i3 - improved tiling WM

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Add ability to escape out of a mouse-resize operation

Patch status: merged

Patch by Tony Crisci

Long description:

Implement #1074. drag_cancel grabs the keyboard and returns DRAG_CANCEL
when the user presses any key during the grab.

To apply this patch, use:
curl http://cr.i3wm.org/patch/242/raw.patch | git am

b/include/floating.h

@@ -134,14 +134,22 @@ void floating_toggle_hide(xcb_connection_t *conn, Workspace *workspace);
 
 #endif
 /**
- * This function grabs your pointer and lets you drag stuff around (borders).
- * Every time you move your mouse, an XCB_MOTION_NOTIFY event will be received
- * and the given callback will be called with the parameters specified (client,
- * border on which the click originally was), the original rect of the client,
- * the event and the new coordinates (x, y).
+ * This is the return value of a drag operation like drag_pointer. DRAG_CANCEL
+ * will indicate the intention of the drag should not be carried out, or that
+ * the drag actions should be undone.
  *
  */
-void drag_pointer(Con *con, const xcb_button_press_event_t *event,
+typedef enum { DRAG_SUCCESS = 0, DRAG_CANCEL } drag_result_t;
+
+/**
+ * This function grabs your pointer and keyboard and lets you drag stuff around
+ * (borders). Every time you move your mouse, an XCB_MOTION_NOTIFY event will
+ * be received and the given callback will be called with the parameters
+ * specified (client, border on which the click originally was), the original
+ * rect of the client, the event and the new coordinates (x, y).
+ *
+ */
+drag_result_t drag_pointer(Con *con, const xcb_button_press_event_t *event,
                   xcb_window_t confine_to, border_t border, int cursor,
                   callback_t callback, const void *extra);
 

b/src/floating.c

@@ -441,8 +441,15 @@ void floating_drag_window(Con *con, const xcb_button_press_event_t *event) {
      * after the user releases the mouse button */
     tree_render();
 
+    /* Store the initial rect in case of user cancel */
+    Rect initial_rect = con->rect;
+
     /* Drag the window */
-    drag_pointer(con, event, XCB_NONE, BORDER_TOP /* irrelevant */, XCURSOR_CURSOR_MOVE, drag_window_callback, event);
+    drag_result_t drag_result = drag_pointer(con, event, XCB_NONE, BORDER_TOP /* irrelevant */, XCURSOR_CURSOR_MOVE, drag_window_callback, event);
+
+    /* If the user cancelled, undo the changes. */
+    if (drag_result == DRAG_CANCEL)
+        floating_reposition(con, initial_rect);
 
     /* If this is a scratchpad window, don't auto center it from now on. */
     if (con->scratchpad_state == SCRATCHPAD_FRESH)
@@ -546,7 +553,14 @@ void floating_resize_window(Con *con, const bool proportional,
 
     struct resize_window_callback_params params = { corner, proportional, event };
 
-    drag_pointer(con, event, XCB_NONE, BORDER_TOP /* irrelevant */, cursor, resize_window_callback, &params);
+    /* get the initial rect in case of cancel */
+    Rect initial_rect = con->rect;
+
+    drag_result_t drag_result = drag_pointer(con, event, XCB_NONE, BORDER_TOP /* irrelevant */, cursor, resize_window_callback, &params);
+
+    /* If the user cancels, undo the resize */
+    if (drag_result == DRAG_CANCEL)
+        floating_reposition(con, initial_rect);
 
     /* If this is a scratchpad window, don't auto center it from now on. */
     if (con->scratchpad_state == SCRATCHPAD_FRESH)
@@ -554,14 +568,14 @@ void floating_resize_window(Con *con, const bool proportional,
 }
 
