input: stay in current input section if mouse button is down

Normally, moving the mouse outside of the mouse area of an input section
will send mouse events somewhere else (because input section mouse areas
are similar to windows/widgets in real GUI toolkits). This was done even
if a mouse button was held down. This is quite different from how GUI
toolkits behave.

Change the code so that if a mouse button is down, the mouse area of the
current input section can't be left. Releasing the mouse button (while
the mouse pointer is outside of the mouse area) will actually leave the
mouse area.

As a side-effect, this commit also tests more often whether the current
mouse input section is valid. This is needed to make releasing a mouse
button trigger the mouse input section change.

1 files changed, 63 insertions, 28 deletions

diff --git a/mpvcore/input/input.c b/mpvcore/input/input.c
index 80fc1f1e58..f6465042c9 100644
--- a/mpvcore/input/input.c
+++ b/mpvcore/input/input.c
@@ -584,6 +584,8 @@ int async_quit_request;
 static int print_key_list(m_option_t *cfg, char *optname, char *optparam);
 static int print_cmd_list(m_option_t *cfg, char *optname, char *optparam);
 
+static void add_key_cmd(struct input_ctx *ictx, struct mp_cmd *cmd);
+
 #define OPT_BASE_STRUCT struct MPOpts
 
 // Our command line options
@@ -1283,6 +1285,8 @@ static struct cmd_bind *find_bind_for_key_section(struct input_ctx *ictx,
 
     // Prefer user-defined keys over builtin bindings
     for (int builtin = 0; builtin < 2; builtin++) {
+        if (builtin && !ictx->default_bindings)
+            break;
         for (int n = 0; n < bs->num_binds; n++) {
             if (bs->binds[n].is_builtin == (bool)builtin &&
                 bind_matches_key(&bs->binds[n], num_keys, keys))
@@ -1292,6 +1296,24 @@ static struct cmd_bind *find_bind_for_key_section(struct input_ctx *ictx,
     return NULL;
 }
 
+static bool any_mouse_buttons_down(int num_keys, int *keys)
+{
+    for (int n = 0; n < num_keys; n++) {
+        if (MP_KEY_IS_MOUSE_BTN_SINGLE(keys[n]))
+            return true;
+    }
+    return false;
+}
+
+static bool depends_on_mouse_pos(int num_keys, int *keys)
+{
+    for (int n = 0; n < num_keys; n++) {
+        if (MP_KEY_DEPENDS_ON_MOUSE_POS(keys[n]))
+            return true;
+    }
+    return false;
+}
+
 static struct cmd_bind *find_any_bind_for_key(struct input_ctx *ictx,
                                               char *force_section,
                                               int n, int *keys)
@@ -1299,21 +1321,29 @@ static struct cmd_bind *find_any_bind_for_key(struct input_ctx *ictx,
     if (force_section)
         return find_bind_for_key_section(ictx, force_section, n, keys);
 
+    bool use_mouse = depends_on_mouse_pos(n, keys);
+    // Check global state, because MOUSE_MOVE in particular does not include
+    // the global state in n/keys.
+    bool mouse_down = any_mouse_buttons_down(ictx->num_key_down, ictx->key_down);
+
+    // First look whether a mouse section is capturing all mouse input
+    // exclusively (regardless of the active section stack order).
+    if (use_mouse && mouse_down) {
+        struct cmd_bind *bind =
+            find_bind_for_key_section(ictx, ictx->mouse_section, n, keys);
+        if (bind)
+            return bind;
+    }
+
     for (int i = ictx->num_active_sections - 1; i >= 0; i--) {
         struct active_section *s = &ictx->active_sections[i];
         struct cmd_bind *bind = find_bind_for_key_section(ictx, s->name, n, keys);
         if (bind) {
-            if (bind->is_builtin && !ictx->default_bindings)
-                goto skip;
             struct cmd_bind_section *bs = bind->owner;
-            for (int x = 0; x < n; x++) {
-                if (MP_KEY_DEPENDS_ON_MOUSE_POS(keys[x]) && bs->mouse_area_set &&
-                    !test_rect(&bs->mouse_area, ictx->mouse_vo_x, ictx->mouse_vo_y))
-                    goto skip;
-            }
-            return bind;
+            if (!use_mouse || !bs->mouse_area_set ||
+                test_rect(&bs->mouse_area, ictx->mouse_vo_x, ictx->mouse_vo_y))
+                return bind;
         }
-    skip: ;
         if (s->flags & MP_INPUT_EXCLUSIVE)
             break;
     }
@@ -1353,6 +1383,24 @@ static mp_cmd_t *get_cmd_from_keys(struct input_ctx *ictx, char *force_section,
     return ret;
 }
 
