),
+			Height: int(screen.height),
+			Width:  int(screen.width),
+		},
+		WorkArea: Rect{
+			X:      int(screen.w_x),
+			Y:      int(screen.w_y),
+			Height: int(screen.w_height),
+			Width:  int(screen.w_width),
+		},
+		Scale:     float32(screen.scale),
+		ID:        C.GoString(screen.id),
+		Name:      C.GoString(screen.name),
+		IsPrimary: bool(screen.isPrimary),
+		Rotation:  float32(screen.rotation),
+	}
+}
+
+func getPrimaryScreen() (*Screen, error) {
+	cScreen := C.GetPrimaryScreen()
+	return cScreenToScreen(cScreen), nil
+}
+
+func getScreens() ([]*Screen, error) {
+	cScreens := C.getAllScreens()
+	defer C.free(unsafe.Pointer(cScreens))
+	numScreens := int(C.GetNumScreens())
+	displays := make([]*Screen, numScreens)
+	cScreenHeaders := (*[1 << 30]C.Screen)(unsafe.Pointer(cScreens))[:numScreens:numScreens]
+	for i := 0; i < numScreens; i++ {
+		displays[i] = cScreenToScreen(cScreenHeaders[i])
+	}
+	return displays, nil
+}
+
+func getScreenForWindow(window *macosWindow) (*Screen, error) {
+	cScreen := C.getScreenForWindow(window.nsWindow)
+	return cScreenToScreen(cScreen), nil
+}

exp/pkg/application/window.go

@@ -52,6 +52,7 @@ type (
 		setFullscreenButtonEnabled(enabled bool)
 		show()
 		hide()
+		getScreen() (*Screen, error)
 	}
 )
 
@@ -545,3 +546,10 @@ func (w *Window) enableSizeConstraints() {
 	w.SetMinSize(w.options.MinWidth, w.options.MinHeight)
 	w.SetMaxSize(w.options.MaxWidth, w.options.MaxHeight)
 }
+
+func (w *Window) GetScreen() (*Screen, error) {
+	if w.impl == nil {
+		return nil, nil
+	}
+	return w.impl.getScreen()
+}

exp/pkg/application/window_darwin.go

@@ -691,6 +691,10 @@ type macosWindow struct {
 	parent   *Window
 }
 
+func (w *macosWindow) getScreen() (*Screen, error) {
+	return getScreenForWindow(w)
+}
+
 func (w *macosWindow) show() {
 	C.windowShow(w.nsWindow)
 }