shell: Animate input panel mapping

We slide it in from below.

src/compositor.h

@@ -725,7 +725,9 @@ weston_zoom_run(struct weston_surface *surface, GLfloat start, GLfloat stop,
 struct weston_surface_animation *
 weston_fade_run(struct weston_surface *surface,
 		weston_surface_animation_done_func_t done, void *data);
-
+struct weston_surface_animation *
+weston_slide_run(struct weston_surface *surface, GLfloat start, GLfloat stop,
+		 weston_surface_animation_done_func_t done, void *data);
 
 void
 weston_surface_set_color(struct weston_surface *surface,

src/shell.c

@@ -1919,12 +1919,17 @@ hide_screensaver(struct desktop_shell *shell, struct shell_surface *surface)
 static void
 show_input_panel(struct desktop_shell *shell, struct shell_surface *surface)
 {
+	if (weston_surface_is_mapped(surface->surface))
+		return;
+
 	wl_list_remove(&surface->surface->layer_link);
 	wl_list_insert(&shell->panel_layer.surface_list, &surface->surface->layer_link);
 	surface->surface->output = surface->output;
 	weston_surface_damage(surface->surface);
 
-	weston_zoom_run(surface->surface, 0.8, 1.0, NULL, NULL);
+	weston_slide_run(surface->surface,
+			 surface->surface->geometry.height, 0,
+			 NULL, NULL);
 }
 
 static void
@@ -2660,7 +2665,9 @@ map(struct desktop_shell *shell, struct weston_surface *surface,
 		break;
 	case SHELL_SURFACE_INPUT_PANEL:
 		bottom_center_on_output(surface, get_default_output(compositor));
-		break;
+		/* Don't map the input panel here, wait for
+		 * show_input_panels signal. */
+		return;
 	case SHELL_SURFACE_POPUP:
 		shell_map_popup(shsurf);
 	case SHELL_SURFACE_NONE:

src/util.c

@@ -234,6 +234,32 @@ weston_fade_run(struct weston_surface *surface,
 					    fade_frame, done, data);
 }
 
+static void
+slide_frame(struct weston_surface_animation *animation)
+{
+	GLfloat scale;
+
+	scale = animation->start +
+		(animation->stop - animation->start) *
+		animation->spring.current;
+	weston_matrix_init(&animation->transform.matrix);
+	weston_matrix_translate(&animation->transform.matrix, 0, scale, 0);
+}
+
+WL_EXPORT struct weston_surface_animation *
+weston_slide_run(struct weston_surface *surface, GLfloat start, GLfloat stop,
+		weston_surface_animation_done_func_t done, void *data)
+{
+	struct weston_surface_animation *animation;
+
+	animation = weston_surface_animation_run(surface, start, stop,
+						 slide_frame, done, data);
+	animation->spring.friction = 900;
+	animation->spring.k = 300;
+
+	return animation;
+}
+
 struct weston_binding {
 	uint32_t key;
 	uint32_t button;