[tklock] Add setting to disable input device grabbing. Fixes MER#1250

There have been issues with unresponsive touch screen in various porting
projects. It is difficult to tell whether problems occur because

a) mce is denying touch events from reaching ui, or
b) ui side does not process touch events as expected

To ease debugging of such issues, add a setting that can be used to
control whether mce is allowed to grab input devices or not.

The setting is enabled by default and can be changed with:

  mcetool --set-input-policy-mode=<enabled|disabled>

The value of the setting persists over mce / device restarts.

builtin-gconf.c

@@ -1225,6 +1225,11 @@ static const setting_t gconf_defaults[] =
     .type = "b",
     .def  = "true",
   },
+  {
+    .key  = MCE_GCONF_TK_INPUT_POLICY_ENABLED,
+    .type = "b",
+    .def  = G_STRINGIFY(DEFAULT_TK_INPUT_POLICY_ENABLED),
+  },
   {
     // MCE_GCONF_TK_DOUBLE_TAP_GESTURE_PATH @ tklock.h
     .key  = "/system/osso/dsm/locks/tklock_double_tap_gesture",

tklock.c

@@ -377,6 +377,11 @@ static gboolean tk_autolock_enabled = DEFAULT_TK_AUTOLOCK;
 /** GConf callback ID for tk_autolock_enabled */
 static guint tk_autolock_enabled_cb_id = 0;
 
+/** Flag: Grabbing input devices is allowed */
+static gboolean tk_input_policy_enabled = DEFAULT_TK_INPUT_POLICY_ENABLED;
+/** GConf callback ID for tk_input_policy_enabled */
+static guint tk_input_policy_enabled_cb_id = 0;
+
 /** Delay for automatick locking (after ON->DIM->OFF cycle) */
 static gint    tklock_autolock_delay = DEFAULT_AUTOLOCK_DELAY;
 /** GConf notifier id for tklock_autolock_delay */
@@ -3845,6 +3850,9 @@ static void tklock_evctrl_rethink(void)
         break;
     }
 
+    if( !tk_input_policy_enabled )
+        grab_ts = false;
+
     /* Grabbing touch input is always permitted, but ungrabbing
      * only when proximity sensor is not covered / proximity
      * blocks input feature is disabled */
@@ -3866,6 +3874,9 @@ static void tklock_evctrl_rethink(void)
 
     bool grab_kp = !enable_kp;
 
+    if( !tk_input_policy_enabled )
+        grab_kp = false;
+
     execute_datapipe(&keypad_grab_wanted_pipe,
                      GINT_TO_POINTER(grab_kp),
                      USE_INDATA, CACHE_INDATA);
@@ -4050,6 +4061,15 @@ static void tklock_gconf_cb(GConfClient *const gcc, const guint id,
         tk_autolock_enabled = gconf_value_get_bool(gcv) ? 1 : 0;
         tklock_autolock_rethink();
     }
+    else if( id == tk_input_policy_enabled_cb_id ) {
+        gboolean old = tk_input_policy_enabled;
+        tk_input_policy_enabled = gconf_value_get_bool(gcv) ? 1 : 0;
+        if( tk_input_policy_enabled != old ) {
+            mce_log(LL_NOTICE, "input grabbing %s",
+                    tk_input_policy_enabled ? "allowed" : "denied");
+            tklock_evctrl_rethink();
+        }
+    }
     else if( id == lid_sensor_enabled_cb_id ) {
         lid_sensor_enabled = gconf_value_get_bool(gcv) ? 1 : 0;
         tklock_lid_sensor_rethink();
@@ -4224,6 +4244,13 @@ static void tklock_gconf_init(void)
                          tklock_gconf_cb,
                          &tk_autolock_enabled_cb_id);
 
