Icon from EXE (windows), see #35.

date_windows.go

@@ -41,7 +41,7 @@ func (dlg *calendarDialog) setup(text string, opts options) (time.Time, error) {
 	defer setup(owner)()
 	dlg.font = getFont()
 	defer dlg.font.delete()
-	icon := getIcon(opts.windowIcon)
+	icon, _ := getIcon(opts.windowIcon)
 	defer icon.delete()
 
 	if opts.ctx != nil && opts.ctx.Err() != nil {

entry_windows.go

@@ -40,7 +40,7 @@ func (dlg *entryDialog) setup(text string, opts options) (string, error) {
 	defer setup(owner)()
 	dlg.font = getFont()
 	defer dlg.font.delete()
-	icon := getIcon(opts.windowIcon)
+	icon, _ := getIcon(opts.windowIcon)
 	defer icon.delete()
 
 	if opts.ctx != nil && opts.ctx.Err() != nil {

internal/win/shell32.go

@@ -284,6 +284,7 @@ func (u *IShellItemArray) GetItemAt(index uint32) (item *IShellItem, err error)
 	return
 }
 
+//sys ExtractAssociatedIcon(instance Handle, path *uint16, icon *uint16) (ret Handle, err error) = shell32.ExtractAssociatedIconW
 //sys SHBrowseForFolder(bi *BROWSEINFO) (ret *IDLIST) = shell32.SHBrowseForFolder
 //sys SHCreateItemFromParsingName(path *uint16, bc *IBindCtx, iid uintptr, item **IShellItem) (res error) = shell32.SHCreateItemFromParsingName
 //sys ShellNotifyIcon(message uint32, data *NOTIFYICONDATA) (ok bool) = shell32.Shell_NotifyIconW

internal/win/zsyscall_windows.go

@@ -65,6 +65,7 @@ var (
 	procGlobalFree                   = modkernel32.NewProc("GlobalFree")
 	procReleaseActCtx                = modkernel32.NewProc("ReleaseActCtx")
 	procCoCreateInstance             = modole32.NewProc("CoCreateInstance")
+	procExtractAssociatedIconW       = modshell32.NewProc("ExtractAssociatedIconW")
 	procSHBrowseForFolder            = modshell32.NewProc("SHBrowseForFolder")
 	procSHCreateItemFromParsingName  = modshell32.NewProc("SHCreateItemFromParsingName")
 	procSHGetPathFromIDListEx        = modshell32.NewProc("SHGetPathFromIDListEx")
@@ -235,6 +236,15 @@ func CoCreateInstance(clsid uintptr, unkOuter *IUnknown, clsContext int32, iid u
 	return
 }
 
+func ExtractAssociatedIcon(instance Handle, path *uint16, icon *uint16) (ret Handle, err error) {
+	r0, _, e1 := syscall.Syscall(procExtractAssociatedIconW.Addr(), 3, uintptr(instance), uintptr(unsafe.Pointer(path)), uintptr(unsafe.Pointer(icon)))
+	ret = Handle(r0)
+	if ret == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
 func SHBrowseForFolder(bi *BROWSEINFO) (ret *IDLIST) {
 	r0, _, _ := syscall.Syscall(procSHBrowseForFolder.Addr(), 1, uintptr(unsafe.Pointer(bi)), 0, 0)
 	ret = (*IDLIST)(unsafe.Pointer(r0))

list_windows.go

@@ -57,7 +57,7 @@ func (dlg *listDialog) setup(text string, opts options) ([]string, error) {
 	defer setup(owner)()
 	dlg.font = getFont()
 	defer dlg.font.delete()
-	icon := getIcon(opts.windowIcon)
+	icon, _ := getIcon(opts.windowIcon)
 	defer icon.delete()
 
 	if opts.ctx != nil && opts.ctx.Err() != nil {

msg_windows.go

@@ -104,11 +104,15 @@ func hookMessageDialog(opts options) (context.CancelFunc, error) {
 			}
 		}
 	}
-	unhook, err := hookDialog(opts.ctx, opts.windowIcon, nil, init)
+	icon, err := getIcon(opts.icon)
-	if err != nil || opts.icon == nil {
+	if err != nil {
-		return unhook, err
+		return nil, err
+	}
+	unhook, err := hookDialog(opts.ctx, opts.windowIcon, nil, init)
+	if err != nil {
+		icon.delete()
+		return nil, err
 	}
-	icon = getIcon(opts.icon)
 	return func() {
 		icon.delete()
 		unhook()

