Add *very* basic login flow

ui/app-window.slint

@@ -1,6 +1,7 @@
 import { AboutSlint, Button, Palette, HorizontalBox, ScrollView } from "std-widgets.slint";
 import { Timeline } from "timeline.slint";
 import { ImageViewer } from "image-viewer.slint";
+import { LoginView } from "login.slint";
 
 import { Global } from "global.slint";
 export { Global }
@@ -34,7 +35,8 @@ export component AppWindow inherits Window {
 
         Header {}
         
-        Timeline {}
+        if !Global.logged-in: LoginView {}
+        if Global.logged-in: Timeline {}
     }
 
     if Global.previewed-image.asset-id != "" : ImageViewer {

ui/global.slint

@@ -1,6 +1,7 @@
 import { ImageBucket, ImagePreview } from "types.slint";
 
 export global Global {
+    in-out property <bool> logged-in: false;
     in-out property <length> min-image-size: 160px;
     in-out property <length> image-margin: 2px;
     in-out property <ImagePreview> previewed-image;
@@ -12,6 +13,7 @@ export global Global {
     in property <length> timeline-height;
     in property <length> timeline-width;
     in property <length> timeline-scroll;
+    callback login-api-key(url: string, api_key: string);
     callback set-timeline-width(length);
     callback timeline-scrolled(length);
 }

ui/login.slint

@@ -0,0 +1,35 @@
+import { TextEdit, LineEdit, Button } from "std-widgets.slint";
+import { Global } from "global.slint";
+
+export component LoginView inherits VerticalLayout {
+    padding: 16px;
+    alignment: center;
+    spacing: 8px;
+
+    HorizontalLayout {
+        alignment: center;
+        Image {
+            width: 128px;
+            height: self.width;
+            source: @image-url("../assets/immich-logo.svg");
+        }
+    }
+
+    url := LineEdit {
+        placeholder-text: "immich url";
+        height: 40px;
+    }
+
+    api-key := LineEdit {
+        placeholder-text: "immich api key";
+        height: 40px;
+    }
+
+    Button {
+        text: "Login";
+        height: 40px;
+        clicked => {
+            Global.login-api-key(url.text, api-key.text);
+        }
+    }
+}