[v3 windows] Fix resizing. Add resize debouncing

v3/go.mod

@@ -3,6 +3,7 @@ module github.com/wailsapp/wails/v3
 go 1.19
 
 require (
+	github.com/bep/debounce v1.2.1
 	github.com/go-ole/go-ole v1.2.6
 	github.com/go-task/task/v3 v3.20.0
 	github.com/google/go-cmp v0.5.9

v3/go.sum

@@ -12,6 +12,8 @@ github.com/MarvinJWendt/testza v0.3.0/go.mod h1:eFcL4I0idjtIx8P9C6KkAuLgATNKpX4/
 github.com/MarvinJWendt/testza v0.4.2/go.mod h1:mSdhXiKH8sg/gQehJ63bINcCKp7RtYewEjXsvsVUPbE=
 github.com/MarvinJWendt/testza v0.5.1 h1:a9Fqx6vQrHQ4CyiaLhktfTTelwGotmFWy8MNhyaohw8=
 github.com/atomicgo/cursor v0.0.1/go.mod h1:cBON2QmmrysudxNBFthvMtN32r3jxVRIvzkUiF/RuIk=
+github.com/bep/debounce v1.2.1 h1:v67fRdBA9UQu2NhLFXrSg0Brw7CexQekrBwDMM8bzeY=
+github.com/bep/debounce v1.2.1/go.mod h1:H8yggRPQKLUhUoqrJC1bO2xNya7vanpDl7xR3ISbCJ0=
 github.com/containerd/console v1.0.3 h1:lIr7SlA5PxZyMV30bDW0MGbiOPXwc63yRuCP0ARubLw=
 github.com/containerd/console v1.0.3/go.mod h1:7LqA/THxQ86k76b8c/EMSiaJ3h1eZkMkXar0TQ1gf3U=
 github.com/creack/pty v1.1.18 h1:n56/Zwd5o6whRC5PMGretI4IdRLlmBXYNjScPaBgsbY=

v3/pkg/application/options_win.go

@@ -48,6 +48,10 @@ type WindowsWindow struct {
 
 	// WebviewGpuIsDisabled is used to enable / disable GPU acceleration for the webview
 	WebviewGpuIsDisabled bool
+
+	// ResizeDebounceMS is the amount of time to debounce redraws of webview2
+	// when resizing the window
+	ResizeDebounceMS uint16
 }
 
 type Theme int

v3/pkg/application/webview_window_windows.go

@@ -5,6 +5,7 @@ package application
 import (
 	"errors"
 	"fmt"
+	"github.com/bep/debounce"
 	"github.com/wailsapp/wails/v2/pkg/assetserver"
 	"io"
 	"net/http"
@@ -12,6 +13,7 @@ import (
 	"net/url"
 	"strconv"
 	"strings"
+	"time"
 	"unicode/utf16"
 	"unsafe"
 
@@ -36,8 +38,9 @@ type windowsWebviewWindow struct {
 	previousWindowPlacement w32.WINDOWPLACEMENT
 
 	// Webview
-	chromium   *edge.Chromium
-	hasStarted bool
+	chromium        *edge.Chromium
+	hasStarted      bool
+	resizeDebouncer func(func())
 }
 
 func (w *windowsWebviewWindow) nativeWindowHandle() uintptr {
@@ -202,6 +205,10 @@ func (w *windowsWebviewWindow) run() {
 		w.setWindowMask(options.Windows.WindowMask)
 	}
 
+	if options.Windows.ResizeDebounceMS > 0 {
+		w.resizeDebouncer = debounce.New(time.Duration(options.Windows.ResizeDebounceMS) * time.Millisecond)
+	}
+
 	if options.Centered {
 		w.center()
 	}
@@ -641,6 +648,26 @@ func (w *windowsWebviewWindow) WndProc(msg uint32, wparam, lparam uintptr) uintp
 		w32.SetFocus(w.hwnd)
 	case w32.WM_MOVE, w32.WM_MOVING:
 		_ = w.chromium.NotifyParentWindowPositionChanged()
+	case w32.WM_SIZING:
+		// If the window is frameless, and we are minimizing, then we need to suppress the Resize on the
+		// WebView2. If we don't do this, restoring does not work as expected and first restores with some wrong
+		// size during the restore animation and only fully renders when the animation is done. This highly
+		// depends on the content in the WebView, see https://github.com/wailsapp/wails/issues/1319
+		if w.parent.options.Frameless && wparam == w32.SIZE_MINIMIZED {
+			return 0
+		}
+
+		// If we have a resize debouncer, use it
+		if w.resizeDebouncer != nil {
+			w.resizeDebouncer(func() {
+				invokeSync(func() {
+					w.chromium.Resize()
+				})
+			})
+		} else {
+			w.chromium.Resize()
+		}
+
 	case w32.WM_GETMINMAXINFO:
 		mmi := (*w32.MINMAXINFO)(unsafe.Pointer(lparam))
 		hasConstraints := false