window: Implement input device grabbing

With all input events going to widgets now, we can grab an input device
to a widget, so that all events are delivered to that widgets handlers.
This lets us implement the last bit of the menu behaviour, that is
the client side grabbing of events.  The result is that we can now pop down
the menu when we receive clicks in the clients own windows and we
don't send motion and button events to other widgets.

2 files changed, 94 insertions, 46 deletions

diff --git a/clients/window.c b/clients/window.c
index bd9107c..7dad315 100644
--- a/clients/window.c
+++ b/clients/window.c
@@ -134,8 +134,6 @@ struct window {
 
 	struct widget *widget;
 	struct widget *focus_widget;
-	uint32_t widget_grab_button;
-
 	struct window *menu;
 
 	void *user_data;
@@ -166,6 +164,9 @@ struct input {
 	int32_t x, y, sx, sy;
 	struct wl_list link;
 
+	struct widget *grab;
+	uint32_t grab_button;
+
 	struct wl_data_device *data_device;
 	struct data_offer *drag_offer;
 	struct data_offer *selection_offer;
@@ -190,6 +191,7 @@ struct frame {
 struct menu {
 	struct window *window;
 	struct widget *widget;
+	struct input *input;
 	const char **entries;
 	uint32_t time;
 	int current;
@@ -1350,13 +1352,6 @@ frame_motion_handler(struct widget *widget,
 }
 
 static void
-break_grab(struct window *window)
-{
-	window->focus_widget = NULL;
-	window->widget_grab_button = 0;
-}
-
-static void
 frame_button_handler(struct widget *widget,
 		     struct input *input, uint32_t time,
 		     int button, int state, void *data)
@@ -1378,7 +1373,7 @@ frame_button_handler(struct widget *widget,
 			if (!window->shell_surface)
 				break;
 			input_set_pointer_image(input, time, POINTER_DRAGGING);
-			break_grab(window);
+			input_ungrab(input, time);
 			wl_shell_surface_move(window->shell_surface,
 					      input_get_input_device(input),
 					      time);
@@ -1393,7 +1388,7 @@ frame_button_handler(struct widget *widget,
 		case WINDOW_RESIZING_BOTTOM_RIGHT:
 			if (!window->shell_surface)
 				break;
-			break_grab(window);
+			input_ungrab(input, time);
 			wl_shell_surface_resize(window->shell_surface,
 						input_get_input_device(input),
 						time, location);
@@ -1436,7 +1431,7 @@ static void
 window_set_focus_widget(struct window *window, struct widget *focus,
 			struct input *input, uint32_t time, int32_t x, int32_t y)
 {
-	struct widget *old;
+	struct widget *old, *widget;
 	int pointer = POINTER_LEFT_PTR;
 
 	if (focus == window->focus_widget)
@@ -1444,15 +1439,22 @@ window_set_focus_widget(struct window *window, struct widget *focus,
 
 	old = window->focus_widget;
 	if (old) {
-		if (old->leave_handler)
-			old->leave_handler(old, input, old->user_data);
+		widget = old;
+		if (input->grab)
+			widget = input->grab;
+		if (widget->leave_handler)
+			widget->leave_handler(old, input, widget->user_data);
 		window->focus_widget = NULL;
 	}
 
 	if (focus) {
-		if (focus->enter_handler)
-			pointer = focus->enter_handler(focus, input, time,
-						       x, y, focus->user_data);
+		widget = focus;
+		if (input->grab)
+			widget = input->grab;
+		if (widget->enter_handler)
+			pointer = widget->enter_handler(focus, input, time,
+							x, y,
+							widget->user_data);
 		window->focus_widget = focus;
 
 		input_set_pointer_image(input, time, pointer);
@@ -1474,19 +1476,44 @@ input_handle_motion(void *data, struct wl_input_device *input_device,
 	input->sx = sx;
 	input->sy = sy;
 
-	if (!window->focus_widget || !window->widget_grab_button) {
+	if (!(input->grab && input->grab_button)) {
 		widget = widget_find_widget(window->widget, sx, sy);
 		window_set_focus_widget(window, widget, input, time, sx, sy);
 	}
 
-	widget = window->focus_widget;
+	if (input->grab)
+		widget = input->grab;
+	else
+		widget = window->focus_widget;
 	if (widget && widget->motion_handler)
-		pointer = widget->motion_handler(widget, input, time, sx, sy,
+		pointer = widget->motion_handler(window->focus_widget,
+						 input, time, sx, sy,
 						 widget->user_data);
 
 	input_set_pointer_image(input, time, pointer);
 }
 
+void
+input_grab(struct input *input, struct widget *widget, uint32_t button)
+{
+	input->grab = widget;
+	input->grab_button = button;
+}
+
+void
+input_ungrab(struct input *input, uint32_t time)
+{
+	struct widget *widget;
+
+	input->grab = NULL;
+	if (input->pointer_focus) {
+		widget = widget_find_widget(input->pointer_focus->widget,
+					    input->sx, input->sy);
+		window_set_focus_widget(input->pointer_focus, widget,
+					input, time, input->sx, input->sy);
+	}
+}
+
 static void
 input_handle_button(void *data,
 		    struct wl_input_device *input_device,
@@ -1496,24 +1523,18 @@ input_handle_button(void *data,
 	struct window *window = input->pointer_focus;
 	struct widget *widget;
 