 /*
- * This function grabs your pointer and lets you drag stuff around (borders).
- * Every time you move your mouse, an XCB_MOTION_NOTIFY event will be received
- * and the given callback will be called with the parameters specified (client,
- * border on which the click originally was), the original rect of the client,
- * the event and the new coordinates (x, y).
+ * This function grabs your pointer and keyboard and lets you drag stuff around
+ * (borders). Every time you move your mouse, an XCB_MOTION_NOTIFY event will
+ * be received and the given callback will be called with the parameters
+ * specified (client, border on which the click originally was), the original
+ * rect of the client, the event and the new coordinates (x, y).
  *
  */
-void drag_pointer(Con *con, const xcb_button_press_event_t *event, xcb_window_t
+drag_result_t drag_pointer(Con *con, const xcb_button_press_event_t *event, xcb_window_t
                 confine_to, border_t border, int cursor, callback_t callback, const void *extra)
 {
     uint32_t new_x, new_y;
@@ -587,16 +601,37 @@ void drag_pointer(Con *con, const xcb_button_press_event_t *event, xcb_window_t
 
     if ((reply = xcb_grab_pointer_reply(conn, cookie, NULL)) == NULL) {
         ELOG("Could not grab pointer\n");
-        return;
+        return DRAG_CANCEL;
     }
 
     free(reply);
 
+    /* Grab the keyboard */
+    xcb_grab_keyboard_cookie_t keyb_cookie;
+    xcb_grab_keyboard_reply_t *keyb_reply;
+
+    keyb_cookie = xcb_grab_keyboard(conn,
+            false, /* get all keyboard events */
+            root, /* grab the root window */
+            XCB_CURRENT_TIME,
+            XCB_GRAB_MODE_ASYNC, /* continue processing pointer events as normal */
+            XCB_GRAB_MODE_ASYNC /* keyboard mode */
+            );
+
+    if ((keyb_reply = xcb_grab_keyboard_reply(conn, keyb_cookie, NULL)) == NULL) {
+        ELOG("Could not grab keyboard\n");
+        return DRAG_CANCEL;
+    }
+
+    free(keyb_reply);
+
     /* Go into our own event loop */
     xcb_flush(conn);
 
     xcb_generic_event_t *inside_event, *last_motion_notify = NULL;
     bool loop_done = false;
+    /* The return value, set to DRAG_CANCEL on user cancel */
+    drag_result_t drag_result = DRAG_SUCCESS;
     /* I’ve always wanted to have my own eventhandler… */
     while (!loop_done && (inside_event = xcb_wait_for_event(conn))) {
         /* We now handle all events we can get using xcb_poll_for_event */
@@ -621,11 +656,20 @@ void drag_pointer(Con *con, const xcb_button_press_event_t *event, xcb_window_t
                     break;
 
                 case XCB_UNMAP_NOTIFY:
-                case XCB_KEY_PRESS:
-                case XCB_KEY_RELEASE:
                     DLOG("Unmap-notify, aborting\n");
                     handle_event(type, inside_event);
                     loop_done = true;
+                    drag_result = DRAG_CANCEL;
+                    break;
+
+                case XCB_KEY_PRESS:
+                case XCB_KEY_RELEASE:
+                    /* Cancel the drag if a key was pressed */
+                    DLOG("A key was pressed during drag, canceling.");
+                    loop_done = true;
+                    drag_result = DRAG_CANCEL;
+
+                    handle_event(type, inside_event);
                     break;
 
                 default:
@@ -648,8 +692,12 @@ void drag_pointer(Con *con, const xcb_button_press_event_t *event, xcb_window_t
         FREE(last_motion_notify);
     }
 
+    xcb_ungrab_keyboard(conn, XCB_CURRENT_TIME);
     xcb_ungrab_pointer(conn, XCB_CURRENT_TIME);
+
     xcb_flush(conn);
+
+    return drag_result;
 }
 
 /*

b/src/resize.c

@@ -154,12 +154,16 @@ int resize_graphical_handler(Con *first, Con *second, orientation_t orientation,
 
     const struct callback_params params = { orientation, output, helpwin, &new_position };
 
-    drag_pointer(NULL, event, grabwin, BORDER_TOP, 0, resize_callback, &params);
+    drag_result_t drag_result = drag_pointer(NULL, event, grabwin, BORDER_TOP, 0, resize_callback, &params);
 
     xcb_destroy_window(conn, helpwin);
     xcb_destroy_window(conn, grabwin);
     xcb_flush(conn);
 
+    /* User cancelled the drag so no action should be taken. */
+    if (drag_result == DRAG_CANCEL)
+        return 0;
+
     int pixels;
     if (orientation == HORIZ)
         pixels = (new_position - event->root_x);

