[PATCH 6/9] shell: Implement alt-tab switcher
Emilio Pozuelo Monfort
pochu27 at gmail.com
Tue Nov 19 02:37:16 PST 2013
Signed-off-by: Emilio Pozuelo Monfort <emilio.pozuelo at collabora.co.uk>
---
src/shell.c | 248 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 248 insertions(+)
diff --git a/src/shell.c b/src/shell.c
index b2bc74a..2a8c04c 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -3344,6 +3344,251 @@ terminate_binding(struct weston_seat *seat, uint32_t time, uint32_t key,
}
static void
+lower_fullscreen_layer(struct desktop_shell *shell);
+
+struct alt_tab {
+ struct desktop_shell *shell;
+ struct weston_keyboard_grab grab;
+
+ struct wl_list *current;
+
+ struct wl_list preview_list;
+};
+
+struct alt_tab_preview {
+ struct alt_tab *alt_tab;
+
+ struct weston_view *view;
+ struct weston_transform transform;
+
+ struct wl_listener listener;
+
+ struct wl_list link;
+};
+
+static void
+alt_tab_next(struct alt_tab *alt_tab)
+{
+ alt_tab->current = alt_tab->current->next;
+
+ /* Make sure we're not pointing to the list header e.g. after
+ * cycling through the whole list. */
+ if (alt_tab->current->next == alt_tab->preview_list.next)
+ alt_tab->current = alt_tab->current->next;
+}
+
+static void
+alt_tab_destroy(struct alt_tab *alt_tab)
+{
+ struct alt_tab_preview *preview, *next;
+ struct weston_keyboard *keyboard = alt_tab->grab.keyboard;
+
+ if (alt_tab->current && alt_tab->current != &alt_tab->preview_list) {
+ preview = wl_container_of(alt_tab->current, preview, link);
+
+ activate(alt_tab->shell, preview->view->surface,
+ (struct weston_seat *) keyboard->seat);
+ }
+
+ wl_list_for_each_safe(preview, next, &alt_tab->preview_list, link) {
+ wl_list_remove(&preview->link);
+ wl_list_remove(&preview->listener.link);
+ weston_view_destroy(preview->view);
+ free(preview);
+ }
+
+ weston_keyboard_end_grab(keyboard);
+ if (keyboard->input_method_resource)
+ keyboard->grab = &keyboard->input_method_grab;
+
+ free(alt_tab);
+}
+
+static void
+alt_tab_handle_surface_destroy(struct wl_listener *listener, void *data)
+{
+ struct alt_tab_preview *preview =
+ container_of(listener, struct alt_tab_preview, listener);
+ struct alt_tab *alt_tab = preview->alt_tab;
+ int advance = 0;
+
+ /* If the preview that we're removing is the currently selected one,
+ * we want to move to the next one. So we move to ->prev and then
+ * call _next() after removing the preview. */
+ if (alt_tab->current == &preview->link) {
+ alt_tab->current = alt_tab->current->prev;
+ advance = 1;
+ }
+
+ wl_list_remove(&preview->listener.link);
+ wl_list_remove(&preview->link);
+
+ free(preview);
+
+ if (advance)
+ alt_tab_next(alt_tab);
+
+ /* If the last preview goes away, stop the alt-tab */
+ if (wl_list_empty(alt_tab->current))
+ alt_tab_destroy(alt_tab);
+}
+
+static void
+alt_tab_key(struct weston_keyboard_grab *grab,
+ uint32_t time, uint32_t key, uint32_t state_w)
+{
+ struct alt_tab *alt_tab = container_of(grab, struct alt_tab, grab);
+ enum wl_keyboard_key_state state = state_w;
+
+ if (key == KEY_TAB && state == WL_KEYBOARD_KEY_STATE_PRESSED)
+ alt_tab_next(alt_tab);
+}
+
+static void
+alt_tab_modifier(struct weston_keyboard_grab *grab, uint32_t serial,
+ uint32_t mods_depressed, uint32_t mods_latched,
+ uint32_t mods_locked, uint32_t group)
+{
+ struct alt_tab *alt_tab = container_of(grab, struct alt_tab, grab);
+ struct weston_seat *seat = (struct weston_seat *) grab->keyboard->seat;
+
+ if ((seat->modifier_state & MODIFIER_ALT) == 0)
+ alt_tab_destroy(alt_tab);
+}
+
+static void
+alt_tab_cancel(struct weston_keyboard_grab *grab)
+{
+ struct alt_tab *alt_tab = container_of(grab, struct alt_tab, grab);
+
+ alt_tab_destroy(alt_tab);
+}
+
+static const struct weston_keyboard_grab_interface alt_tab_grab = {
+ alt_tab_key,
