Update mutation example

examples/mutation.rs

@@ -1,19 +1,36 @@
 extern crate cursive;
 
 use cursive::Cursive;
-use cursive::view::{IdView,TextView,Dialog,Selector};
+use cursive::view::{IdView,TextView,Dialog,Selector,KeyEventView};
+
+fn show_popup(siv: &mut Cursive) {
+
+    siv.add_layer(Dialog::new(TextView::new("Tak!"))
+                  .button("Change", |s,_| {
+                      // Look for a view tagged "text". We _know_ it's there, so unwrap it.
+                      let view = s.find::<TextView>(&Selector::Id("text")).unwrap();
+                      let content: String = view.get_content().chars().rev().collect();
+                      view.set_content(&content);
+                  })
+                  .dismiss_button("Ok"));
+
+}
 
 fn main() {
     let mut siv = Cursive::new();
 
+    let content = "Press Q to quit the application.\n\nPress P to bring back the popup.";
+
     siv.add_global_callback('q' as i32, |s,_| s.quit());
 
-    siv.add_layer(IdView::new("text", TextView::new("Aaahh\nAaaah\nAaaah\nAaaaah\nAaaaah\nAaaaah\nAaaaah\nAaaaaah\nAaaaah")));
+    // Let's wrap the view to give it a recognizable ID, so we can look for it.
+    // We add the P callback on the textview only (and not globally),
+    // so that we can't call it when the popup is already visible.
+    siv.add_layer(KeyEventView::new(IdView::new("text", TextView::new(content)))
+                  .register('p' as i32, |s,_| show_popup(s)));
+
+    show_popup(&mut siv);
 
-    siv.add_layer(Dialog::new(TextView::new("Tak!"))
-                  .button("Change", |s,_| s.find::<TextView>(&Selector::Id("text")).unwrap()
-                          .set_content("Bleeeeh\nBleeeeeeeeeeh\nBleeeh") )
-                  .dismiss_button("Ok"));
 
     siv.run();
 }

src/view/text_view.rs

@@ -33,10 +33,16 @@ impl TextView {
         }
     }
 
+    /// Replace the text in this view.
     pub fn set_content(&mut self, content: &str) {
         self.content = content.to_string();
     }
 
+    /// Returns the current text in this view.
+    pub fn get_content(&self) -> &str {
+        &self.content
+    }
+
     /// Returns the number of lines required to display the content
     /// with the given width.
     fn get_num_lines(&self, max_width: usize) -> usize {