[v3 alpha] implement setIcon on linux (#3354)

* implement `linuxApp.setIcon`

* Move code into `linux_cgo.go`

v3/pkg/application/application_linux.go

@@ -15,7 +15,6 @@ package application
 import "C"
 import (
 	"fmt"
-	"log"
 	"os"
 	"strings"
 	"sync"
@@ -42,6 +41,8 @@ type linuxApp struct {
 	windowMapLock sync.Mutex
 
 	theme string
+
+	icon pointer
 }
 
 func (a *linuxApp) GetFlags(options Options) map[string]any {
@@ -68,10 +69,6 @@ func (a *linuxApp) on(eventID uint) {
 	//C.registerApplicationEvent(l.application, C.uint(eventID))
 }
 
-func (a *linuxApp) setIcon(icon []byte) {
-	log.Println("linuxApp.setIcon", "not implemented")
-}
-
 func (a *linuxApp) name() string {
 	return appName()
 }

v3/pkg/application/linux_cgo.go

@@ -425,6 +425,20 @@ func (a *linuxApp) showAllWindows() {
 	}
 }
 
+func (a *linuxApp) setIcon(icon []byte) {
+	gbytes := C.g_bytes_new_static(C.gconstpointer(unsafe.Pointer(&icon[0])), C.ulong(len(icon)))
+	stream := C.g_memory_input_stream_new_from_bytes(gbytes)
+	var gerror *C.GError
+	pixbuf := C.gdk_pixbuf_new_from_stream(stream, nil, &gerror)
+	if gerror != nil {
+		a.parent.error("Failed to load application icon: " + C.GoString(gerror.message))
+		C.g_error_free(gerror)
+		return
+	}
+
+	a.icon = pointer(pixbuf)
+}
+
 // Clipboard
 func clipboardGet() string {
 	clip := C.gtk_clipboard_get(C.GDK_SELECTION_CLIPBOARD)
@@ -1131,6 +1145,12 @@ func (w *linuxWebviewWindow) setTitle(title string) {
 	}
 }
 
+func (w *linuxWebviewWindow) setIcon(icon pointer) {
+	if icon != nil {
+		C.gtk_window_set_icon(w.gtkWindow(), (*C.GdkPixbuf)(icon))
+	}
+}
+
 func (w *linuxWebviewWindow) gtkWindow() *C.GtkWindow {
 	return (*C.GtkWindow)(w.window)
 }

v3/pkg/application/webview_window_linux.go

@@ -220,6 +220,7 @@ func (w *linuxWebviewWindow) run() {
 		w.enableDND()
 	}
 	w.setTitle(w.parent.options.Title)
+	w.setIcon(app.icon)
 	w.setAlwaysOnTop(w.parent.options.AlwaysOnTop)
 	w.setResizable(!w.parent.options.DisableResize)
 	// only set min/max size if actually set