library: Port Event Controllers demo to Vala

src/Library/demos/Event Controllers/main.vala

@@ -0,0 +1,90 @@
+#!/usr/bin/env -S vala workbench.vala --pkg libadwaita-1
+
+private bool ctrl_pressed = false;
+
+public void main () {
+  Gtk.Window window = workbench.window;
+
+  var pic1 = (Gtk.Picture) workbench.builder.get_object ("pic1");
+  var pic2 = (Gtk.Picture) workbench.builder.get_object ("pic2");
+
+  pic1.file = File.new_for_uri (workbench.resolve ("image1.png"));
+  pic2.file = File.new_for_uri (workbench.resolve ("image2.png"));
+
+  var stack = (Gtk.Stack) workbench.builder.get_object ("stack");
+  var primary_button = (Gtk.Button) workbench.builder.get_object ("primary_button");
+  var middle_button = (Gtk.Button) workbench.builder.get_object ("middle_button");
+  var secondary_button = (Gtk.Button) workbench.builder.get_object ("secondary_button");
+  var ctrl_button = (Gtk.Button) workbench.builder.get_object ("ctrl_button");
+
+  var key_controller = new Gtk.EventControllerKey ();
+  // Gtk.Window hides Gtk.Widget's add_controller method, thus we need to cast it
+  ((Gtk.Widget) window).add_controller (key_controller);
+
+  key_controller.key_pressed.connect ((keyval, keycode, state) => {
+    if (keyval == Gdk.Key.Control_L || keyval == Gdk.Key.Control_R) {
+      ctrl_pressed = true;
+    }
+    return true;
+  });
+
+  key_controller.key_released.connect ((keyval, keycode, state) => {
+    if (keyval == Gdk.Key.Control_L || keyval == Gdk.Key.Control_R) {
+      ctrl_pressed = false;
+    }
+  });
+
+  ctrl_button.clicked.connect (() => {
+    if (ctrl_pressed) {
+      ctrl_button.label = "Click to Deactivate";
+      ctrl_button.add_css_class ("suggested-action");
+    } else {
+      ctrl_button.label = "Ctrl + Click to Activate";
+      ctrl_button.remove_css_class ("suggested-action");
+    }
+  });
+
+  var gesture_click = new Gtk.GestureClick () {
+    button = 0
+  };
+  ((Gtk.Widget) window).add_controller (gesture_click);
+
+  gesture_click.pressed.connect ((gesture, n_press, x, y) => {
+    switch (gesture.get_current_button ()) {
+      case Gdk.BUTTON_PRIMARY:
+        primary_button.add_css_class ("suggested-action");
+        break;
+      case Gdk.BUTTON_MIDDLE:
+        middle_button.add_css_class ("suggested-action");
+        break;
+      case Gdk.BUTTON_SECONDARY:
+        secondary_button.add_css_class ("suggested-action");
+        break;
+    }
+  });
+
+  gesture_click.released.connect ((gesture, n_press, x, y) => {
+    switch (gesture.get_current_button ()) {
+      case Gdk.BUTTON_PRIMARY:
+        primary_button.remove_css_class ("suggested-action");
+        break;
+      case Gdk.BUTTON_MIDDLE:
+        middle_button.remove_css_class ("suggested-action");
+        break;
+      case Gdk.BUTTON_SECONDARY:
+        secondary_button.remove_css_class ("suggested-action");
+        break;
+    }
+  });
+
+  var gesture_swipe = new Gtk.GestureSwipe ();
+  stack.add_controller (gesture_swipe);
+
+  gesture_swipe.swipe.connect ((vel_x, vel_y) => {
+    if (vel_x > 0) {
+      stack.visible_child_name = "pic1";
+    } else {
+      stack.visible_child_name = "pic2";
+    }
+  });
+}