[v2] Introduce size and physical size of screens (#2856)

v2/internal/frontend/desktop/darwin/screen.go

@@ -18,6 +18,8 @@ typedef struct Screen {
 	int isPrimary;
 	int height;
 	int width;
+	int pHeight;
+	int pWidth;
 } Screen;
 
 
@@ -48,14 +50,42 @@ Screen GetNthScreen(int nth, void *inctx){
 	returnScreen.isPrimary = nth==0;
 	returnScreen.height = (int) nthScreen.frame.size.height;
 	returnScreen.width =  (int) nthScreen.frame.size.width;
+
+	returnScreen.pWidth = 0;
+	returnScreen.pHeight = 0;
+
+	// https://stackoverflow.com/questions/13859109/how-to-programmatically-determine-native-pixel-resolution-of-retina-macbook-pro
+	CGDirectDisplayID sid = ((NSNumber *)[nthScreen.deviceDescription
+    	objectForKey:@"NSScreenNumber"]).unsignedIntegerValue;
+
+	CFArrayRef ms = CGDisplayCopyAllDisplayModes(sid, NULL);
+	CFIndex n = CFArrayGetCount(ms);
+	for (int i = 0; i < n; i++) {
+		CGDisplayModeRef m = (CGDisplayModeRef) CFArrayGetValueAtIndex(ms, i);
+		if (CGDisplayModeGetIOFlags(m) & kDisplayModeNativeFlag) {
+			// This corresponds with "System Settings" -> General -> About -> Displays
+			returnScreen.pWidth = CGDisplayModeGetPixelWidth(m);
+			returnScreen.pHeight = CGDisplayModeGetPixelHeight(m);
+			break;
+		}
+	}
+	CFRelease(ms);
+
+	if (returnScreen.pWidth == 0 || returnScreen.pHeight == 0) {
+		// If there was no native resolution take a best fit approach and use the backing pixel size.
+		NSRect pSize = [nthScreen convertRectToBacking:nthScreen.frame];
+		returnScreen.pHeight = (int) pSize.size.height;
+		returnScreen.pWidth = (int) pSize.size.width;
+	}
 	return returnScreen;
 }
 
 */
 import "C"
 import (
-	"github.com/wailsapp/wails/v2/internal/frontend"
 	"unsafe"
+
+	"github.com/wailsapp/wails/v2/internal/frontend"
 )
 
 func GetAllScreens(wailsContext unsafe.Pointer) ([]frontend.Screen, error) {
@@ -65,11 +95,21 @@ func GetAllScreens(wailsContext unsafe.Pointer) ([]frontend.Screen, error) {
 	for screeNum := 0; screeNum < numScreens; screeNum++ {
 		screenNumC := C.int(screeNum)
 		cScreen := C.GetNthScreen(screenNumC, wailsContext)
+
 		screen := frontend.Screen{
 			Height:    int(cScreen.height),
 			Width:     int(cScreen.width),
 			IsCurrent: cScreen.isCurrent == C.int(1),
 			IsPrimary: cScreen.isPrimary == C.int(1),
+
+			Size: frontend.ScreenSize{
+				Height: int(cScreen.height),
+				Width:  int(cScreen.width),
+			},
+			PhysicalSize: frontend.ScreenSize{
+				Height: int(cScreen.pHeight),
+				Width:  int(cScreen.pWidth),
+			},
 		}
 		screens = append(screens, screen)
 	}

v2/internal/frontend/desktop/linux/screen.go

@@ -16,6 +16,7 @@ typedef struct Screen {
 	int isPrimary;
 	int height;
 	int width;
+	int scale;
 } Screen;
 
 int GetNMonitors(GtkWindow *window){
@@ -36,14 +37,16 @@ Screen GetNThMonitor(int monitor_num, GtkWindow *window){
 	screen.isPrimary = gdk_monitor_is_primary(monitor);
 	screen.height = geometry.height;
 	screen.width = geometry.width;
+	screen.scale = gdk_monitor_get_scale_factor(monitor);
 	return screen;
 }
 */
 import "C"
 import (
+	"sync"
+
 	"github.com/pkg/errors"
 	"github.com/wailsapp/wails/v2/internal/frontend"
-	"sync"
 )
 
 type Screen = frontend.Screen
@@ -59,11 +62,21 @@ func GetAllScreens(window *C.GtkWindow) ([]Screen, error) {
 		numMonitors := C.GetNMonitors(window)
 		for i := 0; i < int(numMonitors); i++ {
 			cMonitor := C.GetNThMonitor(C.int(i), window)
+
 			screen := Screen{
 				IsCurrent: cMonitor.isCurrent == 1,
 				IsPrimary: cMonitor.isPrimary == 1,
 				Width:     int(cMonitor.width),
 				Height:    int(cMonitor.height),
+
+				Size: frontend.ScreenSize{
+					Width:  int(cMonitor.width),
+					Height: int(cMonitor.height),
+				},
+				PhysicalSize: frontend.ScreenSize{
+					Width:  int(cMonitor.width * cMonitor.scale),
+					Height: int(cMonitor.height * cMonitor.scale),
+				},
 			}
 			screens = append(screens, screen)
 		}

