wayland: dispatcher: listen for input method (de-)activate events

Hide the keyboard by default and show it when the user is in some text
field.

src/wayland/dispatcher.rs

@@ -32,6 +32,8 @@ use wayland::wlr_layer_shell_unstable_v1::zwlr_layer_shell_v1;
 use wayland::wlr_layer_shell_unstable_v1::zwlr_layer_surface_v1;
 use wayland::fractional_scale_v1::wp_fractional_scale_manager_v1;
 use wayland::fractional_scale_v1::wp_fractional_scale_v1;
+use wayland::input_method_unstable_v2::zwp_input_method_manager_v2;
+use wayland::input_method_unstable_v2::zwp_input_method_v2;
 use wayland::viewporter::wp_viewporter;
 use wayland::viewporter::wp_viewport;
 use wayland::virtual_keyboard_unstable_v1::zwp_virtual_keyboard_manager_v1;
@@ -57,6 +59,10 @@ impl Dispatcher {
         let vk_man = globals.bind(&queue, 1..=1, ())
                             .expect("Compositor must implement zwp_virtual_keyboard_manager_v1");
 
+        let im_man: zwp_input_method_manager_v2::ZwpInputMethodManagerV2
+                   = globals.bind(&queue, 1..=1, ())
+                            .expect("Compositor must implement zwp_input_method_manager_v2");
+
         let frac_scale_man = match globals.bind(&queue, 1..=1, ()) {
             Ok(g) => Some(g),
             Err(_) => None,
@@ -67,6 +73,8 @@ impl Dispatcher {
             Err(_) => None,
         };
 
+        im_man.get_input_method(&seat, &queue, ());
+
         let disp = Surface::new(queue.clone(),
                                 &shm, compositor, layer_shell,
                                 frac_scale_man, vper, 185)?;
@@ -94,6 +102,18 @@ impl Dispatcher {
     {
         self.seat.button_mut().dispatch_timers();
     }
+
+    fn show(&self)
+    {
+        let mut gfx = self.gfx.lock().unwrap();
+        gfx.display_mut().show();
+    }
+
+    fn hide(&self)
+    {
+        let mut gfx = self.gfx.lock().unwrap();
+        gfx.display_mut().hide();
+    }
 }
 
 impl Dispatch<wl_buffer::WlBuffer, u32> for Dispatcher {
@@ -366,6 +386,42 @@ impl Dispatch<zwlr_layer_surface_v1::ZwlrLayerSurfaceV1, ()> for Dispatcher {
     }
 }
 
+impl Dispatch<zwp_input_method_manager_v2::ZwpInputMethodManagerV2, ()> for Dispatcher {
+    fn event(_ctx: &mut Dispatcher,
+             _im_man: &zwp_input_method_manager_v2::ZwpInputMethodManagerV2,
+             _evt: zwp_input_method_manager_v2::Event,
+             _data: &(),
+             _conn: &Connection,
+             _qh: &QueueHandle<Dispatcher>)
+    {
+        eprintln!("warn: unknown zwp_input_method_manager_v2 event emitted");
+    }
+}
+
+impl Dispatch<zwp_input_method_v2::ZwpInputMethodV2, ()> for Dispatcher {
+    fn event(ctx: &mut Dispatcher,
+             _im: &zwp_input_method_v2::ZwpInputMethodV2,
+             evt: zwp_input_method_v2::Event,
+             _data: &(),
+             _conn: &Connection,
+             _qh: &QueueHandle<Dispatcher>)
+    {
+        match evt {
+            zwp_input_method_v2::Event::Activate => {
+                ctx.show();
+            },
+            zwp_input_method_v2::Event::Deactivate => {
+                ctx.hide();
+            },
+            zwp_input_method_v2::Event::TextChangeCause { .. } => (),
+            zwp_input_method_v2::Event::ContentType { .. } => (),
+            zwp_input_method_v2::Event::SurroundingText { .. } => (),
+            zwp_input_method_v2::Event::Done => (),
+            _ => eprintln!("warn: unknown zwp_input_method_v2 event emitted"),
+        }
+    }
+}
+
 impl Dispatch<zwp_virtual_keyboard_manager_v1::ZwpVirtualKeyboardManagerV1, ()> for Dispatcher {
     fn event(_ctx: &mut Dispatcher,
              _vk_man: &zwp_virtual_keyboard_manager_v1::ZwpVirtualKeyboardManagerV1,

src/wayland/surface.rs

@@ -64,7 +64,7 @@ impl<T: Dispatch<WlBuffer, u32>
         let buf1 = Buffer::new(queue.clone(), shm, 0)?;
         let buf2 = Buffer::new(queue.clone(), shm, 1)?;
 
-        let mut surf = Surface {
+        Ok(Surface {
             bufs: [buf1, buf2],
 
             queue: queue.clone(),
@@ -81,11 +81,7 @@ impl<T: Dispatch<WlBuffer, u32>
             configured: false,
             scale: 120,
             height,
-        };
-
-        surf.show();
-
-        Ok(surf)
+        })
     }
 
     pub fn configured(&self) -> bool