[listview] Add extra checks before resolving pointer.

Issue: #1703

1 files changed, 40 insertions, 13 deletions

diff --git a/source/widgets/listview.c b/source/widgets/listview.c
index 2b8f5d81..52146702 100644
--- a/source/widgets/listview.c
+++ b/source/widgets/listview.c
@@ -583,13 +583,20 @@ unsigned int listview_get_selected(listview *lv) {
 }
 
 void listview_set_selected(listview *lv, unsigned int selected) {
-  if (lv && lv->req_elements > 0) {
+  if (lv == NULL) {
+    return;
+  }
+  if (lv->req_elements > 0) {
     lv->selected = MIN(selected, lv->req_elements - 1);
     lv->barview.direction = LEFT_TO_RIGHT;
     widget_queue_redraw(WIDGET(lv));
-    lv->sc_callback(lv, lv->selected, lv->sc_udata);
+    if (lv->sc_callback) {
+      lv->sc_callback(lv, lv->selected, lv->sc_udata);
+    }
   } else if (lv->req_elements == 0) {
-    lv->sc_callback(lv, UINT32_MAX, lv->sc_udata);
+    if (lv->sc_callback) {
+      lv->sc_callback(lv, UINT32_MAX, lv->sc_udata);
+    }
   }
 }
 
@@ -790,7 +797,9 @@ static void listview_nav_up_int(listview *lv) {
   lv->selected--;
   lv->barview.direction = RIGHT_TO_LEFT;
 
-  lv->sc_callback(lv, lv->selected, lv->sc_udata);
+  if (lv->sc_callback) {
+    lv->sc_callback(lv, lv->selected, lv->sc_udata);
+  }
   widget_queue_redraw(WIDGET(lv));
 }
 static void listview_nav_down_int(listview *lv) {
@@ -805,7 +814,9 @@ static void listview_nav_down_int(listview *lv) {
                      ? MIN(lv->req_elements - 1, lv->selected + 1)
                      : 0;
   lv->barview.direction = LEFT_TO_RIGHT;
-  lv->sc_callback(lv, lv->selected, lv->sc_udata);
+  if (lv->sc_callback) {
+    lv->sc_callback(lv, lv->selected, lv->sc_udata);
+  }
   widget_queue_redraw(WIDGET(lv));
 }
 void listview_nav_next(listview *lv) {
@@ -824,14 +835,18 @@ void listview_nav_prev(listview *lv) {
 static void listview_nav_column_left_int(listview *lv) {
   if (lv->selected >= lv->cur_columns) {
     lv->selected -= lv->cur_columns;
-    lv->sc_callback(lv, lv->selected, lv->sc_udata);
+    if (lv->sc_callback) {
+      lv->sc_callback(lv, lv->selected, lv->sc_udata);
+    }
     widget_queue_redraw(WIDGET(lv));
   }
 }
 static void listview_nav_column_right_int(listview *lv) {
   if ((lv->selected + lv->cur_columns) < lv->req_elements) {
     lv->selected += lv->cur_columns;
-    lv->sc_callback(lv, lv->selected, lv->sc_udata);
+    if (lv->sc_callback) {
+      lv->sc_callback(lv, lv->selected, lv->sc_udata);
+    }
     widget_queue_redraw(WIDGET(lv));
   }
 }
@@ -890,7 +905,9 @@ void listview_nav_left(listview *lv) {
   }
   if (lv->selected >= lv->max_rows) {
     lv->selected -= lv->max_rows;
-    lv->sc_callback(lv, lv->selected, lv->sc_udata);
+    if (lv->sc_callback) {
+      lv->sc_callback(lv, lv->selected, lv->sc_udata);
+    }
     widget_queue_redraw(WIDGET(lv));
   }
 }
@@ -911,7 +928,9 @@ void listview_nav_right(listview *lv) {
   }
   if ((lv->selected + lv->max_rows) < lv->req_elements) {
     lv->selected += lv->max_rows;
-    lv->sc_callback(lv, lv->selected, lv->sc_udata);
+    if (lv->sc_callback) {
+      lv->sc_callback(lv, lv->selected, lv->sc_udata);
+    }
     widget_queue_redraw(WIDGET(lv));
   } else if (lv->selected < (lv->req_elements - 1)) {
     // We do not want to move to last item, UNLESS the last column is only
@@ -923,7 +942,9 @@ void listview_nav_right(listview *lv) {
     // If there is an extra column, move.
     if (col != ncol) {
       lv->selected = lv->req_elements - 1;
-      lv->sc_callback(lv, lv->selected, lv->sc_udata);
+      if (lv->sc_callback) {
+        lv->sc_callback(lv, lv->selected, lv->sc_udata);
+      }
       widget_queue_redraw(WIDGET(lv));
     }
   }
@@ -949,7 +970,9 @@ static void listview_nav_page_prev_int(listview *lv) {
   } else {
     lv->selected -= (lv->max_elements);
   }
-  lv->sc_callback(lv, lv->selected, lv->sc_udata);
+  if (lv->sc_callback) {
+    lv->sc_callback(lv, lv->selected, lv->sc_udata);
+  }
   widget_queue_redraw(WIDGET(lv));
 }
 static void listview_nav_page_next_int(listview *lv) {
@@ -964,7 +987,9 @@ static void listview_nav_page_next_int(listview *lv) {
     lv->selected = MIN(new, lv->req_elements - 1);
     lv->barview.direction = LEFT_TO_RIGHT;
 
-    lv->sc_callback(lv, lv->selected, lv->sc_udata);
+    if (lv->sc_callback) {
+      lv->sc_callback(lv, lv->selected, lv->sc_udata);
+    }
     widget_queue_redraw(WIDGET(lv));
     return;
   }
@@ -972,7 +997,9 @@ static void listview_nav_page_next_int(listview *lv) {
   if (lv->selected >= lv->req_elements) {
     lv->selected = lv->req_elements - 1;
   }
-  lv->sc_callback(lv, lv->selected, lv->sc_udata);
+  if (lv->sc_callback) {
+    lv->sc_callback(lv, lv->selected, lv->sc_udata);
+  }
   widget_queue_redraw(WIDGET(lv));
 }