Port 'Label' demo to Vala (#159)

src/Label/main.vala

@@ -0,0 +1,61 @@
+#! /usr/bin/env -S vala workbench.vala --pkg libadwaita-1
+
+public void main () {
+    var label = (Gtk.Label) workbench.builder.get_object ("label");
+    var justification_row = (Adw.ComboRow) workbench.builder.get_object ("justification_row");
+    var style_row = (Adw.ComboRow) workbench.builder.get_object ("style_row");
+    var single_line_switch = (Adw.SwitchRow) workbench.builder.get_object ("single_line_switch");
+
+    string[] style_classes = {
+        "none",
+        "title-1",
+        "title-2",
+        "title-3",
+        "title-4",
+        "monospace",
+        "accent",
+        "success",
+        "warning",
+        "error",
+        "heading",
+        "body",
+        "caption-heading",
+        "caption"
+    };
+
+    string short_label =
+        "<b>Lorem ipsum</b> dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore disputandum putant.";
+
+    string long_label =
+        "     <b>Lorem ipsum</b> dolor sit amet, consectetur adipiscing elit,
+        sed do eiusmod tempor incididunt ut labore et dolore magnam aliquam quaerat voluptatem.
+        Ut enim mortis metu omnis quietae vitae status perturbatur,
+        et ut succumbere doloribus eosque humili animo inbecilloque ferre miserum est,
+        ob eamque debilitatem animi multi parentes, multi amicos, non nulli patriam,
+        plerique autem se ipsos penitus perdiderunt, sic robustus animus et excelsus omni.";
+
+    label.label = (short_label);
+
+    single_line_switch.notify["active"].connect (() => {
+        if (!single_line_switch.active) {
+            label.label = long_label;
+        } else {
+            label.label = short_label;
+        }
+    });
+
+    justification_row.notify["selected"].connect (() => {
+        label.justify = (Gtk.Justification) justification_row.selected;
+    });
+
+    style_row.notify["selected"].connect (() => {
+        foreach (string style_class in style_classes) {
+            label.remove_css_class (style_class);
+        }
+
+        if (style_row.selected == 0)return;
+
+        string new_style_class = style_classes[style_row.selected];
+        label.add_css_class (new_style_class);
+    });
+}