Undo/redo text in chat input

main/CMakeLists.txt

@@ -82,6 +82,7 @@ SOURCES
     src/ui/add_conversation/list_row.vala
     src/ui/add_conversation/select_jid_fragment.vala
     src/ui/avatar_generator.vala
+    src/ui/chat_input/edit_history.vala
     src/ui/chat_input/occupants_tab_completer.vala
     src/ui/chat_input/smiley_converter.vala
     src/ui/chat_input/view.vala

main/src/ui/chat_input/edit_history.vala

@@ -0,0 +1,77 @@
+using Gdk;
+using Gee;
+using Gtk;
+
+using Dino.Entities;
+
+namespace Dino.Ui.ChatInput {
+
+class EditHistory {
+
+    private StreamInteractor stream_interactor;
+    private Conversation? conversation;
+    private TextView text_input;
+
+    private HashMap<Conversation, Gee.List<string>> histories = new HashMap<Conversation, Gee.List<string>>(Conversation.hash_func, Conversation.equals_func);
+    private HashMap<Conversation, int> indices = new HashMap<Conversation, int>(Conversation.hash_func, Conversation.equals_func);
+
+    public EditHistory(TextView text_input, GLib.Application application) {
+        this.stream_interactor = stream_interactor;
+        this.text_input = text_input;
+
+        text_input.key_press_event.connect(on_text_input_key_press);
+    }
+
+    public void initialize_for_conversation(Conversation conversation) {
+        this.conversation = conversation;
+        if (!histories.has_key(conversation)) {
+            reset_history();
+        }
+    }
+
+    public bool on_text_input_key_press(EventKey event) {
+        if ((event.state & ModifierType.CONTROL_MASK) > 0) {
+            if (event.keyval == Key.z) {
+                undo();
+            } else if (event.keyval == Key.Z) {
+                redo();
+            }
+        } else if (event.keyval in new uint[]{ Key.space, Key.Tab, Key.ISO_Left_Tab }) {
+            if (indices[conversation] < histories[conversation].size - 1) {
+                histories[conversation] = histories[conversation].slice(0, indices[conversation] + 1);
+            }
+            save_state();
+        }
+        return false;
+    }
+
+    private void undo() {
+        if (histories[conversation][indices[conversation]] != text_input.buffer.text) {
+            save_state();
+        }
+        if (indices[conversation] > 0) {
+            indices[conversation] = indices[conversation] - 1;
+            text_input.buffer.text = histories[conversation][indices[conversation]];
+        }
+    }
+
+    private void redo() {
+        if (indices[conversation] < histories[conversation].size - 1) {
+            indices[conversation] = indices[conversation] + 1;
+            text_input.buffer.text = histories[conversation][indices[conversation]];
+        }
+    }
+
+    private void save_state() {
+        histories[conversation].add(text_input.buffer.text);
+        indices[conversation] = indices[conversation] + 1;
+    }
+
+    public void reset_history() {
+        histories[conversation] = new ArrayList<string>();
+        histories[conversation].add("");
+        indices[conversation] = 0;
+    }
+}
+
+}

main/src/ui/chat_input/view.vala

@@ -19,11 +19,13 @@ public class View : Box {
     private int vscrollbar_min_height;
     private OccupantsTabCompletor occupants_tab_completor;
     private SmileyConverter smiley_converter;
+    private EditHistory edit_history;
 
     public View(StreamInteractor stream_interactor) {
         this.stream_interactor = stream_interactor;
         occupants_tab_completor = new OccupantsTabCompletor(stream_interactor, text_input);
         smiley_converter = new SmileyConverter(stream_interactor, text_input);
+        edit_history = new EditHistory(text_input, GLib.Application.get_default());
 
         scrolled.get_vscrollbar().get_preferred_height(out vscrollbar_min_height, null);
         scrolled.vadjustment.notify["upper"].connect_after(on_upper_notify);
@@ -33,6 +35,7 @@ public class View : Box {
 
     public void initialize_for_conversation(Conversation conversation) {
         occupants_tab_completor.initialize_for_conversation(conversation);
+        edit_history.initialize_for_conversation(conversation);
 
         if (this.conversation != null) entry_cache[this.conversation] = text_input.buffer.text;
         this.conversation = conversation;
@@ -81,6 +84,7 @@ public class View : Box {
                 text_input.buffer.insert_at_cursor("\n", 1);
             } else if (text_input.buffer.text != ""){
                 send_text();
+                edit_history.reset_history();
             }
             return true;
         }