From de255729e6d160b29a51b9de15acf0380968910f Mon Sep 17 00:00:00 2001
From: Lea Anthony <lea.anthony@gmail.com>
Date: Sun, 15 Aug 2021 20:17:58 +1000
Subject: [PATCH] [windows-x] Support window drag

---
 v2/internal/frontend/windows/frontend.go | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/v2/internal/frontend/windows/frontend.go b/v2/internal/frontend/windows/frontend.go
index e11d2d2c8..4204864a1 100644
--- a/v2/internal/frontend/windows/frontend.go
+++ b/v2/internal/frontend/windows/frontend.go
@@ -3,8 +3,10 @@ package windows
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"github.com/jchv/go-webview2/pkg/edge"
 	"github.com/tadvi/winc"
+	"github.com/tadvi/winc/w32"
 	"github.com/wailsapp/wails/v2/internal/binding"
 	"github.com/wailsapp/wails/v2/internal/frontend"
 	"github.com/wailsapp/wails/v2/internal/frontend/assetserver"
@@ -215,6 +217,13 @@ func (f *Frontend) processRequest(req *edge.ICoreWebView2WebResourceRequest, arg
 
 func (f *Frontend) processMessage(message string) {
 	println("msg:", message)
+	if message == "drag" {
+		err := f.startDrag()
+		if err != nil {
+			f.logger.Error(err.Error())
+		}
+		return
+	}
 	err := f.dispatcher.ProcessMessage(message)
 	if err != nil {
 		f.logger.Error(err.Error())
@@ -227,6 +236,14 @@ func (f *Frontend) Callback(message string) {
 	})
 }
 
+func (f *Frontend) startDrag() error {
+	if !w32.ReleaseCapture() {
+		return fmt.Errorf("unable to release mouse capture")
+	}
+	w32.SendMessage(f.mainWindow.Handle(), w32.WM_NCLBUTTONDOWN, w32.HTCAPTION, 0)
+	return nil
+}
+
 func NewFrontend(appoptions *options.App, myLogger *logger.Logger, appBindings *binding.Bindings, dispatcher frontend.Dispatcher) *Frontend {
 
 	result := &Frontend{