183	@@ -154,12 +154,16 @@ int resize_graphical_handler(Con first, Con second, orientation_t orientation,
184
185	const struct callback_params params = { orientation, output, helpwin, &new_position };
186
187	- drag_pointer(NULL, event, grabwin, BORDER_TOP, 0, resize_callback, &params);
188	+ drag_result_t drag_result = drag_pointer(NULL, event, grabwin, BORDER_TOP, 0, resize_callback, &params);
189
190	xcb_destroy_window(conn, helpwin);
191	xcb_destroy_window(conn, grabwin);
192	xcb_flush(conn);
193
194	+ /* User cancelled the drag so no action should be taken. */
195	+ if (drag_result == DRAG_CANCEL)
196	+ return 0;
197	+
198	int pixels;
199	if (orientation == HORIZ)
200	pixels = (new_position - event->root_x);

17	@@ -134,14 +134,22 @@ void floating_toggle_hide(xcb_connection_t conn, Workspace workspace);
18
19	#endif
20	/**
21	- * This function grabs your pointer and lets you drag stuff around (borders).
22	- * Every time you move your mouse, an XCB_MOTION_NOTIFY event will be received
23	- * and the given callback will be called with the parameters specified (client,
24	- * border on which the click originally was), the original rect of the client,
25	- * the event and the new coordinates (x, y).
26	+ * This is the return value of a drag operation like drag_pointer. DRAG_CANCEL
27	+ * will indicate the intention of the drag should not be carried out, or that
28	+ * the drag actions should be undone.
29	*
30	*/
31	-void drag_pointer(Con con, const xcb_button_press_event_t event,
32	+typedef enum { DRAG_SUCCESS = 0, DRAG_CANCEL } drag_result_t;
33	+
34	+/**
35	+ * This function grabs your pointer and keyboard and lets you drag stuff around
36	+ * (borders). Every time you move your mouse, an XCB_MOTION_NOTIFY event will
37	+ * be received and the given callback will be called with the parameters
38	+ * specified (client, border on which the click originally was), the original
39	+ * rect of the client, the event and the new coordinates (x, y).
40	+ *
41	+ */
42	+drag_result_t drag_pointer(Con con, const xcb_button_press_event_t event,
43	xcb_window_t confine_to, border_t border, int cursor,
44	callback_t callback, const void *extra);
45