+    /* Grabbing input devices allowed */
+    mce_gconf_track_bool(MCE_GCONF_TK_INPUT_POLICY_ENABLED,
+                         &tk_input_policy_enabled,
+                         DEFAULT_TK_INPUT_POLICY_ENABLED,
+                         tklock_gconf_cb,
+                         &tk_input_policy_enabled_cb_id);
+
     /* Touchscreen/keypad autolock delay */
     mce_gconf_track_int(MCE_GCONF_AUTOLOCK_DELAY,
                         &tklock_autolock_delay,
@@ -4395,6 +4422,9 @@ static void tklock_gconf_quit(void)
     mce_gconf_notifier_remove(tk_autolock_enabled_cb_id),
         tk_autolock_enabled_cb_id = 0;
 
+    mce_gconf_notifier_remove(tk_input_policy_enabled_cb_id),
+        tk_input_policy_enabled_cb_id = 0;
+
     mce_gconf_notifier_remove(tklock_autolock_delay_cb_id),
         tklock_autolock_delay_cb_id = 0;
 

tklock.h

@@ -227,6 +227,10 @@ enum
 #define MCE_GCONF_EXCEPTION_LENGTH_ACTIVITY     MCE_GCONF_LOCK_PATH"/exception_length_activity"
 #define DEFAULT_EXCEPTION_LENGTH_ACTIVITY       2000
 
+/** Is mce allowed to grab input devices */
+#define MCE_GCONF_TK_INPUT_POLICY_ENABLED       MCE_GCONF_LOCK_PATH "/touchscreen_policy_enabled"
+#define DEFAULT_TK_INPUT_POLICY_ENABLED         true
+
 /** Name of D-Bus callback to provide to Touchscreen/Keypad Lock SystemUI */
 #define MCE_TKLOCK_CB_REQ		"tklock_callback"
 

tools/mcetool.c

@@ -4340,6 +4340,33 @@ static void xmce_get_memnotify_level(void)
         free(str);
 }
 
+/* ------------------------------------------------------------------------- *
+ * input policy
+ * ------------------------------------------------------------------------- */
+
+/* Set input policy mode
+ *
+ * @param args string suitable for interpreting as enabled/disabled
+ */
+static bool xmce_set_input_policy_mode(const char *args)
+{
+        gboolean val = xmce_parse_enabled(args);
+        mcetool_gconf_set_bool(MCE_GCONF_TK_INPUT_POLICY_ENABLED, val);
+        return true;
+}
+
+/* Show input policy mode
+ */
+static void xmce_get_input_policy_mode(void)
+{
+        gboolean val = 0;
+        char txt[32] = "unknown";
+
+        if( mcetool_gconf_get_bool(MCE_GCONF_TK_INPUT_POLICY_ENABLED, &val) )
+                snprintf(txt, sizeof txt, "%s", val ? "enabled" : "disabled");
+        printf("%-"PAD1"s %s\n", "Input grab policy:", txt);
+}
+
 /* ------------------------------------------------------------------------- *
  * touch input unblocking
  * ------------------------------------------------------------------------- */
@@ -4779,6 +4806,7 @@ static bool xmce_get_status(const char *args)
 #endif
         xmce_get_tklock_blank();
         xmce_get_lipstick_core_delay();
+        xmce_get_input_policy_mode();
         xmce_get_touch_unblock_delay();
         xmce_get_exception_lengths();
 
@@ -5718,6 +5746,21 @@ static const mce_opt_t options[] =
                 .usage       =
                         "set the delay for dumping core from unresponsive lipstick\n"
         },
+        {
+                .name        = "set-input-policy-mode",
+                .with_arg    = xmce_set_input_policy_mode,
+                .values      = "enabled|disabled",
+                .usage       =
+                        "allow/deny grabbing of input devices based on input policy\n"
+                        "\n"
+                        "Normally this should be always set to 'enabled'.\n"
+                        "\n"
+                        "Setting to 'disabled' can be useful when debugging things like\n"
+                        "unresponsive touch screen: If the issue goes away when mce is\n"
+                        "allowed to grab input device, problem is likely to reside in\n"
+                        "mce policy logic. If the problem persists, the problem is more\n"
+                        "likely to exist at the ui side input handling logic.\n"
+        },
         {
                 .name        = "set-touch-unblock-delay",
                 .with_arg    = xmce_set_touch_unblock_delay,