notify_windows.go

@@ -38,7 +38,7 @@ func notify(text string, opts options) error {
 	case ErrorIcon:
 		args.InfoFlags |= win.NIIF_ERROR
 	default:
-		icon := getIcon(opts.icon)
+		icon, _ := getIcon(opts.icon)
 		if icon.handle != 0 {
 			defer icon.delete()
 			args.Icon = icon.handle

progress_windows.go

@@ -120,7 +120,7 @@ func (dlg *progressDialog) setup(opts options) error {
 	defer setup(owner)()
 	dlg.font = getFont()
 	defer dlg.font.delete()
-	icon := getIcon(opts.windowIcon)
+	icon, _ := getIcon(opts.windowIcon)
 	defer icon.delete()
 
 	if opts.ctx != nil && opts.ctx.Err() != nil {

pwd_windows.go

@@ -50,7 +50,7 @@ func (dlg *passwordDialog) setup(opts options) (string, string, error) {
 	defer setup(owner)()
 	dlg.font = getFont()
 	defer dlg.font.delete()
-	icon := getIcon(opts.windowIcon)
+	icon, _ := getIcon(opts.windowIcon)
 	defer icon.delete()
 
 	if opts.ctx != nil && opts.ctx.Err() != nil {

util_windows.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"os"
+	"path/filepath"
 	"runtime"
 	"strconv"
 	"sync"
@@ -12,6 +13,7 @@ import (
 	"unsafe"
 
 	"github.com/ncruces/zenity/internal/win"
+	"golang.org/x/sys/windows"
 )
 
 const (
@@ -106,12 +108,13 @@ func newDialogHook(ctx context.Context, icon any, title *string, init func(wnd w
 	if hk == 0 {
 		return nil, err
 	}
+	ico, _ := getIcon(icon)
 
 	hook := dialogHook{
 		ctx:   ctx,
 		tid:   tid,
 		hook:  hk,
-		icon:  getIcon(icon),
+		icon:  ico,
 		title: title,
 		init:  init,
 	}
@@ -253,8 +256,7 @@ type icon struct {
 	destroy bool
 }
 
-func getIcon(i any) icon {
+func getIcon(i any) (icon icon, err error) {
-	var res icon
 	var resource uintptr
 	switch i {
 	case ErrorIcon:
@@ -267,38 +269,52 @@ func getIcon(i any) icon {
 		resource = win.IDI_INFORMATION
 	}
 	if resource != 0 {
-		res.handle, _ = win.LoadIcon(0, resource)
+		icon.handle, err = win.LoadIcon(0, resource)
-		return res
+		return icon, err
 	}
 
 	path, ok := i.(string)
 	if !ok {
-		return res
+		return icon, nil
 	}
 
 	data, err := os.ReadFile(path)
 	if err != nil {
-		return res
+		return icon, err
 	}
 
 	switch {
 	case bytes.HasPrefix(data, []byte("\x00\x00\x01\x00")):
-		res.handle, _ = win.LoadImage(0,
+		icon.handle, err = win.LoadImage(0,
 			strptr(path),
 			win.IMAGE_ICON, 0, 0,
 			win.LR_LOADFROMFILE|win.LR_DEFAULTSIZE)
-		res.destroy = true
+		icon.destroy = true
 	case bytes.HasPrefix(data, []byte("\x89PNG\r\n\x1a\n")):
-		res.handle, _ = win.CreateIconFromResourceEx(
+		icon.handle, err = win.CreateIconFromResourceEx(
 			data, true, 0x00030000, 0, 0,
 			win.LR_DEFAULTSIZE)
-		res.destroy = true
+		icon.destroy = true
+	case bytes.HasPrefix(data, []byte("MZ")):
+		var instance windows.Handle
+		instance, err = win.GetModuleHandle(nil)
+		if err != nil {
+			break
 		}
-	return res
+		path, err = filepath.Abs(path)
+		if err != nil {
+			break
+		}
+		var i uint16
+		icon.handle, err = win.ExtractAssociatedIcon(
+			instance, strptr(path), &i)
+		icon.destroy = true
+	}
+	return icon, err
 }
 
 func (i *icon) delete() {
-	if i.destroy && i.handle != 0 {
+	if i.handle != 0 && i.destroy {
 		win.DestroyIcon(i.handle)
 		i.handle = 0
 	}