+static void update_mouse_section(struct input_ctx *ictx)
+{
+    struct cmd_bind *cmd =
+        find_any_bind_for_key(ictx, NULL, 1, (int[]){MP_KEY_MOUSE_MOVE});
+
+    char *new_section = cmd ? cmd->owner->section : "default";
+
+    char *old = ictx->mouse_section;
+    ictx->mouse_section = new_section;
+
+    if (strcmp(old, ictx->mouse_section) != 0) {
+        struct mp_cmd *cmd =
+            get_cmd_from_keys(ictx, old, 1, (int[]){MP_KEY_MOUSE_LEAVE});
+        if (cmd)
+            add_key_cmd(ictx, cmd);
+    }
+}
+
 static void release_down_cmd(struct input_ctx *ictx)
 {
     if (ictx->current_down_cmd && ictx->current_down_cmd->key_up_follows) {
@@ -1413,6 +1461,7 @@ static mp_cmd_t *interpret_key(struct input_ctx *ictx, int code)
         release_down_cmd(ictx);
         ictx->key_down[ictx->num_key_down] = code & ~MP_KEY_STATE_DOWN;
         ictx->num_key_down++;
+        update_mouse_section(ictx);
         ictx->last_key_down = mp_time_us();
         ictx->ar_state = 0;
         ictx->current_down_cmd = get_cmd_from_keys(ictx, NULL, ictx->num_key_down,
@@ -1425,6 +1474,7 @@ static mp_cmd_t *interpret_key(struct input_ctx *ictx, int code)
             remove_key_down(ictx, code);
             release_down_cmd(ictx);
         }
+        update_mouse_section(ictx);
         return NULL;
     } else {
         // Press of key with no separate down/up events
@@ -1432,6 +1482,7 @@ static mp_cmd_t *interpret_key(struct input_ctx *ictx, int code)
             // Mixing press events and up/down with the same key is not allowed
             mp_tmsg(MSGT_INPUT, MSGL_WARN, "Mixing key presses and up/down.\n");
         }
+        update_mouse_section(ictx);
         // Add temporarily (include ongoing down/up events)
         int num_key_down = ictx->num_key_down;
         int key_down[MP_MAX_KEY_DOWN];
@@ -1508,6 +1559,7 @@ static void mp_input_feed_key(struct input_ctx *ictx, int code)
         mp_msg(MSGT_INPUT, MSGL_V, "input: release all\n");
         ictx->num_key_down = 0;
         release_down_cmd(ictx);
+        update_mouse_section(ictx);
         return;
     }
     int unmod = code & ~MP_KEY_MODIFIER_MASK;
@@ -1576,23 +1628,6 @@ void mp_input_put_axis(struct input_ctx *ictx, int direction, double value)
     input_unlock(ictx);
 }
 
-static void trigger_mouse_leave(struct input_ctx *ictx, char *new_section)
-{
-    if (!new_section)
-        new_section = "default";
-
-    char *old = ictx->mouse_section;
-    ictx->mouse_section = new_section;
-
-    if (old && strcmp(old, ictx->mouse_section) != 0) {
-        struct mp_cmd *cmd =
-            get_cmd_from_keys(ictx, old, 1, (int[]){MP_KEY_MOUSE_LEAVE});
-        if (cmd)
-            add_key_cmd(ictx, cmd);
-    }
-}
-
-
 void mp_input_set_mouse_pos(struct input_ctx *ictx, int x, int y)
 {
     input_lock(ictx);
@@ -1606,11 +1641,10 @@ void mp_input_set_mouse_pos(struct input_ctx *ictx, int x, int y)
     ictx->mouse_vo_x = x;
     ictx->mouse_vo_y = y;
 
+    update_mouse_section(ictx);
     struct mp_cmd *cmd =
         get_cmd_from_keys(ictx, NULL, 1, (int[]){MP_KEY_MOUSE_MOVE});
 
-    trigger_mouse_leave(ictx, cmd ? cmd->input_section : NULL);
-
     if (cmd) {
         cmd->mouse_move = true;
         cmd->mouse_x = x;
@@ -2161,6 +2195,7 @@ struct input_ctx *mp_input_init(struct MPOpts *opts)
         .ar_delay = input_conf->ar_delay,
         .ar_rate = input_conf->ar_rate,
         .default_bindings = input_conf->default_bindings,
+        .mouse_section = "default",
         .test = input_conf->test,
         .wakeup_pipe = {-1, -1},
     };