+ alt_tab_modifier,
+ alt_tab_cancel,
+};
+
+static int
+view_for_alt_tab(struct weston_view *view)
+{
+ if (!get_shell_surface(view->surface))
+ return 0;
+
+ if (get_shell_surface_type(view->surface) == SHELL_SURFACE_TRANSIENT)
+ return 0;
+
+ if (view != get_default_view(view->surface))
+ return 0;
+
+ return 1;
+}
+
+static void
+alt_tab_binding(struct weston_seat *seat, uint32_t time, uint32_t key,
+ void *data)
+{
+ struct alt_tab *alt_tab;
+ struct desktop_shell *shell = data;
+ struct weston_output *output = get_default_output(shell->compositor);
+ struct workspace *ws;
+ struct weston_view *view;
+ int num_surfaces = 0;
+ int x, y, side, margin;
+
+ wl_list_for_each(view, &shell->compositor->view_list, link) {
+
+ if (view_for_alt_tab(view))
+ num_surfaces++;
+ }
+
+ if (!num_surfaces)
+ return;
+
+ alt_tab = malloc(sizeof *alt_tab);
+ if (!alt_tab)
+ return;
+
+ alt_tab->shell = shell;
+ wl_list_init(&alt_tab->preview_list);
+ alt_tab->current = &alt_tab->preview_list;
+
+ restore_all_output_modes(shell->compositor);
+ lower_fullscreen_layer(alt_tab->shell);
+
+ alt_tab->grab.interface = &alt_tab_grab;
+ weston_keyboard_start_grab(seat->keyboard, &alt_tab->grab);
+ weston_keyboard_set_focus(seat->keyboard, NULL);
+
+ ws = get_current_workspace(shell);
+
+ /* FIXME: add some visual candy e.g. prelight the selected view
+ * and/or add a black surrounding background à la gnome-shell */
+
+ /* Determine the size for each preview */
+ side = output->width / num_surfaces;
+ if (side > 200)
+ side = 200;
+ margin = side / 4;
+ side -= margin;
+
+ x = margin;
+ y = (output->height - side) / 2;
+
+ /* Create a view for each surface */
+ wl_list_for_each(view, &shell->compositor->view_list, link) {
+ struct alt_tab_preview *preview;
+ struct weston_view *v;
+ float scale;
+
+ if (!view_for_alt_tab(view))
+ continue;
+
+ preview = malloc(sizeof *preview);
+ if (!preview) {
+ alt_tab_destroy(alt_tab);
+ return;
+ }
+
+ preview->alt_tab = alt_tab;
+
+ preview->view = v = weston_view_create(view->surface);
+ v->output = view->output;
+ weston_view_restack(v, &ws->layer.view_list);
+ weston_view_configure(v, x, y, view->geometry.width, view->geometry.height);
+
+ preview->listener.notify = alt_tab_handle_surface_destroy;
+ wl_signal_add(&v->destroy_signal, &preview->listener);
+
+ if (view->geometry.width > view->geometry.height)
+ scale = side / (float) view->geometry.width;
+ else
+ scale = side / (float) view->geometry.height;
+
+ wl_list_insert(&v->geometry.transformation_list,
+ &preview->transform.link);
+ weston_matrix_init(&preview->transform.matrix);
+ weston_matrix_scale(&preview->transform.matrix,
+ scale, scale, 1.0f);
+
+ weston_view_geometry_dirty(v);
+ weston_compositor_schedule_repaint(v->surface->compositor);
+
+ /* Insert at the end of the list */
+ wl_list_insert(alt_tab->preview_list.prev, &preview->link);
+
+ x += side + margin;
+ }
+
+ /* Start at the second preview so a simple <alt>tab changes window.
+ * We set `current' to the first preview and not the second because
+ * we're going to receive a key press callback for the initial
+ * <alt>tab which will make `current' point to the second element. */
+ alt_tab_next(alt_tab);
+}
+
+static void
rotate_grab_motion(struct weston_pointer_grab *grab, uint32_t time,
wl_fixed_t x, wl_fixed_t y)
{
@@ -5606,6 +5851,9 @@ shell_add_bindings(struct weston_compositor *ec, struct desktop_shell *shell)
weston_compositor_add_key_binding(ec, KEY_BACKSPACE,
MODIFIER_CTRL | MODIFIER_ALT,
terminate_binding, ec);
+ weston_compositor_add_key_binding(ec, KEY_TAB,
+ MODIFIER_ALT,
+ alt_tab_binding, shell);
weston_compositor_add_button_binding(ec, BTN_LEFT, 0,
click_to_activate_binding,
shell);
--
1.8.4.rc3
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