book: Add check in todo whether entry is empty

Author: Hofer-Julian

book/listings/todo_app/1/window/mod.rs

@@ -65,6 +65,9 @@ impl Window {
         // Get content from entry and clear it
         let buffer = self.imp().entry.buffer();
         let content = buffer.text();
+        if content.is_empty() {
+            return;
+        }
         buffer.set_text("");
 
         // Add new task to model

book/listings/todo_app/2/window/mod.rs

@@ -127,6 +127,9 @@ impl Window {
         // Get content from entry and clear it
         let buffer = self.imp().entry.buffer();
         let content = buffer.text();
+        if content.is_empty() {
+            return;
+        }
         buffer.set_text("");
 
         // Add new task to model

book/listings/todo_app/3/window/mod.rs

@@ -119,6 +119,9 @@ impl Window {
         // Get content from entry and clear it
         let buffer = self.imp().entry.buffer();
         let content = buffer.text();
+        if content.is_empty() {
+            return;
+        }
         buffer.set_text("");
 
         // Add new task to model

book/listings/todo_app/4/window/mod.rs

@@ -116,6 +116,9 @@ impl Window {
         // Get content from entry and clear it
         let buffer = self.imp().entry.buffer();
         let content = buffer.text();
+        if content.is_empty() {
+            return;
+        }
         buffer.set_text("");
 
         // Add new task to model