-	if (window->focus_widget && window->widget_grab_button == 0 && state)
-		window->widget_grab_button = button;
+	if (window->focus_widget && input->grab == NULL && state)
+		input_grab(input, window->focus_widget, button);
 
 	widget = window->focus_widget;
 	if (widget && widget->button_handler)
-		(*widget->button_handler)(widget,
-					  input, time,
-					  button, state,
-					  widget->user_data);
-
-	if (window->focus_widget &&
-	    window->widget_grab_button == button && !state) {
-		window->widget_grab_button = 0;
-		widget = widget_find_widget(window->widget,
-					    input->sx, input->sy);
-		window_set_focus_widget(window, widget, input, time,
-					input->sx, input->sy);
-	}
+		(*input->grab->button_handler)(widget,
+					       input, time,
+					       button, state,
+					       input->grab->user_data);
+
+	if (input->grab && input->grab_button == button && !state)
+		input_ungrab(input, time);
 }
 
 static void
@@ -1554,7 +1575,7 @@ input_remove_pointer_focus(struct input *input, uint32_t time)
 	if (!window)
 		return;
 
-	window_set_focus_widget(window, NULL, NULL, 0, 0, 0);
+	window_set_focus_widget(window, NULL, input, 0, 0, 0);
 
 	input->pointer_focus = NULL;
 	input->current_pointer_image = POINTER_UNSET;
@@ -2051,11 +2072,15 @@ static void
 handle_popup_done(void *data, struct wl_shell_surface *shell_surface)
 {
 	struct window *window = data;
-	struct menu *menu = window_get_user_data(window);
+	struct menu *menu = window->widget->user_data;
+
 	/* FIXME: Need more context in this event, at least the input
-	 * device.  Or just use wl_callback. */
+	 * device.  Or just use wl_callback.  And this really needs to
+	 * be a window vfunc that the menu can set.  And we need the
+	 * time. */
 
 	menu->func(window->parent, menu->current, window->parent->user_data);
+	input_ungrab(menu->input, 0);
 	window_destroy(window);
 }
 
@@ -2294,7 +2319,7 @@ window_create_transient(struct display *display, struct window *parent,
 	return window;
 }
 
-static int
+static void
 menu_set_item(struct menu *menu, int sy)
 {
 	int next;
@@ -2304,8 +2329,6 @@ menu_set_item(struct menu *menu, int sy)
 		menu->current = next;
 		widget_schedule_redraw(menu->widget);
 	}
-
-	return POINTER_LEFT_PTR;
 }
 
 static int
@@ -2313,7 +2336,12 @@ menu_motion_handler(struct widget *widget,
 		    struct input *input, uint32_t time,
 		    int32_t x, int32_t y, void *data)
 {
-	return menu_set_item(data, y);
+	struct menu *menu = data;
+
+	if (widget == menu->widget)
+		menu_set_item(data, y);
+
+	return POINTER_LEFT_PTR;
 }
 
 static int
@@ -2321,13 +2349,21 @@ menu_enter_handler(struct widget *widget,
 		   struct input *input, uint32_t time,
 		   int32_t x, int32_t y, void *data)
 {
-	return menu_set_item(data, y);
+	struct menu *menu = data;
+
+	if (widget == menu->widget)
+		menu_set_item(data, y);
+
+	return POINTER_LEFT_PTR;
 }
 
 static void
 menu_leave_handler(struct widget *widget, struct input *input, void *data)
 {
-	menu_set_item(data, -200);
+	struct menu *menu = data;
+
+	if (widget == menu->widget)
+		menu_set_item(data, -200);
 }
 
 static void
@@ -2338,11 +2374,13 @@ menu_button_handler(struct widget *widget,
 {
 	struct menu *menu = data;
 
-	/* Either relase after press-drag-release or click-motion-click. */
 	if (state == 0 && time - menu->time > 500) {
+		/* Either relase after press-drag-release or
+		 * click-motion-click. */
 		menu->func(menu->window->parent, 
 			   menu->current, menu->window->parent->user_data);
-		window_destroy(widget->window);
+		input_ungrab(input, time);
+		window_destroy(menu->widget->window);
 	}
 }
 
@@ -2409,8 +2447,10 @@ window_create_menu(struct display *display,
 	menu->widget = window_add_widget(menu->window, menu);
 	menu->entries = entries;
 	menu->count = count;
+	menu->current = -1;
 	menu->time = time;
 	menu->func = func;
+	menu->input = input;
 	window->type = TYPE_MENU;
 	window->x = x;
 	window->y = y;
@@ -2426,6 +2466,8 @@ window_create_menu(struct display *display,
 	widget_set_motion_handler(menu->widget, menu_motion_handler);
 	widget_set_button_handler(menu->widget, menu_button_handler);
 
+	input_grab(input, menu->widget, 0);
+
 	return window;
 }
 
diff --git a/clients/window.h b/clients/window.h
index 051c690..b9be2af 100644
--- a/clients/window.h
+++ b/clients/window.h
@@ -358,6 +358,12 @@ input_get_position(struct input *input, int32_t *x, int32_t *y);
 uint32_t
 input_get_modifiers(struct input *input);
 
+void
+input_grab(struct input *input, struct widget *widget, uint32_t button);
+
+void
+input_ungrab(struct input *input, uint32_t time);
+
 struct wl_input_device *
 input_get_input_device(struct input *input);