Merge pull request #25 from mfontanini/hot-reload-jumps

Jump to slide if layout changes

src/diff.rs

@@ -73,6 +73,10 @@ impl ContentDiff for RenderOperation {
             }
             (RenderImage(original), RenderImage(updated)) if original != updated => true,
             (RenderPreformattedLine(original), RenderPreformattedLine(updated)) if original != updated => true,
+            (InitColumnLayout { columns: original }, InitColumnLayout { columns: updated }) if original != updated => {
+                true
+            }
+            (EnterColumn { column: original }, EnterColumn { column: updated }) if original != updated => true,
             // This is only used for footers which are global. Ignore for now.
             (RenderDynamic(_), RenderDynamic(_)) => false,
             _ => false,
@@ -136,6 +140,9 @@ mod test {
         }
     ))]
     #[case(RenderOperation::RenderDynamic(Rc::new(Dynamic)))]
+    #[case(RenderOperation::InitColumnLayout{ columns: vec![1, 2] })]
+    #[case(RenderOperation::EnterColumn{ column: 1 })]
+    #[case(RenderOperation::ExitLayout)]
     fn same_not_modified(#[case] operation: RenderOperation) {
         let diff = operation.is_content_different(&operation);
         assert!(!diff);
@@ -168,6 +175,20 @@ mod test {
         assert!(!lhs.is_content_different(&rhs));
     }
 
+    #[test]
+    fn different_column_layout() {
+        let lhs = RenderOperation::InitColumnLayout { columns: vec![1, 2] };
+        let rhs = RenderOperation::InitColumnLayout { columns: vec![1, 3] };
+        assert!(lhs.is_content_different(&rhs));
+    }
+
+    #[test]
+    fn different_column() {
+        let lhs = RenderOperation::EnterColumn { column: 0 };
+        let rhs = RenderOperation::EnterColumn { column: 1 };
+        assert!(lhs.is_content_different(&rhs));
+    }
+
     #[test]
     fn no_slide_changes() {
         let presentation = Presentation::new(vec![

src/presentation.rs

@@ -100,6 +100,11 @@ impl Presentation {
         self.current_slide_mut().jump_chunk(chunk_index);
     }
 
+    /// Get the current slide's chunk.
+    pub(crate) fn current_chunk(&self) -> usize {
+        self.current_slide().current_chunk()
+    }
+
     /// Render all widgets in this slide.
     pub(crate) fn render_slide_widgets(&mut self) -> bool {
         let slide = self.current_slide_mut();
@@ -170,6 +175,10 @@ impl Slide {
         self.visible_chunks = (chunk_index + 1).min(self.chunks.len());
     }
 
+    fn current_chunk(&self) -> usize {
+        self.visible_chunks.saturating_sub(1)
+    }
+
     fn show_first_chunk(&mut self) {
         self.visible_chunks = 1;
     }

src/presenter.rs

@@ -157,6 +157,9 @@ impl<'a> Presenter<'a> {
                 if let Some(modification) = PresentationDiffer::find_first_modification(current, &presentation) {
                     presentation.jump_slide(modification.slide_index);
                     presentation.jump_chunk(modification.chunk_index);
+                } else {
+                    presentation.jump_slide(current.current_slide_index());
+                    presentation.jump_chunk(current.current_chunk());
                 }
                 self.state = PresenterState::Presenting(presentation)
             }