Add possibility to cancel the DrawingState with Undo/Redo/Cancel commands

To match the new MovingCelState behavior.

src/app/ui/editor/drawing_state.cpp

@@ -249,8 +249,11 @@ bool DrawingState::onKeyDown(Editor* editor, KeyMessage* msg)
   Params params;
   if (KeyboardShortcuts::instance()
         ->getCommandFromKeyMessage(msg, &command, &params)) {
-    // We accept zoom commands.
-    if (command->id() == CommandId::Zoom()) {
+    // We accept some commands...
+    if (command->id() == CommandId::Zoom() ||
+        command->id() == CommandId::Undo() ||
+        command->id() == CommandId::Redo() ||
+        command->id() == CommandId::Cancel()) {
       UIContext::instance()->executeCommandFromMenuOrShortcut(command, params);
       return true;
     }
@@ -330,9 +333,22 @@ bool DrawingState::canExecuteCommands()
           !m_mousePressedReceived);
 }
 
-void DrawingState::onBeforeCommandExecution(CommandExecutionEvent& cmd)
+void DrawingState::onBeforeCommandExecution(CommandExecutionEvent& ev)
 {
-  if (canExecuteCommands() && m_toolLoop) {
+  if (!m_toolLoop)
+    return;
+
+  if (canExecuteCommands() ||
+      // Undo/Redo/Cancel will cancel the ToolLoop
+      ev.command()->id() == CommandId::Undo() ||
+      ev.command()->id() == CommandId::Redo() ||
+      ev.command()->id() == CommandId::Cancel()) {
+    if (!canExecuteCommands()) {
+      // Cancel the execution of Undo/Redo/Cancel because we've
+      // simulated it here
+      ev.cancel();
+    }
+
     m_toolLoop->cancel();
     destroyLoopIfCanceled(m_editor);
   }

src/app/ui/editor/drawing_state.h

@@ -56,7 +56,7 @@ namespace app {
   private:
     void handleMouseMovement(const tools::Pointer& pointer);
     bool canExecuteCommands();
-    void onBeforeCommandExecution(CommandExecutionEvent& cmd);
+    void onBeforeCommandExecution(CommandExecutionEvent& ev);
     void destroyLoopIfCanceled(Editor* editor);
     void destroyLoop(Editor* editor);