50	@@ -441,8 +441,15 @@ void floating_drag_window(Con con, const xcb_button_press_event_t event) {
51	* after the user releases the mouse button */
52	tree_render();
53
54	+ /* Store the initial rect in case of user cancel */
55	+ Rect initial_rect = con->rect;
56	+
57	/* Drag the window */
58	- drag_pointer(con, event, XCB_NONE, BORDER_TOP /* irrelevant */, XCURSOR_CURSOR_MOVE, drag_window_callback, event);
59	+ drag_result_t drag_result = drag_pointer(con, event, XCB_NONE, BORDER_TOP /* irrelevant */, XCURSOR_CURSOR_MOVE, drag_window_callback, event);
60	+
61	+ /* If the user cancelled, undo the changes. */
62	+ if (drag_result == DRAG_CANCEL)
63	+ floating_reposition(con, initial_rect);
64
65	/* If this is a scratchpad window, don't auto center it from now on. */
66	if (con->scratchpad_state == SCRATCHPAD_FRESH)
67	@@ -546,7 +553,14 @@ void floating_resize_window(Con *con, const bool proportional,
68
69	struct resize_window_callback_params params = { corner, proportional, event };
70
71	- drag_pointer(con, event, XCB_NONE, BORDER_TOP /* irrelevant */, cursor, resize_window_callback, &params);
72	+ /* get the initial rect in case of cancel */
73	+ Rect initial_rect = con->rect;
74	+
75	+ drag_result_t drag_result = drag_pointer(con, event, XCB_NONE, BORDER_TOP /* irrelevant */, cursor, resize_window_callback, &params);
76	+
77	+ /* If the user cancels, undo the resize */
78	+ if (drag_result == DRAG_CANCEL)
79	+ floating_reposition(con, initial_rect);
80
81	/* If this is a scratchpad window, don't auto center it from now on. */
82	if (con->scratchpad_state == SCRATCHPAD_FRESH)
83	@@ -554,14 +568,14 @@ void floating_resize_window(Con *con, const bool proportional,
84	}
85
86	/*
87	- * This function grabs your pointer and lets you drag stuff around (borders).
88	- * Every time you move your mouse, an XCB_MOTION_NOTIFY event will be received
89	- * and the given callback will be called with the parameters specified (client,
90	- * border on which the click originally was), the original rect of the client,
91	- * the event and the new coordinates (x, y).
92	+ * This function grabs your pointer and keyboard and lets you drag stuff around
93	+ * (borders). Every time you move your mouse, an XCB_MOTION_NOTIFY event will
94	+ * be received and the given callback will be called with the parameters
95	+ * specified (client, border on which the click originally was), the original
96	+ * rect of the client, the event and the new coordinates (x, y).
97	*
98	*/
99	-void drag_pointer(Con con, const xcb_button_press_event_t event, xcb_window_t
100	+drag_result_t drag_pointer(Con con, const xcb_button_press_event_t event, xcb_window_t
101	confine_to, border_t border, int cursor, callback_t callback, const void *extra)
102	{
103	uint32_t new_x, new_y;
104	@@ -587,16 +601,37 @@ void drag_pointer(Con con, const xcb_button_press_event_t event, xcb_window_t
105
106	if ((reply = xcb_grab_pointer_reply(conn, cookie, NULL)) == NULL) {
107	ELOG("Could not grab pointer\n");
108	- return;
109	+ return DRAG_CANCEL;
110	}
111
112	free(reply);
113
114	+ /* Grab the keyboard */
115	+ xcb_grab_keyboard_cookie_t keyb_cookie;
116	+ xcb_grab_keyboard_reply_t *keyb_reply;
117	+
118	+ keyb_cookie = xcb_grab_keyboard(conn,
119	+ false, /* get all keyboard events */
120	+ root, /* grab the root window */
121	+ XCB_CURRENT_TIME,
122	+ XCB_GRAB_MODE_ASYNC, /* continue processing pointer events as normal */
123	+ XCB_GRAB_MODE_ASYNC /* keyboard mode */
124	+ );
125	+
126	+ if ((keyb_reply = xcb_grab_keyboard_reply(conn, keyb_cookie, NULL)) == NULL) {
127	+ ELOG("Could not grab keyboard\n");
128	+ return DRAG_CANCEL;
129	+ }
130	+
131	+ free(keyb_reply);
132	+
133	/* Go into our own event loop */
134	xcb_flush(conn);
135
136	xcb_generic_event_t inside_event, last_motion_notify = NULL;
137	bool loop_done = false;
138	+ /* The return value, set to DRAG_CANCEL on user cancel */
139	+ drag_result_t drag_result = DRAG_SUCCESS;
140	/* I’ve always wanted to have my own eventhandler… */
141	while (!loop_done && (inside_event = xcb_wait_for_event(conn))) {
142	/* We now handle all events we can get using xcb_poll_for_event */
143	@@ -621,11 +656,20 @@ void drag_pointer(Con con, const xcb_button_press_event_t event, xcb_window_t
144	break;
145
146	case XCB_UNMAP_NOTIFY:
147	- case XCB_KEY_PRESS:
148	- case XCB_KEY_RELEASE:
149	DLOG("Unmap-notify, aborting\n");
150	handle_event(type, inside_event);
151	loop_done = true;
152	+ drag_result = DRAG_CANCEL;
153	+ break;
154	+
155	+ case XCB_KEY_PRESS:
156	+ case XCB_KEY_RELEASE:
157	+ /* Cancel the drag if a key was pressed */
158	+ DLOG("A key was pressed during drag, canceling.");
159	+ loop_done = true;
160	+ drag_result = DRAG_CANCEL;
161	+
162	+ handle_event(type, inside_event);
163	break;
164
165	default:
166	@@ -648,8 +692,12 @@ void drag_pointer(Con con, const xcb_button_press_event_t event, xcb_window_t
167	FREE(last_motion_notify);
168	}
169
170	+ xcb_ungrab_keyboard(conn, XCB_CURRENT_TIME);
171	xcb_ungrab_pointer(conn, XCB_CURRENT_TIME);
172	+
173	xcb_flush(conn);
174	+
175	+ return drag_result;
176	}
177
178	/*