v2/internal/frontend/desktop/windows/screen.go

@@ -5,10 +5,12 @@ package windows
 
 import (
 	"fmt"
-	"github.com/pkg/errors"
-	"github.com/wailsapp/wails/v2/internal/frontend/desktop/windows/winc/w32"
 	"syscall"
 	"unsafe"
+
+	"github.com/pkg/errors"
+	"github.com/wailsapp/wails/v2/internal/frontend/desktop/windows/winc"
+	"github.com/wailsapp/wails/v2/internal/frontend/desktop/windows/winc/w32"
 )
 
 func MonitorsEqual(first w32.MONITORINFO, second w32.MONITORINFO) bool {
@@ -66,13 +68,26 @@ func EnumProc(hMonitor w32.HMONITOR, hdcMonitor w32.HDC, lprcMonitor *w32.RECT,
 		return w32.TRUE
 	}
 
-	height := lprcMonitor.Right - lprcMonitor.Left
-	width := lprcMonitor.Bottom - lprcMonitor.Top
+	width := lprcMonitor.Right - lprcMonitor.Left
+	height := lprcMonitor.Bottom - lprcMonitor.Top
 	ourMonitorData.IsPrimary = monInfo.DwFlags&w32.MONITORINFOF_PRIMARY == 1
-	ourMonitorData.Height = int(width)
-	ourMonitorData.Width = int(height)
+	ourMonitorData.Height = int(height)
+	ourMonitorData.Width = int(width)
 	ourMonitorData.IsCurrent = MonitorsEqual(*currentMonInfo, *monInfo)
 
+	ourMonitorData.PhysicalSize.Width = int(width)
+	ourMonitorData.PhysicalSize.Height = int(height)
+
+	var dpiX, dpiY uint
+	w32.GetDPIForMonitor(hMonitor, w32.MDT_EFFECTIVE_DPI, &dpiX, &dpiY)
+	if dpiX == 0 || dpiY == 0 {
+		screenContainer.errors = append(screenContainer.errors, fmt.Errorf("unable to get DPI for screen"))
+		screenContainer.monitors = append(screenContainer.monitors, Screen{})
+		return w32.TRUE
+	}
+	ourMonitorData.Size.Width = winc.ScaleToDefaultDPI(ourMonitorData.PhysicalSize.Width, dpiX)
+	ourMonitorData.Size.Height = winc.ScaleToDefaultDPI(ourMonitorData.PhysicalSize.Height, dpiY)
+
 	// the reason we need a container is that we have don't know how many times this function will be called
 	// this "append" call could potentially do an allocation and rewrite the pointer to monitors. So we save the pointer in screenContainer.monitors
 	// and retrieve the values after all EnumProc calls

v2/internal/frontend/frontend.go

@@ -48,8 +48,21 @@ const (
 type Screen struct {
 	IsCurrent bool `json:"isCurrent"`
 	IsPrimary bool `json:"isPrimary"`
-	Width     int  `json:"width"`
-	Height    int  `json:"height"`
+
+	// Deprecated: Please use Size and PhysicalSize
+	Width int `json:"width"`
+	// Deprecated: Please use Size and PhysicalSize
+	Height int `json:"height"`
+
+	// Size is the size of the screen in logical pixel space, used when setting sizes in Wails
+	Size ScreenSize `json:"size"`
+	// PhysicalSize is the physical size of the screen in pixels
+	PhysicalSize ScreenSize `json:"physicalSize"`
+}
+
+type ScreenSize struct {
+	Width  int `json:"width"`
+	Height int `json:"height"`
 }
 
 // MessageDialogOptions contains the options for the Message dialogs, EG Info, Warning, etc runtime methods

website/src/pages/changelog.mdx

@@ -36,6 +36,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added sveltekit.mdx guide. Added by @figuerom16 in [PR](https://github.com/wailsapp/wails/pull/2771)
 - Added ProgramName option to [linux.Options](/docs/reference/options#linux). Added by @lyimmi in [PR](https://github.com/wailsapp/wails/pull/2817)
 - Added new community tempalte wails-sveltekit-ts. Added by [@haukened](https://github.com/haukened) in [PR](https://github.com/wailsapp/wails/pull/2851)
+- Added support for retrieving the logical and physical screen size in the screen api. Added by @stffabi in [PR](https://github.com/wailsapp/wails/pull/2856)
 
 ### Changed